基于表型及经济性状构建蒜头果初选核心种质

Construction of Primary Core Collection of Malania oleiferaBased on Phenotypic and Economic Traits

为尽快明确天然林中蒜头果种质资源收集保存的策略和目标,本研究基于21个表型及经济性状,构建蒜头果核心种质,明确了建立蒜头果育种和保存群体的目标材料,为其资源保育提供依据。在系统聚类和优先取样法的基础上,分别利用遗传多样性法、比例法和对数法,设定10%、20%和30%3种取样比例,产生7种构建策略;采用8个参数评价7种策略构建的核心种质,得到参数最优的核心种质;采用4重方法验证核心种质的有效性和代表性。结果表明,(1)“优先取样法+遗传多样性法+30%取样比例”形成的核心种质,8个评价参数最优,核心种质包含28个样本,取样比例为28.87%。(2)4种验证方法均表明,构建的核心种质具有较好的代表性。多样性指数的t检验表明,核心种质与原种质在21个性状上的多样性指数差异均不显著(0.05);符合率检验表明,核心种质与原种质在21个性状上的均值、极大值、极小值和多样性指数的符合率均在80%以上;主成分检验表明,核心种质与原种质具有相近的特征值、贡献率和累计贡献率;核心种质与原种质的样品分布表明,两者具有相似的分布结构。研究认为,构建的蒜头果核心种质具备代表性、有效性和实用性等特征,可作为蒜头果种质资源收集保存和建立育种群体的依据。

In order to identify the strategies and objectives for the collection and conservation of Malania oleifera germplasm resources in natural forests,we constructed the core collection of M.oleifera based on 21 phenotypic and economic traits,and identified the target materials for the establishment of M.oleifera breeding and conservation populations,which provided the basis for the resource conservation of M.oleifera.On the basis of systematic clustering and preferential sampling method,according to genetic diversity method,proportional method and logarithmic method,we set three sampling ratios of 10%,20%and 30%,resulting in a total of seven sampling strategies.Eight parameters were used to evaluate the core collection constructed by the seven strategies,and the core collection with the best parameters was obtained.Four methods were used to verify the validity and representativeness of the core collection.The results showed that, (1) the core collection formed by “priority sampling method + genetic diversity method+30% sampling ratio” had the best 8 evaluation parameters, and the core collection contained 28 sampleswith a sampling ratio of 28.87%. (2) All the four verification methods showed that the constructedcore collection had a good representation. t-test of Shannon-Weaver index showed that there was no significantdifference between core collection and initial collection on 21 traits (0.05). The coincidence rate testshowed that the coincidence rate of mean value, maximum value, minimum value and Shannon-Weaver indexof 21 traits between core collection and initial collection was more than 80%. Principal component testshowed that the core collection had similar characteristic value, contribution rate and cumulative contributionrate to the initial collection. The distribution maps of core collection and initial collection showed thatthey had similar distribution structure. It was concluded that the constructed M . oleifera core collectionhad the characteristics of representativeness, validity and practicability, which could be used as the basisfor the collection and preservation of M . oleifera germplasm resources and the establishment of breedingpopulation.