Table of Content

12 October 2005, Volume 31 Issue 10

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ORIGINAL PAPERS

Molecular Cloning and Characterization of TaLon1 Gene in Wheat

LIU Li-Ke;GUO Xiao-Li;LIU Dong-Cheng;LIU Chun-Guang;WANG Hua-Bo;ZHANG Ai-Min

Acta Agron Sin. 2005, 31(10):  1247-1252. 

Abstract ( 1982 )   PDF (7985KB) ( 1064 )   Save

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The ATP-dependent Lon protease plays an important role in removal of the abnormal proteins and maintaining mtDNA integrity in yeast and human. In this paper, using RT-PCR and RACE techniques, a gene that encodes a product belonging to the Lon protease family was isolated from wheat. This gene, designated as TaLon1 with similarity of 94% to Lon1 in indica rice and 92% to Lon1 in maize, was predicted to encode an 886 amino acid protein. TaLon1 showed a constitutive expression pattern in wheat, which indicating its housekeeping role in wheat. It has been indirectly demonstrated that the Lon protease was probably relevant to cytoplasmic male sterility (CMS) in common bean. But there was no difference in expression of TaLon1 between CMS lines with Agiolops kotschyi cytoplasm and normal lines in wheat. Unlike the lon gene in yeast and E. coli, the TaLon1 didn’t respond to heat-shock at 42℃ for 90 min. Furthermore, the expression of TaLon1 was reduced by salt treatment with 250 mmol/L NaCl for 24 h.

QTL Analysis of Yield Components in Maize under Different Environments

LAN Jin-Hao;LI Xin-Hai;GAO Shu-Ren;ZHANG Bao-Shi;ZHANG Shi-Huang

Acta Agron Sin. 2005, 31(10):  1253-1259. 

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Maize (Zea mays L.) is one of the crops studied widely by QTL mapping. There are a lot of reports about QTL for important traits, including yield components, plant height, grain moisture and growth data and so on. Thereinto, grain yield is a very complicated quantitative trait, existing interactions not only with gene by gene, but also gene by environment. Studying the relationship of the interaction between genes and environments and finding the yield QTL expressed in given environment are of importance in practice for cultivating new varieties adapting to some area. If consensus QTL of yield and its adjacent marker can be found, it will provide possibility for molecular breeding by marker assisted selection (MAS). The objective of this experiment was to analysis the expression character of QTL controlling yield, and to detect common genetic loci of yield, as well as adjacent marker, in different environment, which could provide technical basis for fine mapping of yield QTL and MAS. One hundred and ninety-one F₂ individuals derived from the cross, Mo17×Huangzao4, were genotyped by SSR and AFLP markers to construct the genetic linkage map, and 184 corresponding F_2∶3 families were phenotyped for maize yield components in Beijing and Xinjiang. The performance and correlations among 5 yield components including ears per plant (EPP), row number per ear (RN), kernel number per row (KR), 100-kernel weight (KW) and grain yield per plant (GY) were evaluated, and the quantitative trait loci (QTL) were characterized. Totally, 47 QTLs were identified for 5 traits, locating on 9 chromosomes with exception of the chromosome 10. 10, 13, 9, 10 and 5 QTLs were detected for EPP, RN, KR, KW and GY, respectively. Each of these QTLs could explain 5.3% to 25.6% phenotypic variation of EPP, 4.5% to 23.2% of RN, 5.4% to 13.7% of KR, 4.9% to 13.3% of KW and 6.1% to 35.8% of GY. Most of the QTLs are detected in single environment, indicating the significant interactions between QTL and environments. Different QTLs relevant to the yield components which are correlated each other can be identified easily in the same or adjacent chromosome regions. Several regions with clustered QTLs relevant to multiple yield components identified in the study may provide the genetic loci of the universal yield QTLs.

Inheritance of Resistance in Infection and Resistance in Development to Soybean Mosaic Virus in Soybeans

ZHI Hai-Jian;GAI Jun-Yi;HE Xiao-Hong

Acta Agron Sin. 2005, 31(10):  1260-1264. 

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Soybean mosaic virus (SMV) is one of the most broad-distributed and destructive diseases of soybeans in China. It causes severe yield loss and seed quality deficiency. Studies on performances and inheritance of resistance in infection (RI) to SMV have been reported. However, resistance in development (RD) to SMV was not reported until Dongfang described it in his PhD dissertation. Recent studies have demonstrated that the mechanisms of resistance in infection and in development to SMV are different. Some cultivars with RI or RD to SMV have been screened out. In the present study, ten crosses between materials with RI or RD in different degree were used to reveal the inheritance of resistances. The results showed that the resistances in infection and in development were controlled by different genetic systems: the former by a single dominant gene, while the latter by one additive major gene plus additive-dominant polygenes. The heritability values of resistance in development were about 90%, those of major and polygene were 23.91%－74.97% and 18.43%－37.04% in F₂, and 49.46%－82.42% and 17.42%－39.93% in F_2∶3, respectively. Both kinds of resistance can be used in soybean improvement. For utilizing resistance in development, attention should be paid to using high resistant parent and major gene selection in breeding programs.

Accumulation of the γ-aminobutyric Acid in Brown Rice—A New Rice Strain W025 with Giant-embryo during Water Soaking

LIU Ling-Long;JIANG Ling;LIU Shi-Jia;ZHOU Shi-Rong;ZHANG Wen-Wei;WANG Chun-Ming;Chen Liangming;Zhai Huqu;Wan Jianmin

Acta Agron Sin. 2005, 31(10):  1265-1270. 

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Hypertension is a common chronic disease and causes serious damages to human health. The rice variety rich in γ-aminobutyric acid (GABA) has a blood-pressure-lowering effect and is paid more and more attention. W025 is a new rice strain developed from chemical inducement and cross breeding. It has a giant embryo that is controlled by a single recessive gene. The content of GABA and activity of glutamate decarboxylase (GAD) in W025 and its original variety Kinmaze were investigated after the rice grain was soaked in water for 0, 1, 2, 4, 8, 16, 32 h. To measure the expression of GAD homologous genes in steeped rice grain, a Semi-quantitative RT-PCR method was developed using the housekeeping gene Actin as the control. The results indicated that GABA was accumulated mainly in the embryo, and its content in W025 was significantly higher than that in Kinmaze. Meanwhile, the activity of glutamate decarboxylase was found gradually increasing during water soaking, and the enzyme activity in embryo of W025 was markedly higher than that of Kinmaze. The content of GABA in embryo was significantly and positively correlated with the activity of glutamate decarboxylase treated with 2 mmol/L cysteine, which suggested that the accumulation of GABA was due to the enzyme action of glutamate decarboxylase. Gene expression studies indicated OsGAD1 and OsGAD2 had no difference in the transcript level between W025 and Kinmaze. It provided the possibility that there existed other uncharacterized genes of glutamate decarboxylase, which might play a dominant role to GABA accumulation during water soaking.

Plant Average-based Maximum Likelihood Mapping of Quantitative Traits Loci Controlling Endosperm Traits

XU Chen-Wu;WANG Wei;HU Zhi-Qiu;SUN Chang-Sen

Acta Agron Sin. 2005, 31(10):  1271-1276. 

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Endosperm traits are important in determining grain quality in cereals. Endosperm, which is derived from two polar nuclei fusing with one sperm, is a triploid tissue whose genetic constitution is more complex than common diploid tissue. Current statistical methods for mapping quantitative trait loci (QTL) under diploid genetic control have not been effective for dealing with endosperm traits because of the complexity of their triploid inheritance. Based on the quantitative genetic models for triploid endosperm traits and mixture distribution theory, a new maximum likelihood method implemented via expectation-maximization algorithm which included the exact and approximate EM algorithms for mapping of quantitative trait loci (QTL) underlying endosperm traits was proposed in this paper. The method used the DNA molecular marker genotypes of each plant in segregation population such as F2, backcross etc. and the plant average of several endosperms of each plant as data set to map QTL. Because the method considered the mixture distribution property of QTL genotypes within flanking marker genotypes, it was expected that the proposed method not only increase the statistical power of QTL mapping but also improved the accuracy and precision of QTL effect estimates. Efficiency and feasibility of the methods have been verified through Monte Carlo simulation studies. The means and standard deviations of the estimated QTL effects and locations as well as the empirical powers under different QTL heritabilities and sampling strategies were listed in Table 1. Results of simulation showed that: (1) Whether the exact EM algorithm or the approximate EM algorithm, the method may provide accurate estimates of both the QTL effects and locations with very high statistical power; (2) Though the exact EM algorithm can’t significantly increase the statistical power of QTL detecting and the accuracy of QTL locations compared with the approximate EM algorithm, it may apparently increase the precision of QTL locations. The exact EM algorithm had less standard deviation of the estimated QTL locations than the approximate EM algorithm under the investigated treatments. The next step of endosperm QTL mapping is to consider both the maternal diploid genotype and the triploid endosperm genotypes jointly.

Detection of Allelic Variation for Grain Hardness in CIMMYT Common Wheats

CHEN Feng;HE Zhong-Hu;Morten Lillemo;XIA Xian-Chun

Acta Agron Sin. 2005, 31(10):  1277-1283. 

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Kernel hardness, controlled by a major gene Ha on the short arm of chromosome 5D, has a profound influence on milling performance and end-use quality of common wheat (Triticum aestivum L.). puroindoline protein, expressed by Ha gene and including puroindoline a and b (PINA and PINB), sets up the molecular and genetics basis of wheat kernel hardness. Evaluation of the allelic variation of grain hardness is beneficial to wheat quality improvement. A total of 138 CIMMYT historical cultivars and lines from 23rd Elite Spring Wheat Yield Trial (ESWYT) and 10th Semiarid Wheat Yield Trial (SAWYT) were examined by Single Kernel Characterization System (SKCS) and STS (sequence tagged site) marker to understand the distribution of grain hardness and its puroindoline alleles. Modified SDS-PAGE (sodium dodecyl-sulfate polyacrylamide gel electrophoresis) of Triton X-114 soluble protein, 10% glycerol substituting of water for resolving gels and PDA (piperiazine diacrylamide) substituting of N,N’-methylene bisacrylamide for gels, were used to distinguish PINA and PINB proteins for identifying Pina-D1b/Pinb-D1a allele (a null mutation of puroindoline a). Both serine-codon specific and non-specific primers were used to identify Pina-D1a/Pinb-D1b allele for confirming results of the PCR (polymerase chain reaction) amplification of genome DNA. The results indicated that Pina-D1b/Pinb-D1a was the most popular genotype in the CIMMYT common wheats, and the percentages of Pina-D1b/Pinb-D1a, Pina-D1a/Pinb-D1b and Pina-D1a/Pinb-D1a (wild type) were 85.5%, 6.5% and 8.0% in the surveyed wheats, respectively. SKCS hardness index for Pina-D1b/Pinb-D1a and Pina-D1a/Pinb-D1b genotypes were much higher than that for wild type Pina-D1a/Pinb-D1a. Genotype with Pina-D1b/Pinb-D1a allele showed significantly higher grain hardness than Pina-D1a/Pinb-D1b allele. It was previously reported that Pina-D1a/Pinb-D1b genotype was more desirable for milling and end products quality than Pina-D1b/Pinb-D1a genotype. Therefore, it is recommend that other types of puroindoline allele mutation for reducing the negative influence of the Pina-D1b/Pinb-D1a genotype on processing quality should be introduced in CIMMYT wheat breeding program. Meanwhile, when we introduce cultivars from CIMMYT for the purpose of improving some wheat characters, it is necessary to fully consider the negative effect of the Pina-D1b/Pinb-D1a genotype on milling and baking quality.

Drought Resistance of Elite Maize Inbred Lines in Different Water Stress Conditions

LU Gui-He; DAI Jing-Rui;ZHANG Shu-Kui;LI Wen-Ming;CHEN Shao-Jiang;E Li-Zhu;Zhang Yi-Rong

Acta Agron Sin. 2005, 31(10):  1284-1288. 

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Drought is one of the important factors affecting the yield stability of maize (Zea mays L.) in China and some other areas in the world. In order to provide materials and academic basis for maize drought resistance breeding, 84 elite main inbred lines were grown at Hainan and Gansu provinces in China in 2002 and 2003. Two levels of drought treatment were imposed, well-watered and water-stressed. Experiments were arranged in a complete random block design with three replications. Each genotype was grown in one row of 10 plants, 3 m long and 0.67 m apart. The drought resistance of the materials was evaluated according to drought coefficient and drought index. Based on the drought coefficient, 12 genotypes, S22, Zheng 22, Shen 5003, K10, Longkang 11, Hai 014, Chang 3, Ji 853, Shuang 741, Danhuang 02, Xi 502 and D978 were with high drought resistance; 15 genotypes, Ye 478, Ben 7884, Ye 8112, Dong 237, Tian 77, B73, Chang 72, Hai 1134, Wu 109, Yan 812, Nan 21-3, Q1261, Mo 113, Luyuan 92 and D892 were with medium drought resistance. Based on the drought index, eight genotypes, Zheng 22, K10, Chang 3, Ye 8001, Danhuang 02, K22, Xi 502 and D978 were with high drought resistance and high yield; 17 genotypes, Ye 478, Ji 444, Ben 7884, Huangyesi 3, Cheng 200B, Qi 319, Za C546, Tian 77, B73, Tie 7922, Chang 72, Dan 9064, Wu 109, Yan 812, K14, Ye 5237 and D863 were with medium drought resistance and high yield. The results showed that there existed inbred lines with different types of drought resistance and of high yield and drought resistance, which were the important germplasms for drought resistant breeding in China. Among the inbred lines some showed drought resistance in both middle and later period of growth, some only in one period. The high yield with high drought resistance was realized through different ways, some through higher index of kernel number and 100-kernel weight, some through higher index of kernel number and others through higher index of 100-kernel weight. It is possible to get elite cultivars with both high yield and high drought resistance by using different inbred lines above in the breeding for drought resistance.

Analysis of QTLs with Main, Epistasis and G×E Interaction Effects of Starch Paste Viscosity in Rice

SHEN Sheng-Quan;ZHUANG Jie-Yun;SHU Qing-Yao;BAO Jin-Song;WU Dian-Xing;XIA Ying-Wu

Acta Agron Sin. 2005, 31(10):  1289-1294. 

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The rice starch viscosity profile, also termed the RVA profile, is a paste curve of rice flour when the paste is subjected to a standard temperature- programmed heat-hold-cool-hold protocol. The RVA profile has proved to be useful for the evaluation of eating and cooking quality in rice breeding program. In order to understand the genetic basis of the paste viscosity characteristics, the recombinant inbred line populations derived from Zhenshan 97B/ Milyang 46（ZM-RIL）and its genetic linkage map were used to map the QTLs controlling starch pasteviscosity which could be expressed by five parameters: peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity (CPV), breakdown viscosity (BDV) and setback viscosity (SBV) in two environments, Hainan and Hangzhou. The results indicated that among 9 QTLs with significant main effects for the five traits the qPKV5 was located on chromosome 5 while all others were located on chromosome 6. For each trait, a QTL flanking RM197-RZ516 on chromosome 6 with which Wx gene was in the same region was detected. QTLs at RM197-RZ516 for PKV, HPV, CPV and BDV were detected to show positive significant G×E interaction effects in Hainan environment. 10 pairs of epistatic effects involving QTLs for the five traits were detected, but no epistasis×environment interaction effect was found.

AFLP Mapping for the Gene “Ms^ch” Controlling the Dominant Male Sterility in Foxtail Millet (Setaria italica)

YUAN Jin-Cheng;SHI Yun-Su;HU Hong-Kai;ZHAO Zhi-Hai;SONG Yan-Chun;SHI Yan-Hua;Li Yu;Wang Tian-Yu

Acta Agron Sin. 2005, 31(10):  1295-1299. 

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Foxtail millet (Setaria italica (L.) Beauv.) is an old and important food crop in China, India and other countries of East Asia. It is still grown as birdseed in Europe and as fodder plant in South America. As a drought resistant crop, foxtail millet has been playing an important role on dry farming. Utilizing heterosis is one of the most economic and effective approached to improving yield of crops, and the use of male sterility is an economic and effective way to utilize heterosis in foxtail millet. After seventies of last century, obvious progress has been made on the study of male sterility, and several sterile germplasms of foxtail millet were produced. “Chifeng sterility”, a nuclear genic interaction type of dominant male sterility in foxtail millet, was discovered from the hybrids of Australia millet and Tulufan millet. To identify AFLP markers linked to the gene “Ms^ch” conferring the dominant male sterility, sterile bulk (SB) and fertile bulk (FB) prepared from the NILs were subjected to polymorphism screening in AFLP analysis. A total of 400 random AFLP primer combinations were used to screen polymorphic markers. Two markers (P17/M37₂₂₄ and P35/M52₂₀₈, Fig.2 and 3 ) tightly linked to the dominant male-sterility gene were identified, with a map distance to the gene of 2.1 cM and 1.4 cM, respectively. These two markers may play an important role in the identification of Ms^ch lines through marker-assisted selection in foxtail millet to improve the breeding efficiency.

The Use of RAPD，ISSR and AFLP Markers for Analyzing Genetic Relationships among Sweetpotato Cultivars with Known Origin

HE Xue-Qin;LIU Qing-Chang;ZHAI Hong;WANG Yu-Ping

Acta Agron Sin. 2005, 31(10):  1300-1304. 

Abstract ( 1999 )   PDF (6258KB) ( 999 )   Save

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Sweetpotato, Ipomoea batatas (L.) Lam., is an important crop as food, feed and industrial materials grown worldwide. Because of its many biological complexities such natural heterozygote and cross-incompatibility, the analysis of the genetic relationships among cultivars is of interest not only for germplasm conservation but also for breeding purposes. Molecular techniques have been used broadly for germplasm characterization, variety identification, phylogenetic study and diversity analysis. There has been no report on analyzing genetic relationships among sweetpotato cultivars with known origin using molecular Markers. In the present study genetic relationships among seven sweetpotato cultivars with known origin were analysed using RAPD, ISSR and AFLP markers (Fig.1). Twenty-four RAPD primers, 14 ISSR primers and 9 AFLP primer pairs generated 173, 174 and 168 polymorphic bands, respectively (Fig.2, Table 1). For detecting the genetic differences among sweetpotato cultivars, the correlations among RAPD, ISSR and AFLP markers were significant with the highest correlation coefficient between RAPD and ISSR markers (0.9328). The ISSR-based genetic distances among the 7 sweetpotato cultivars, ranging from 0.1286 to 1.0932 with an average of 0.4883, were higher than those calculated with the other two markers. The dendrograms based on RAPD, ISSR and AFLP markers separately could detect genetic relationships of the 7 sweetpotato cultivars and the ISSR-based dendrogram was the best in agreement with their known origin, suggesting that ISSR is the powerful marker for analyzing genetic ralationships among sweetpotato cultivars (Fig.3).

Dynamic Changes of Starch Accumulation and Enzymes Relating to Starch Synthesis in the Grain of Three Winter Wheat Cultivars with Different Quality Types

WANG Wen-Jing;LIU Lin-Ye;LUO Yi;JIANG Yu-Mei

Acta Agron Sin. 2005, 31(10):  1305-1309. 

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Starch is the major component of wheat endosperm and an important source of carbon and energy in human food and animal fodder. Starch consists of amylose and amylopectin. Starch synthesis and accumulation takes place during grain filling in wheat. Many enzymes take part in starch synthesis, including sucrose synthase (SS), ADP-glucose pyrophosphorylase (AGPP), granule-bound starch synthase (GBSS), soluble starch synthase (SSS), starch branching enzyme (SBE), starch debrabching enzyme (DBE) and so on. According to the present studies, AGPP, starch synthase and SBE were the key enzymes controlling starch synthesis. Many scientists had studied the changes of enzymes activities，involved in starch synthesis in the grain in the grain filling. But to date there have been no report about the dynamic changes of starch accumulation and enzymes relating to starch synthesis in the grain during grain filling of winter wheat cultivars with different quality types. For this reason, three winter wheat cultivars with different quality types，Gaomai 8901（strong gluten），Yumai 49（medium gluten） and Luomai 1（weak gluten）cultured in the soil pool，were used for the research. Starch content was measured by the method of Xu et al. Starch accumulation was obtained by multiplying starch content with grain weight. The rate of starch accumulating was determined by the amount of starch accumulated over time. AGPP activity was tested according to the method described by Douglas et al. SSS and SBE activities were measured according to the methods described by Nakamura et al. ^[12] Main results indicated that the amylopectin synthesis was synchronous with the amylose synthesis（Fig.1），and the amylopectin was synthetised faster than the amylose during the medium to later grain filling. The accumulating rates of amylose，amylopectin and starch in the grain of Yumai 49 were higher than that of other two cultivars. Changes in activities of AGPP，UGPP，SSS，GBSS and SBE of different cultivars all showed a single-peak curve. The peak level of the enzymes in Yumai 49 was higher than that in other two cultivars（Fig.2，Fig.3），and most of the tested enzymes kept higher activities during the medium to later grain filling. It suggests that the medium gluten cultivar Yumai 49 has stronger ability for starch synthesis，compared with Gaomai 8901 and Luomai 1.

Correlation and Path Analysis for Quantitative Traits of Kosteletzkya virginica

RUAN Cheng-Jiang;QIN Pei;HE Zhen-Xiang

Acta Agron Sin. 2005, 31(10):  1310-1313. 

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Correlation and path analysis for 16 traits of Kosteletzkya virginica was carried out. The results were as follows: (1) Seed yield had highly significant positive correlations with number of fruits (r = 0.945), collar diameter (r = 0.770), ratio of bearing branches to branches (r = 0.567), number of bearing branches (r = 0.497) and hundred-seed weight (r = 0.397), and significant positive correlations with crude fat content (r = 0.348); but significant negative correlations with height of bearing branches (r =－0.343); crude fat content exhibited significant positive correlations with hundred-seed weight (r = 0.389), bottom diameter of bearing branches (r = 0.383) and collar diameter (r = 0.358), but significant negative correlations with height of bearing branches (r =－0.397). (2) The number of fruits had the highest positive direct relationship with seed yield followed by leaf length, collar diameter, length of bearing branch, hundred-seed weight, the number of branches, angle of bearing branches, the height of bearing branches and plant height; five of 14 seed yield components exhibited negative direct relationships with seed yield, including leaf width, ratio of leaf length to width, the number of bearing branches, bottom diameter of bearing branches and ratio of bearing branches to branches. The analyses, combining correlation, direct effects and indirect effects, showed that direct selection for the number of fruits, collar diameter and hundred-seed weight would likely be effective in increasing seed yield; it is logical to select plants with lower height of bearing branches for the improvement of seed yield; the direct selection for the number of bearing branches and ratio of bearing branches to branches would be helpful for increasing seed yield due to their high indirect effects via the number of fruits and collar diameter to seed yield.

Effects of Exogenous CaM and TFP on Development of Rice(Oryza sativa L.) Early Embryos in vitro

WU Juan-Zi;ZHAO Jie

Acta Agron Sin. 2005, 31(10):  1314-1321. 

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Calmodulin (CaM), as the most important Ca²⁺ sensor, controls diverse cellular and physiological processes in higher plant. Many studies suggest that CaM plays vital roles during plant sexual reproductive process. The effects of CaM on development of early embryos in vitro are poorly understood despite those effects of CaM on zygotic embryo development reported from some researches. In this study the line of indica rice Xiaogan-01 was used to investigate the effects of CaM and trifluoperazine (TFP) on development of rice early embryos of 3－5 DAP (days after pollination) in vitro by adding 10^-8, 10^-7, 10^-6 or 10^-5 mol/L exogenous CaM to medium, and 10^-7, 10^-6, 10^-5 or 10^-4 mol/L TFP to the medium with 10^-7 mol/L CaM. CaM and TFP were found to exert different effects on the development of 3 to 5-day-old embryos in rice. The influence of CaM on the development of 3 to 5-day-old embryos in vitro was related to the concentration of CaM and the age of embryos. With the high concentration of CaM (10^-6－10^-5 mol/L), the growth and the development of 3 to 5-day-old embryos were inhibited in a certain degree, the higher the concentration of CaM used, the more evident the inhibition was (Fig.1). With 10-7 mol/L CaM, all embryos grew rapidly and the highest frequency of normal embryogenesis was reached. At the same concentration of CaM, the older the embryos were, the more quickly they grew and the higher their frequency in normal embryogenesis and in total induction (Table 1). The development of 3 to 5-day-old embryos in vitro was inhibited by TFP which was related to the concentration of TFP and the age of embryos. The younger the embryos were, the more obvious the inhibition appeared (Fig.2). The growth speed of all embryos in vitro, the frequency of normal embryogenesis and the total induction frequency were decreased with increasing TFP concentration (Table.2). The results indicate that CaM and TFP have very important and complex effects on the development of rice early embryos in vitro.

Uptake and Use of Sparingly Soluble Phosphorus by Rice Genotypes with Different P-efficiency

GUO Zai-Hua;HE Li-Yuan;XU Cai-Guo

Acta Agron Sin. 2005, 31(10):  1322-1327. 

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Four low-P tolerant rice genotypes named 99011, 580, 508 and 99112 were used with two low-P sensitive rice genotypes named 99012 and 99056 as reference, to investigate the genetic differences for growth as influenced by different inorganic phosphorus supply, and availability and uptake ability to three insoluble P named organic P, Al-P and RP, using solution culture and sand quartz culture respectively. The results demonstrated that biomass and root dry weight of rices were reduced by low P, but R/S was affected by both supplied P level and uptake ability of plant to low P. Under the condition of low P, the biomass and root dry weight with different inorganic phosphorus treatments were P> CK+Al-P > CK+RP > CK; root dry weight and root shoot ratio of four low-P tolerant rice genotypes were larger than those of two low-P sensitive rice genotypes; For R/S, 580 and 99011 were CK+RP > CK+Al-P > CK> P, 508, 99112 and 99012 were CK> CK+RP > CK+Al-P > P, but 99056 was CK+Al-P > CK+RP > P> CK. The availability of sparingly soluble phosphates and organic phosphorus absorbed by rice seedlings was OP> Al-P> RP, but different rice cultivars had significant difference in response to three insoluble P compounds. P uptake amount for organic phosphorus was 99011> 508> 580> 99012> 99112> 99056, for Al-P was 580> 99011> 99112> 508> 99056> 99012, and for RP was 580> 99112> 99011> 508> 99012> 99056. Furthermore 508 has highest uptake efficiency to low phosphorus; 580 has highest P utilization efficiency , and absorbed more sparingly soluble phosphorus especially Al-P and RP than others; They are maybe one of the important reasons in 508 and 580 for low-P tolerance in 508 and 580. Low-P tolerant rice genotype 99112, a special material, it has small biomass and achieve high relative grain yield. As for low-P sensitive rice genotype 99056, its utilization efficiency to phosphorus is not low, but it just has small root system, only active and uptake a little sparingly soluble phosphorus, and can not absorb low concentration phosphorus.

Cloning and Expression Properties of Plant Stress Inducible Promoter mwcs120

DU Juan;ZHU Zhen;LI Wan-Chen

Acta Agron Sin. 2005, 31(10):  1328-1332. 

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Growth and development of plant are heavily influenced by abiotic stress. In recent years, different resistant genes have been cloned and transferred into less resistant species. It was attempted to improve crops for their resistance to abiotic stress. In most cases, however, forceful constitutive promoter was used to promote over expression of stress gene. This was disadvantageous to some activities of physiological metabolism, although the transgenic plant was improved for its stress resistance. In this study, stress inducible promoter mwcs120 was cloned by specific PCR from wheat genomic DNA. Sequence analysis showed that this promoter was 97.1% homologous with cold inducible promoter wcs120. Even though mutations were found at two locations, conservative elements for stress regulation were still kept unchanged. Transient expression experiment indicated that, both in monocotyledonous and dicotyledonous plants, promoter mwcs120 was induced by low temperature and high salt stress to increase expression of gene GUS. Therefore, promoter mwcs120 was hopeful to be used to gene engineering of crop improvement for stress resistance.

Spectral and Recongnized Method for Different Plant Type Wheat Cultivars

LU Yan-Li;LI Shao-Kun;WANG Ji-Hua;XIE Rui-Zhi;HUANG Wen-Jiang;GAO Shi-Ju;Liu Liangyun;Wang Zhijie

Acta Agron Sin. 2005, 31(10):  1333-1339. 

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With the application of remote sensing in estimating crop biochemical composition, the estimation precision has became a research focus. Plant-type is the main influential factor to canopy spectral due to its influence on canopy structure. It is very important to identify plant type of wheat cultivars for improving estimation accuracy. 10 winter wheat cultivars with two plant types were used to discuss their canopy spectral reflectance and the method to identify plant type using spectral characteristics and vegetation coverage (COV). The results were as follows: (1) Their canopy spectral reflectance had obvious difference in near infrared bands at earlier stages, especially at jointing stage (Fig.1). It was proved that Jointing was the best stage to identify plant-type, and in this stage there was a big differences for canopy spectral reflectance between 2 plant types in wavebands of 680 nm and 760－900 nm (Table 2). These bands lied in the position of red edge and near infrared, which were the plant canopy sensitive bands. So it was very useful to improve the measurement accuracy of leaf biochemical composition. (2) Leaf area index (LAI) was positively correlated with normal difference vegetable index [NDVI(680, 890)]. The correlation coefficient was different at different stage(Fig.3,4). The correlation between LAI and NDVI was the foundation to identify plant type by using NDVI and COV(vegetable coverage). (3）With COV increasing, NDVI was increased, but the difference between two plant types became diminishing. It reflected their plant-type characteristics, that is to say, leaves are erect and upwards in erect cultivars but horizontal and downwards in horizontal cultivars. So COV of horizontal cultivars was higher than that of erect ones under the same NDVI. On the other hand, when COV of the two cultivars was equal, NDVI of the erect leaf type varieties was higher than that of horizontal leaf type cultivars (Fig.5). As for wheat, jointing stage with low and different COV in two pant-type cultivars is the best stage to identify plant-type. There was significant difference in NDVI of erect and horizontal cultivars (P＜0.05) at jointing stage. It is feasible to know plant type information using COV and NDVI. This method is fast and non-destructive. It provides the foundation to assess plant biochemical composition quantitatively by remote sensing.

Impacts of Climate Change on Wheat Yield in China

JU Hui;XIONG Wei;XU Yin-Long;LIN Er-Da

Acta Agron Sin. 2005, 31(10):  1340-1343. 

Abstract ( 1841 )   PDF (5812KB) ( 1348 )   Save

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Wheat (Triticum aestivum L.) is the second most important grain crop in China. Understanding the relationship between climate change and wheat yields will not only help to optimize agricultural practices, but also benefit to adapt climate change. The regional climate mode PRECIS (Providing Regional Climate for Impacts Study) and CERES-wheat model were used to simulate wheat yield change under future climate change scenarios. The preliminary results indicated that both the yields of rain-fed and irrigated wheat would be decreased in 2070s by about 20% with climate change. The yields of rain-fed wheat loss more than irrigated wheat, and spring wheat or spring-habit winter wheat would be decreased more than winter wheat and winter-habit wheat with climate change in 2070s. The areas that yield decreased remarkable are located in Northeast China where plants with spring wheat and Southwest China with winter wheat.

Comparison of Nutritive Composition in Different Types of Forage Crops

ZHANG Xiao-Yan;DONG Shu-Ting;WANG Kong-Jun;ZHANG Ji-Wang;LIU Peng

Acta Agron Sin. 2005, 31(10):  1344-1348. 

Abstract ( 1773 )   PDF (6184KB) ( 879 )   Save

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Three kinds of forage crop, Sudan Grass—Wancao2, Euchlaena perennis Hitchc. and ND108 which is also used as food were used to compare the nutritive composition. Both fresh matter yield and dry matter yield of Wancao2 was the highest, that of E. perennis the median, and ND108 the lowest relatively. Main component of dry weight was leaves in Wancao2 and E. perennis, while stems in ND108. The yields of crude protein(CP), nitrogen-free extract(NFE), acid-washed fiber (AWF), ether extract (EE) and crude ashes (CA) were higher in Wancao2 than in E. perennis and ND108 significantly, however, the content of CP and CA was the highest in E. perennis and the lowest in ND108. In addition, the total energy (GE) of Wancao2 was 1 448.024×10⁶ J·hm^-2 and 2 339.687×10⁶ J·hm^-2 higher than that of E. perennis and ND108, respectively. The degradation rate of dry matter and CP were the highest in ND108, which was 57.880% and 12.424%. The degradation rate of crude fiber was higher in E. perennis than in Wancao2. The differences of degradation rate of CP and dry matter between E. perennis and Wancao2 are not significant. In conclusion, the difference of nutrition among the three kinds of forage crops results from their different biological characteristics.

Identification of AFLP Markers for Resistance to Seed Infection by Aspergillus flavus in Peanut (Arachis hypogaea)

LEI Yong;LIAO Bo-Shou;WANG Sheng-Yu;LI Dong;JIANG Hui-Fang

Acta Agron Sin. 2005, 31(10):  1349-1353. 

Abstract ( 1786 )   PDF (7280KB) ( 977 )   Save

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Aflatoxin contamination is an important constraint to peanut industry worldwide. Genetic improvement for host resistance in peanut to fungal infection and aflatoxin production has been among the approaches for integrated management of the problem. However, the progress in peanut breeding for resistance to aflatoxin has been slow due to various reasons, among which, lack of cost-effective method for resistance identification in breeding materials or segregating progenies has been encountered in most breeding programs. Hence there is a need to develop a rapid and reliable screening method for selecting Aspergillus flavus infection resistance in peanut. Here we report two DNA markers closely linked with resistance to A. flavus infection using AFLP technique based on bulked segregant pools derived from F₂ progeny of Zhonghua 5×J11. J11 is resistant to seed infection by Aspergillus flavus and Zhonghua 5 is susceptible, two DNA markers linked with resistance to A. flavus infection were identified. The two specific fragments linked with seed infection resistance were, one about 440 bp which was named as marker E45/M53-440, and the other was about 520 bp, named as marker E44/M53-520, the former marker linkage distance to the resistant gene was 6.6 cM, while the latter was 8.8 cM. Twenty peanut genotypes with resistance to infection of A. flavus and seven susceptible genotypes were used to verify the reliability of the resistance markers, and high correlation between the molecular markers and the resistance result. The result shows that the potential of the markers which can be used in other resistant peanut genotypes to seed infection by A. flavus.

Molecular Detection of Transformed Wheat with Anti-PLDγ Gene and It’s Agronomic Characters

WANG Rui-Xia;GAO Qing-Rong;CUI De-Cai;LIU Zheng-Bin;QIAO Xiao-Lin;LI Hong-Li

Acta Agron Sin. 2005, 31(10):  1354-1358. 

Abstract ( 1806 )   PDF (7171KB) ( 723 )   Save

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Antisense phospholipase D_γ (PLD_γ) gene was introduced into LK906 wheat mediated by improved earstem injecting of Agrobacterium. The transformants were screened by PCR and PCR-Southern technique and the variation between transformation lines and receptor was analyzed. The results indicated that（1）400 bp special fragment to the plasmid was amplified in three plants（03039,03048,03050）, which showed that anti-PLD_γ gene was integrated into wheat genomes, thus the transgenic wheats of anti-PLD_γ gene were obtained in the world first. (2) There were distinct differences between transgenic lines and receptor in agronomic characters, such as plant height, 1 000-kernel weight and spike number per plant that were higher in transgenic lines than in receptor. Compared with in the receptor, in transgenic lines the plant height was from 79.2 cm to 83.8 cm and 13.4 cm higher; the average value of spike number per plant was 3.82 and higher significantly too; and 1 000-kernel weight was from 50.53 g to 52.98 g and 6.94 g higher. While the spike length, number of spikelet and grain number per spike were lower (Table 1). (3) The mature date of CK was on June tenth, those of transgenic plants (03048,03039,03050) were on June second, June third, June sixth respectively, and 4 to 8 days shorter than that of receptor. It showed that anti-PLDγ gene was good to advance mature date. Complete male sterile was observed in T₁ and the following generations and it would play an important role in heterosis utilization.

The Linkage Drag Analysis of Flanked opaque2 by SSR Markers in Two Maize BC₁F₁ Population

FANG Ming-Jing;DING Dong;YANG Wen-Peng;XU Shang-Zhong;ZHENG Yong-Lian

Acta Agron Sin. 2005, 31(10):  1359-1364. 

Abstract ( 2019 )   PDF (8110KB) ( 855 )   Save

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In order to get rid of the linkage drag of target gene and get more selected individuals with better genetic recovery, two backcrossing populations (SCBC₁F₁ and HCBC₁F₁ ) of maize were constructed with its size up to 1 416 and 1 627 individuals each. Five SSR markers which are localized in and linked closely to opaque2 (o2) gene (Fig.1) were employed to analyze linkage drag of o2 in SCBC₁F₁ and HCBC₁F₁ populations. Foreground and background selection were processed in the two populations by those five SSR markers (Fig.2－5). Compared with the computer simulation results proposed by Ribaut (Table 2), the MAS results were more exercisable and convictive. It suggests that, when the MAS program is put in practice of plant backcrossing breeding process, to make sure the size of the backcrossing F₁ population is appropriate, not only the number of the selected individuals ultimately (N_i), but also the number of the selected individuals ultimately with enough seeds (N_j) need to be considered (Table 1). Moreover, the length of the linkage drag is also an important parameter to estimate the size of BC₁F₁ population.

Cloning and Characterization of Phosphoenolpyruvate Carboxylase Gene from Echinochloa crusgalli

ZHANG Gui-Fang;ZHAO Ming;DING Zai-Song;ZHANG Li;XIAO Jun-Tao

Acta Agron Sin. 2005, 31(10):  1365-1369. 

Abstract ( 2093 )   PDF (7149KB) ( 823 )   Save

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Phosphoenolpyruvate carboxylase (PEPCase) has a variety of functions in plants. In order to elucidate structural and functional characters of PEPCase from Echinochloa crusgalli, and search a new approach to improve crops photosynthesis, a full-length cDNA for PEPCase was isolated from E. crusgalli. Using the program of BLAST on NCBI GenBank database, the sequence presented a very high match with the genes from other plants. After alignment on ClustalW program, the identities of the cloned fragment with PEPCase genes from Setaria italica C₃- form, Sorghum valgare C₄- form, Zea mays C₄- form and Oryza sativa C₃- form were about 94.8%, 93.2%, 93.0% and 89.7%, respectively. E. crusgalli ppc ORF is 2 886 bp, encoding 961 amino acid residues. The sequence has been submitted to the GenBank database, the accession number is AY251482. Alignment and phylogenetic analysis of the amino acid sequence deduced from the fragment and the PEPCase sequences of other plants retrieved from GenBank were carried out by ClustalW program, which showed that the sequences homology of E. crusgalli with C₃- form was higher than with C ₄- form. To identify amino acid residues and/or domains responsible for C₄/ C₃-specific properties, we found the putative amino acid sequence contains a C₃ conserved alanine at position 771, and the sequence shared a homology of 96.5%, 96.4% with the C₃-2- form PEPCase of Zea mays and Sorghum valgare，83.8%, 84.3% with the C_3-1- form PEPCase of Zea mays and Sorghum valgare，and 82.2%,79.1%,77.1%,76.6% with the C ₄- form PEPCase of S. italica, Z. mays, S. spontaneum and Sorghum valgare. So we can conclude that the cloned sequence is a C₃-2- form of PEPCase gene from E. crusgalli. The domain, active sites and fuction sites of Echinochloa crusgalli PEPC protein are predicted.

RESEARCH NOTES

Effects of Photoperiod Treatment for Different Fall-dormants of Alfalfa on Phytochrome B (PhyB) and Abscisis Acid(ABA) Levels

WANG Cheng-Zhang;HAN Jin-Feng;HU Xi-Feng;ZHANG Chun-Mei;PAN Xiao-Jian

Acta Agron Sin. 2005, 31(10):  1370-1372. 

Abstract ( 1472 )   PDF (4250KB) ( 832 )   Save

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Isolation of cDNA Clones Related to Bacterial-blight Resistance of Rice by mRNA Differential Display

WANG Jie;WANG Chun-Lian;FAN Jin-Juan;ZHANG Qi;KONG Fan-Ling;ZHAO Kai-Jun

Acta Agron Sin. 2005, 31(10):  1373-1376. 

Abstract ( 1444 )   PDF (5347KB) ( 915 )   Save

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Analysis of cbf1 Flanking Sequences in Transgenic Tobacco by TAIL-PCR

SONG Da-Feng;HAN Ning;BIAN Hong-Wu;ZHU Mu-Yuan

Acta Agron Sin. 2005, 31(10):  1377-1379. 

Abstract ( 1581 )   PDF (3755KB) ( 850 )   Save

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Agronomic Traits Analysis of Early-generation-stable-lines in Rice

ZHOU Li-Jun;AO Guang-Hui;WU Xian-Jun;XIAO Yi;LIAO Yong-Xiang;LI Shi-Gui

Acta Agron Sin. 2005, 31(10):  1380-1385. 

Abstract ( 1546 )   PDF (7577KB) ( 765 )   Save

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The Rapid Discrimination Based on PCR on Cytoplasmic Types of Male Sterile Line of Maize (Zea mays L.)

ZHANG Zu-Xin;FANG Ming-Jing;DU He-Wei;DENG Li-Rong;ZHENG Yong-Lian

Acta Agron Sin. 2005, 31(10):  1386-1388. 

Abstract ( 1653 )   PDF (4122KB) ( 783 )   Save

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