杨桃果实性状与橘小实蝇危害严重度的关系
Traits and Damage of Carambola Fruit by Bactrocera dorsalis
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摘要: 在调查分析不同成熟度杨桃果实对橘小实蝇为害影响的基础上,运用相关性分析,逐步回归分析、通径分析及决策系数计算的方法,探讨成熟期杨桃果实性状与橘小实蝇危害严重度的关系。结果表明,杨桃果内橘小实蝇幼虫数量随着果实成熟度的增加而增加,果实越成熟,硬度值越小,可溶性固形物含量越高,果内橘小实蝇幼虫数量越多,橘小实蝇危害程度越重;果实主要性状与果内橘小实蝇幼虫数量的相关程度依次为:果实硬度(X4)>酒石酸(X7)>还原性总糖含量(X3)>pH值(X2)>氨基酸总量(X5)>草酸(X6)>粗蛋白(X1);运用多元逐步回归分析法,筛选出作用显著的最优性状,得出最优回归方程为Y=459.2219+91.6060 X1-91.2226 X2-100.8494 X4+0.4432 X11(X11为柠檬酸),决定系数R2=0.999 83,表明这4个性状对果内橘小实蝇幼虫数量的相关影响达到99.983%;4个入选性状的决策系数依次为硬度>粗蛋白含量>pH值>柠檬酸,表明杨桃果实的硬度和粗蛋白含量是影响橘小实蝇危害严重度的主决策性状,pH值的决策系数最小,是主要限制性状,柠檬酸为适当限制性状。Abstract: Stepwise regression and path analyses,as well as the decision-making factor calculation,were used to evaluate the correlation between the traits of carambola(Averrhoa carambola Linn.) and the severity of damage on the fruits infested by Bactrocera dorsalis Hensel.The results showed that the number of the insect larvae on the infested fruits increased with the maturity,soluble solids content and softness of the fruits.The correlations decreased in the order of:fruit firmness(X4)>tartaric acid(X7)>reductive sugar(X3)>pH value(X2)>total amino acid content(X5)>oxalic acid(X6)>crude protein(X1).The regression equation of the correlation was∶ Y=459.2219 + 91.6060X1-91.2226X2-100.8494X4 + 0.4432X11(citric acid),with a correlation coefficient of 99.98%.The decision coefficients of the 4 studied traits were found to be:fruit firmness(X4)>crude protein(X1)>pH value(X1)>citric acid(X11).Hence,the main decision-making factors on the fruit damage by B.dorsalis were fruit firmness and crude protein content,the primary restricted trait was pH value,and the appropriate restricted trait was citric acid.The results could help better determine the timing for effective pest control of B.dorsalis larvae.