松突圆蚧对不同马尾松品系危害程度的单向通径分析

为了寻找重要指标, 从而研究松突圆蚧Hemiberlesia pitysophila Takagi对不同马尾松Pinus massoniana品系的危害程度, 揭示昆虫数量指标所反映的直接和间接危害程度。选取一块林场试验地, 通过虫口密度等6个指标进行调查, 采用单向通径分析法分析。结果表明：直接影响最大正向指标为虫口密度和有虫针束率, 间接影响最大负向指标为有虫针束率。综合起来, 反映危害程度加大的重要指标依次为：虫口密度、有虫株率、定殖虫口数量、1龄若虫存活率、2龄若虫存活率、有虫针束率。28个马尾松品系可分为4类, 其中最受危害的是390和439, 危害最小的是469和458。分析结果之间基本一致, 与实际基本相符。因此, 本文结果对选取考察指标及其抗虫品系的选育提供了重要的参考价值。单向通径分析法在理论上有一定的合理性和创新性, 在实际上是可行的, 值得研究和推广。

One-way path analysis of hazard degrees of different strains of masson pine (Pinus massoniana) infested by Hemiberlesiaa pitysophila (Homoptera: Diaspididae)

In order to study the hazard degree of Hemiberlesia pitysophila Takagi to different strains of Pinus massoniana, and reveal the direct and indirect damage reflected by indicators of the number of insects, six indicators consisting of population density etc. in a selected test forest was investigated, and one-way path analysis method was adopted. The results showed that the most positive indicators of direct impact were population density and the ratio of damaged needle, but the largest negative indicator of indirect impact just was the ratio of damaged needle. Generally speaking, the important indicators reflecting the increasing degree of damage were successively as follows: population density, the ratio of infested slash pine trees, the number of the breeding insects in a certain time, the survival rate of the 1st instar larvae, the survival rate of the 2nd instar larvae, the ratio of damaged needle. The 28 masson pine strains surveyed could be divided into four categories, of which no. 390 and no. 439 strains were the most damaged, while no. 458 and no. 469 strains were the least damaged. The analyzed results were basically coherent and in line with the reality. Therefore, the results provided an important reference to select study indicators and the selecting and breeding of insect-resistant pedigree. One-way path analysis method, with a certain degree of rationality and innovation in theory, was feasible in practice and worthy of research and popularization.