东北三省2021年水稻审定品种的核心亲本遗传多样性与籼粳分化北大核心CSCD

为了阐明东北三省近年育成水稻品种的遗传基础,该研究通过对2021年育成的256个水稻新品种的系谱进行分析,确定了20个材料为育种核心亲本,并利用44对多态性SSR分子标记和34对InDel籼粳特异性分子标记分析了它们的遗传多样性和籼粳分化程度。结果表明:(1)SSR标记能够高效评价参试材料的多样性水平,共检测到130个等位基因,每个位点检测等位基因(Na)变异为2~5个,平均为2.95个;基因多样性指数(H)变异为0.10~0.75,平均为0.41;多态性信息含量(PIC)变异为0.09~0.70,平均为0.36。(2)遗传多样性分析表明,东北三省20份水稻核心亲本的整体多样性水平较低,黑龙江省核心亲本多样性略高于辽宁省和吉林省。(3)NJ聚类分析表明,20份核心亲本可以划分为3个类群,分别为辽宁类群、吉林类群和黑龙江类群。(4)遗传结构分析表明,20份核心亲本可划分为2个稳定的类群,其中辽宁省核心亲本均处于A类群,黑龙江省核心亲本均处于B类群。(5)籼粳分化分析表明,20份核心亲本遗传背景均为粳稻类型,但都含有少数籼型位点,其籼型基因频率F在0.01~0.19范围内。研究认为,东北三省水稻育种核心亲本遗传基础狭窄、使用频率较高是导致育成品种遗传多样性水平较低的可能原因,在育种中亟待挖掘新种质、引入新资源,丰富遗传背景。

Genetic Diversity and Xian geng Differentiation of Core Parents from 2021 Approved Rice Varieties in Northeast China

In order to clarify the genetic basis of rice varieties bred in the three provinces of Northeast China in recent years, 20 materials were selected as the breeding core parents by analyzing the pedigree of 256 approved rice varieties which bred in 2021. And 44 SSR polymorphic markers and 34 InDel xian geng specific markers were used to analyze on their genetic diversity and xian geng differentiation. The results showed that: (1) all selected markers can be applied extensively for the genetic diversity level of rice. A total of 130 alleles were detected between these varieties, and the alleles (Na) per locus ranged from 2 to 5 with the mean value of 2.95. The gene diversity indices (H) varied from 0.10 to 0.75 with an average of 0.41. The polymorphism information content (PIC) was changed from 0.09 to 0.70 with the average of 0.36. (2) Genetic diversity analysis showed that the overall diversity level of the test materials in Northeast China at a lower level, and the diversity of the core parents in Heilongjiang was slightly higher than that in Liaoning and Jilin. (3) The NJ cluster analysis indicated that all tested materials could be divided into three groups, such as Liaoning group, Jilin group and Heilongjiang group. (4) The genetic structure analysis showed that the 20 core parents could be divided into two stable groups. The core parents of Liaoning Province were in group A, and the core parents of Heilongjiang Province were in group B. (5) Analysis of xian geng differentiation found that the 20 materials were geng type, but all of these materials contained a few number of xian loci, and the xian gene frequency (F_x) range was 0.01-0.19. Studies have shown that the possible reasons for the low level of genetic diversity of breeding varieties is the narrow genetic basis and high utilization frequency of breeding core parents in the three provinces of Northeast China. It is urgent to excavate new germplasm, introduce new resources in breeding to broaden the genetic background.