基于形态性状的甘薯核心种质取样策略研究

Sampling Strategies of Sweet Potato Core Collection Based on Morphological Traits

选取15%的总体取样比例,采用2种分组方法、3种组内取样量比例和2种组内个体选择方法,分析了476份广西甘薯种质资源的18个农艺性状数据,构建出13个甘薯初级核心种质样本。为确定这些样本的代表性,分别与总体进行了5个指标的比较,包括表型保留比例、表型频率方差、遗传多样性指数、变异系数、极差符合率。结果表明,按资源类型分组优于按来源地分组;组内取样量以对数法代表性最好,简单比例法的代表性其次,平方根法最差;在个体选择中,最小距离逐步取样法优于随机法。因此,按资源类型分组,再按对数比例法确定组内取样量,通过最小距离逐步取样法选择个体是甘薯核心种质构建的最佳取样策略。

With 15% sampling ratio, two ways in dividing groups,three ways in determining sampling numbers in each group, and two methods for selecting individuals, 18 agronomic characteristics of 476 sweet potato accessions in Guangxi province were analyzed and 13 samples of primary core collections were developed. To determine the ef- fectiveness,each of primary core collection was compared with the whole collection for 5 parameters including ratio of phenotype retained, variance of phenotypic frequency, index of genetic diversity, coefficient of variation, and coin- cidence rate of range. The result showed that the way of according to the resources type was significantly better than according to the source in developing core collection. Among the methods to determine the sampling numbers in each group,logarithm method was the best,followed by proportioned and square root method. On the selection of in- dividuals,least distance stepwise sampling method was better than random method. Therefore,the optimum sampling strategy for developing sweet potato core collection is firstly to group by resource type,then determine the sampling numbers in each group by proportion of logarithm, and finally choose individuals through least distance stepwise sampling method.