关键词: 豌豆蚜, 竞争, 性比, 保幼激素3, 繁殖

Abstract: To investigate the effect of clonal interactions to sex differentiation in pea aphids. Three pea aphid clones (MS clone,PS clone,and Y clone) were used in this study. Firstly,the agar method was selected to induce sexuparae under low temperature and short-day light,and then using the sexupara of each clone to prepare a single aphid treatment and two-aphids treatment,as well as mixed clonal treatments consisting of different clones,and to investigate the daily aphid production of sexuparae,the sexual differentiation of the progeny,and the juvenile hormone III titer of sexuparae in each treatment. The results showed that in a single aphid treatment of the MS clone,the ratio of male to female progeny was about 1∶1,and the number of oviparous female aphids in the progeny increased and the number of male aphids decreased when the initial number of sexuparae was increased or coexisted with the non-self clone. When cohabitated with the MS clone,the PS clone exhibited a reduction in the count of oviparous females and males,alongside a marked increase in the population of viviparous aphids,in comparison to a single treatment,yet,the sexual differentiation observed in the progeny from the two-aphids treatment did not significantly deviate from that in a single aphid treatment. On the other hand,none of the Y clones showed significant differences in sex differentiation among treatments. The juvenile hormone III titer of sexuparae was negatively correlated with the number of male aphids,and positively correlated with the number of viviparous aphids. The findings of this study suggest that pea aphid sexuparae can adjust offspring sex ratios according to the type and density of peripheral clones to optimize their ecological fitness and gene transmission efficiency.

Key words: Acyrthosiphon pisum, Competition, Sex ratios, Juvenile hormone 3, Reproduction