Miyatake T
Okinawa Prefectural Agricultural Experiment Station, 4-222 Sakiyama-cho, Naha, Okinawa 903, Japan.
Heredity (Edinb). 1997 Jan;78(Pt 1):93-100. doi: 10.1038/sj.hdy.6880900.
The response to selection on age at reproduction was measured to test for a genetic trade-off between early fecundity and longevity in the melon fly Bactrocera cucurbitae (Coquillett). Three replicate lines were selected for propagation by breeding from young (Y-lines) and old (O-lines) adults, respectively. Selection was continued for 24 and 9 generations for Y- and O-lines, respectively. Females from O-lines lived longer than Y-line females as an indirect response to selection, indicating that longevity is a trait under genetic control. Females from Y-lines had higher fecundity early in the lifespan, a shorter preoviposition period, and a shorter prepeak fecundity period than females from O-lines. However, total fecundity did not differ between lines from the two selection regimes. These results suggest the existence of a genetic trade-off between early fecundity and longevity in the population examined, which may be controlled by pleiotropy. The larval period of the O-lines was longer than that of the Y-lines, whereas there were no significant effects of selection regime on egg hatchability or preadult survival rate. The trade-off relationship between early fecundity and longevity is discussed in relation to mass production of the melon fly for the sterile insect technique programme.
为了测试瓜实蝇（Bactrocera cucurbitae (Coquillett)）在繁殖年龄选择上的反应，以检验早期繁殖力和寿命之间的遗传权衡。分别从年轻成虫（Y系）和老龄成虫（O系）中选育，建立了三个重复品系用于繁殖。Y系和O系分别持续选育了24代和9代。作为选择的间接反应，O系的雌蝇比Y系的雌蝇寿命更长，这表明寿命是一个受遗传控制的性状。Y系的雌蝇在寿命早期具有更高的繁殖力，产卵前期更短，繁殖力高峰期前的时期也比O系的雌蝇短。然而，两种选择方案的品系之间总繁殖力没有差异。这些结果表明，在所研究的种群中，早期繁殖力和寿命之间存在遗传权衡，这可能受基因多效性控制。O系的幼虫期比Y系长，而选择方案对卵孵化率或成虫前存活率没有显著影响。结合瓜实蝇在不育昆虫技术计划中的大量繁殖，讨论了早期繁殖力和寿命之间的权衡关系。
