›› 2014, Vol. 57 ›› Issue (7): 745-753.

• 研究论文 •    下一篇

轮纹异痂蝗卵的过冷却能力与其体内水分和生化物质含量的关系

李娜, 周晓榕, 庞保平* , 王振   

  1. (内蒙古农业大学草地昆虫研究中心, 呼和浩特 010019)
  • 出版日期:2014-07-20 发布日期:2014-07-20

Supercooling capacity in relation to the contents of water and biochemical substances in eggs of Bryodemella tuberculatum dilutum (Orthoptera: Oedipodidae)


LI Na, ZHOU Xiao-Rong, PANG Bao-Ping*, WANG Zhen   

  1. (Research Center for Grassland Insects, Inner Mongolia Agricultural University, Hohhot 010019, China)
  • Online:2014-07-20 Published:2014-07-20

摘要:
【目的】低温是影响昆虫生长发育和存活的关键因子之一。为明确轮纹异痂蝗Bryodemella tuberculatum dilutum卵的抗寒性及其机理, 研究了其过冷却能力与其体内水分及其他抗寒性相关生化物质含量的关系。【方法】采用热电偶法测定了轮纹异痂蝗卵的过冷却点,同时采用烘干法、残余法、氨基酸自动分析仪和高效液相色谱法分别测定了其卵的含水量、脂肪、氨基酸及小分子糖醇的含量。【结果】土壤含水量对轮纹异痂蝗滞育前卵的含水量、脂肪含量(鲜重)及过冷却点有极显著的影响(P<0.01)。随着土壤含水量从4%增加到13%,卵含水量从45.12%上升到55.25%,卵脂肪含量(鲜重)从10.39%下降到9.39%,而过冷却点从-30.11℃上升到-25.69℃。不同发育阶段卵的过冷却点、含水量、脂肪、氨基酸及小分子糖醇含量存在极显著差异(P<0.01)。从卵产下当天至120 d,卵过冷却点从-26.78℃下降至-30.18℃,含水量从51.93%下降至46.69%,脂肪含量分别从9.99%(鲜重)和17.37%(干重)上升至13.92%(鲜重)和25.29%(干重)。滞育卵的过冷却点显著低于滞育前卵的过冷却点。从卵中共检测到17种氨基酸,其中5种与过冷却点存在显著的相关关系(P<0.05)。卵过冷却点随着甘氨酸和脯氨酸含量的升高而降低,而随着胱氨酸、亮氨酸及天冬氨酸含量的增加而升高。随着卵的发育,海藻糖、甘油、肌醇和山梨醇含量逐渐上升,而葡萄糖和果糖含量逐渐下降。在卵发育过程中,海藻糖和甘油的含量显著高于其他4种物质的含量。卵过冷却点与上述6种小分子糖醇均存在显著的相关关系,其中与海藻糖和葡萄糖的相关性最强。过冷却点随海藻糖、甘油、肌醇和山梨醇含量的升高而降低,而随葡萄糖和果糖含量的升高而上升。【结论】轮纹异痂蝗卵在发育过程中,通过降低含水量,积累脂肪、脯氨酸、甘氨酸及海藻糖、甘油、肌醇和山梨醇等抗寒物质,从而提高其过冷却能力。

关键词: 轮纹异痂蝗, 抗寒性, 过冷却点, 脂肪, 氨基酸, 小分子糖醇

Abstract: 【Aim】 Low temperature is one of the key factors affecting the growth, development and survival of insects. In order to clarify the cold hardiness of Bryodemella tuberculatum dilutum eggs and its mechanisms, we investigated the relationship between supercooling capacity and the contents of water and biochemical substances related to cold resistance in eggs in the laboratory. 【Methods】 The supercooling points (SCPs) were measured by thermocouple method, and the contents of water, fat, amino acids, low molecular sugars and polyols were determined by oven-drying method, residue method, automatic amino acid analyzer and high performance liquid chromatograph (HPLC), respectively. 【Results】 Soil water contents significantly influenced the SCPs, and water and fat contents in the pre-diapause eggs (P<0.01). Water content in eggs increased from 45.12% to 55.25% and fat content (fresh weight) decreased from 10.39% to 9.39%, whereas the SCP rose from -30.11℃ to -25.69℃ with the increase of soil water content from 4% to 13%. The SCPs and the contents of water, fat, amino acids, low molecular sugars and polyols in eggs had extremely significant differences among different developmental stages (P<0.01). From 1 to 120 d after oviposition, the SCP decreased from -26.78℃ to -30.18℃, water content declined from 51.93% to 46.69%, whereas fat content increased from 9.99% (fresh weight) and 17.37% (dry weight) to 13.92% (fresh weight) and 25.29% (dry weight),respectively. The SCPs of diapause eggs were significantly lower than those of pre-diapause eggs. Seventeen amino acids were detected in eggs, five of which were significantly correlative with the SCPs (P<0.05). The SCPs declined with the increase of glycin and proline contents whereas increased with the increase of cystine, leucine and aspartic acid contents. With the egg development, the contents of trehalose, glycerol, myo-inositol and sorbitol increased, whereas the contents of glucose and fructose decreased. The contents of trehalose and glycerol were much higher than those of the other low molecular sugars and polyols in the developmental process of eggs. There were significant correlations between the SCPs and contents of six low molecular sugars and polyols, among which trehalose and glucose contents were the most correlative with the SCPs. The SCPs decreased with the increase of trehalose, glycerol, myo-inositol and sorbitol contents whereas increased with the increase of glucose and fructose contents. 【Conclusion】 In the developmental progress of B. tuberculatum dilutum eggs, the supercooling capacity is enhanced by the reduction of water content and the accumulation of cryoprotectants such as fat, glycin, praline, trehalose, glycerol, myo-inositol and sorbitol.

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