Applied BioSciences, Macquarie University, Sydney, NSW, 2109, Australia.
Land and Water, CSIRO, Canberra, ACT, 2601, Australia.
BMC Genet. 2020 Dec 18;21(Suppl 2):135. doi: 10.1186/s12863-020-00935-2.
The highly polyphagous Queensland fruit fly (Bactrocera tryoni Froggatt) expanded its range substantially during the twentieth century and is now the most economically important insect pest of Australian horticulture, prompting intensive efforts to develop a Sterile Insect Technique (SIT) control program. Using a "common garden" approach, we have screened for natural genetic variation in key environmental fitness traits among populations from across the geographic range of this species and monitored changes in those traits induced during domestication.
Significant variation was detected between the populations for heat, desiccation and starvation resistance and wing length (as a measure of body size). Desiccation resistance was correlated with both starvation resistance and wing length. Bioassay data for three resampled populations indicate that much of the variation in desiccation resistance reflects persistent, inherited differences among the populations. No latitudinal cline was detected for any of the traits and only weak correlations were found with climatic variables for heat resistance and wing length. All three stress resistance phenotypes and wing length changed significantly in certain populations with ongoing domestication but there was also a strong population by domestication interaction effect for each trait.
Ecotypic variation in heat, starvation and desiccation resistance was detected in Australian Qfly populations, and these stress resistances diminished rapidly during domestication. Our results indicate a need to select source populations for SIT strains which have relatively high climatic stress resistance and to minimise loss of that resistance during domestication.
高度多食性的昆士兰果蝇（Bactrocera tryoni Froggatt）在 20 世纪大幅扩大了其分布范围，现已成为澳大利亚园艺业中最重要的经济昆虫害虫，促使人们积极努力开发不育昆虫技术（SIT）控制计划。我们采用“共同花园”方法，对该物种地理分布范围内的种群进行了关键环境适应性特征的自然遗传变异筛选，并监测了驯化过程中这些特征的变化。
在种群之间检测到耐热性、耐旱性和耐饥饿性以及翅膀长度（作为身体大小的衡量标准）的显著差异。耐旱性与耐饥饿性和翅膀长度相关。对三个重新取样的种群的生物测定数据表明，耐旱性的大部分变异反映了种群之间持久的、遗传的差异。任何特征都没有发现纬度梯度，并且仅发现耐热性和翅膀长度与气候变量之间存在弱相关性。所有三种应激抗性表型和翅膀长度在某些正在驯化的种群中发生了显著变化，但每个特征的种群与驯化的相互作用效应也很强。
在澳大利亚 Qfly 种群中检测到耐热性、耐饥饿性和耐旱性的生态型变异，这些应激抗性在驯化过程中迅速降低。我们的结果表明，需要选择具有相对较高气候应激抗性的 SIT 菌株的来源种群，并在驯化过程中尽量减少这种抗性的丧失。
