基于农艺性状分级对317份甘蔗种质资源的评价

Evaluation of 317 Sugarcane Germplasm Based on Agronomic Traits Rating Data

【目的】采用重要农艺性状快速分级的方法对甘蔗种质资源进行评价,为种质资源的进一步精准评价和杂交利用提供参考。【方法】基于大田试验,在成熟期选择株高、茎径、有效茎、叶部病害程度(花叶病、锈病、褐条病等叶部病害田间自然发病的综合反映)和总体生势等5个重要农艺性状,对317份国内外甘蔗种质资源(2重复)进行分级评价。每个性状分为5级,其中株高以1级为最高,依次递减,5级最矮;同理,茎径以1级最粗,5级最细;有效茎以1级最多,5级最少;总体生势以1级最好,5级最差;叶部病害以1级为无或轻,5级最严重。各性状分级由分级小组成员共同完成。基于农艺性状分级数据,采用方差、广义遗传力、主成分、聚类和判别分析等统计方法,对317份种质资源进行综合评价分析,筛选农艺性状表现优良的种质资源。并在此基础上,采用一次旋光法,对筛选出的优良种质资源甘蔗糖分进行评价。【结果】方差和广义遗传力分析结果表明,317份甘蔗种质各个农艺性状指标分级数据间均存在极显著差异(P<0.01),广义遗传力在0.61—0.72,其中广义遗传力最高为茎径(0.72),最低为株高(0.61)。主成分分析结果表明,5个农艺性状可简化为1个主成分因子,即5个农艺性状的综合叠加,且此主成分所提供的信息占全部信息量的63.57%,特征根显著高于其他主成分的特征根之和。基于主成分结果,对317份种质进行聚类分析,将其划分为5类,第Ⅰ类包含20份种质,第Ⅱ类包含97份,第Ⅲ类包含82份,第Ⅳ类包含80份,第Ⅴ类包含38份;农艺性状表现以第Ⅰ类和第Ⅱ类的117份种质资源最优(占全部种质数的36.91%)。聚类结果的逐步判别分析显示,平均判对概率为95.85%。聚类结果充分体现了种质资源在田间试验中的实际表现。基于农艺性状聚类分析结果,对第Ⅰ类和第Ⅱ类共计117份种质的甘蔗糖分进行评价。结果显示,117份种质11月至翌年3月平均蔗糖分在5.0%—17.10%,最高为云蔗09-1601(17.1%),最低为CP79-318(5.0%)。平均蔗糖分15.0%以上的种质有43份,其中有11份超过16.0%。【结论】株高、茎径、有效茎、叶部病害程度和总体生势等是反映甘蔗种质资源田间表现的重要农艺性状指标。基于重要农艺性状快速分级的方法可以作为大量甘蔗种质资源评价的另一途径。

【Objective】Evaluation of sugarcane germplasm via rapid rating their important agronomic traits could provide reference for their further evaluation hybridization.【Method】Based on the field experiment, 317 sugarcane germplasm resources(2 replicates) were rated and evaluated by selecting five important agronomic traits at maturity stage, which were plant height, stalk diameter, millable stalks, leaf disease degree(comprehensive reflection of natural leaf diseases such as mosaic, rust, brown stripe disease) and general vigor. Each trait was divided into five grades, in which plant height was highest in grade 1, and the shortest in grade 5;similarly, stalk diameter was thickest in grade 1 and finest in grade 5;millable stalk was the most in grade 1 and the least in grade 5;general vigor was the best in grade 1 and the worst in grade 5;leaf diseases were the best in grade 1 and the worst in grade 5.The rating of each trait was accomplished by the members of the rating group. Based on the rating data of agronomic traits, 317 germplasm resources were comprehensively evaluated by statistical methods such as variance, broad-sense heritability, principal component analysis, clustering and discriminant analysis, and the germplasm resources with excellent agronomic traits were screened.Further, the sucrose content of the selected excellent germplasm was evaluated by primary rotation.【Result】The results of variance and broad-sense heritability analysis showed significant differences among 317 sugarcane germplasm in the classification data of agronomic traits(P<0.01) and the broad-sense heritability ranged from 0.61 to 0.72. The stalk diameter performed the highest broad-sense heritability(0.72) and the plant height performed the lowest(0.61). The results of principal component analysis showed that the five agronomic traits could be simplified to one principal component factor, i.e. the comprehensive superposition of five agronomic traits. The information provided by the principal component accounted for 63.57% of the total information, and the characteristic roots were significantly higher than the sum of the characteristic roots of other principal components. Based on the results of principal component analysis, 317 germplasms were classified into five categories, including 20 in the first category, 97 in the second category, 82 in the third category, 80 in the fourth category and 38 in the fifth category. 117 germplasm in the first and the second categories were the best in agronomic traits(36.91% of the total germplasms). The stepwise discriminant analysis of clustering results showed that the average probability of pairing is 95.85%. The clustering results fully reflected the actual performance of germplasm in field experiments. Based on cluster analysis of agronomic traits, the sucrose content of 117 germplasm in Class I and Class II was evaluated. The results showed that the average sucrose content of 117 germplasms ranged from 5.0% to17.10% from November to next March, the highest was YZ09-1601(17.1%) and the lowest was CP79-318(5.0%). There were 43 germplasm with an average sugar content of more than 15.0%, of which 11 were more than 16.0%.【Conclusion】Plant height, stalk diameter, millable stalks, leaf disease and general vigor are important agronomic traits reflecting the field performance of sugarcane germplasm resources. The rapid classification method based on important agronomic traits is a promising alternative for evaluating large number of sugarcane germplasm resources.