香梨优斑螟滞育特征及FADs基因表达规律研究

Euzophera pyriella Yang (Lepidoptera Pyralidae) is merely caused concern since the recent 20 years in Xinjiang, and it mainly damage fruit trees that are pear, apple, apricot and jujube. In particular, korlar pear has been destroyed worst, for the rate of trees suffering injury it is up to 100%. Larva bores the fruit, phloem of branches and trunk, causing severe economic loss of fruit farmers. E. pyriella can overwinter at different Instars of larva diapause, through data from the overwintering investigation and annual occurrence regularity, it was found that overwintering young larvae had high mortality. And combined with the difference of fatty acid and biology of larve, it was speculated that they may have different response strategy to environmental change. Therefore with the problem for diapause of the overwintering E. pyriella, our research team plans to study the relationship between larvae's cold-hardiness and the change trends of some major physiological and biochemical indicators, such as larvae's weight during the winter, water and sugar, fats, glycerin, protein, amino acids. It would compare the physiological and biochemical characteristics of diapause between in Turpan district and in alaer district. Then it should be researched on the relationship between fatty acid and diapause, and the relationship between cold resistance and FADs genes expression or unsaturated fatty acid. These are all in order to reveal the diapause mechanism of E. pyriella. We can apply the results of this research to judge whether E. pyriella is or not a alien species, and to reveal the catastrophe mechanisms of the pest in Xinjiang, providing theoretical support for the prevention and control system of the pest.

香梨优斑螟（Euzophera pyriella）属鳞翅目螟蛾科，近20年在新疆区域内才首次被人们关注，主要寄主有梨、苹果、杏和枣等。其中，香梨受害最重，受害株率达100%，幼虫可蛀食果实和枝干韧皮部，果农损失严重。香梨优斑螟能以不同龄期幼虫滞育越冬，根据冬季调查与全年成虫发生数据分析，发现低龄幼虫越冬过程中死亡率较高，结合越冬期幼虫脂肪酸组成和生物学差异推测，不同龄期幼虫对冬季环境变化可能有不同的响应策略。因此，针对香梨优斑螟越冬的滞育问题，开展滞育过程及非滞育时期幼虫的表型特征（生化指标、耐寒性、体重和含水量等）变化研究，比较南疆阿拉尔市与北疆吐鲁番市香梨优斑螟的滞育表形特征，并研究虫体脂类变化与滞育、耐寒性及FADs基因表达之间的关系，以探究香梨优斑螟的滞育机理。研究成果有助于揭示香梨优斑螟是否为外来物种及其成灾机制，为其构建科学防控体系提供理支持。

香梨优斑螟（Euzophera pyriella）属鳞翅目螟蛾科，近20年在新疆区域内才首次被人们关注，主要寄主有梨、苹果、杏和枣等。香梨优斑螟能以幼虫滞育越冬，针对香梨优斑螟越冬的滞育问题，开展滞育时期幼虫的表型特征变化研究香梨优斑螟的滞育特征，并研究虫体脂类变化与滞育、耐寒性及FADs基因表达之间的关系，以探究香梨优斑螟的滞育机理。香梨优斑螟幼虫滞育前期、滞育期和滞育后期在含水率波动较大，而总脂含量和甘油三酯含量，均呈先下降后上升的U型变化趋势；总糖含量呈下降趋势，直至次年2月中旬出现回升趋势；不饱和脂肪酸相对含量变化较大。通过转录组测序获得大量基因信息，研究了内参基因稳定性、FAS、FADs和HSPs等基因表达特征，初步明确了香梨优斑螟滞育特征。