荞麦种子蛋白质组分分析

研究了不同品种荞麦种子中蛋白质组分情况，结果表明：养麦种子蛋白质主要由清蛋白、球蛋白、谷蛋白和醇溶蛋白构成。而不同类型蛋白质在总蛋白质中所占比例有明显差异，清蛋白是荞麦种子中的主要蛋白质，占总蛋白质含量的71．4％左右，其中以平荞最高。醇溶蛋白在荞麦种子总蛋白中所占比例较小，平均约为7．4％，榆养2号最高。球蛋白和谷蛋白所占比例非常接近，其中球蛋白平均约占9．1％，最高为日本大粒养。谷蛋白大约占总蛋白的12．1％，以京养1号最高。     

Ca/GA对渗透胁迫下小麦种子萌发中蛋白质变化的调节

小麦萌发时,种子胚乳总蛋白含量逐渐下降,其中由于提供萌发所需氮化物球蛋白,醇溶蛋白和谷蛋白逐渐减少,合成数种启动种子萌发所需酶蛋白等的清蛋白逐渐增加,胚中蛋白质各组分随种子萌发过程垃逐渐增加,渗透胁迫下,萌发种子胚乳清蛋白和胚中蛋白质中组分的增加,以及胚乳中球蛋白,醇溶蛋白和谷蛋白的降解均受抑制,因此,种子萌发与其基因蛋白质密切相关,Ｃａ处理在萌发后期才对种子蛋白质变化起促进作用,ＧＡ和Ｃａ＋ＧＡ     

高粱籽粒蛋白质及其组份的配合力与杂种优势分析

本文以格里芬双列杂交模式Ⅱ设计,分析了高梁籽粒粗蛋白质含量及其4种组份和赖氨酸、色氨酸含量的配合力与杂种优势。结果表明,粗蛋白、清蛋白、球蛋白、谷蛋白、醇溶谷蛋白、赖氨酸含量等6个品质性状的σ_(gca)~2和σ_(sca)~2均达1％或5％显著平准,受加性和非加性基因效应的共同作用,其中加性基因效应作用占优势;色氨酸含量     

新型水稻57H突变体的发掘与表征

在正常型水稻的发育种子中,谷蛋白与醇溶蛋白在胚乳细胞内质网被合成后,作为主要储藏蛋白质分别被蓄积成液泡型蛋白体与内质网衍生型蛋白体。一些57H变异导致57 kD谷蛋白前体高量增加与成熟型谷蛋白显著减少,是关于水稻储藏蛋白蓄积的基因突变。本研究采用SDS-PAGE技术,从水稻种质资源中,发现并获得2个57H突变体。种子全蛋白的SDS-PAGE分析显示, 这2个突变体兼具57 kD多肽链大量增加与13 kD多肽链缺失的性状,但并没有成熟型谷蛋白等其它储藏蛋白性状的变化;谷蛋白电泳与免疫印染分析显示它们中高量增加的多肽链是57 kD谷蛋白前体;醇溶蛋白电泳分析显示它们中缺失的多肽链是13 kD醇溶蛋白。这些结果表明所得的2份突变体具有与已报道57H突变体不同的性状。它们可能含有关于储藏蛋白质合成表达的未知遗传信息,是全面阐明储藏蛋白合成蓄积遗传调控机制的有用素材。     

藜麦EST-SSR的开发及通用性分析

藜麦因营养均衡受到越来越多的关注,但尚未深入开展其基础研究。开发微卫星序列重复SSR分子标记将为藜麦的遗传分析提供重要资源。本研究利用NCBI数据库中藜麦RNA测序RNA-Seq及表达序列标签EST数据挖掘、验证及评价藜麦EST-SSR,共发现1862个藜麦非单核苷酸EST-SSR。其中,二核苷酸重复最多(38.3%),六核苷酸重复最少(11.7%)。不同重复类型SSR的数量随着核苷酸数目的增加呈下降趋势。在随机选取验证的119个EST-SSR标记中,66 (55.9%)个能够扩增出清晰条带,39个在4份藜麦资源中具有多态性,且其多态性与重复序列长度不具有显著相关性。t测验显示,多态性EST-SSR在藜麦与其他藜科种质间不存在显著差异,说明其具有良好的通用性,可用于藜科物种的遗传关系分析。     

The pattern of genetic diversity in the Andean grain crop quinoa (Chenopodium quinoa Willd). I. Associations between characteristics

Summary A germplasm collection comprising 294 accessions of quinoa was evaluated at Cambridge, England, to assess its potential as a break crop for arable agriculture at temperate latitudes. The origins of the accessions ranged from 40°S to 2°N and from sea level to an altitude of 3800 m, and 19 discrete and continuous characteristics describing the plants' pigmentation and morphology and the duration of developmental phases were noted or measured. There was significant variation among accessions for all the continuous characteristics, and the plant and inflorescence dimensions were all fairly strongly correlated, but the associations between the durations of developmental phases were surprisingly weak, suggesting that there is great scope for manipulation of the pattern of development through breeding. Contingency tables revealed associations between pairs of discrete characteristics. The means and variances of many continuous characteristics differed according to the discrete characteristics: for example accessions with branched plants took longer to germinate and were more variable in this respect than those with unbranched plants. Sometimes one form of a discrete characteristic was associated with a homogeneous group of accessions but the alternative form was not: such a relationship would be easily lost in a multivariate analysis. On the basis of there relationships, and using knowledge of the accessions' origins, they were classified into seven groups. It is concluded that the plant characteristics required for temperate agriculture are present to a large extent in the accessions from near sea level in southern-central Chile, but that the seed characteristics are scattered throughout the germplasm.     

An agronomic and seed-quality evaluation of noug (Guizotia abyssinica Cass.) germplasm in Ethiopia

Noug (Guizotia abyssinica Cass.), a member of the Compositae family, is grown as an oilseed crop in Ethiopia. The crop grows best on poorly drained, heavy clay soils. This study investigates the genetic variability of agronomic and seed quality characteristics of 241 noug germplasm collections from different parts of Ethiopia evaluated in a field test at Ghinchi, near Addis Ababa, Ethiopia, in 1992. The maturity of the noug accessions ranged from 132 to 168 days. Seed oil contents ranged from 39.8 to 46.9% with linoleic acid being the major fatty acid of the oil (76.6% of total fatty acids). The results of this field study indicated that genetic differences for maturity existed among the noug accessions. Oil content variation was continuous, without clear separation of accessions into oil content groups. It is concluded that the genetic variation observed among these accessions could be utilized in a breeding programme to develop high-yielding, well-adapted, high-oil-content noug cultivars for production in Ethiopia.     

Employment of hordein subunit polymorphisms in establishing selection criteria for high quality malting barley (Hordeum vulgare L.)

Cereal seed storage proteins are encoded by complex multigene families and their subunit profiles are highly related to end-use qualities. Each fraction of albumin and hordein was extracted and its subunit profile was evaluated in related to malt and grain quality parameters. The purpose of this study was to provide selection criteria for high quality malting barley using grain and malt quality parameters and biochemical-genetic information. Grain and malt quality of 13 local adaptability test (LAT) lines were evaluated for malting process. A total of 16 germplasm accessions of high or low seed storage protein content were also evaluated for biochemicalgenetic analysis. The correlation coefficients among quality parameters were analyzed. Several important quality parameters in brewing process showed significant positive or negative correlations. Seed storage protein subunits of albumin and hordein of all tested lines and accessions were evaluated using 12% 1D SDS-PAGE. Scored data of protein subunit’s presence or absence was applied to Agglomerative Hierarchical Clustering (AHC) for statistical analysis and showed specific grouping patterns among tested lines. Clustered lines with subunit information were highly related with agricultural performance and grain and malt qualities. Based on the profiles of seed storage protein subunits, association of hordein subunit of 38, 43, and 65 kDa with high malt scored lines was found. The obtained results would provide improved selection criteria for high quality malting barley in the malting barley breeding program.     

Study of genetic diversity in Indian and exotic sesame (Sesamum indicum L.) germplasm using random amplified polymorphic DNA (RAPD) markers

Fifty-eight accessions of sesame (Sesamum indicum L.), an important oil seed crop of the tropics and subtropics were analysed using random amplified polymorphic DNA (RAPD) technique. The material analysed comprised 36 collections from 18 different states of India and four adjoining countries of the Indian subcontinent, and 22 exotic accessions from 21 sesame growing countries around the world. The results from PCR amplifications with the selected 24 random 10-mer primers were statistically analysed. The value of Jaccard’s similarity coefficients ranged from 0.19 to 0.89. The results indicated the presence of high level of genetic diversity. However, the extent of genetic diversity was greater in the collections from Indian subcontinent as compared to the exotics. Among the Indian accessions, the collections from Rajasthan and North-eastern states were highly diverse. The phenetic analysis grouped 48 out of 58 accessions in six clusters and the remaining highly diverse accessions were placed outside these close-knit clusters. The Bootstrap estimates obtained by Wagner parsimony analysis were significant for seven out of 49 nodes in the majority-rule consensus tree (<95% occurrence). The results of both the analyses were, however, broadly comparable when the constitution of the individual clusters were considered. The principal components analysis indicated that the first two components accounted for only 21% of the total variations and in order to explain <75% of variations 18 components were required. The high level of genetic diversity prevalent among the Indian collections is probably indicative of the nativity of this crop species. Similarly, the relatively lower level of polymorphism in exotic germplasm could be ascribed to the comparatively recent introductions of limited germplasm of this crop into some of the non-traditional sesame growing countries. This revised version was published online in August 2006 with corrections to the Cover Date.     

SHORT COMMUNICATION: Effect of Salt Stress on Peruvian Germplasm of Chenopodium quinoa Willd.: A Promising Crop

Soil salinity is a major problem in today’s agriculture. Quinoa has become an important crop because it exhibits high levels of salinity tolerance. In addition, its seeds contain an excellent balance of carbohydrates, lipids, amino acids and proteins for human nutrition. The quinoa germplasm includes almost 2500 accessions, some of which have been tested under salt stress. Here, we report the effect of NaCl on the germination of 182 previously untested accessions. When seeds were irrigated with saline water at 30 dS m^?1 EC, the stress appeared to be too high: all accessions showed less than 60 % germination. In contrast, irrigation with 25 dS m^?1 EC saline water allowed over 60 % germination in 15 accessions. These latter accessions’ agricultural traits were then evaluated. The overall coefficients of variation indicated that quinoa genotype and salt treatment dramatically influence root dry mass per plant, but do not noticeably affect the length of the plant’s life cycle. Unexpectedly, salt treatment resulted in increased plant height, leaf dry mass and grain yield. Using Euclidean distance for the simultaneous selection of these five agricultural traits, accessions 100, 136, 127 and 105 proved to be the best performing genotypes under salt stress.     

荞麦籽粒蛋白质组分特性研究

采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)方法研究了荞麦的2个栽培种苦荞与甜荞的总蛋白、清蛋白、球蛋白及谷蛋白特性。试验结果表明,甜荞籽粒总蛋白及蛋白质各组分的谱带具有丰富的多态性,而苦荞籽粒总蛋白及蛋白质各组分谱带的多态性有限;荞麦清蛋白主要由低分子量的亚基构成;甜荞球蛋白组分包含由中等到低分子量范围的5~12种亚基,苦荞球蛋白主要由8种亚基组成;甜荞谷蛋白主要由分子量在43~66.2 kDa之间的3~5种亚基组成,苦荞谷蛋白主要由分子量在31~43 kDa间的2种亚基组成。     

Relationships among seed quality characteristics in a collection of western wheatgrass germplasms

Although western wheatgrass [Pascopyrum smithii (Rydb.)] is an important perennial grass species for agriculture and conservation management in central and western North America, its lack of adequate seed production and seedling vigor limits its effectiveness. To address the weaknesses a study was conducted to assess rhizome spread, seed production, seed weight, germination percentage, and emergence rate of seed produced from 48 western wheatgrass cultivars and germplasm accessions at a field site near Nephi, UT, USA during 2007 and 2008. The western wheatgrass cultivars had approximately two times higher seed production than the germplasm accessions during both 2007 and 2008 and also had higher seed weight in 2007 and emergence rate in 2008. The germplasm accessions had higher seed weight in 2008. For the remaining traits there were no differences among the different germplasm sources. Based on principle component analysis a subset of cultivars and germplasm accessions with high seed production and emergence rate were identified that could be used to produce improved cultivars and germplasms. There was little evidence of strong relationship between geographic, genetic, and phenotypic distances among the various lines examined. Additionally, based on genetic marker data, a subset of lines was grouped into three populations. Based on these results, selection among lines could occur to maximize agricultural performance regardless of site of origin, or within population selection could be practiced to meet conservation goals of minimizing hybridization among populations.     

Downy mildew resistance in opium poppy: resistance sources,inheritance pattern,genetic variability and strategies for crop improvement

Downy mildew (DM) caused by Peronospora arborescens is the most destructive disease of opium poppy which assumes considerable importance in India and other poppy growing countries. The present study was aimed at identification and evaluation of stable resistance sources of DM in opium poppy. Furthermore, genetic variability and inheritance pattern of DM resistance has also been studied which can help in making strategy for crop improvement. Evaluation of 35 selected germplasm accessions of opium poppy under glasshouse and field conditions during the three consecutive years (2004–2005 to 2006–2007) resulted in identification of two genotypes (I-14 and Pps-1) as highly resistant and stable sources for DM resistance. Genetic studies of DM resistance revealed polygenic control with the dominance of susceptibility over resistance. Significant reciprocal differences were found largely due to maternal transmission of DM resistance indicating the involvement of cytoplasmic genes in addition to nuclear control. Analysis of genetic variability and selection parameters indicated predominance of additive effects for DM resistance and other yield contributing traits. Multivariate analysis resulted in classification of 35 selected accessions into 11 different clusters revealing very high level of diversity among the genotypes. Cluster analysis suggested that hybridization program involving genotypes from cluster V (which included highly resistant genotypes Pps-1 and I-14) and cluster IX (which included highly susceptible Jawahar-16 having good economically important traits like seed yield) could be expected to give best recombinants for improvement in terms of DM resistance and high seed and straw yield in opium poppy. Analysis of selection parameters like heritability and genetic advance also suggested that simple selection methods will be effective in stabilizing resistance traits following hybridization with high yielding genotypes.     

灌浆温度和氮肥及其互作效应对稻米贮藏蛋白组分的影响

灌浆结实期温度与氮肥施用量是影响稻米品质的两个重要生态因子,尤其是与稻米蛋白含量及米饭食味关系密切。本文以多个水稻主栽品种为材料,通迆灌浆结实期的人工控温试验、大田长期定位点的施氮处理试验和盆栽条件下的温氮两因素复合处理试验,探讨了水稻灌浆结实期温度对稻米贮藏蛋白含量与组分影响及其有别于氮肥处理效应的差异觃律,幵分析了温度与氮肥两个因素对稻米贮藏蛋白及其组分影响的交互作用特点。结果表明,高温胁迫和增施氮肥均引起水稻籽粒总蛋白及其谷蛋白组分含量(%)的显著增加,但两者对稻米醇溶蛋白影响却存在明显差别。其中,高温处理引起醇溶蛋白含量显著下降,提高稻米谷蛋白/醇溶蛋白比值,而增施氮肥引起稻米谷蛋白和醇溶蛋白含量明显增加,但对谷蛋白/醇溶蛋白比值与贮藏蛋白各亚基的组成比例影响相对较小。在高温处理下,谷蛋白的57kD前体亚基组分含量有所提高,而37kD酸性亚基和22kD碱性亚基随温度处理的差异变化却因品种而异,且高温处理对水稻籽粒蛋白绝对含量(mg grain~(–1))的影响程度也进没有其对蛋白相对含量(%)的影响明显。高氮×高温处理组合对稻米总蛋白与谷蛋白含量的影响程度显著大于单一高温或高氮处理,但在高氮水平下由高温引起稻米醇溶蛋白含量的下降幅度却小于其低氮对照,有利于稻米醇溶蛋白含量在不同温度处理下的相对稳定。     

Evaluation of soybean germplasm conserved in NIAS genebank and development of mini core collections

Genetic variation and population structure among 1603 soybean accessions, consisted of 832 Japanese landraces, 109 old and 57 recent Japanese varieties, 341 landrace from 16 Asian countries and 264 wild soybean accessions, were characterized using 191 SNP markers. Although gene diversity of Japanese soybean germplasm was slight lower than that of exotic soybean germplasm, population differentiation and clustering analyses indicated clear genetic differentiation among Japanese cultivated soybeans, exotic cultivated soybeans and wild soybeans. Nine hundred ninety eight Japanese accessions were separated to a certain extent into groups corresponding to their agro-morphologic characteristics such as photosensitivity and seed characteristics rather than their geographical origin. Based on the assessment of the SNP markers and several agro-morphologic traits, accessions that retain gene diversity of the whole collection were selected to develop several soybean sets of different sizes using an heuristic approach; a minimum of 12 accessions can represent the observed gene diversity; a mini-core collection of 96 accession can represent a major proportion of both geographic origin and agro-morphologic trait variation. These selected sets of germplasm will provide an effective platform for enhancing soybean diversity studies and assist in finding novel traits for crop improvement.     

Seed quality attributes of food-grade soybeans from the U.S. and Asia

Diversity of food-grade soybeans is critical for utilization of genetic resources in cultivar development, germplasm enhancement, and end-product commercialization. The objective of this study was to assess seed quality attributes and phenotypic variability among 54 U.S. and 51 Asian food-grade cultivars and breeding lines. The results showed greater genetic diversity of protein content, calcium content, seed hardness, and seed size uniformity than other quality traits in both small- and large-seeded genotypes evaluated in this study. Among the small-seeded soybeans, the U.S. genotypes were more diverse and exhibited higher swell ratio and oil content but lower stone seed ratio and protein content than Asian accessions. Among the large-seeded accessions, U.S. genotypes had higher stone seed ratio and oil content but lower swell ratio and protein content, and were less diverse than Asian genotypes. The characterization of diverse food-grade soybeans will facilitate parent selection in specialty soybean breeding.     

Regional variation in Brassica nigra and other weedy crucifers for disease reaction to Alternaria brassicicola and Xanthomonas campestris pv. campestris

For Brassica crop breeders, weedy crucifers are potential sources of disease resistance and other useful traits. However, few species have been evaluated or are well represented in germplasm collections. In this study, we evaluated 24 Eurasian crucifer species for disease reaction to North American isolates of the crop pathogens A. brassicicola and X. campestris pv. campestris. The test array comprised 190 entries (genebank accessions and weed populations), including 108 B. nigra entries from four geographic regions and 34 entries of Camelina sativa. Disease reaction was highly variable between species and within some species. Reaction to A. brassicicola was variable between entries of C. sativa, a species reported as highly resistant to Alternaria pathogens. In B. nigra, disease reaction was variable between geographic regions and between entries within some regions. Most of the B. nigra entries rated as disease resistant were weed populations from North America, but disease reaction was not related to the geographic distance between these populations. In summary, disease reaction to two crop pathogens was variable in crucifer weed taxa, including species considered to contain little genetic variation. We identified entries with promising levels of disease resistance and highlighted the potential value of weedy crucifer genetic resources. This revised version was published online in July 2006 with corrections to the Cover Date.     

Exploring the natural variation for reproductive thermotolerance in wild tomato species

Climate change has become a serious threat for crop productivity worldwide. The increased frequency of heat waves strongly affects reproductive success and thus yield for many crop species, implying that breeding for thermotolerant cultivars is critical for food security. Insight into the genetic architecture of reproductive heat tolerance contributes to our fundamental understanding of the stress sensitivity of this process and at the same time may have applied value. In the case of tomato (Solanum lycopersicum), germplasm screenings for thermotolerance have often used yield as the main measured trait. However, due to the complex nature of yield and the relatively narrow genetic variation present in the cultivated germplasm screened, there has been limited progress in understanding the genetic basis of reproductive heat tolerance. Extending the screening to wild accessions of related species that cover a range of climatic conditions might be an effective approach to find novel, more tolerant genetic resources. The purpose of this study was to provide insight into the sensitivity of individual reproductive key traits (i.e. the number of pollen per flower, pollen viability and style protrusion) to heat-wave like long-term mild heat (LTMH), and determine the extent to which genetic variation exists for these traits among wild tomato species. We found that these traits were highly variable among the screened accessions. Although no overall thermotolerant species were identified, several S. pimpinellifolium individuals outperformed the best performing cultivar in terms of pollen viability under LTMH. Furthermore, we reveal that there has been local adaptation of reproductive heat tolerance, as accessions from lower elevations and higher annual temperature are more likely to show high pollen viability under LTMH.     

Variation in seed proteins from mutagen-treated cultivars and selected lines of Vigna unguiculata L. Walp

The storage protein profiles of the seeds of two IITA cowpea cultivars (‘IT84E–124’ and ‘Vita 7’) exposed to three mutagens—sodium azide (NaN₃), ethyl methane sulphonate (EMS) and ⁶⁰Co gamma rays—and those of 18 selected M₃ lines were investigated by sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis (PAGE). The total seed protein, globulin and albumin fractions showed differences in number and intensity of subunit bands, but the least differences were found in the albumin fraction. Both high and low molecular weight bands were observed, the highest being 94.5 kDa and the lowest 12.0 kDa.‘Vita T showed less variability compared with ‘IT84E–124’, as indicated by the relative similarity indices (S.I.) of the two cultivars. The lowest S.I. of 0.200 was found among ‘IT84E–124’ lines while the lowest S.I. among ‘Vita T lines was 0.4706. A number of lines with particular traits were found to be characterized by the presence of specific polypeptide bands. This study demonstrates that induced mutation could create additional variability to supplement existing germplasm and that SDS-PAGE is a useful tool for discriminating and estimating genetic similarities among selections.     

Mining Elite Sea-Island Cotton Germplasm Based on Phenotyping and SSR Markers

[Objective] An elite germplasm resource of sea-island cotton with outstanding traits was mined in order to accelerate the breeding process of new varieties. [Method] The core collections of sea-island cotton germplasm consisted of 178 accessions were used as experimental materials in this study. Analyses of variability and diversity were performed through detecting phenotypic data of six main breeding-targeted traits, including boll weight, boll number per plant, lint percentage, fiber length, fiber strength, and micronaire. The elite germplasm of sea-island cotton was selected according to 10% optimal sampling strategy based on the phenotypic value of each trait. The 120 pairs of polymorphic simple sequence repeat (SSR) primers were used to analyze the polymorphism of 178 accessions of the core collections. Then, we conducted the population structure and clustering analysis based on the genotyping results. According to the results of cluster analysis, the primary elite germplasm was further selected, and the final elite germplasm of sea-island cotton was identified. [Result] The results showed that there was a high variability and abundant genetic diversity in the 6 studied traits. In 178 accessions of sea-island cotton, 262 alleles were detected by 120 pairs of SSR primers, with an average of 2.18 loci. The average polymorphism information content (PIC) was 0.067 8-0.630 0, with an average of 0.296 0, showing moderate polymorphism. The cluster analysis showed that the core collection of sea-island cotton was divided into six groups. twenty-three elite germplasm resources of sea-island cotton were identified based on phenotypic value and cluster analysis of SSR markers. [Conclusion] The germplasm of sea-island cotton can be analyzed and evaluated based on the phenotyping and SSR markers, and then the elite germplasm of sea-island cotton can be identified. These results provided the material basis for the genetic breeding of sea-island cotton, as well as the important reference and basis for the mining and identification of crop elite germplasm.