基于因子分析和聚类分析的甘蔗品种抗螟性评价

为明确甘蔗品种（系）抗螟性评价指标，建立甘蔗品种（系）抗螟性综合评价体系。在田间自然虫源条件下，以螟害株率、螟害节率、螟害指数、枯梢率、蛀道数、蛀道长度和羽化率为甘蔗生长中后期抗螟性评价候选指标，对19个甘蔗新品种（系）的抗螟性进行因子分析和聚类分析。结果表明：除螟害株率外，其余6个候选指标均有望作为抗螟性评价指标，其中螟害指数与单茎重损失量、蔗糖分损失量间同时具有显著正相关，是评价甘蔗受害程度的最佳指标。因子分析结果表明，6个抗性相关指标可简化为3个公因子，即植株受害因子、蛀道解剖因子和螟虫生长发育因子。根据品种因子得分，对19个甘蔗新品种（系）抗螟性进行系统聚类分析，结果显示，粤甘42号对螟虫抗性最高，福农38号、桂糖29号、柳城03-1137和桂糖31号对螟虫抗性最低。本研究结果不仅提供了甘蔗抗螟性评价指标与综合抗性评价方法，还明确了19个甘蔗新品种（系）对甘蔗螟虫的抗性。

Evaluation of Sugarcane Varieties Resistance to Borers Based on Factor Analysis and Cluster Analysis

In order to determine the evaluation indices of sugarcane varieties resistance to sugarcane borer, a comprehensive evaluation system for the sugarcane borer resistance was established. According to seven candidate parameters of the percentage of bored stalks, the percentage of bored internodes, the borer damage index, the percentage of bored tips, the number of tunnels per stalk, the tunnels length per individual stalk and the adult emergence rate collected in the middle and late sugarcane growth periods, the factor and cluster analysis on resistance of nineteen new sugarcane varieties under the natural population of the target pest were studied. The results showed that except the percentage of bored stalks, the values of all the six candidate parameters had potential to be used to evaluate the borer resistance. A correlation was investigated between each of the six parameters to the loss of sugarcane stalk weight and the loss of sucrose content, but only the borer damage index was found to be a significant positive correlation with both of the loss, suggesting that the parameter of the borer damage index was the best one for the evaluation of sugarcane damage. In terms of the results of factor analysis, the six parameters could be simplified to three main factors including damage factors of plant, anatomy factors of borer tunnels, growth and development factors of borer. The nineteen new sugarcane varieties were clustering analysis according to the scores of factors, in which YT42 showed to be the highest borer resistance and FN38, YG29, LC03-1137 and YG31, were the opposite. The results of this study not only provided the parameters and the method for the evaluation of sugarcane borer resistance, but also made clear the borer resistance of these nineteen new sugarcane varieties.