Cold tolerance and trehalose accumulation in overwintering larvae of the codling moth, Cydia pomonella (Lepidoptera: Tortricidae)
Cold tolerance and trehalose accumulation in overwintering larvae of the codling moth, Cydia pomonella (Lepidoptera: Tortricidae)
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DOI：
10.14411/eje.2007.057
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发表时间：
2007-07-25
影响因子：
1.3
通讯作者：
Barzegar, Mohsen
中科院分区：
文献类型：
--
作者：
Khani, Abbas;Moharramipour, Saeid;Barzegar, Mohsen
研究了田间采集的冷蛾幼虫过冷点、低温存活率和含糖量的季节变化。野外采集的幼虫过冷点从2004年8月的-13.4℃（取食幼虫）下降到2004年12月的-22.0℃（越冬幼虫）。在-20℃/24 h条件下，初秋的存活率为0%，而在冬季则增加到约60%。低温存活期与过冷点密切相关。9月至10月，滞育幼虫的过冷点从-16.9℃降至-19.7℃，幼虫离开食物来源结茧。对于早滞育幼虫，5℃/30 d的暴露有额外的作用，将过冷点从-19.7℃降低到-21.3℃。越冬幼虫暴露于5℃1个月，滞育早期幼虫死亡率为23%，而驯化后的滞育幼虫死亡率仅为4%。越冬幼虫在冬季积累海藻糖。滞育开始时的海藻糖含量（5.1 mg/g鲜重）和滞育完全发育时的海藻糖含量（18.4 mg/g鲜重）在1月份增加了约3倍。海藻糖含量与过冷性、低温成活率和耐冷性相关，表明海藻糖可能在该物种的耐冷性发育中起一定作用。
Seasonal variations in the supercooling point, survival at low temperatures and sugar content were studied in field-collected codling moth larvae. The supercooling point of field-collected larvae decreased significantly from a mean value of -13.4 degrees C in August 2004 (feeding larvae) to -22.0 degrees C in December 2004 (overwintering larvae). Survival at -20 degrees C/24 h was 0% during early autumn, whereas it increased to approximately 60% during winter. The survival at low temperature was well correlated with the supercooling point. The supercooling point of the diapause destined larvae decreased from -16.9 to -19.7 degrees C between September and October as the larvae left the food source and spun a cocoon. For early-diapause larvae, exposure to 5 degrees C/30 days has an additional effect and decreased the supercooling point from -19.7 to -21.3 degrees C. One-month exposure of overwintering larvae to 5 degrees C led to a mortality of 23% in early diapause larvae, while only 4% of diapause larvae died after acclimation. Overwintering larvae accumulated trehalose during winter. There was approximately a threefold increase in trehalose content between larvae at the onset of diapause (5.1 mg/g fresh weight) and larvae in a fully developed diapause (18.4 mg/g fresh weight) collected in January. Trehalose content was correlated with supercooling capacity, survival at low temperatures and chilling tolerance, suggesting that trehalose may play some role in the development of cold tolerance in this species.