基于穗形特征与分子标记进行中国节节麦核心种质的创建

节节麦是普通小麦D基因组供体,遗传多样性丰富,而我国节节麦资源是有别于中东节节麦资源的重要基因源。为了合理高效地管理、评价、保护和利用我国节节麦资源,本研究将野生采集的762份中国节节麦资源作为试验材料,基于SSR标记分组状况,利用小穗长、护颖长、护颖宽、外稃长、外稃宽、内稃长、内稃宽、穗宽、粒长和粒宽等10个穗形性状指标,在欧氏距离、马氏距离和4种取样比例下构建节节麦核心种质候选集。进而采用均值差异百分率、极差符合率、方差差异百分率及变异系数变化率4个指标对不同方法构建的核心种质候选集的可行性和有效性进行评价,并利用原种质和核心种质的主成分分析法进行验证,最终确定基于欧氏距离、10%取样比例下、采用最小距离逐步取样法构建的包含76个样品的节节麦核心种质能够以最小的资源份数、最大限度地代表我国节节麦的遗传多样性。

Construction of Core Collection of Chinese Aegilops tauschii Coss.Germplasm Resource Based on Spike Morphological Traits and Molecular Markers

Aegilops tauschii Coss.is the donor of wheat D genome and hosts abundant genetic variation in the germplasm resources.The Ae.tauschii Coss.germplasm accessions from China which genetically differ from the resources in Middle East are an important source.In order to better protect and utilize the Ae.tauschii Coss.resources,762 accessions collected from China were subjected for the diversity analysis using the molecular markers and the spike traits.Followed by the grouping results of SSR analysis,the candidate sets of Ae.tauschii Coss.core collection were constructed by using 10 spike morphological traits including spike width,spike length,lemma width,lemma length,glume width,glume length,grain width and grain length under different genetic distances and different sampling ratios.Four parameters including mean difference percentage,coincidence rate of range,variance difference percentage and changeable rate of coefficient of variation were deployed to evaluate the usability of the candidate core sets,followed by a test using principal coordinate analysis.As a result,the core collection which was constructed by Euclidean distance and LDSS method with 10%sampling ratio was able to maximize the genetic diversity of Ae.tauschii Coss.in China with the smallest number of accessions.