牛角花齿蓟马若虫持续为害对苜蓿生长的影响

以筛选扦插的抗蓟马无性系R-1和感蓟马无性系I-1为材料,测定了不同虫口密度牛角花齿蓟马若虫持续为害后苜蓿的受害指数及生长变化。结果表明:随着虫口压力的增大,R-1和I-1的受害指数均升高,但R-1的受害指数显著低于I-1(P0.05);受害后,R-1和I-1的株高,茎粗、节间长和叶面积均显著下降,在7头/枝条压力下,株高分别下降了33.44%和36.90%,茎粗分别下降了18.64%和28.98%,节间长分别下降了21.64%和23.60%,叶面积分别下降了23.39%和37.91%;受害后,R-1和I-1的节间数均显著持续增加,在5头/枝条压力下分别增加了29.85%和37.78%;在低虫口压力下,R-1和I-1的单株生物量显著上升,在高虫口压力下单株生物量显著下降。说明R-1、I-1在牛角花齿蓟马低虫口密度为害下产生补偿生长,在高虫口密度下表现为不足补偿。此次试验表明,抗蓟马无性系R-1受害后的各项生长指标和补偿生长能力均优于感蓟马无性系I-1。

Effect of Odontothrips loti nymphs sustainable damage on alfalfa growth

Effects of Odontothrips loti nymphs sustainable damage on damaged index and growth characteristics of the resistant (R-1) and susceptible (I-1) alfalfa were investigated in this paper.The results showed that the damage index of R-1 and I-1 alfalfa increased with Odontothrips loti nymphs population increasing,and the damage index of R-1 was significantly lower than that of I-1.The height,stem diameters,internode length and leaf area of alfalfa decreased significantly after being damaged by Odontothrips loti nymphs.In seven Odontothrips loti nymphs per branch,the height of R-1 and I-1 decreased by 33.44％ and 36.90％,respectively,while the stem diameter of R-1 and I-1decreased by 18.64％ and 28.98％.The internode length of R-1 and I-1 reduced by 21.64％ and 23.60％,respectively,while leaf area R-1 and I-1 reduced by 23.39％ and 37.91％.However,the node number of R-1 and I-1 increased by 29.85％ and 37.78％ in five Odontothrips loti nymphs per branch.The single plant biomass increased significantly in the low Odontothrips loti nymphs population per branch,but decreased significantly in the high Odontothrips loti nymphs population per branch.The agronomical traits and compensation growth of the resistant R-1 were better than that of susceptible I-1 alfalfa.