韭菜迟眼蕈蚊的性别分化及其生态与进化意义

性别分化是遗传学、进化生物学和生殖行为生态学研究的重要领域之一,对于研究生物的遗传与进化关系、分析生物种群数量动态具有重要意义。对韭菜迟眼蕈蚊BradysiaodoriphagaYangetZhang的性别分化研究结果表明,韭菜迟眼蕈蚊的生殖对策主要以产单性别方式为主,其次是产优势性别方式,2种方式占92%,且产雌产雄的比例基本呈对称现象。用雌雄试虫都来自单性别的种群,连续繁殖3代,其性别分化如同上述,每一代种群的性比基本保持在1∶1。用双性别后代雌虫所产的雌雄虫进行近亲繁殖,连续繁殖3代,结果表明双性别后代的比例明显增大。鉴于以上实验结果,对韭菜迟眼蕈蚊生殖对策的生态与进化意义进行了分析。

Sex differentiation of Bradysia odoriphaga and the ecological and evolutionary significance

Sex differentiation is one of the important fields in genetics, evolutionary biology and reproductive behavioral ecology, and has a great significance in the study of the relationships between heredity and evolution and in the analysis of population dynamics. This paper reports a preliminary investigation on the sex differentiation of Bradysia odoriphaga Yang et Zhang. Ninety-two percent females of this insect produced progenies of only one sex or progenies predominated by one sex. When females and males from the unisexual progenies were crossed and their progeny reared for 3 successive generations, the pattern of sex differentiation was the same as described above and the sex ratio of each generation was kept at 1∶1. When females and males from bisexual progeny were crossed and their progeny reared for 3 successive generations (i.e. full-sib crosses), the proportion of females producing bisexual progenies increased. The ecological and evolutionary significance of this reproductive strategy of B. odoriphaga was discussed.