云南保山稻种资源多样性初步分析

Preliminary analysis of rice germplasms diversity collected in Baoshan,Yunnan

【目的】分析保山稻种资源遗传多样性,为充分挖掘保山稻种资源有利性状提供依据。【方法】从保山市农业科学研究所保存的1800多份稻种资源中随机选取96份稻种资源,用农业行业标准(NY/T1433—2014)公布的水稻品种DNA分子鉴定的48对SSR引物进行基因型评价,并对其中的52份在1987年做了相关表型记录的稻种资源进行分析。【结果】随机抽取的96份稻种资源中有52份有表型记载,包括株高、产量、穗长、穗粒数、实粒数、空秕率、千粒重、全生育期等8个性状在1987年的表型变异系数分别是8.7%、21.8%、9.4%、17.3%、21%、85.2%、10.7%和7%,说明保山保存的稻种资源农艺性状具有表型多样性;这52份稻种资源于2020年在保山市农科所试验站种植后再次评价其株高,得出1987和2020年的株高变异系数分别是8.7%和7.8%,株高差异不显著(T=19.627,P<0.0001,df=51),说明经过30多年后,其株高性状遗传稳定;水稻品种DNA分子鉴定的48对SSR引物中有35对SSR引物具有多态性(73%),具有多态性的35对引物共检测到100个等位基因、平均等位基因数3.14,基因多样性指数变异范围为0~0.71、平均为0.33,遗传多态信息含量(PIC)的变异范围为0~0.66、平均为0.3,说明保山保存的稻种资源遗传多样性丰富;用邻接法(Neighbor-Joining,NJ)进行聚类,这96份稻种资源在遗传距离为0.4693时可划分为2大类群,而第2类群又可以再划分为3类,进一步说明保山保存的稻种资源具有较为丰富的遗传多样性;同时发现,记录为相同名称的7个稻种分别在遗传距离0.3554、0.4693、0.428、0.3663、0.4693、0.4085、0.4384时分到不同的类群,而当遗传距离最小为0.0648时有2份稻种资源记录为不同名称,说明保山保存的稻种资源存在同名异种或异名同种的现象。【结论】保山稻种资源的表型及遗传多样性丰富,性状的遗传稳定,是稻作遗传改良的重要基因库,有必要深入开发利用这些重要的稻种资源为水稻遗传改良服务,同时有必要进一步探讨地方稻种资源的保护和利用策略。

[Objective]The present study aimed to analyze the diversity of rice germplasms in Baoshan and provide a basis for fully exploiting the desirable traits of the germplasm resources in Baoshan.[Method]Ninety six rice germplasms were randomly selected from more than 1800 germplasms preserved by Baoshan Academy Agricultural Sciences,and 48 pairs of SSR primers of molecular markers recommended by Industrial Standard of Agriculture(NY/T1433-2014)'were used for genotype evaluation,and 52 rice germplasms with relevant phenotypic records in 1987 were analyzed.[Result]Firstly,the germplasms preserved in Baoshan had phenotypic diversity based on 8 variation coefficients of agronomic traits.According to the 1987 records,the 52 samples recorded among 96 germplasms were evaluated for plant height,yield,panicle length,grains per panicle,filled grains,empty-unfilled grains,1000-grain weight and growth duration,and their variation coefficients were 8.7%,21.8%,9.4%,17.3%,21%,85.2%,10.7%,and 7%,respectively.When reevaluating these 52 samples a-gain in 2020,the variation coefficients of plant height in 1987 and 2020 were respectively 8.7%and 7.8%,showing no significant difference(T=19.627,P<0.0001,df=51).This indicated that the trait of these germplasms remained steady for over 30 years.In addition,the germplasms preserved in Baoshan had high genetic diversity.Among the 48 pairs of SSR primers,35 pairs of primers detected polymorphic loci,and 100 alleles were detected by 35 pairs of primers with an average of 3.14 alleles per locus.The genetic diversity index ranged from 0 to 0.71,with an average of 0.33.The polymorphic information content(PIC)ranged from 0 to 0.66,with an average of 0.3.As indicated by the NJ clustering results,the 96 germplasms could be divided into two groups when genetic distance was 0.4693,among which the second group could be divided into three subgroups.This also showed the genetic diversity of the germplasms preserved in Baoshan.Mo­reover,these germplasm variants could form homogeneous and heterogeneous groups.Seven germplasms of the same name belonged to differ­ent groups when the genetic distance was 0.3554,0.4693,0.428,0.3663,0.4693,0.4085,and 0.4384,respectively,while 2 germ­plasms of different names to the same group with the shortest genetic distance of 0.0648.[Conclusion]Generally,with its phenotypic and genetic diversity and steady genetic characteristics,the germplasms preserved in Baoshan is a crucial gene pool for rice genetic improvement.At the same time,it is necessary to further explore the conservation and utilization of rice germplasm resources.