Table of Content

12 November 2007, Volume 33 Issue 11

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ORIGINAL PAPERS

Screening of Chromosome-Specific Markers for Chromosome 1R of Secale cereale, 1V of Haynaldia villosa and 1Rk^#1 of Roegneria kamoji

WANG Chun-Mei;FENG Yi-Gao;ZHUANG Li-Fang;CAO Ya-Ping;QI Zeng-Jun;BIE Tong-De;CAO Ai-Zhong;CHEN Pei-Du

Acta Agron Sin. 2007, 33(11):  1741-1747. 

Abstract ( 1951 )   PDF (1812KB) ( 932 )   Save

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Many useful genes of wheat-relative species have been transferred to common wheat by chromosome addition, substation and translation and need to be identified. The comparative genomics shows obvious colinearity between wheat and its relative species. A lot of molecular makers have been developed and used to identify alien chromosomes, chromosome segments and genes. Wheat EST sequences are especially valuable as molecular markers because they are derived from gene transcripts and are more likely to be conserved among species. In the present study, in order to develop chromosome-specific markers for chromosome 1R of Secale cereale, 1V of Haynaldia villosa and 1Rk^#1 of Roegneria kamoji, 104 STS primers were designed based on EST sequences downloaded from Graingenes distributed on chromosome 1A, 1B, and 1D of Triticum aestivum using software primer5.0. Out of them, fifty-three pairs of primers amplified polymorphic bands between T. aestivum “Chinese Spring (CS)” and S. cereale, H. villosa, and R. kamoji. Five STS markers, CINAU 19-₅₀₀, CINAU20-₉₅₀, CINAU21-₁₅₀₀, CINAU22-₃₁₀ and CINAU23-₂₀₀₀ amplified specific fragments from S. cereal, T. aestivum-S. cereale amphiploid and 1R addition line, but not from CS and 2R-7R addition lines, were specific to 1R of S. cereale. Five STS markers, CINAU23-₁₇₀₀, CINAU24-₁₀₅₀, CINAU25-₁₆₅₀, CINAU26-₅₀₀ and CINAU27-₆₂₀ were specific to 1V of H. villosa because they amplified corresponding patterns from H. villosa, T. durum-H. villosa amphiploid, and 1V addition, not from CS and 2V-7V addition lines. And five STS markers, CINAU27-₉₆₀, CINAU28-₁₃₆₀, CINAU29-₄₈₀, CINAU30-₅₆₀ and CINAU31-₅₂₀ specific to 1Rk^#1 of R. kamoji were screened by amplifying specific fragments from R. kamoji, Wheat-R. kamoji DA1Rk^#1 and DS1Rk^#1 (1A). Furthermore, markers CINAU27-₉₆₀ and CINAU29-₄₈₀ were located on the short arm, CINAU28-₁₃₆₀ and CINAU31-₅₂₀ on the long arm and CINAU30-₅₆₀ close to the region of centremere of chromosome 1Rk^#1, respectively. This result indicated that STS markers derived from the EST of common wheat are useful for identifying corresponding specific chromosomes of wheat relatives.

Cloning and Expression of a Full-Length cDNA of SoFtsH Gene in Potato under Drought Stress

FAN Min;JIN Li-Ping;HUANG San-Wen;XIE Kai-Yun;LIU Qing-Chang;QU Dong-Yu

Acta Agron Sin. 2007, 33(11):  1748-1754. 

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Filamentation temperature-sensitive H (FtsH) is an ATP dependent metalloprotease and chaperone identified in many prokaryotes and eukaryotes; its homologs have been identified in many plants. FtsH belongs to a larger family of proteins collectively known as the AAA proteins (ATPases associated with diverse cellular activities). Function studies have revealed an important role for FtsH in stress responses. On the basis of one cDNA-AFLP differential fragment isolated from induced mRNA under drought in the potato （Solanum tuberosum L.） genotype H145 that is diploid with drought tolerance, the full length cDNA of a putative FtsH gene, SoFtsH gene was cloned by rapid amplification of cDNA ends (RACE). The gene consists of 723 bp encoding a predicted protein of 129 amino acids. Sequence analysis revealed that it has two 2Fe-2S ferredoxins, iron-sulfur binding regions. The putative signal-peptide, transmembane regions and the Zn²⁺ binding domain, characteristic of FtsH metalloproteases family, were found in the SoFtsH protein. Alignment and phylogenetic analysis of the amino acid sequence deduced from the fragment and the FtsH sequences of other plants retrieved from GenBank were performed with ClustalX program, which showed that SoFtsH shares high identity (>90%) with FtsH reported in tomato, tobacco and Arabidopsis etc. Transcription level of of SoFtsH was investigated by semi-quantitative RT-PCR and Northern blot, using actin gene as a control. The result showed that the transcript of SoFtsH was significantly enhanced under drought. The different profiles of transcript of SoFtsH gene were detected under continuous drought between drought tolerant H145 and drought sensitive H214 that is susceptive to drought. The results suggest that SoFtsH gene is closely related with the drought tolerance in potato.

QTL Analysis of Epistatic Effects on Yield and Yield Component Traits for Elite Hybrid Derived-RILs in Upland Cotton

WANG Bao-Hua;WU Yao-Ting;HUANG Nai-Tai;GUO Wang-Zhen;ZHU Xie-Fei;ZHANG Tian-Zhen

Acta Agron Sin. 2007, 33(11):  1755-1762. 

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Yield and yield component traits of cotton are inherited quantitatively with low heretibility and tend to vary with environmental variation. Classical quantitative genetics has indicated that epistasis is the foundation of such complex traits. In this study, a genetic linkage map was constructed using the recombinant inbred line (RIL) populations developed from an elite upland cotton hybrid Xiangzamian 2 (XZM2). Yield and yield component traits were investigated in F8 and F9 generations of RILs in three environments in China. The purpose of the study was to map epistatic QTL and analyze QTL by environment interactions in yield and yield components of cotton. Epistatic QTL were detected for all yield and yield component traits. Altogether 16 pairs of QTL interactions (AA) were identified. However, only 4 of the loci involved had single-locus effects, indicating the complexity of epistasis and their important contributions to yield and yield component traits. Altogether 17 pairs of QTL by environments interactions (AE) and 14 pairs of epistasis by environment (AAE) interactions were detected, indicating that environment influenced yield and yield componment traits greatly. The results suggest that epistatic effects might be importantly involved in the genetic basis of heterosis in the cotton hybrid of XZM2. Superior genotypes under different environments were predicted for all traits, indicating that there existed potential of increasing yield and yield components from XZM2-derived RILs. Due to influence of AE and AAE, the predicted SLs in different environments might be different. In cotton breeding, it is a practical strategy to perform breeding program according to special environment.

Characterizing Nitrogen Form Variations in Different Organs of Two Wheat Genotypes under Three Nitrogen Rates

YANG Tie-Gang;DAI Ting-Bo;JIANG Dong;JING Qi;CAO Wei-Xing

Acta Agron Sin. 2007, 33(11):  1763-1770. 

Abstract ( 1666 )   PDF (1660KB) ( 907 )   Save

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Wheat grains obtain nitrogen continuously through decomposition and assimilation of nitrogen compounds from vegetative organs after anthesis. The ability of grains obtaining nitrogen is an important factor to improve the yield and quality of wheat. To assess the ability differences, the field experiments were conducted under different nitrogen application rates using two wheat cultivars, Yumai 47 (grain protein content 15.5%) and Yumai 50 (grain protein content 12.4%). The results showed that Grain of Yumai47 had greater ability of obtaining nitrogen from its vegetative organs than that of Yumai 50. To reveal the physiological mechanism causing the difference between the two cultivars, investigation was carried out for the dynamic changes of three nitrogen forms as assimilable nitrogen (AN), functional nitrogen (FN) and structural nitrogen (SN) in wheat plants in responses to varied nitrogen rates. The data showed that AN, FN, and SN were affected more significantly by cultivars than by nitrogen rates, especially after anthesis. AN content in stems and leaves of low grain protein genotype Yumai 50 declined continuously after anthesis, while that of high grain protein genotype Yumai 47 increased. In grains, AN content in Yumai 50 decreased slowly from 1.98–2.35 mg g–1 to 1.38–1.70 mg g^–1 after flowering. However, in Yumai 47 it declined sharply from 5.51–5.70 mg g^–1 to 1.15–1.38 mg g^–1 at 17 days after anthesis, and then increased from 1.15–1.38 mg g^–1 to 3.01–3.29 mg g^–1 under different nitrogen rates at maturity. The continuous increase of AN content in the stems and leaves from jointing to filling was closely related to the demand of grain protein formation in high protein genotype Yumai 47. FN content, which participated in absorption and assimilation within leaves, was not significantly different in two different genotypes. In addition to a sharper decrease of SN content in Yumai 47 than Yumai 50 after anthesis, SN content in stems and leaves showed a similar trend over development stages. They all increased with a peak at anthesis, and then exhibited a decreasing trend. In grains, changes of SN contents in two cultivars showed a similar trend, decreasing from anthesis to maturity, although Yumai 47 had a much higher SN content (3.70%–4.28%) at anthesis than Yumai 50(1.38%–1.74%). The results suggest that the higher SN content in grains at anthesis is the key factor caused greater nitrogen gain from the vegetative organs in Yumai 47. SN synthesis determines the direction of nitrogen flow, and the decomposition of SN in leaves and stems provided the key source for nitrogen translocation into grain.

Mapping QTL for Rice Grain Weight across Different Environments

WU Xiu-Ju;WAN Xiang-Yuan;JIANG Ling;XIAO Ying-Hui;LIU Shi-Jia;CHEN Liang-Ming;ZHAI Hu-Qu;WAN Jian-Min

Acta Agron Sin. 2007, 33(11):  1771-1776. 

Abstract ( 1690 )   PDF (1291KB) ( 846 )   Save

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Grain weight is one of the important traits in rice for it determines grain yield and affects appearance quality in some degree. Grain weight is controlled by quantitative trait loci (QTLs) and determined by grain width, length, thickness and plumpness. To date, many QTLs have been identified, however only two QTLs have been fine mapped. It is urgent for identifying more QTLs expressed in different environments and genetic backgrounds so that they could be used in further fine mapping and breeding applications. So a chromosome segment substitution line (CSSL) population consisting of 65 lines, derived from Asominori and IR24 cross with the genetic background of Asominori, were grown in different environments to detect grain-weight related QTLs based on the stepwise regression of the traits and markers. The phenotypic values for milled rice weight (MRW) and brown rice weight ( BRW) showed a continuous distribution and some transgressive lines were also observed in the CSSLs population. A total of six QTLs for grain weight were detected in five environments, which located on the chromosomes 1, 6, 7, 8, and explained 13%–35% of phenotypic variance. The qMRW-1a and qPRW-1 could express stably in all experiment environments, both being in the same chromosome location of nearest marker XNpb113 on chromosome 1. Thus the markers could be used for marker assisted selection (MAS) of rice grain weight. MRW and PRW differed significantly between the CSSLs harboring the QTL allele and Asominori. In comparision with previous studies, they were found to be expressed in various genetic populations, and also had the similar chromosomal location with the gene for sucrose phosphate synthase. Therefore we deduced the QTL was associated with rice starch metabolism. qMRW-1a and qPRW-1, which had highly stable expression characteristic, should be used for fine mapping to elucidate the genetic basis of the rice grain weight.

Stalk Quality Traits and Their Correlations of Maize Inbred Lines in China

BAI Qi-Lin;CHEN Shao-Jiang;DAI Jing-Rui

Acta Agron Sin. 2007, 33(11):  1777-1781. 

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Maize stalk is the main resource for ruminant feed, which is above 50% of total plant. In order to provide materials and exploit them rationally in the process of high quality silage maize breeding, 102 domestic and foreign inbred lines, including 91 normal oil corn (NOC) and 11 high oil corn (HOC) inbred lines were evaluated on seven stalk quality traits such as in vitro dry matter digestibility (IVDMD), crude protein (CP), ether extract (EE), the water soluble carbohydrate (WSC), acid detergent fiber (ADF), acid detergent lignin (ADL), and neutral detergent fiber (NDF). The technique of near infrared diffuse reflectance spectroscopy (NIDRS) were used to determine these values. The results showed that every quality trait had highly significant variation, the coefficient of variation (CV) of WSC was the highest (33.15%). IVDMD and other quality parameters were almost in normal distribution respectively. The correlation analysis among quality traits of inbred lines showed that IVDMD had a significant negative correlation with NDF, ADF, and ADL at P<0.01, but a significant positive correlation with WSC, EE, and CP at P<0.01 or P<0.05. The order of the traits influencing stalk quality from large to small was IVDMD, ADF, NDF, WSC, ADF, CP, and EE. Five elite inbred lines with high IVDMD and WSC and low ADF and NDF were selected to be further used for breeding programs.

Development of Ee-Chromosome-Specific RGAP Markers for Lophopyrum elongatum (Host) A. Löve in Wheat Background by Using Resistance Gene Analog Polymorphism

CHEN Guo-Yue;DONG Pang;WEI Yu-Ming;HE Kun;LI Wei;ZHENG You-Liang

Acta Agron Sin. 2007, 33(11):  1782-1787. 

Abstract ( 1917 )   PDF (1281KB) ( 859 )   Save

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The wild species of common wheat were confirmed to have many agronomically useful characters such as tolerance to salt stress, resistance of diseases and high quality. Interest in Lophopyrum elongatum as a source of genes for wheat improvement has been enhanced by the development of its amphiploids and addition, subbstitution and translocation lines. In order to rapidily further exploit and utilize key genes in this wild species of wheat, in this paper, forty-two degenerate primers, which were designed from the conserved motifs of known plant resistance gene products, were used to amplify the resistance gene analog polymorphisms (RGAP) from the genomic DNAs of common wheat cultivar Chinese Spring (CS), Lophopyrum elongatum, CS-Lo. elongatum ampliploid, and their addition and substitute lines. The amplification products could be obtained from 38 primers combinations, among which 35 primers combinations could amplify the polymorphic fragments between CS and CS-Lo. elongatum ampliploid, with an average of 38.5 bands per primers combination. A total of 275 bands were detected on E^e genome of Lo. elongatum in Chinese Spring background, with a polymorphic frequency of 17.44%, indicating that Ee genome showed high genetic diversity in common wheat background. To establish a set of specific resistance gene analogues markers for E chromosomes, RGAP molecular marker technology was used with 26 primer combinations to reveal polymorphism between Chinese Spring and the amphiploid, and the polymorphic bands also appeared in their addition and substitute lines, respectively. This indicated that the polymorphic bands were the specific RGAP markers of E chromosomes. A total of 30 specific RGAP markers, which were distributed in the diferent E specific chromosomes, were detected. The development of chromosome-specific markers of Lo. elongatum could be useful for scanning the alien chromosomes or chromosome fragments of Lo. elongatum in common wheat backgrounds.

Dough Properties and Loaf Quality Stability in Wheat Cultivar Jimai 20 and Their Relationship with Protein Fractions

TANG Jian-Wei;LIU Jian-Jun;ZHANG Ping-Ping;ZHANG Yan;LI Hao-Sheng;ZHAO Zhen-Dong;QU Yan-Ying;HE Zhong-Hu

Acta Agron Sin. 2007, 33(11):  1788-1793. 

Abstract ( 1990 )   PDF (1453KB) ( 1088 )   Save

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A total of 24 samples of newly released high quality cultivar Jimai 20 collected from 2005–2006 cropping season at 24 locations were used to evaluate quality traits, and quantify the protein fractions by reversed-phase high-performance liquid chromatography (RP-HPLC) and size-exclusion high-performance liquid chromatography (SE-HPLC) methods. Relations between the quantity of protein fractions and dough properties, and pan bread quality were analyzed. The results indicated that except kernel hardness, farinogram dough development time and stability and loaf spring, most quality traits showed small variation as determined by coefficients of variation across locations. Dough property and bread quality were mainly affected by test weight, grain hardness and protein content. Grain hardness was significantly and positively correlated with dough extension area and maximum resistance, with correlation coefficients of 0.53 (P<0.01) and 0.47 (P<0.05), respectively. Kernel protein content was significantly and positively correlated with dough water absorption, development time and extensibility, with correlation coefficients of 0.46 (P<0.05), 0.71 (P<0.001) and 0.77 (P<0.001), respectively. Test weight and grain hardness were significantly and positively correlated with loaf score, with correlation coefficients of 0.62 (P<0.01) and 0.50 (P<0.05), respectively. Kernel protein content was significantly and positively correlated with loaf volume (correlation coefficient = 0.55，P<0.01). The quantity of total glutenin and gliadin, SDS extractable polymeric protein and quantity of HMW-GS and LMW-GS were significantly and positively correlated with dough development time and extensibility, with correlation coefficients of 0.55–0.79 (P<0.01 or P<0.001), and the ratio of HMW-GS to LMW-GS was positively correlated with dough extensibility(correlation coefficient = 0.46, P<0.05). The quantity of HMW-GS and the ratio of HMW-GS to LMW-GS were significantly and positively correlated with loaf volume (r= 0.66 and 0.64, P<0.001), respectively. Percent SDS-unextractable polymeric protein (UPP%) was significantly and positively correlated with loaf structure and loaf score, with correlation coefficients of 0.53 (P<0.01) and 0.48 (P<0.05), respectively. The information has potential value for improvement of quality stability in China.

Analysis on Energy Accumulation and Calorific Value of Early-Season Rice and Its Ratooning Rice under Different Cultivation Models

LIN Rui-Yu;CHEN Hong-Fei;DENG Jia-Yao;LIANG Yi-Yuan;LIANG Kang-Jing;LIN Wen-Xiong

Acta Agron Sin. 2007, 33(11):  1794-1801. 

Abstract ( 1772 )   PDF (2039KB) ( 1010 )   Save

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A new hybrid rice Ⅱ Youhang 1 was used to analyze accumulated dry weight, energy fixation and calorific value in early-season rice and its ratooning rice under super high-yield cultivation (SHC) and conventional cultivation (CC) models. The results showed that accumulated dry weight in the plants at mature stage under SHC was 2 220.04 g m^-2 and 1 697.62 g m^-2 for early- season and ratooning rice, respectively, being 1.26 and 1.29 folds higher than that under CC. Calorific value in leaf, grain, sheath and culm of the plant was 14 848.7–18 494.9 J g^-1, 15 810.3–17 438.0 J g^-1, 14 029.1–17 039.6 J g^-1, 14 405.4–17 576.5 J g^-1 under SHC, respectively. The calorific values in leaf and grain were significantly higher than those in culm and sheath, but no significant difference was found under the two cultivation models. The accumulated energy in the plants at mature stage was 35.71 and 26.24 MJ m^-2 under SHC for early season and ratooning rice, respectively, being 27.4% and 29.6% higher than that under CC. The ratio of accumulated energy partitioned into grains was 52.7% for early-season rice under SHC, which was 1.2% higher than that under CC, and for ratooning rice (51.5%), there was no significant difference between the two models. During grain filling, the ratio of energy remobilized from leaf, culm and sheath was 39.7% for early- season rice under SHC, being significantly higher than that under CC (23.1%), and the value was 16.9% for ratooning rice, which was also higher than that under CC (14.7%). It implied that the energy flow in rice community under SHC was much more smoothly than that under CC. In addition, at yellow mature stage, the energy exportation ratio of root was 7.9% under SHC, being obviously lower than that of CC, it was ensured for grain filling and regeneration of ratooning rice, and the energy of grains remobilized from the stubble of ratooning rice was 25.9% apparently, indicating that the grain yield under SHC relied less on the photosynthate in the period of grain filling, which was beneficial to steady and high yield of ratooning rice.

Characteristics of Matter Production and Accumulation in Rice Genotypes with Different N Use Efficiency

WEI Hai-Yan;ZHANG Hong-Cheng;DAI Qi-Gen;HUO Zhong-Yang;XU Ke;HANG Jie;MA Qun;ZHANG Sheng-Fei;ZHANG Qing;LIU Yan-Yang

Acta Agron Sin. 2007, 33(11):  1802-1809. 

Abstract ( 1864 )   PDF (1855KB) ( 1031 )   Save

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N use efficiency is varied in different rice genotypes. Therefore it is necessary to identify the physiological mechanism of N absorption and utilization in different rice genotypes in order to increase N use efficiency through rice cultivar improvement. In this research, a field experiment with 225 kg ha^-1 N fertilizer application was carried out in 2006 on the farm of Yangzhou University, Jiangsu province, China. Using twelve rice genotypes (6 N-efficient and 6 N-inefficient ) selected from 120 rice cultivars in 2004 and 2005 to investigate the characteristics of rice matter production and accumulation. Relationship between N use efficiency and indexes of rice matter production and accumulation also analyzed. Results showed that although there was no significant difference in number of tillers per unit ground area between two rice types with different N use efficiencies, the percentage of productive tillers of N efficient rice type was obviously higher than that of N inefficient rice type. The characteristics of rice matter production and accumulation at different growth stages and their correlations with N use efficiency revealed that, for N efficient rice type, the rice matter production and accumulation was steady in early growth period, a little in middle growth period and large in later growth period. That is to say the N efficient rice type had proper leaf area index (LAI), photosynthetic potential (PP), crop growth rate (CGR), and a superior matter accumulation before the critical stage of productive tillering, although its ratio of dry matter to the total accumulation in whole life was relatively low; the LAI, PP, CGR and dry matter accumulation were lower during the period from the critical stage of productive tillering to elongating; and an increased leaf area, photosynthetic potential and an accelerated crop growth rate resulting from better population quality after the stage of elongating. According to the research results, the different characteristics of rice matter production and accumulation could not only illustrate the diversity of N use efficiency in different rice genotypes, but also provide feasible regulation approaches to increase N use efficiency in rice production.

Analysis on the Factors Affecting Frost Resistance for Winter Wheat

ZHONG Xiu-Li;WANG Dao-Long;YOSHIDA Hisashi;HU Xin;ZHAO Peng;HAN Li-Shuai;WANG Xiao-Guang;HUANG Shao-Hua;HUANG Jian-Ying;SUN Zhong-Fu

Acta Agron Sin. 2007, 33(11):  1810-1814. 

Abstract ( 1812 )   PDF (1305KB) ( 1046 )   Save

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rost often causes young ear injury at the elongation stage of wheat, the frost-sensitive period, leading to yield reduction. The objectives of this study were to understand how frost resistance of young ears (FRYE) varied with development progression to find the most frost-sensitive stage, and the factors affecting the FRYE, which is of importance for determining the feasible phase to evaluate the frost resistance of different wheat cultivars and, providing guidance to select the cultivars with frost resistance, as well as developing the frost prevention technologies. In this study, change in FRYE with development progression was investigated with 4 cultivars of winter wheat (Triticum aestivum L.), using the Movable Artificial Climate Chamber. Frost resistance of young ears of 21 cultivars were tested at earlier stage of anther connective formation phase (ACFP) using the Room Climate Chamber and the effects of several factors on FRYE, such as cultivars, varietal types, winter hardiness, and soluble sugar content of leaves were analyzed. Degree of injury was examined using the microscopes. The results showed that there was a decreasing trend for FRYE with process of development and a sharp drop at the beginning of ACFP, suggesting that the sensitive phase to low temperature for young ears started with ACFP. Frost resistance of young ears closely related to development progression, and difference in frost injury among cultivars was mostly caused by differences in plant development progression; no significant differences could be found among most of the cultivars, except a few ones with a strong frost resistance; no significant correlations existed between varietal pattern and FRYEs, between FRYEs and winter hardiness, and between FRYEs and soluble sugar contents of leaves. Therefore, evaluation of FRYE and selection of cultivars with frost resistance need to perform in same development stage, especially in the frost-sensitive stage. And some indices for winter hardiness can not be used to estimate frost resistance of cultivars.

Identification of Anthracnose Resistant Genes Based on SCAR Markers in Common Bean (Phaseolus vulgaris L.)

ZHAO Xiao-Yan;WANG Xiao-Ming;WANG Shu-Min

Acta Agron Sin. 2007, 33(11):  1815-1821. 

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Bean Anthracnose is one of the main diseases, which causes 20%–30% reduction of output in common bean. Based on the evaluated results of disease resistance to anthracnose with No. 81 physiological race from 1986 to 2000, 127 accessions of resistant and high resistant germplasm resources were selected to be used in this study. In order to identify different types of resistance genes in these materials, we assessed the reliability and effectiveness of 7 SCAR primers（SBB14_1150/1050, SAS13₉₅₀, SCAreoli₁₀₀₀, SH18₁₁₀₀, SAB3₄₀₀, SB12₃₅₀, and SCF10¹⁰⁷²）which linked with resistant anthracnose genes. 12 identification host varieties of common bean were used as control. The results showed that SBB14_1150/1050 had no differential amplification and SAS13₉₅₀ had no target amplification. The further identification of anthracnose resistant genes was conducted by using 5 SCAR primers in 127 accessions of common bean. There were no SCAR markers detected in 82 accessions. 1–3 SCAR markers appeared in 45 accessions respectively. SCAreoli₁₀₀₀ (Co-2) marker appeared in 13, SH181100 (Co-42) marker in 13, SAB3₄₀₀ (Co-5) marker in 5, SB12₃₅₀ (Co-9) marker in 9, SCF10₁₀₇₂ (Co-10) marker in 11 accessions of common bean. The results also revealed that there were 5 accessions with broad-spectrum resistance to anthracnose and there was a correlation between the resistant genes and origin of the germplasm resource. This study provided an important genetic information for breeding program on disease resistance in common bean.

Effect of Anti-Sense PPO Gene on the Tuber-Browning of Solanum tuberosum L.

WANG Qing;HUANG Hui-Ying;MA Wen-Fang;WANG Di

Acta Agron Sin. 2007, 33(11):  1822-1827. 

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The technique of reverse genetics such as anti-sense RNA has been used to down regulate gene expression of some important agronomic characters of crops. In this study anti-sense polyphenol oxidase (PPO) gene POT32 was transformed into potato (S. tuberosum L.) and the PPO effect on tuber browning in those transgenic potatoes was assessed. Potato tubers from twelve transgenic lines and the non-transformed control were analyzed for their PPO activity, phenolic substance content，browning index and browning intensity when the tubers were harvested and stored for 5 months respectively. The results showed that browning indexes of transgenic tubers were significantly lower than those of control. The PPO activity in transgenic tubers decreased by 26.01% to 48.65% compared with that in the control, and the content of phenolic substance decreased by 22.83% to 54.81%. The browning intensity of the transgenic line GD-9-qc-1 was 40.45% to 46.78% lower than that of the control. Although the browning could be observed in all transgenic lines when tubers were cut, the extent of browning was less and occurred much slower in most transgenic potato tubers than in control. The tuber browning index was 88.0% to 98.86% lower in transgenic lines than in control. The down regulation of the PPO gene also resulted in the decrease of the content of phenolic substance in transgenic potato tubers. Furthermore, the browning showed mainly in the vascular region of most of the transgenic tubers but in whole tuber cross section of the control. The down regulation of PPO gene performed well particularly in transgenic line GD-9-qc-1 and very little polyphenol oxidase was found in its tuber. The results above indicated that the anti-sense POT32 gene has suppressed or partially suppressed the expression of PPO gene in the transgenic potatoes.

Grain Yield and Protein Components Responses to Irrigation in Strong Gluten Wheat

ZHAO Guang-Cai;CHANG Xu-Hong;LIU Li-Hua;YANG Yu-Shuang;LI Zhen-Hua;ZHOU Shuang-Yue;GUO Qing-Xia;LIU Yue-Jie

Acta Agron Sin. 2007, 33(11):  1828-1833. 

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Appropriate cultivation management avails high yield and good quality of crops, of which irrigation plays very important role. The effects of water to the grain yield and quality of wheat (Triticum aestivum L.) were not identical upon different experiments corresponding to soil and fertilizer condition, rainfall, the frequency, quantity, and period of irrigation, and cultivar type. To study the effects of irrigation treatment on grain yield, protein components, and sedimentation, therefore, put forward water saving cultivation management in wheat production, we conducted a split plot design with 3 replicates under the fertilization level of 225 kg N ha^-1 (50% basal and 50% top dressing), 172.5 kg P₂O₅ ha^-1 (basal), and 90 kg K₂O ha^-1 (basal) in the Renqiu (Hebei province) experiment site of the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences in 2005–2006 growth season. Four irrigation treatments (supplied 40 m³ water per irrigation) with frequency of 1 (A1), 2 (A2), 3 (A3), and 4 (A4) times and seven bread wheat cultivars (8901-11, Yumai 34, Yannong 19, Jimai 20, Wanmai 38, Shaan 253, and Linyou 145) with high gluten content were set as main and subsidiary factors, respectively. Only 47.9 mm rainfall was received during the whole growth period. The grain yield and thousand-grain weight of A3 treatment (irrigated at the 2nd and 5th leaves emergence and anthesis, respectively) were the highest, and significantly (P<0.05) higher than those of A1 treatment (irrigated at the 5th leaf emergence). Yannong 19 had the highest grain yield with significant difference (P<0.05) to other cultivars. The gliadin content was affected significantly (P<0.05) by irrigation, and gained the highest value in A3 treatment with significant difference (P<0.05) to A1 and A2 (irrigated at the 5th leaf emergence and anthesis, respectively) treatments. The average contents of the protein components and total protein were significantly different (P<0.05) and always showed glutenin > gliadin > albumin > globulin (ratio of 3.6:2.7:1.7:1) in different cultivars and irrigation treatments. The coefficients of variance (CV) of albumin, globulin, gliadin, and glutenin were 5.64%, 8.15%, 5.50%, and 11.14%, respectively, indicating glutenin content had the largest variance in the four protein components. The effects on sedimentation were significantly different (P<0.01) in cultivars, but not (P>0.05) in irrigation treatments. Considering yield and protein components, we suggest to irrigate 3 times at double ridge stage, pistil and stamen differentiation and anthesis for strong gluten wheat in dry growth conditions.

Analyses of Fe, Zn, Cu, and Mn Contents in Grains and Grouping Based on the Contents for Main Kindred Germplasm of Common Wheat (Triticum aestivum)

HAO Zhi;TIAN Ji-Chun;JIANG Xiao-Ling

Acta Agron Sin. 2007, 33(11):  1834-1839. 

Abstract ( 1750 )   PDF (1398KB) ( 1029 )   Save

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The mineral nutrition is an important aspect of wheat (Triticum aestivum L.) grain quality, and becomes one of the most important targets for breeding. The main kindred germplasm of common wheat, which carry many fine genes, act as important donors in the evolution and breeding of common wheat. To screen breeding materials from these kindred germplasm with high or low mineral element content, we assessed the content level of four essential elements (iron, zinc, copper, and manganese) in grain of 19 main kindred germplasm of common wheat including (T. boeoticum, T. monococcum, Ae. tauschii, Secale, Secale vaviloviim, T. dicoccodes, T. dicoccum, T. polonicum, T. carthlicum, T. turanicum, Ae. triuncialis, T. spelta, T. compactum, T. sphaeroccum, T. aestivum concv. ramulostachye, T. aestivum subsp. tibetanum, T. aestivum subsp. yunnanese, Triticale (6×), Triticale (8×), Chinese Spring.) in 2005–2006. The common wheat cultivar Chinese Spring was employed as control. After dry digestion, Fe, Zn, Cu, and Mn were determined by flame atomic accessory spectrometry (FAAS). The results showed that the mean content and the improving potential of all materials were 50.94 μg g^-1 and 121.94% for Fe, 34.89 μg g^-1 and 40.46% for Zn, 6.96 μg g^-1 and 41.17% for Cu, 33.21 μg g^-1 and 73.03% for Mn, respectively. Based on the contents of Fe, Zn, Cu, and Mn, all materials were classified into three groups by using clustered analysis. T. turanicum was classified as Fe rich material with the highest content of 124.32 μg g^-1. T. boeoticum, T. monococcum, and other four samples were classified as Zn rich materials, whose Zn content on average was 49.91 μg g^-1. T. aestivum concv. Ramulostachye, and Triticale (8×) were classified as Cu rich materials, whose Cu content on average was 8.66 μg g^-1. T. spelta was classified as Mn rich materials, with the highest content of 63.85 μg g^-1. The Tetraploid materials had the highest mean contents of Fe, Zn and Mn, and the Octoploid materials had the highest mean content of Cu. The materials with AABB genome had the highest mean contents of Fe, Zn, and Mn, followed by the materials with AA genome. The materials with AABBDDRR genome had the highest mean content of Cu. These results are useful for parent’s selection and utilization of fine genes in wheat.

Type, Activity, and Purification of Starch-Debranching Enzymes during Grain Filling Period in Wheat

WANG Yun-Fei;ZHAO Fa-Mao;LI Tian-Jiao;JU Qian;WANG Xian-Ze

Acta Agron Sin. 2007, 33(11):  1840-1844. 

Abstract ( 1854 )   PDF (1197KB) ( 1201 )   Save

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Amylopectin is a major constituent of starch in plant tissues, physical and chemical analysis of granular starch have led to a widely accepted model for amylopectin structure called “cluster model”, in which amorphous and crystalline regions alternate with a defined periodicity. Within amylopectin the crystalline component is composed of parallel arrays of linear chains packed tightly in double helices. Branch linkages, which account for approximate 5% of the glucosyl linkages in amylopectin, are located at the root of each cluster in the amorphous region. This periodic clustering of branches allows for the alignment of the intervening linear chains and their dense packing into crystalline regions, thus providing an efficient mechanism for nutrient storage. Biochemical analysis of su-1 mutants of maize (Zea mays L.) and rice (Oryza sativa L.) endosperm indicate that debranching enzymes (DBE) are proposed to play an essential role in the final determination of amylopectin structure. The precise way in which debranching enzymes involved in amylopectin synthesis is difficult to assess because of the lack of information about the occurrence and nature of these enzymes in starch-synthesizing organs and relatively little is known about these enzymes in higher plants. To provide more information about the occurrence and possible role of debranching enzymes in starch synthesis, six wheat (Triticum aestivum L.) cultivars corresponding to Lumai 21 and Yanyou 361 (low amylopectin), Lumai 1 and Jining 13 (medium amylopectin), and Jinan16 and Nuomai 2 (high amylopectin) were used in the present study. Activity changes, activity difference and types of DBE were studied during grain filling period by using spectrophotometer, native-PAGE and HPLC. The DBEs were also purified by salting out with ammonium sulphate, DEAE-cellulose column chromatograthy, and gel filtration using sephadex G-100. The results showed that two types of DBE were identified during starch synthesis and they all reached the highest activity at the 15th day after anthesis, the activity changes of isoamylase appeared as a single-peak curve, but those of pullulanase appeared as an undulatory curve, with another high activity around the 25th day after flowering. The molecular weights of isoamylase and pullulanase were determined to be 83 and 100 kD by SDS-PAGE respectively. HPLC analysis showed that activities of starch debranching enzymes to amylopectin and pullulan were similar among the six wheat cultivars. Glucose and dextrin were identified as the major hydrolysis products of amylopectin by isoamylase and maltotriose was identified as a major hydrolysis product of pullulan by pullulanase.

Effects of Post Anthesis Drought and Waterlogging on Contents of High Molecular Weight Glutenin Subunits and Glutenin Macropolymer in Wheat Grain

YUE Hong-Wei;TAN Wei-Na;JIANG Dong;DAI Ting-Bo;JING Qi;CAO Wei-Xing

Acta Agron Sin. 2007, 33(11):  1845-1849. 

Abstract ( 1775 )   PDF (1102KB) ( 759 )   Save

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High molecular weight glutenin subunit (HMW-GS) and glutenin macropolymer (GMP) play key roles in determining grain quality in wheat (Triticum aestivum L.). The aim of this study was to evaluate effects of drought and waterlogging post anthesis on HMW-GS and GMP contents in grains of two wheat cultivars, Yumai 34 (strong gluten) and Yumai 9(weak gluten). According to our previously reported quantification protocol, each HMW-GS content was calorimetrically determined, following the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The treatments of waterlogging, drought, and moderate water supply (CK) were used from anthesis to maturity. The results showed that HMW-GS of both cultivars under drought and those of Yumai 34 under waterlogging appeared in grains at about 10 days post anthesis (DPA), while those of Yangmai 9 under waterlogging and of both cultivars under moderate water supply were firstly found at about 15 DPA. The results indicated that water stress post anthesis showed significantly negative impact on the formation of HMW-GS in grains of both cultivars, and drought enhanced the initial formation of HMW-GS in grains of both cultivars. Compared with the control, drought promoted the HMW-GS accumulation at early grain filling stage, while the case was just opposite at late grain filling stage. Waterlogging showed more obviously negative impact on HMW-GS and GMP accumulation than drought. Finally, the control had the highest total HMW-GS and GMP contents, followed by drought treatment, and waterlogging was the lowest for both wheat cultivars. Under the same water treatment, each HMW-GS content of grains was higher in Yumai 34 than in Yangmai 9.

Relationship between Isozyme Genotypes and Activities of Starch Branching Enzyme in Wheat Grain

ZHAO Fa-Mao;BI Jian-Jie;LI Tian-Jiao;PANG Xiao-Yun;WANG Xian-Ze

Acta Agron Sin. 2007, 33(11):  1850-1855. 

Abstract ( 1652 )   PDF (1423KB) ( 794 )   Save

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To elucidate distribution of alleles, genotype composition and correlation between isozyme genotypes and enzyme activities of starch branching enzyme (SBE) in wheat (Triticum aestivum L.) grains, total activity of SBE was measured in seventy-one wheat cultivars with different provenances, including some typical hexaploid wheat from various province of China and some high-yielding modern varieties as well as eight exotic ones. The allele loci and genotypes of SBE isozymes were also investigated using native polyacrylamide gel electrophoresis (Native-PAGE). The results showed that there were two loci of starch branching enzyme, SBEⅠ and SBEⅡ. SBEⅡ failed to exhibit genetic polymorphism but SBEⅠmanifested genetic diversity. Four alleles were identified at SBEⅠ locus, that was A, B, D_ⅰ, and D_ⅱ, with frequency 9.9%, 76.1%, 95.8%, and 57.8%, respectively. Nine genotypes were determined, of them genotype D_ⅰD_ⅱB, D_ⅰB, and D_ⅰDⅱ took on high frequency with 45.1%, 28.2%, and 8.5%, respectively. From single locus analysis, starch branching enzyme activity correlated to SBEⅠ locus, but no significant correlation to SBEⅡ was observed. Therefore it indicated that different gene loci and genotypes of starch branching enzyme in wheat had different genetic impacts on enzyme activities.

Predicting Superior Genotype for Grain Weight per Panicle Based on QTL Mapping in Rice

ZHAO Yan-Hong;ZHU Jun;YANG Jian;XU Hai-Ming;GAO Yong-Ming;SONG You-Sheng;SHI Chun-Hai;XING Yong-Zhong

Acta Agron Sin. 2007, 33(11):  1856-1861. 

Abstract ( 1821 )   PDF (1330KB) ( 961 )   Save

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Selecting individuals with improved genotype is important in breeding practice, while predicting superior genotype is the basis of selection. An immortalized F₂ population in rice (Oryza sativa L.) derived from F1 hybrid between Zhenshan 97 and Minghui63 was used for QTL mapping on grain weight per panicle (GWP). Based on the results of QTL mapping, the genotypes and genetic effects of superior lines (SL) and superior hybrids (SH) in two different environments were predicted. Results showed that a total of nine QTLs controlling grain weight per panicle were detected in two environments. Epistatic effects were largely contributed to GWP as well as QE interaction effects had an impact on GWP. The genotypes and genetic effects of SL and SH in the two environments were different. The genetic effects of the predicted SH were the highest in the two environments, so SH could fully bring out the great potentialities of GWP. Nearly a half of QTLs of the predicted SHs in two environments were homozygous, which implyed that heterozygotes at all nine loci were not always advantageous for performance. The paper also mainly discussed how to obtain SL and SH in breeding.

Genetic Differentiation of Non-Heading Chinese Cabbage (Brassica campestris ssp. chinensis Makino) Germplasm Based on SRAP Markers

HAN Jian-Ming;HOU Xi-Lin;XU Hai-Ming;SHI Gong-Jun;GENG Jian-Feng;DENG Xiao-Hui

Acta Agron Sin. 2007, 33(11):  1862-1868. 

Abstract ( 1982 )   PDF (1525KB) ( 779 )   Save

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The genetic diversity and differentiation were assessed in 64 accessions of non-heading Chinese cabbage from all the world by SRAP (Sequence-related amplified polymorphism) markers. Two hundred and fifteen loci were detected by 21 pairs of SRAP primers. Among them, 112 were polymorphic, the polymorphic rate was 52.09%, and 10.24 loci and 5.33 polymorphic loci were amplified by each pair primer an average. The Nei’s gene diversity index and Genetic richness of B. compestris var. communis were 0.1410 and (190) 88.37% respectively, the highest among different types of non-heading Chinese cabbage, and 0.1451 and (185) 86.05% respectively in Jianghuai Plain, the highest among all the regions zeeted. These two indices were respectively 0.1293 and (188) 87.44% higher in domestic cabbage than in the foreign cabbage. The measurement of genetic variation showed that the coefficient of genetic differentiation was 58.22%. Most of the genetic variation existed among populations. The gene flow (0.4031) was less among populations, indicating that the degree of genetic differentiation was higher. Six groups were clustered according to genetic similarity coefficient of 0.872.

Changes in Carbohydrate Contents during Guar Plant Development

HU Chun-Mei;WANG Xiu-Feng;JI Jun-Jie;ZHU Yue-Lin

Acta Agron Sin. 2007, 33(11):  1869-1873. 

Abstract ( 1887 )   PDF (1129KB) ( 1192 )   Save

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Guar (Cyamposis Tetragonoloba (L.) Taub.) is an important raw material for guar gum, in which galactomannan (GM) is the active component. GM is a main storage carbohydrate in guar seeds, which is an analogue to that of starch in cereal grains. Sucrose is a common precursor for the biosynthesis of GM and starch. Studies were made on the changes in sucrose synthetic enzymes and carbohydrate contents in guar plants, to understand the effect of soluble sugar biosynthesis on accumulation of endospermic polysaccharides in this special plant. Sucrose synthetase (SS) and sucrose phosphate synthetase (SPS) activities, compositions and contents of carbohydrates in guar leaves, seeds and pod peels were determined. The results showed that SS and SPS activities in leaves, pod peels and seeds decreased with the development of seeds. SS and SPS activities in the seeds were higher than those in leaves and pod peels. SS activity showed a positive correlation with SPS activity in seeds. Glucose content was significantly higher than sucrose content in leaves. Contents of soluble sugar and sucrose increased in pod peels, till the diameter of seed was about 5 mm, and then decreased quickly, they were well correlated with each other. Soluble sugar of seeds decreased gradually during seed development. Sucrose content in pod peels showed a negative correlation with total carbohydrate contents (soluble sugar + polysaccharides) in seeds, and it is an important source of the carbohydrate in the seeds. It took part in the carbohydrate synthesis and also the establishment of seed sink. Carbohydrates in the leaves, as sucrose transported to and temporarily deposited in the pod peels in the early period of seed development, and then transported rapidly from pod peels into seeds at the seed diameter of about 5 mm. However, there was less sucrose in seeds than in pod peels, it suggested that sucrose was inverted into other reduced sugars after transported into seeds. Starch accumulated quickly in the seeds when the seed diameter was about 4 to 5 mm, a critical period for pod peels changing from ‘sink’ to ‘source’, and galactomannan increased dramatically in the seeds after that.

Comparison of rDNA Internal Transcribed Spacer Sequences in Oryza sativa L.

DAI Xiao-Jun;LIANG Man-Zhong;CHEN Liang-Bi

Acta Agron Sin. 2007, 33(11):  1874-1878. 

Abstract ( 1777 )   PDF (1130KB) ( 847 )   Save

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The cultivated rice has been differentiated and became not only two distinctly discriminative subspecies, i. e. O. sativa ssp. indica and O. sativa ssp. japonica but also many ecotypes of these two subspecies respectively. What is the variation law of the ITS1 and ITS2 sequences in varieties of a certain species with high biological diversity? Can the ITS region be a useful tool to study the phylogenetic relationships among these cultivars? Both of these are worthy of investigation. In this study, a comparative analysis of the rDNA internal transcribed spacers (ITS) entire sequences of 18 cultivars in Oryza sativa L. was carried out with O. rufipogon as outgroup. In the 18 cultivars, there were 9 O. sativa ssp. indica varieties, 6 typical O. sativa ssp. japonica, 2 O. sativa ssp. javanica and 1 upland rice. The result indicated that there were 23 variational loci which were 5.41% of entire bases and 8 informative loci which were 1.82% of entire bases in Oryza sativa. The length range of ITS sequence in O. sativa ssp. indica was from 425 to 430 bp; the percentage of G+C content varied from 74.25% to 75.59%. The length of ITS sequence in O. sativa ssp. japonica was 425 bp and the percentage of G+C content varied from 74.25% to 75.59%. The phylogenetic tree constructed on the basis of the ITS sequences showed that Oryza sativa was discriminated indica and japonica subspecies clearly, meanwhile, Oryza sativa ssp. javanica had closer relationships with O. sativa ssp. indica. The study shows that the sequences analysis of the internal transcribed spacer is a good tool to discriminate between subspecies of Oryza sativa and was significant in research the of Oryza sativa evolution.

Photosynthetic Characteristics of Different Wheat Cultivars and Their Offspring of Hybridization

HU Mei-Jun;WANG Yi-Qin;ZHANG Liang;WANG Chao;SHEN Yun-Gang;LI Zhen-Sheng;LI Hong-Wei;TONG Yi-Ping;LI Bin

Acta Agron Sin. 2007, 33(11):  1879-1883. 

Abstract ( 1730 )   PDF (1178KB) ( 936 )   Save

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Xiaoyan 54 is a wheat cultivar created by crossing Triticum aestivum L. with Thinopyrum ponticum，and has special features of inherent higher cyclic photophosphorylation activity during photosynthesis and its higher tolerance to stresses. In this paper, we studied the photosynthetic characteristics of the lines selected from crosses between Xiaoyan 54 and wheat cultivar Jing 411 or wheat line 8602 during heading and grain filling stages in two experimental fields at suburb of Beijing. In one experiment, it was found that the net photosynthetic rates of the two selected offspring bred from cross between Xiaoyan 54 and the other two lines were a little higher than those of their parents during the heading and grain filling stages. This is an interesting phenomenon, as these two offspring are good enough to be new varieties, although they were selected without using photosynthetic rate as a criterion previously. It means that the higher photosynthetic rate is often closely related to high yield of crops. In the other experiment, three recombinant inbred lines which were selected from the cross between Xiaoyan 54 and Jing 411 by the single seed descent method with special features respectively showed similar levels of net photosynthetic rates and chlorophyll contents compared to their parents. However, the adenosine triphosphate (ATP) content in the leaves of Xiaoyan 54 and its offspring was generally higher than that in Jing 411, and was more than two-fold higher in one of the offspring than in its parents during heading and grain filling stages. This phenomenon may be related to the inherence of higher cyclic photophosphorylation activity from Xiaoyan 54.

Relationship of Water Use Efficiency with Photoassimilate Accumulation and Transport in Wheat under Deficit Irrigation

HU Meng-Yun;ZHANG Zheng-Bin;XU Ping;DONG Bao-Di;LI Wei-Qiang;LI Jing-Juan

Acta Agron Sin. 2007, 33(11):  1884-1891. 

Abstract ( 1973 )   PDF (1923KB) ( 1053 )   Save

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Deficit irrigation in winter wheat (Triticum aestivum L.) has been practiced in the areas with limited irrigation water resources. The objectives of this study were to (i) investigate the effect of different deficit irrigations on yield and water use efficiency (WUE); and (ii) understand the physiological mechanisms of drought resistance, water saving and high yield under deficit irrigation in wheat. A field experiment was conducted using four wheat (Jinmai 47 and Xifeng 20 in dryland, Shijiazhuang 8 and 4185 in dry-wet land) with the treatments of rainfed (T0), watering once at jointing (T1) and watering twice at jointing and anthesis (T2). The amount of irrigation is 60 mm each time. The physiological parameters measured included net photosynthetic rate (P_n), stomatal conductance (G_s), leaf area index, dry matter accumulation and partitioning, root distribution, yield components and water consumption, as well as the corelation between WUE and yield components. Non-irrigation before jointing and deficit irrigation from jointing to anthesis could significantly improve dry matter production and deep root development, and significantly save irrigation water. Both grain yield and WUE were conically related with water consumption. Non-irrigation significantly decreased dry matter accumulation and number of spikes. Low available soil water from booting to late grain filling resulted in the lowest biomass, grain yield, harvest index and WUE in T0 treatment. The increased yield in T1 and T2 was mainly contributed by the increased number of spikes, and seeds per spike. The increased WUE was mainly contributed by increased HI. Water stress during grain filling reduced Pn and G_s, and accelerated photosynthetic leaf senescence. However, the water stress during grain filling induced remobilization of pre-anthesis carbon reserves to grains, significantly contributing the increased grain yield and HI. It is concluded that deficit irrigation between jointing and anthesis can change the root spread and develop deep root system, and significantly increase soil water use efficiency. Increasing both photosynthesis and photosynthetic duration, as well as increasing the remobilization of pre-anthesis carbon reserves and HI must increase wheat yield and WUE.

RESEARCH NOTES

Effect of Different Intercropping and Mixture Modes on Forage Yield and Quality of Oat and Common Vetch

WANG Xu;ZENG Zhao-Hai;ZHU Bo;HU Yue-Gao

Acta Agron Sin. 2007, 33(11):  1892-1895. 

Abstract ( 2020 )   PDF (966KB) ( 1123 )   Save

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It is an important measure of intercropping and mixture modes of oat and common vetch to increase forage yield and quality. The experiment was carried out to study the effects of different intercropping and mixture modes on forage yield and quality of oat and common vetch under low soil nitrogen environment in Yanqing County of Beijing. The results indicated the forage yield and quality of oat and common vetch were the highest during the oat dough stage and common vetch scorch stage by comparing and analyzing 12 different modes. Compared with oat monoculture, the best planting mode was intercropping of oat and common vetch at 3:1 by which the land utilization ratio (LER） increased by 76%. Dry forage yield was increased by 47% in milking stage and 40% in dough stage. Forage nitrogen yield was also enhanced by 52.6% than oat monoculture and 2.6% than common vetch in milking stage and 97.2% and 103.2% in dough stage, which have been notably differentiated in monoculture（P<0.05）.The dry forage yield in mixture was higher than in monoculture (P<0.05), but have no notably difference in these treatments. Forage nitrogen yield was highest in the mixture of oat and common vetch at 1:2 in two harvest time and LER was increased by 51%. Intercropping and mixture of oat and common vetch can increase 0.3%–22.7% RFV than monoculture. Combined with forage yield, quality, and LER, the best intercropping mode is oat and common vetch at 3:1. The increased forage yield might be related with reasonable row proportion and strap distance in the intercropping.

Nitrogen Use Characteristic in Maize Relay-Cropping System of Different Cultivars

NING Tang-Yuan;JIAO Nian-Yuan;ZHANG Min;ZHENG Yan-Hai;ZHAO Chun;AN Yan-Yan;LI Zeng-Jia

Acta Agron Sin. 2007, 33(11):  1896-1901. 

Abstract ( 1751 )   PDF (1377KB) ( 876 )   Save

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Three different cultivars, premature cultivars Luyuandan 14, medium cultivars Yedan 22 and late maturing cultivars Yedan 13, were chosen to study the effects of different maize cultivars on nitrogen (N) use characteristic and yield of relay-planted spring-sown and summer-sown maize compared with those of mono-planted. The results indicated that the N uptake of spring-sown maize was increased with longer growth duration. But when the longer growth duration cultivars of spring-sown maize with highest N uptake ability were used in relay-cropping, the N uptake by summer-sown maize were decreased obviously, which was not benefit to increase the annual yield. The N uptake efficiency (N accumulation in plant /N supplied, NUPE), N use efficiency (grain yield/N accumulation in plant, NUE) and N harvest index (N accumulation in grain/N accumulation in plant, NHI) were higher under relay-cropping than under sole cropping, while the N production efficiency (grain yield/N supplied, NPE) of relay cropping was between the range of spring-sown maize and summer-sown maize under sole cropping. Relay cropping of spring-sown maize with suitable N uptake ability and summer-sown maize with highest N uptake ability could enhance the advantages of the cropping system. The average land equivalent ratio for N yield of cropping system relay-planted with spring-sown maize of Luyuandan 14, Yedan 22, and Yedan 13 were 2.46, 1.63, and 2.04, respectively. While those for biomass yield were 1.91, 1.60, and 1.78, respectively. The relay cropping modes with higher N yield and biomass yield were Yedan 13/Yedan 22, Yedan 13/Yedan 13, and Luyuandan 14/Yedan 13. Compared with sole cropping maize, the relay-cropping system can get higher N productive ability and biomass yield by using more suitable cultivars.

Analysis of Physiologic Characteristics for Cd²⁺ Tolerance on Transgenic Tobacco Expressing Metallothionein Gene (MT1)

JIANG Ting-Bo;CHEN Hong;TANG Xin-Huan;DING Bao-Jian;WANG Yu-Cheng;LI Feng-Juan;LI Shao-Chen

Acta Agron Sin. 2007, 33(11):  1902-1905. 

Abstract ( 1936 )   PDF (945KB) ( 916 )   Save

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A metallothionein gene (MT₁, GenBank accession No. AB298390) from Tamarix sp. was directionally cloned and transformed into the pBI121 binary vector, in place of the XbaⅠ–SacⅠGUS cassette. The Cauliflower mosaic virus (CaMV) 35S promoter/-nopalin synthase terminator system and kanamycin resistant gene NPTⅡ (neomycin phosphotransfers Ⅱ) were used for these constitutive expression systems. The plasmid was then introduced into Agrobacterium tumefaciens (strain EHA105) by electroporation. Tobacco (Nicotiana tobacum) primary transformants were produced by leaf disc transformation. Southern and Northern hybridization indicated that exogenous gene was integrated into the transgenic tobacco plants, and correctly expressed under the control of 35S promoter. The Physiologic Characters of transgenic tobacco for Cd²⁺ tolerance was studied. The results showed that the activity of SOD and concentration of chlorophyll were increased, whereas the activity of POD and accumulation of MDA were decreased in transgenic tobacco than in non- transformant. Enhanced growth of transgenic tobacco was observed at the early development stages, resulting in plant height and fresh weights significantly greater than those of non-transformant. These results demonstrate that the exogenous metallothionein expression increase the ability of cleaning up reactive oxygen than that of non-transformant, showing a stronger tolerance to Cd²⁺ stress.

Genetic Analysis and Molecular Mapping of a Dominant Heading Period Gene Hd(t)

GONG Xiao-Ping;YANG Zheng-Lin;ZHAO Fang-Ming;ZHONG Bing-Qiang;LING Ying-Hua;HE Guang-Hua

Acta Agron Sin. 2007, 33(11):  1906-1909. 

Abstract ( 1779 )   PDF (845KB) ( 871 )   Save

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A restoring line N91 with late heading period (from 110 d to 114 d) was found from the offspring of a cross (Jinhui 10/R21), and N91 was crossed and backcrossed with Jin 23A, which was sterile line with early heading period (89–94 d). The frequency distribution of heading period showed double peaks in F2 and BC₁F₁ population and χ square test demonstrated the heading period was controlled by a major gene, which tentatively named as Hd(t), and other minor genes. Bulkled segregant analysis was used to map the Hd(t) by the backcross population, and 5 out of 400 SSR primer pairs showed polymorphism between late and early genome pools. Linkage analysis demonstrated the Hd(t) linked with two SSR loci (RM1364, RM3555) on chromosome 7. The Hd(t) were 32.7 and 22.5 cM from loci RM1364 and RM3555 respectively, and two SSR loci located at the same side of the Hd(t). Based on the targeted interval, 8 pairs of primers were selected from the public SSR primer pairs according to rice physical map. Through linkage analysis, RM22143 was added into the interval of the RM3555 and Hd(t) on the distal end of long arm of chromosome 7, and Hd(t) was 12.9 cM from RM22143. The present result establishes a basic for fine mapping, molecular marker assisted breeding and gene cloning of the Hd(t).

Genetic Diversity Analysis among Hulless Barley Varieties from the Major Agricultural Areas of Tibet

MENG Fan-Lei;QIANG Xiao-Lin;SHE Kui-Jun;TANG Ya-Wei;HU Yin-Gang

Acta Agron Sin. 2007, 33(11):  1910-1914. 

Abstract ( 2085 )   PDF (1018KB) ( 1024 )   Save

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To investigate the genetic diversity among hulless barley (Hordeum vulgare var. nudum Hook. f.）varieties in the major agricultural areas of Tibet and to promote the efficient utilization of those varieties, the genetic diversity among 29 hulless barley varieties and 3 landraces from those areas were analyzed using PCR with intron-splice junction primers and long random primers. The results indicated that 39 distinct PCR bands in total were amplified using 5 primers selected, and 26 of them were polymorphic. A [1, 0] data matrix was established based on the PCR patterns, and the genetic similarity coefficients among those cultivars were calculated using Dice’s index of NTSYSpc 2.1 software. Cluster analysis of the hulless barley varieties was then conducted based on the genetic similarity coefficients using UPMGA method of the same software. The result showed that there were some diversities among those hulless barley cultivars, but in general, their genetic differences were less and the genetic distances were relatively narrow; and the dendrogram obtained from cluster analysis could reflect the distribution and the geographic characteristics of those cultivars clearly.