基于表型多样性构建向日葵核心种质

为鉴定评价我国向日葵（Helianthus annuus L.）种质资源在南方地区的表现,筛选构建向日葵核心种质,以422份向日葵种质为材料,在进行2年鉴定观察的基础上,采用描述性统计、相关性分析、主成分分析等方法对11个表型农艺性状进行分析评价。结果表明,原始群体的这些农艺性状具有较大的变异幅度,其变异系数（CV）为3.60%~83.32%,平均变异系数为20.93%,其中分枝株率（0%~62.5%）、单株粒重（9.70~232.35 g）、百粒重（4.60~14.92 g）、叶片数（14.40~48.38个）和株高（103.75~260.00 cm）变异幅度较大;性状间表现出显著的相关性,主成分分析表明,影响性状的4个主要成分解释了总方差的71.72%。采用QGAstation 2.0软件构建了72组核心种质候选群体,并根据均值差异百分数（MD）、方差差异百分率（VD）,极差符合率（CR）和变异系数百分率（VR）,获得组获得1组包含84份材料的最佳核心种质群体。聚类分析将84份核心资源分为5大类,与原群体相比,所选核心种质均值无显著差异,方差显著提高,能最大限度代表原始油葵种质资源保存和利用。     

Identification of diverse germplasm lines for agronomic traits in a chickpea (Cicer arietinum L.) core collection for use in crop improvement

Utilization of exotic and diverse germplasm is needed to enhance the genetic diversity of cultivars. Genetically diverse lines provide ample opportunity to create favorable gene combinations, and the probability of producing a unique genotype increases in proportion to the number of genes by which the parents differ. Representative core collections (10% of the entire collection) have been suggested as a means to identify useful parents for crop improvement programs. The chickpea core collection (1956 accessions) was evaluated for 14 agronomic traits in two seasons to identify diverse agronomically superior chickpea germplasm. Season (year) and genotypic effects were significant for 13 of the 14 traits, while genotype × season effect was significant for 8 traits. The desi, kabuli, and intermediate type chickpeas differed significantly for days to maturity, basal secondary branches, pods per plant, seed yield, and 100-seed weight. In comparison to controls, 12 accessions flowered early, 15 produced greater seed yield, and 29 had greater 100-seed weight. Based on days to 50% flowering, pods per plant, seed yield, and 100-seed weight, 19 desi, 15 kabuli and 5 intermediate type chickpea germplasm lines originating from 10 countries were selected. The selected desi accessions produced 8.5% more seed yield and had 32% larger seeds than the control cultivar Annigeri while the selected kabuli accessions yielded at par with control L 550 but had 84% larger seeds. The 39 selected accessions and two control cultivars (Annigeri and L 550) were grouped by their first five principal components (PCs) into three clusters. Cluster 1 consisted of early maturing large-seeded kabuli types, cluster 2 early and late maturing desi types, and cluster 3 late maturing intermediate and kabuli types. Clusters 2 and 3 accessions had small to medium sized seeds. These accessions can be used in chickpea breeding programs to develop high yielding desi and kabuli cultivars with a broad genetic base.     

Genetic diversity for grain nutrients contents in a core collection of finger millet (Eleusine coracana (L.) Gaertn.) germplasm

Finger millet is a promising source of micronutrients and protein besides energy and can contribute to the alleviation of iron (Fe), zinc (Zn) and protein malnutrition affecting women and preschool children in African and south-east Asian countries. The most cost effective approach for mitigating micronutrient and protein malnutrition is to introduce staple crop cultivars selected and/or bred for Fe, Zn and protein dense grain. Breeding finger millet for enhanced grain nutrients is still in its infancy. Analysis, detection and exploitation of the existing variability among the germplasm accessions are the initial steps in breeding micronutrient and protein-dense finger millet cultivars. Evaluation of finger millet core collection for grain nutrients and agronomic traits revealed a substantial genetic variability for grain Fe, Zn, calcium (Ca) and protein contents. The accessions rich in nutrient contents were identified and their agronomic diversity assessed. The accessions rich in Zn content have significantly higher grain yield potential than those rich in Fe and protein content. Grain nutrient-specific accessions and those contrasting for nutrient contents were identified for use in the strategic research and cultivar development in finger millet.