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    12 May 2008, Volume 34 Issue 05
      Sequence Polymorphism of waxy Genes in Landraces of Waxy Maize from Southwest China
      TIAN Meng-Liang;HUNAG Yu-Bi;TAN Gong-Xie;LIU Yong-Jian;RONG Ting-Zhao
      Acta Agron Sin. 2008, 34(05):  729-736.  doi:10.3724/SP.J.1006.2008.00729
      Abstract ( 2421 )   PDF (608KB) ( 1842 )   Save
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      In order to understand the DNA polymorphism of the waxy genes in waxy maize and flint maize landraces from Southwest China, the 25 sequences from the ninth exon to the fourteenth exon of waxy gene were cloned and sequenced. The sampled landraces included 16 waxy maize cultivars (Zea mays L. ceratina Kulesh.) and seven flint maize cultivars from Southwest China, and tow waxy maize cultivars from Argentina. Additionally we downloaded 16 homologous sequences from six Z. mays subsp. parviglimis individuals, five Z. luxurians individuals and five American landraces from NCBI. The sequences were aligned and DNA variations among them were analyzed. We found waxy maize, flint maize, and parviglumis had 14, 19, and 40 polymorphic sites, respectively. Within the Z. taxa samples, Chinese waxy maize contained 30% of the genetic diversity in Chinese flint maize and 14% of the genetic diversity in Z. mays subsp. parviglimis, respectively. The statistical Tajima’D significance was only found in Chinese waxy maize population. Seventy five percent of the Chinese waxy maize landraces contained one deletion of fifteen nucleotides, which encodes the amino acid sequence NKEAL and is located at the start site of the glycosyl transferases group 1 of waxy gene. Chinese waxy maize might be originated from one special mutant of flint maize and experienced one domestication bottleneck in the process of evolution. The founder effect made the nucleotide diversity of waxy gene in waxy maize lower than that in its relatives. To improve the quality and quantity of starch in maize different alleles from its relatives should be introduced into maize genome.
      Mapping QTL for Seed Dormancy in Weedy Rice
      JING Wen;JIANG Ling;ZHANG Wen-Wei;ZHAI Hu-Qu;WAN Jian-Min
      Acta Agron Sin. 2008, 34(05):  737-742.  doi:10.3724/SP.J.1006.2008.00737
      Abstract ( 2312 )   PDF (294KB) ( 1456 )   Save
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      The genetic basis of the seed dormancy of a weedy rice was dissected using a segregation population derived from a cross with a japonica cultivar. Two QTLs were located on chromosomes 1 and chromosomes 2, and two on chromosome 6. These QTLs explained 7.8%, 7.1%, 5.5%, and 4.5% of the overall phenotypic variance, respectively. The QTL on chromosome 2 appears to represent a novel source of genetic variation for seed dormancy. A multi-way analysis of variance indicated that the gene action of these four QTLs was additive. A significant negative correlation was found between germination rate and flowering time. A single heading date QTL was identified, to be either pleiotropic on or linked to a seed dormancy QTL on chromosome 6, thereby accounting for the observed correlation between seed dormancy and flowering time.
      Cloning and Analysis of BnMPK4, A Novel MAP Kinase Gene Induced by Oligochitosan in Brassica napus
      YIN Heng;YANG Jin-Li;LI Shu-Guang;ZHAO Xiao-Ming;BAI Xue-Fang;MA Xiao-Jun;DU Yu-Guang
      Acta Agron Sin. 2008, 34(05):  743-747.  doi:10.3724/SP.J.1006.2008.00743
      Abstract ( 1903 )   PDF (451KB) ( 1500 )   Save
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      Oligochitosan prepared by enzymatic hydrolysis of chitosan is a potential plant defense elicitor, but how the oligochitosan induces the resistance of plants to pathogens is still unclear. So we try to explore the signal transduction pathways of oligochitosan inducing defense. We isolated a new cDNA coding for mitogen-activated protein kinase (MAPK), designated BnMPK4 (GenBank: DQ206628), from oilseed (Brassica napus L.) based on our former microarray data. BnMPK4 encodes a 373-amino-acid protein with high sequence similarity to previously reported plant MAPK genes such as AtMPK4 and belongs to the B subgroup of plant MAPK. Bioinformatic analysis showed BnMPK4 contains one phosphorylation motif (TEY) and a conserved CD domain in its C-terminal extension. By using Semi-Quantitative RT-PCR technique we found that BnMPK4 had a constitutive expression in seedling leaves and was further up-regulated by treatment with plant hormone jasmonic acid (JA) and fungal elicitor oligochitosan but did not respond to salicylic acid (SA) and abscisic acid (ABA). These results suggest a role for BnMPK4 in oligochitosan-induced and JA/ET-regulated defense signalling pathway.
      Inheritance and QTL Analysis of Submergence Tolerance at Seedling Stage in Soybean [Glycine max (L.) Merr.]
      WANG Fang;ZHAO Tuan-Jie;YU De-Yue;CHEN Shou-Yi;GAI Jun-Yi
      Acta Agron Sin. 2008, 34(05):  748-753.  doi:10.3724/SP.J.1006.2008.00748
      Abstract ( 2122 )   PDF (450KB) ( 1777 )   Save
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      Flooding is often a serious natural disaster in the world. Flooding tolerance has been recognized in two categories: tolerance to soil waterlogging and tolerance to submergence. The objective of the present study was to reveal the inheritance and then to map the QTLs of tolerance to submergence in soybean. The survival percentage of seedlings of the RIL population NJRIKY derived from Kefeng No.1 (highly tolerant) × Nannong 1138-2 (sensitive) was evaluated under completely submerged condition in a pot experiment. The results from segregation analysis under major gene plus polygene mixed inheritance model showed that submergence tolerance of soybean was dominated by three major genes with the heritability of 42.40% and no polygene detected. With composite interval mapping (CIM) and multiple interval mapping (MIM) under Win QTL Cartographer Version 2.5, three QTLs associated with submergence tolerance were identified, which located in Satt648-K418_2V, Satt531-A941V and Satt038-Satt275 (B53B-Satt038) on linkage groups A1, D1a and G, respectively, explaining 4.4-7.6% of the total phenotypic variation. The results from segregation analysis and QTL mapping appeared relatively consistent and could be verified each other.
      Genetic Diversity of Brassica juncea from Western China
      XU Ai-Xia;MA Chao-Zhi;XIAO En-Shi;QUAN Jing-Chun;MA Chang-Zhen;TIAN Guang-Wen;TU Jin-Xing;FU Ting-Dong;ZHANG Gai-Sheng
      Acta Agron Sin. 2008, 34(05):  754-763.  doi:10.3724/SP.J.1006.2008.00754
      Abstract ( 2192 )   PDF (394KB) ( 1517 )   Save
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      A better understanding of genetic diversity and its distribution are essential for its conservation and use. The research of it will help us to determin what and where to be conserved, and improve our understanding of the taxonomy, origin and evolution of plant species. The genetic diversities of 108 accessions including 101 entries of Brassica juncea from western China, 2 from Australia, 4 entries of B. rapa, and 1 entiry of Eruca sativa Mill.were analysed by SRAP with 23 pairs of primer combinations, AFLP with 11 primer combinations, and SSR with 10 pairs of primer combinations. The results showed that totally 313 loci were detected in these materials. The genetic similarity coefficients of 108 accessions varied from 0.378–0.936, while 103 accessions of B. juncea from 0.545–0.936. The clustering analysis indicated that the genetic similarity coefficients of 5 checks including B. rapa, Eruca sativa Mill., were less than 0.558. At the point of genetic similarity coefficient, 0.700, the 103 accessions of B. juncea were divided into 5 groups, those were group A from Yunnan-Guizhou and Southern Shaanxi, group B from Guanzhong of Shaanxi, group C and group D from Xinjiang, and group E from western China. Groups A and B were winter type, groups C, D, and E were spring type. The genetic difference among the accessions in group A was the largest, and higher than that in group B. The accessions from Shaanxi and Xinjiang were distributed into 3 groups respectively, and showed abundant genetic diversity. Group E including the most spring accessions, was divided into 3 sub-groups. The accessions in the sub-group I were from Tibet, with the genetic similarity coefficient higher than 0.83, belonging to an independent genetic system with narrow genetic background. The accessions of yellow mustard in the sub-group II were from Northern Shaanxi, showed higher genetic diversity and belonged to another independent genetic system. In the sub-group III, two accessions from Australia were similar to the spring type in China. Therefore the genetic differences in B. juncea were mainly related to geological and biological conditions. The genetic diversities in winter type of B. juncea were higher than those in spring type in China. The genetic background of B. juncea in Shaanxi and Xinjiang was wide.
      Analysis of Self-Incompatibility Locus Gene in Brassica napus
      KE Li-Ping;ZHENG Tao;WU Xue-Long;HE Hai-Yan;CHEN Jin-Qing
      Acta Agron Sin. 2008, 34(05):  764-769.  doi:10.3724/SP.J.1006.2008.00764
      Abstract ( 2129 )   PDF (413KB) ( 1354 )   Save
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      Self-incompatibility (SI) is one of the most important mechanisms in flowering plants to prevent inbreeding and promoter outcrossing. In Brassica, the diploid varieties of Brassica oleracea (CC) and B. campestris (AA) were self-incompatibility, while the amphidiploid B. napus varieties (AACC) were usually self-compatible. In the SI response, SLG gene was one of the S-locus genes that supposed to contribute to receptor—ligand interactions and signal transduction. SLG gene shares a similarity of 85–98% with eSRK (SRK ectodomain) in the same S haplotype, while in different S haplotypes, the SLGs and SRKs behave dif-ferently. In order to make out whether the S-locus exist in B. napus, the SLG gene in the S-locus in several varieties of B. napus were cloned. By PCR analysis and sequences comparison, the class II SLG gene was found in all tested varieties of B. napus, while class I SLG genes were only found in 5 of the 10 tested varieties. Further studies indicated that the five varieties that had the class I SLG genes were probably derived from the same S haploid years ago. The results would provide scientific reference for further study and exploitation on the mechanistic studies of self-compatibility in Brassica napus L.
      Differential Gene Expression in Uppermost Internode between Wheat Hybrid and Its Parents
      ZHANG Yi;NI Zhong-Fu;YAO Ying-Yin;SUN Qi-Xin
      Acta Agron Sin. 2008, 34(05):  770-776.  doi:10.3724/SP.J.1006.2008.00770
      Abstract ( 2247 )   PDF (523KB) ( 1422 )   Save
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      Heterosis is defined as the advantage of hybrid performance over its parents in growth and productivity. Previous studies showed that differential gene expression in hybrids and their parents is responsible for the heterosis. Plant hormones, especially GAs are found to be related to heterosis in development of shoot and plant height. However, information on systematic identification and characterization of the differentially expressed genes in shoots of hybrid and their parents are not found, and molecular evidence for the contribution of plant hormone to plant heterosis are also absent. The purpose of this paper was to investigate the differential gene express in stems of hybrid and their parents, and further, to investigate the possible role of genes participating hormone signaling in the formation of heterosis of plant stem. Using a wheat cross combination that exhibited vigorous heterosis in plant height, the differential gene expression in upper-most internode of wheat hybrids and their parents was analyzed by cDNA-AFLP. Ninety-eight differentially expressing cDNA fragments were obtained, which were sequenced and analyzed by Blast-x. Reverse Northern hybridization was performed in order to test the expression pattern of isolated ESTs in hybrid and their parents. The differentially expressed genes included a cdc2 gene and a PAS1 gene, which were induced by GAs and CTKs respec-tively and participated in plant cell division. The cdc2 gene was up-regulated in hybrid while the expression of PAS1 in hybrid was near the higher parent. The differentially expressed genes also included kinase participating in signal transduction, genes in-volved in metabolism and genes related to transcription regulations. It can be inferred that numerous genes were differentially expressed in the upper-most internode of hybrids and their parents, including genes participating in cell division and cell expan-sion, kinase related to signal transduction and so on. Reverse Northern blot analysis indicated that the expression pattern in our cDNA-AFLP analysis is credible. Since it has been much reported that genes participating in cell division and cell expansion are involved in plant stem growth and elongation, and genes that participate in gibberellins signals have been proved to be up-regulated in wheat hybrid and contributed to heterosis in wheat plant height, it can be modestly speculated that the differential expression of genes involved in phytohormone signals may be related to heterosis in wheat intenode elongation and plant height.
      Cloning of A S-Adenosylmethionine Synthetase Gene from Broomcorn Millet (Panicum miliaceum L.) and Its Expression during Drought and Re-Watering
      LIN Fan-Yun;WANG Shi-Qiang;HU Yin-Gang;HE Bei-Ru
      Acta Agron Sin. 2008, 34(05):  777-782.  doi:10.3724/SP.J.1006.2008.00777
      Abstract ( 2190 )   PDF (661KB) ( 1506 )   Save
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      To explore more genes for the improvement of drought-tolerance and water use efficiency in plants, broomcorn millet (Panicum miliaceum L.) was used to investigate the differential gene expression during drought stress and re-watering after serious drought stress by constructing SSH-cDNA library in previous study. A full-length cDNA of S-adenosylmethionine synthetase (SAMS) gene was amplified from broomcorn millet using PCR. The PCR primers were designed based on an EST sequence highly similar to SAMS gene in the SSH-cDNA library and the sequences of SAMS genes from rice and barley. The full-length cDNA sequence of SAMS gene amplified from broomcorn millet was 1 293 bp in length and designated as PmSAMS, encoding 396 amino acids with the 3 typical domains of SAMS (N terminal domain, inter domain and C terminal domain). Multiple alignment analysis based on the amino acids encoded by some SAMS genes from broomcorn millet (P. miliaceum L.), potato (S. tuberosum), Arabidopsis (A. thaliana), sugar beet (B. vulgaris), barley (H. vulgare), litchi (L. chinensis), tomato (L. esculentum), and rice (O. sativa) indicated that SAMS was very conserved among different species of plants with 92–97% of sequence similarity of amino acids, and PmSAMS had the highest similarity with that of rice (97%). The expression patterns of PmSAMS during drought and re-watering after serious drought were investigated by means of semi-quantitative RT-PCR. The results showed that the ex-pressions of PmSAMS were great at the beginning of drought treatment (soil relative moisture of 36%), then declined under seri-ous drought (soil relative moisture of 24%) to less than the normal level, and increased at 2 h after re-watering, declined to the normal level at 6 h after re-watering. The expression patterns of PmSAMS during drought and re-watering after serious drought indicated that it was involved in the response of broomcorn millet to drought and re-watering and might be one of the key genes for drought tolerance and water use efficiency of broomcorn millet. The cloning of this gene provides the potential for its utiliza-tion in the improvement of drought-tolerance and water use efficiency in other plants.
      Obtainment of atzA-Transgenic Tobacco Plants and Analysis of Their Phytoremediation Capability
      WANG Hui-Zhuan;CHEN Xi-Wen;WANG Yong-Qin;CAI Bao-Li;CHEN De-Fu
      Acta Agron Sin. 2008, 34(05):  783-789.  doi:10.3724/SP.J.1006.2008.00783
      Abstract ( 2054 )   PDF (470KB) ( 1243 )   Save
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      Atrazine (2-chloro-4-ethylamino-6-isopropylamno-1,3,5-triazine) is a wildly used herbicide in the world for controlling broad-leaf weeds in corn and sugarcane. However, atrazine is degraded slowly in the environment with an average half-life ranging from 4 to 57 weeks, and has been detected in soil as well as in ground and surface water in several countries. Atrazine chlorohydrolase (AtzA) catalyses the hydrolytic dechlorination and detoxification of atrazine to hydroxyatrazine, a non-herbicidal and non-toxic substance and is more strongly sorbed to soil than atrazine. In the present paper, atzAs were amplified from pMD4 plasmid (containing atzA-ADP) and pET21b-atzA-NK plasmid (containing atzA-NK), and inserted into plant expression plasmid pBin438. The recombinant plasmid was successfully introduced into tobacco leaf disks by Agrobacterium-mediated transformation and 136 plantlets were regenerated from selected medium contained 20 mg L-1 kanamycin and 150 μg mL-1 atrazine, and then were subjected to analyses of PCR and RT-PCR. The PCR using primers atzA-7/atzA-2, atzA-5/atzA-8, and atzA-7/atzA-8, which are specific for atzA, revealed that 42 of 72 (58.3%) pBin438-atzA-ADP and 38 of 64 (59.4%) of pBin438-atzA-NK regenerated plants were transgenic, respectively. Further RT-PCR indicated that 38.1% (16 of 42) of atzA-ADP and 28.9% (11 of 38) of atzA-NK, expressed AtzA in transgenic tobacco plants, respectively. After 50 days’ growth on 1/2MS medium contained 150 mg L-1 atrazine, the transgenic plants degraded a large amount of atrazine presented in the medium with degrading as high as 79.26% in line 401, whereas 0.47% in the wild type. These results indicated that the transgenic tobacco plants can catalyze atrazine effi-ciently.
      Rice RVA Profile Characteristics and Correlation with the Physical/ Chemical Quality
      JIA Liang;DING Xue-Yun;WANG Ping-Rong;DENG Xiao-Jian
      Acta Agron Sin. 2008, 34(05):  790-794.  doi:10.3724/SP.J.1006.2008.00790
      Abstract ( 2264 )   PDF (226KB) ( 3137 )   Save
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      In this paper, we determined rice RVA profile characteristics and their physical/chemical quality indicators of 124 varieties grown in Sichuan Province, and studied the relationship among RVA profile characteristics and between RVA profile characteristics and physical/chemical indicators. To study the differences of RVA profile characteristics of rice varieties with different amylose contents (AC), we divided these varieties into six groups, including waxy rice, low AC, moderate lower AC, moderate AC, moderate higher AC, high AC, and analyzed the differences of RVA profile characteristics between the latter five groups of no-waxy varieties, and the influence of AC on RVA profile characteristics. There were no significant correlation between peak viscosity (PKV) and cool paste viscosity (CPV), and between PKV and consistence (CSV), but significant correlations among other RVA profile characteristics with each other at P = 0.01 except hot paste viscosity (HPV) with breakdown (BDV) at P = 0.05. CPV significantly positive correlated to CSV, with the correlation coefficients of 0.94. Six RVA profile characteristics had signifi-cant correlations with AC and gel consistency (GC) at P = 0.01, AC significantly positively correlated to GC, with the correlation coefficients of -0.82 at P = 0.01; alkali-spreading value (ASV) had no significant correlation with AC, GC, and six RVA profile characteristics. Varieties with different AC had different RVA profile characteristics, when AC was higher, setback (SBV) and CSV were higher and BDV lower.
      Starch Granule Size Distribution in Wheat Grains under Irrigated and Rainfed Conditions
      DAI Zhong-Min;YIN Yan-Ping;ZHANG Min;LI Wen-Yang;YAN Su-Hui;CAI Rui-Guo;WANG Zhen-Lin
      Acta Agron Sin. 2008, 34(05):  795-802.  doi:10.3724/SP.J.1006.2008.00795
      Abstract ( 2417 )   PDF (411KB) ( 1320 )   Save
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      Starch granules comprise A and B types in mature wheat (Triticum aestivum L.) grains, which are different in chemical composition and functional properties. The granule size distribution of wheat starch is affected by both genotype and environment factors. Currently little information is available about the different distribution of starch granule size in wheat under different cultivation conditions. We used two wheat cultivars, Lumai 21 (starch content 68.9%) and De 99-3 (starch content 64.6%), to investigate the distribution of grain starch granule size under irrigated and rainfed conditions at Tai’an and Dezhou of Shandong Province in 2004–2005 growth season. The irrigated treatment received 3 irrigations with the total water amount of 2 250 m2 ha-1 during the whole growth period (750 m3 ha-1 each at before sowing, pre-wintering, and jointing stages, respectively), while the rainfed treatment had no irrigation. In mature grains, the diameter of starch granules ranged from 0.37 to 52.60 mm, and the percent volume distribution showed a 2-peak curve with the mean granule diameter of 5 (B type) and 25 mm (A type) at each peak. The volume percentages of A and B types were 56.1–65.5% and 34.5–43.9%, respectively. A 2-peak curve was also shown in percent surface area distribution of starch granules, but only one peak in percent number, because the number of B-type granules accounted for over 99% of the total starch granules. As compared with irrigated treatment, rainfed treatment affected the distribution of starch granules in grains of both cultivars through increasing the percent volume and percent surface area of 2.0-9.8 mm and <9.8 mm starch granules and decreasing those of >18.8 mm starch granules. The soil water deficit also decreased the contents of amylose and starch in grains and increased protein content, peak viscosity and final viscosity, suggesting that rianfed treatment may improve wheat grain quality. The contents of amylose, starch, and protein in grains were significantly correlated with the percent volume of starch granules with different diameter ranges. For starch, the r was -0.560*, -0.831** (2.0-9.8 mm) and -0.597*, -0.812** (<9.8 mm); and for protein, the r was 0.799**, 0.603*, (2.0-9.8 mm) and 0.799**, 0.578* (<9.8 mm), respectively. The result suggested that small starch granules (2.0-9.8 mm and <9.8 μm) are low in contents of amylose and starch, and high in protein content, whereas big starch granules (9.8–18.8 mm and >9.8 μm) high in contents of amylose and starch.
      Influence of Rhizosphere Oxygen Concentration on Rice Root Growth
      WANG Dan-Ying;HAN Bo;ZHANG Xiu-Fu;SHAO Guo-Sheng;XU Chun-Mei;FU Guan-Fu
      Acta Agron Sin. 2008, 34(05):  803-808.  doi:10.3724/SP.J.1006.2008.00803
      Abstract ( 2095 )   PDF (321KB) ( 2158 )   Save
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      The growth of rice root needs oxygen, which is consumed in root respiration and contained in soil also influencing the ecological environment of rhizosphere. Although rice plant can transport atmospheric oxygen from its shoot through its continuous aerenchymatous system to its roots, rice can not grow well in submerged, anoxic soil; there exists affinitive relation between the aeration condition of soil and the growth of rice plant. In this study, various rice cultivars were cultivated in hydropotic to study the influence of rhizosphere oxygen concentration enhanced by aeration on rice root growth. The results showed that aeration significantly increased the oxygen concentration of hydroponic solution during the whole plant growth stage. Rice plant had the highest oxygen absorption ability at heading stage, compared to the no rice planting treatment, the oxygen concentration at this stage was decreased 73.62% for Guodao 1 and 68.50% for Shanyou 63, and the decrease extent was more than that at booting stage and grain filling stage. Compared to control, length of single root, length of the longest root of rice planted in higher oxygen concentration solution were longer, the dry weight percent of rice root ranging from 10 to 20 cm and longer than 20 cm from root base to tip increased accordingly, and the number of roots per plant was less. While in the treatment with anoxic condition, the number of rice root increased and the length decreased. Genotype difference existed in the influence of rhizosphere oxygen con-centration on root vitality. Under aeration condition, the root active absorption area per plant and root vitality of hybrid rice Guo-dao 1 and Shanyou 63 increased significantly at full heading stage; the root vitality of conventional rice genotype Xiangzaoxian 11 and Yongjing 18 which had high root vitality also increased significantly, while the root vitality changed little in low root vital-ity genotype Xiangzaoxian 24 and Chunjiang 06. When rice growed in anoxic condition, root vitality decreased.
      Comparisons in Agronomic and Physiological Traits of Rice Genotypes Differing in Cadmium-Tolerance
      HUANG Dong-Fen;XI Ling-Lin;YANG Li-Nian;WANG Zhi-Qin;YANG Jian-Chang
      Acta Agron Sin. 2008, 34(05):  809-817.  doi:10.3724/SP.J.1006.2008.00809
      Abstract ( 2132 )   PDF (565KB) ( 1204 )   Save
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      Cadmium (Cd) is one of major contaminants in agricultural soil, threatening agricultural production and human health. To understand agronomic and physiological characteristics of rice genotypes differing in Cd-tolerance would have great significance in selecting or breeding a Cd-tolerant cultivar. In this study, two Cd-tolerant rice genotypes of Shanyou 63 (indica hybrid) and Yangjing 9538 (japonica) and two Cd-susceptible genotypes of Yangdao 6 (indica) and Wuyunjing 7 (japonica) were pot-grown at a farm of Yangzhou University, Yangzhou, Jiangsu Province in 2004 and 2005. 150 mg kg-1 Cd was added into pot soil before seedling transplanting (Cd treatment), and no Cd addition was taken as control (CK). Under the Cd treatment, the grain yield was reduced by 6.2–8.9% for the Cd-tolerant genotypes and by 38.3–47.1% for the Cd-susceptible ones when compared with their respective CKs. The reduction in grain yield was mainly attributed to the reductions of panicles per pot and spikelets per panicle. The differences in seed-setting rate and 1 000-grain weight were not significant between the Cd treatment and CK. The Cd treatment markedly inhibited the tillering of the Cd-susceptible genotypes, resulting in the reduction in dry matter accumulation during the whole growth period. Cd little affected the translocation of non-structural carbohydrate from culms and sheaths and harvest index. For Cd-susceptible genotypes, the Cd treatment significantly reduced root oxidation activity and photosynthetic rate, activities of superoxide dismutase and catalase of leaves, and obviously increased contents of superoxidate radical and hydrogen peroxide and ethylene evolution rate of leaves, and the concentration of 1-aminocylopropane-1-carboxylic acid in root bleedings from the tillering to jointing stages, while the Cd treatment much less affected the above physiological traits for the Cd-tolerant genotypes. The differences in the above traits at heading and afterwards and abscisic acid content in leaves during the whole growth period were not significant between the Cd treatment and CK. The results indicate that the effects of Cd on rice growth and development are mainly during the early growth period (from tillering to jointing), and more tillers, stronger root activity and antioxidative defense system, and less ethylene synthesis in the plants during this period would be considered as agronomic and physiological traits of Cd-tolerant genotypes of rice.
      Effects of Exogenous Nitric Oxide Donor Sodium Nitroprusside on Photosynthetic Pigment Content and Light Use Capability of PS II in Wheat under Water Stress
      SHAO Rui-Xin;SHANG-GUAN Zhou-Ping
      Acta Agron Sin. 2008, 34(05):  818-822.  doi:10.3724/SP.J.1006.2008.00818
      Abstract ( 2451 )   PDF (332KB) ( 1502 )   Save
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      Nitric oxide (NO) has emerged as a key molecule involving in the regulation of various abiotic stresses that induces physiological responses in plants. NO acts as an antioxidant to protect chloroplast from oxidative damages by maintaining chloroplast membrane intactness, thus keeps high activity of PS II. The experiment was conducted under PEG stress of -0.5 MPa, while we chose 0.1 mmol L-1 sodium nitroprusside (SNP) as NO donor. The effects of SNP on the content of photosynthetic pigments and the ability of utilizing the light in PS II of winter wheat (Triticum aestivum L.) under drought stress were studied through chlorophyll fluorescence kinetic technique. The results showed that the content of photosynthetic pigment increased, but the pro-portion of opened PSII reaction centers (indicated by qP) decreased under drought stress, thus drought restricted the utilization of light-energy in PS II (F’v/F’m) and the exertion of photosynthetic function (LPFD). SNP could help to increase photosynthetic pig-ment content, and decrease the cell permeability, thus avoided decreasing the confined value of photosynthetic function (LPFD) by drought. Furthermore, SNP increased the proportion of opened PS II reaction centers (indicated by qP), leading to transference of the more excited light-energy to PS II function center, decreased the dissipation of excited energy in antenna pigments (NPQ), which increased the more absorbed light to participate in photochemical reaction (F’v/F’m). In addition, SNP alleviated the excited pressure in PS II reaction center imposed by drought and lowered the deoxidization of QA (1 - qP). Therefore, exogenous nitric oxide donor (SNP) may participate in the synthesis of photosynthetic pigments and the utilization of light-energy in PS II of wheat under drought stress.
      Effect of AsA-GSH Cycle on Hg2+-Tolerance in Rice Mutant
      ZENG Bin;WANG Fei-Juan;ZHU Cheng;SUN Zong-Xiu
      Acta Agron Sin. 2008, 34(05):  823-830.  doi:10.3724/SP.J.1006.2008.00823
      Abstract ( 2062 )   PDF (642KB) ( 1276 )   Save
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      Mercury (Hg) toxicity is an in rice growth problem throughout the world. In the present study, Zhonghua 11 and a Hg2+-tolerant rice mutant (MT) were used in a solution culture to investigate the effect of 0.4 mmol L-1 Hg2+ treatment on reactive
      oxygen species (ROS) metabolism and dynamic change of ascorbate-glutathione (AsA-GSH) cycle. The results indicated that the
      H2O2 content, evolution rate, MDA content, GSSG and DHAcontents of the leaves were higher in the wild type than in the
      mutant; both the ratio of GSH to GSSG and the ratio of AsA to DHA were higher in the mutant than in the wild type, while the accumulation of Hg2+ in roots and stems of the mutant was more than that of the wild type. The results reveal that AsA-GSH cycle was less inhibited in the mutant than in the wild type, thus the mutant was able to scavenge ROS more. An effective AsA-GSH cycle is important for the mercury resistance of mutant.
      Hyperspectral Features of Winter Wheat after Frost Stress at Jointing Stage
      LI Zhang-Cheng;ZHOU Qing-Bo;LÜ Xin;LIN Hai-Rong;LI Sen
      Acta Agron Sin. 2008, 34(05):  831-837.  doi:10.3724/SP.J.1006.2008.00831
      Abstract ( 2091 )   PDF (548KB) ( 1433 )   Save
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      The North China Plain is the main production zone of winter wheat (Triticum aestivum L.), where wheat is affected seriously by later spring frostbite. Hyperspectral remote sensing is proved feasible in monitoring crop growth, especially after stresses. But the relationship between hyperspectral feature and crop growth characteristics after frostbite has been rarely studied so far. So we conducted a pot experiment with the artificial frost box to simulate frostbite (-5℃ and -7℃ respectively) in 2006–2007 winter wheat growing season. The wheat seedlings were treated in the box for 4 and 8 hours at jointing stage (treated only once either on April 9 or 15, 2007) respectively. The canopy hyperspectral reflectance curves were measured with ASD FieldSpec, and simultaneously, chlorophyll content (Chl) was tested with SPAD502. The result showed that chlorophyll content in control (CK) was 2–5 units more than that in the treatments after frostbite. In the early stage after frostbite, the reflectance and shape of hyperspectral curves were similar between treatments. After 20 days, frostbitten leaves turned into yellow in advance of CK, hyperspectral reflectance increased distinctly in yellow and red regions, the ‘red well’ (RW) was not distinctive, the shape of curves became plane. The relationship between chlorophyll content and hyperspectral reflectance ρ, logarithm of the reciprocal of ρ [log10 (1/ρ)], the first derivative of ρ (dρ/dλ) were analyzed, results indicated that ‘red edge’ (RE) shifted to shorter wavelength and RW to near infrared after frostbite. There were higher correlation between values of hyperspectral curve at special positions and frostbite stress levels, the correlation coefficients of frostbite degree with green peaks (ρg), RE, RW and the spectral absorbance index (SAI) were 0.36*, 0.69** , 0.42**, and 0.33* respectively, with the sum of reflectance in wide bands of blue(SBρ), green (SGρ), yellow (SYρ), and red(SRρ) were 0.34*, 0.43**, 0.45**, and 0.44* respectively, with the normalized difference vegetation index (NDVIa) between RE and RW was -0.33*, with the NDVIb between sum of reflectance at near infrared (SNirρ) and SRρ was -0.39**, with the chlorophyll content was -0.49**. In terms of distinct mean difference analysis, it is feasible to identify the frostbite injury and to estimate the injury degree based on the difference of the NDVIb.
      Effects of Ridge and Furrow Planting for Rainfall Harvesting on Photosynthetic Characteristics and Yield in Corn in Semi-Arid Regions
      REN Xiao-Long;JIA Zhi-Kuan;CHEN Xiao-Li;HAN Juan;HAN Qing-Fang;DING Rui-Xia
      Acta Agron Sin. 2008, 34(05):  838-845.  doi:10.3724/SP.J.1006.2008.00838
      Abstract ( 1958 )   PDF (353KB) ( 1585 )   Save
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      Ridge and furrow planting of rainfall harvesting (RFPRH) is a cultivation technique by covering ridges with plastic films and planting crops in furrows. RFPRH has been extending in the semi-arid areas of Loess Plateau in Northwest China because it can alleviate drought stress by collecting rainfalls from the ridges and promote water use efficiency (WUE) and crop yield. To investigate the optimal quantity of rainfall in RFPRH system, we studied the effects of RFPRH, taking traditional cultivation as the control, on soil water storage, photosynthetic indexes, fluorescence parameters and chlorophyll relative content (SPAD) in functional leaves, and grain yield of summer corn (Zea mays L.) under three simulated rainfall treatments. The rainfall was given 12 times (at 5–15 d interval) in corn growth duration with the total amount of 230, 340, and 440 mm, respectively. In the RFPRH system, the net photosynthetic rate (Pn), stomatal conductance (Gs) and chlorophyll fluorescence parameters (Fm, Fv, Fv/Fm, Fv/F, and qP) were significantly (P<0.05) higher than those in control, and the SPAD value increased by 17.7% and 13.9% in 230 and 340 mm rainfall treatments, respectively. Compared to the control, the instantaneous WUE in leaves increased by 26.9% and 10.1%, and the grain yield by 75.4% and 36.7% under 230 and 340 mm rainfall treatments, respectively. The Fm, Fv/Fm, Fv/Fo, qP, and SPAD value at jointing stage and Gs at heading stage increased significantly (P<0.05), but Pn decreased sharply at heading and booting stages under 440 mm rainfall treatment in RFPRH system. The WUE of the whole growth duration of RFPRH was lower by 13.2% than that of control. The results indicate that the RFPRH system can promote Pn and leaf WUE of corn in arid years, and 440 mm may be the upper limit of rainfall during the whole growth period in the RFPRH system.
      Effects of Silver Thiosulfate (STS) on Growth and Physiological Characteristics of Potato Plantlets in vitro
      YUAN Hua-Ling;JIN Li-Ping;HUANG San-Wen;XIE Kai-Yun;LI Ying;QU Dong-Yu
      Acta Agron Sin. 2008, 34(05):  846-850.  doi:10.3724/SP.J.1006.2008.00846
      Abstract ( 2118 )   PDF (339KB) ( 1312 )   Save
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      Ethylene accumulation often occurs in plant tissue culture owing to limited gas exchange. The effect of silver thiosulfate (STS), an inhibitor of ethylene activity, on reducing ethylene-induced plant abnormalities was investigated in three diploid potato (Solanum tuberosum L.) genotypes (HS66, ED13, and DH401) with different concentrations (0, 1, 2, 4, and 8 mg L-1) of STS in culture medium. The results showed that the leaf areas and total chlorophyll contents in three genotypes increased and aerial root could be eliminated by addition of 1 mg L-1 STS into culture medium as compared with control (0 mg L-1). Toxic symptoms like black purple pigment accumulation and callus occurring on leaf abaxial surface were observed on plantlets when the STS concentration was over 4 mg L-1. The soluble protein, proline, and malondialdehyde (MDA) contents in three genotypes decreased first and increased then with the STS concentration increase. They declined in the medium containing 1 mg L-1 STS compared with control. Addition of 2 mg L-1 STS resulted in the ascending of soluble protein and proline contents in DH401 and MDA content in HS66. The soluble protein, proline, and MDA contents of three genotypes increased with STS concentration increasing in the medium containing 4–8 mg L-1 STS. These results indicated that supplement of 1 mg L-1 STS in medium could alleviate ethylene stress and improve plantlet growth. No morphological abnormality was observed in plantlets, but some physiological parameters showed STS toxicity to plantlets of HS66 and DH401 in the medium containing 2 mg L-1 STS. Both morphological and physiological parameters indicated that higher concentration (4–8 mg L-1) of STS in the medium was toxic to three genotypes in vitro.
      Effects of Different Organic Acids on Quality and Yield in Tobacco (Nicotiana tabacum L.)
      LIU Shi-Liang;DU Jun;HUA Dang-Ling;JIE Xiao-Lei;WANG Wei-Chao;WANG Xue-Fen;HAN Fu-Gen
      Acta Agron Sin. 2008, 34(05):  851-858.  doi:10.3724/SP.J.1006.2008.00851
      Abstract ( 1952 )   PDF (252KB) ( 1385 )   Save
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      Reasonable combination chemical fertilizer with organic fertilizer which is applied traditional can significantly improve tobacco quality. Malic acid, oleic acid, and fulvic acid were used to study the effects of organic acids on quality and yield in tobacco in the trial. The main results showed that three organic acids could obviously increase P, K, total sugar, reducing sugar contents, K/Cl ratio and reducing sugar/nicotine ratio, as well as the contents of furfural, nenzaldehyde, solanone, megastigmatrienone, and neopphytidiene, the main aroma component in tobacco leaves, and these were in favor of high quality of aroma in tobacco leaves. However, the three organic acids could obviously reduce N, Cl, starch, protein and nicotine contents of flue-tobacco leaves. Those were in favor of coordinating and balancing chemical compositions of flue-cured tobacco leaves, improving quality of tobacco leaves. The effect of malic acid was better than that of fulvic acid and oleic acid. In addition, malic acid could obviously improve unit price and the proportion of the superior and secondary classes of flue-cured leaves. Fulvic acid could also improve the proportion of the superior and secondary classes, output value and yield of flue-cured leaves.
      Difference of Physiological Characteristics of Cotton Bolls in Development of Fiber Thickening and Its Relationship with Fiber Strength
      ZHANG Wen-Jing;HU Hong-Biao;CHEN Bing-Lin;WANG You-Hua;ZHOU Zhi-Guo
      Acta Agron Sin. 2008, 34(05):  859-869.  doi:10.3724/SP.J.1006.2008.00859
      Abstract ( 2151 )   PDF (418KB) ( 1058 )   Save
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      Fiber strength is one of the most important quality indexes of cotton (Gossypium) fiber and contributes highly to the yarn strength. Normally, fiber strength is determined by fiber’s secondary wall thickening stage in which many complex physiological and biochemical processes are involved. To investigate the physiological characteristic of cotton fiber thickening in seasonal bolls and its relationship with fiber strength, the experiments were carried out in Nanjing, Jiangsu Province in 2004–2005 by choosing four cultivars with significant difference in fiber strength as materials. Boll samples were labeled on anthesis day (July 15, July 25, Aug. 25, and Sept. 10) and expressed as PSB (pre-summer boll), SB (summer boll), EAB (early autumn boll) and LAB (late autumn boll), respectively. The results of two-year experiments showed that there were great differences in matter transformation and related enzyme activities during cotton fiber thickening in seasonal bolls, and which resulted in different fiber strengths. The diversity of physiological indexes between bolls with different anthesis dates was similar in every cultivar (genotype). Under suitable temperature condition (mean daily temperature 26.0–28.5℃ during boll age from 10 to 50 days) and plant physiological age (about the third-ninth fruit branch), the cotton seasonal bolls (PSB and SB), which had more soluble sugar and sucrose transformed, higher β-1,3-glucan content at the onset of the secondary wall thickening, and higher activities of sucrose synthetase and β-1,3-glucanase, would get longer and tempered cellulose accumulation and higher strength fiber. EAB had worse temperature environment for fiber development than PSB during the later period, but it had higher matter transformation rate and better characteristic of cellulose deposition than PSB. As the result, fiber strength of EAB was higher than that of PSB. With the worse temperature condition (mean daily temperature lower than 20℃ during boll age from 10 to 50 days) and cotton plant se-nescence (above the sixteenth fruit branch), LAB had the longest period for cellulose rapid deposition, the lowest matter transfor-mation rate and cellulose accumulation speed. And all these resulted in the lowest fiber strength.
      Effects of Irrigation Amount on Nitrogen Uptake, Distribution, Use, and Grain Yield and Quality in Wheat
      ZHANG Yong-Li;YU Zhen-Wen
      Acta Agron Sin. 2008, 34(05):  870-878.  doi:10.3724/SP.J.1006.2008.00870
      Abstract ( 2227 )   PDF (277KB) ( 1604 )   Save
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      Irrigation is one of the most important measures to regulate plant nitrogen metabolism in winter wheat (Triticum aestivum L.). However, excessive irrigation will cause the decline of nitrogen use efficiency and water use efficiency instead of higher yield and better quality. To determine the effects of irrigation amount on the uptake, distribution, use efficiency of nitrogen, the consumption and use efficiency of water as well as grain yield and quality, we experimented with wheat cultivars, Jimai 20 and Taishan 23 in 2004–2005 (in clay-soil field) and 2006–2007 (in sandy-soil field) wheat growth seasons. In the 2004–2005 growth season in which total rainfall was 196.10 mm, the irrigation treatments were 0 (no irrigation), 180 mm (irrigated 3 times at pre-sowing, jointing, and anthesis stages), 240 mm (irrigated 4 times at pre-sowing, pre-wintering, jointing, and anthesis stages), and 300 mm (irrigated 5 times at pre-sowing, pre-wintering, jointing, anthesis, and grain filling stages), respectively. In the 2006–2007 growth season in which total rainfall was 171.30 mm, the irrigation treatments were 0 (no irrigation), 120 mm (irrigated 2 times at pre-sowing and jointing stages), 180 mm (irrigated 3 times at pre-sowing, jointing, and anthesis stages), and 240 mm (irrigated 4 times at pre-sowing, pre-wintering, jointing, and anthesis stages), respectively. The amount of irrigation was 60 mm each time in both growth seasons. The two cultivars showed similar results in both growth seasons. In the 2004–2005 growth season, nitrogen uptake efficiency and nitrogen accumulation in grain in no irrigation treatment were lower than those in irrigation treatments, and resulted in lower grain yield and nitrogen fertilizer productive efficiency, but the nitrogen distribution proportion in grain at maturity and nitrogen use efficiency were higher in no irrigation treatment. Water use efficiency of two cultivars decreased with the increase of irrigation amount. Before jointing stage, the nitrogen uptake intensity in the treatment of irrigation with 180 mm water was significantly (P<0.05) higher than that of the other two irrigation treatments, but turned converse after jointing stage. The accumulation amount and uptake efficiency of nitrogen in plant had no significant differences among the 3 irrigation treatments at maturity. In Jimai 20, the irrigation treatment with water amount of 240 mm showed more favorable for nitrogen accumulation and distribution in grain, and the nitrogen fertilizer productive efficiency and use efficiency, grain yield (9 159.30 kg ha-1) were significantly (P<0.05) higher than the other 2 irrigation treatments. But for integrated consideration of nitrogen uptake and accumulation, grain yield and quality, as well as water consumption and use efficiency, the treatment of irrigated 180 mm water was also recommended. In Taishan 23, the nitrogen accumulation amount and distribution proportion in grain at maturity, nitrogen use efficiency, nitrogen fertilizer productive efficiency, and grain quality had no significant difference among the 3 irrigation treatments, indicating that the cultivar was not as sensitive to irrigations as Jimai 20; but the higher grain yields of 9 682.65 and 9 698.55 kg ha-1 (with water consumptions of 468.54 and 532.35 mm accordingly) were obtained under irrigated treatments with water amounts of 180 and 240 mm, respectively. In the 2006–2007 growth season, the highest grain yields (6 651.23 and 6 942.49 kg ha-1) of Jimai 20 and Taishan 23 were obtained under the 240 mm irrigation with water consumptions of 490.88 and 474.88 mm, respectively. Our results implied that proper irrigation can increase grain yield, nitrogen use efficiency, and water use efficiency, and improve grain quality; higher grain yield is not resulted from higher amount of irrigation and water consumption. We suggest the following water regimes of Jimai 20 and Taishan 23 in wheat production: irrigating 3 or 4 times at pre-sowing, pre-wintering, jointing, and anthesis stages with water amount of 180–240 mm, and the irrigation at pre-wintering can be ignored based on rainfall and soil water content.
      Effects of Different Ca Applications on Physiological Characteristics, Yield and Quality in Peanut
      ZHOU Lu-Ying;LI Xiang-Dong;WANG Li-Li;TANG Xiao;LIN Ying-Jie
      Acta Agron Sin. 2008, 34(05):  879-885.  doi:10.3724/SP.J.1006.2008.00879
      Abstract ( 2327 )   PDF (311KB) ( 1777 )   Save
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      Calcium, associated with the yield formation and quality improvement in peanut, is one of the important nutrient elements in peanut growth and development. To investigate the proper calcium applying amount and the effects on physiological characteristics, yield and quality in peanut (Arachis hypogea), four treatments of 0 (CK), 150, 300, and 450 kg ha-1 of CaO were set by top dressing at seedling stage using peanut cultivar Fenghua 1 in the Experimental Station of Shandong Agricultural University in 2004 and 2005 with randomized complete block design and three replications. The results showed the main stem height and branch length were shortened, chlorophyll content and leaf photosynthetic rate raised, the activities of superoxide dismutase (SOD), peroxi-dase (POD), and catlase (CAT), and the soluble protein content increased but the content of a lipid peroxidation product, malondialdeyde (MDA) content decreased with the Ca application. The Ca treatment significantly increased total pod and kernel weight because of the increase of pod weight, kernel rate and pod number per plant. The Ca treatment increased not only the content of fat and protein in peanut kernel, but also the ratio of oleic acid to linoleic acid (O/L), and the contents of lysine and methionine. It was suggested that 300 kg ha-1 Ca application gave the highest yield and the good quality in the peanut seed.
      Utilization and Balance of Nitrogen and Proper Application Amount of Nitrogen Fertilizer in Winter Wheat in High-Yielding Regions
      GUO Tian-Cai;SONG Xiao;FENG Wei;MA Dong-Yun;XIE Ying-Xin;WANG Yong-Hua
      Acta Agron Sin. 2008, 34(05):  886-892.  doi:10.3724/SP.J.1006.2008.00886
      Abstract ( 2007 )   PDF (239KB) ( 1538 )   Save
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      Application of nitrogen fertilizers is one of the most important measures to increase crop yields. Lankao’aizao 8 is a famous large-spike wheat (Triticum aestivum L.) cultivar planted widely in North China. To optimize the nitrogen application in Lankao’aizao 8 for the integrated purposes of yield, economic benefit, and environmental influence, a field experiment was carried out at Henan Agricultural University in 2005—2006 growth seasons. The nitrogen fertilizer treatments were arranged with application rates of 0 (N1), 90 (N2), 180 (N3), and 360 kg N ha-1 (N4) in the randomized block design with three replicates, respectively. A half of the nitrogen fertilizer was applied before sowing as basic fertilizer together with 150 kg P2O5 ha-1 and 150 kg K2O ha-1 and the other a half topdressed at jointing stage. Time-course measurements were taken on plant dry weight, nitrogen content, grain protein content, soil mineral nitrogen (N min) content during the experiment. The results showed that the grain yield and protein content increased with increasing nitrogen application amount, but the grain yield at N4 level (8 299.45 kg ha-1) was lower than that at N3 level (8 602.92 kg ha-1) though there was no significant difference. The N accumulation in shoots increased constantly with more nitrogen fertilizer applied. The N uptake in plants during jointing to heading accounted for 45.6%, 53.0%, and 49.7% of whole uptake amount in N2, N3, and N4 treatments, respectively, indicating wheat plants are sensitive to nitrogen from jointing to heading stages. The analysis on N balance further indicated that the unutilized nitrogen by the current crop mainly lost in forms of residual Nmin in soil and apparent N, which increased accordingly with more nitrogen applications. Considering grain yield and protein content, economic benefit, and ecological effect synthetically, the proper amount of nitrogen fertilizer for Lankao’aizao 8 in production in areas similar to the experimental condition is 202–239 kg ha-1 calculated by the Marginal Revenue Analysis and the Coase theory of environmental economics. Accordingly, the expected grain yield and protein content are 8 628–8 680 kg ha-1 and 14.6–14.8% under the current cultivation techniques, respectively.
      Genetic Diversity Analysis of Sea-Island Cotton Cultivars Using SRAP Markers
      LI Wu;NI Wei;LIN Zhong-Xu;ZHANG Xian-Long
      Acta Agron Sin. 2008, 34(05):  893-898.  doi:10.3724/SP.J.1006.2008.00893
      Abstract ( 2056 )   PDF (244KB) ( 1663 )   Save
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      Sea-island cotton (Gossypium barbadense) is important due to its fine fiber quality. However, genetic diversity analysis of this specie is still poorly documented, which is important for in situ and ex situ germplasm conservation and useful for breeding programs. Using 132 out of 238 SRAP markers, genetic diversity of 56 sea-island cotton cultivars including 20 introduced from other countries was assessed, 419 polymorphism loci were detected. The number of polymorphic loci per primer ranged from 2 to 9 with an average of 3.17. Jaccard’s genetic similarity coefficients were calculated and dendrograms were constructed by the unweighted pair group method of arithmetic average (UPGMA) using the NTSYS-pc version 2.10. The most of the accessions with relative relationship in their pedigrees were clustered into the same group. The genetic similarity coefficient of 56 accessions ranged from 0.312 to 0.876, with an average of 0.497, indicating that there was high level of genetic variation in the G. barbadense collections. The average genetic similarity coefficients of the domestic accessions in the first, second and third breed-ing periods were 0.501, 0.507, and 0.548, respectively, which implied that the genomic difference among the modern accessions has been gradually decreasing compared to that among the early accessions. These results suggest an overview of the genetic di-versity of the sea-island cotton accessions, and provide a reference for breeders to develop new cultivars efficiently.
      Activity of Serine/Threonine Protein Phosphatase Type-2C (PP2C) and Its Relationships to Drought Tolerance in Maize
      HE Liang;LI Fu-Hua;SHA Li-Na;FU Feng-Ling;LI Wan-Chen
      Acta Agron Sin. 2008, 34(05):  899-903.  doi:10.3724/SP.J.1006.2008.00899
      Abstract ( 2225 )   PDF (276KB) ( 1769 )   Save
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      Based on the previous study, we cloned the full length cDNA sequence of serine/threonine protein phosphatase 2C (PP2C) by electronic cloning and reverse transcription PCR, assayed its expression difference and enzyme activity among different inbred lines under drought stress by fluorescence quantitative real-time PCR and non-radioactive labeled method respectively, and analysed the relationships between the enzyme activity and drought tolerance in maize. The result indicated that the full length cDNA sequence we cloned is a new member of PP2C gene family in maize, and its open reading frame of 1 164 bp encodes 388 amino acid residues. This gene was denominated as ZmPP2Ca and registered at GenBank (accession number: EF195257). Under drought stress, its down-regulated expression decreased enzyme activity of PP2C in drought-tolerant inbred lines, and its up-regulated expression increased enzyme activity of PP2C in drought-sensitive inbred lines. The differential expression of gene ZmPP2Ca and difference of PP2C activity are speculated to be implicated in signal transduction in maize cells under drought stress.
      Genetic Effects of Quality Protein Maize on Kernel Traits
      TAN Jing;YAO Wen-Hua;XU Chun-Xia;LUO Li-Ming;FAN Xing-Ming
      Acta Agron Sin. 2008, 34(05):  904-908.  doi:10.3724/SP.J.1006.2008.00904
      Abstract ( 2095 )   PDF (216KB) ( 1228 )   Save
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      To efficiently use tropical hard quality protein maize (QPM) germplasm in enriching temperate QPM germplasm, improving kernel traits, and developing hard QPM hybrids, the genetic effects and heterosis of 8 QPM inbreds with different endosperm traits and their F1 and F2 progenies were evaluated via Griffing I diallel mating design. The hundred-kernel weight (HKW), hundred-kernel volume (HKV), endosperm modification (EM), and kernel density (KD) showed positive heterosis in F1 and F2 generations. EM showed differences in F1 reciprocal crosses, indicating obvious maternal effect. Correlation analysis showed that values of HKW, HKV, EM, and KD in F2 generation had the biggest correlation coefficients with the average parental values. Maternal effect was the main factor on HKW, HKV, and KD, while direct genetic effect was mainly on EM. Gene actions for HKW, HKV, EM, and KD were dominant, dominant, additive, and additive & dominant, respectively. Cytoplasmic effect was little for the above 4 kernel traits suggesting that kernel traits are mainly controlled by nuclear genes.
      Effect of Subunit Composition of 7S Globulin on Soybean Quality Cha- racteristics
      LIU Shan-Shan;TIAN Fu-Dong;GAO Li-Hui;WANG Zhi-Kun;GE Yu-Jun;DIAO Gui-Zhu;LI Wen-Bin;
      Acta Agron Sin. 2008, 34(05):  909-913.  doi:10.3724/SP.J.1006.2008.00909
      Abstract ( 2295 )   PDF (266KB) ( 1511 )   Save
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      Rare soybean (Glycine max) germplasm with typical variations in subunit composition was tested to analysis the effect of 7S globulin subunit composition on soybean nutrient quality. The results showed that the 7S globulin subunit composition affected the contents of protein, fat, 5 fatty acids, and 15 amino acids (especially, the greatest effect on Cys) excluding Val and Ile. There were significant differences between the null types with different 7S globulin subunit compositions and their corresponding normal types on the contents oleic acid, linoleic, and stearic acid.
      Relationship between Main Chemical Components in Leaf and Leaf Length in Different Positions in Tobacco (Nicotiana tabacum L.)
      LI Dong-Liang;ZHANG Shui-Cheng;XU Zi-Cheng
      Acta Agron Sin. 2008, 34(05):  914-918.  doi:10.3724/SP.J.1006.2008.00914
      Abstract ( 2028 )   PDF (205KB) ( 1362 )   Save
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      It is important for cigarette industry to get flue-cured tobacco leaves with accordant quality between agronomic characters and chemical components. Agronomic characters, however, are often inconsistent with chemical components, and this problem brings the difficulty of blending and decreases the benefits of cigarette industry. The purpose of this paper was to study the correlation between agronomic characters and chemical components and to provide theory basis for tobacco grading. By applying methods of descriptive statistics, ANOVA, multiple comparisons and degree distribution, 166 leaf samples of different positions including three grades of B2F, C3F, and X2F from K326, a flue-cured tobacco cultivar widely planted in main tobacco areas in southern China, were selected as materials to study the relationship between chemical components and leaf length. The results indicated that there existed extensive variation among samples for chemical components and leaf length. The differences were not significant for chlorine content and ratio of potassium to chlorine (K2O/Cl-), and were significant for leaf length, nicotine content, ratio of total nitrogen to nicotine (TN/nicotine) and ratio of reducing sugar to nicotine (RS/nicotine) among positions of flue-cured tobacco leaves. For total nitrogen and reducing sugar (RS) contents, cutters and lower leaf did not show significant difference, but both had significant difference with these in upper leaf. Similarly, for potassium (K2O) content, these were non-significant difference in cutters and upper leaf, but significant difference in lower leaf. In the given range, the contents of nicotine, TN and K2O increased with the increase of leaf length of upper leaf; however, TN/nicotine decreased with the increase of leaf length of upper leaf. The nicotine, RS, K2O contents, and K2O/ Cl- content increased with the increase of leaf length of cutters; Cl- content and T N/nicotine decreased with the increase of leaf length of cutters. The RS content, RS/nicotine, and K2O/ Cl- increased with the increase of leaf length of lower leaf; nicotine, TN and Cl- content decreased with the increase of leaf length of lower leaf. More than 63.0 cm was a sensitive leaf length for nicotine, TN contents and RS/nicotine of upper leaf and K2O and Cl- content of lower leaf.

the Crop Science Society of China
the Institute of Crop Science, CAAS
China Science Publishing & Media Ltd.
Published: Science Press
Editor-in-chief: Wan Jian-min
Associate Editors-in-Chief:
Chen Xiao-ya Yang Jian-chang Zhang Xian-long Wang Jian-kang Xu Ming-liang Liu Chun-ming Wang Dao-wen Sun Chuan-qing Ding Yan-feng Jin Wei-wei Chu Cheng-cai Cheng Wei-hong
Director of the editorial department:
Cheng Wei-hong
CN 11-1809/S
ISSN 0496-3490
Post subscription code: 82-336

  • Started in 2013
  • Covered by SCIE
  • Open access in ScienceDirect

Editor in chief: Wan Jian-min
CN 10-1112/S
ISSN 2095-5421, 2214-5141(online)
Online published:
Submission: https://www.editorialmanager.com/cj/
E-mail: cropjournal@caas.cn
Tel: 8610-82108548