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为检测东北地区亚洲玉米螟Ostrinia furnacalis滞育幼虫在越冬期间生理指标的变化情况以及各地理种群间抗寒能力的差异,采用热电偶法于2013年11月—2014年4月对北至黑龙江省黑河市、南到辽宁省瓦房店市的12个地理种群滞育幼虫的过冷却点、冰点、虫体含水量和脂肪含量进行了测定。结果表明,不同地理种群亚洲玉米螟过冷却点在-5~-25℃、冰点在-2.5~-15℃范围内,随着环境温度的变化,过冷却点呈先下降后上升的趋势,最低点出现在1、2月且随地理纬度的升高而降低。不同种群的虫体含水量在50%~70%之间,时序上呈先下降后上升的趋势,与环境温度、过冷却点变化趋势一致;最高含水量出现在4月,最低含水量随着地理纬度的降低而升高。不同种群的虫体脂肪含量在45%~70%之间,时序上呈先上升后下降的趋势;最高脂肪含量随着地理纬度的降低而降低。幼虫最低过冷却点、最低冰点与虫体最低含水量和最高脂肪含量均显著相关,相关系数分别为0.733、-0.736、0.643和-0.636。表明亚洲玉米螟滞育幼虫的抗寒性存在明显的地理分化,高纬度地区种群抗寒力强于低纬度地区种群,幼虫减少体内含水量、增加脂肪积累是提高其抗寒能力的重要生理变化。
In order to detect the change of physiological index of Ostrinia furnacalis diapause larvae in northeastern China during winter and the difference of cold tolerance ability between geographic populations, thermocouple method was used to measure the change of diapause larvae from November 2013 to April 2014 in Heilongjiang Province The subcooling point, freezing point, water body and fat content of diapause larvae of 12 geographic populations in Heihe City and south to Wafangdian City in Liaoning Province were measured. The results showed that the subcooling points of Asian corn borer (Oryza sativae) in different geographic populations ranged from -5 to -25 ℃ and the freezing point ranged from -2.5 to -15 ℃. With the change of ambient temperature, the subcooling point showed the tendency of first descending and then increasing and the lowest The point appears in January and February and decreases with increasing geographic latitude. The body water content of different populations was between 50% and 70%, which showed the trend of decreasing firstly and then increasing with the trend of environmental temperature and subcooling point. The highest water content occurred in April and the lowest water content was Geographic latitude decreases and increases. The body fat content of different species ranged from 45% to 70%, and the timing showed the trend of first rising and then decreasing; the highest fat content decreased with the decrease of geographical latitude. The minimum supercooling point and the lowest freezing point of larvae were significantly correlated with the lowest water content and the highest fat content of the parasites. The correlation coefficients were 0.733, -0.736, 0.643 and -0.636, respectively. The results showed that the cold tolerance of Asian corn borer diapause larvae had obvious geographical differentiation. The cold resistance of high latitude population was stronger than that of low latitude population. The larvae reduced the body water content and increased the fat accumulation, which were the important physiologic changes to improve their cold resistance ability .