灰飞虱长、短翅型品系对高、低温的适应能力差异

Difference in the adaptability of the long-and short-winged strains of Laodelphax striatellus(Hemiptera:Delphacidae) to high and low temperatures

【目的】灰飞虱Laodelphax striatellus种群存在长翅和短翅个体,其翅型分化受遗传和环境条件的影响。本研究旨在明确经连续定向选育的灰飞虱长、短翅型品系对高、低温的适应能力差异。【方法】在室内分别长期定向筛选63和65代建立灰飞虱长、短翅型品系,并在南京田间采集灰飞虱自然种群;分别在25℃,30℃和35℃恒温条件下测定上述灰飞虱长、短翅型品系和自然种群的繁殖力、存活率和发育历期,测定若虫在5℃和-20℃下的存活率以及若虫和成虫的过冷却点,通过品系间存活率、发育历期、生殖力和过冷却点的比较分析,确定灰飞虱长、短翅型品系对高温和低温的耐受能力。【结果】在25℃,30℃和35℃下,灰飞虱自然种群雌成虫的繁殖力均显著高于室内筛选后的长、短翅型品系,而长、短翅型品系雌成虫之间的繁殖力均无显著差异;长、短翅型品系的繁殖力在25℃和30℃之间均无显著差异,但自然种群在25℃下的繁殖力显著高于30℃条件下的繁殖力;35℃下长、短翅型品系基本无若虫产生。25℃下长翅型品系、短翅型品系和自然种群若虫的存活率无显著差异,但在30℃下,短翅型品系若虫的存活率显著低于自然种群,而与长翅型品系差异不显著;35℃下长、短翅型品系的若虫最长只能存活到3龄,且两品系间无显著差异,而自然种群可存活到5龄。25℃下,短翅型品系若虫的发育历期显著短于自然种群,而与长翅型品系无差异;但是在30℃下,短翅型品系若虫历期显著长于长翅型品系和自然种群。长翅型品系、短翅型品系和自然种群灰飞虱3-4龄若虫在5℃低温下的存活天数无显著差异,并且长翅和短翅型品系在-20℃极端低温下暴露10 min后其死亡率也无显著差异且均显著高于自然种群。3个品系(种群)成虫的过冷却点无显著差异,但5龄若虫的过冷却点表现为短翅型品系显著高于自然种群,而与长翅型品系无显著差异。【结论】经连续定向选育的灰飞虱长、短翅型品系对低温和高温的适应力基本相当,且低于自然种群。在高温条件下灰飞虱短翅型品系的发育速率低于长翅型品系。

【Aim】There are long-winged and short-winged morphs in populations of the small brown planthopper(SBPH),Laodelphax striatellus.The wing morphs of SBPHs are affected by the genetic and environmental factors.The aim of this study is to illustrate the adaptability of the long-winged and short-winged strains of SBPHs to high and low temperatures.【Methods】The selection of long-winged and short-winged strains in SBPHs was performed under a constant condition,and the strains with long and short wings were set up after 63 and 65 generations of selection,respectively.The fecundity,survival rates and developmental duration of populations of the long-winged and short-winged strains and a wild population collected from rice filed in Nanjing were measured at 25,30 and 35℃.The survival rates of nymphs of these three populations were measured after exposure to 5℃and-20℃.The supercooling points of nymphs and adults of these three populations were also measured.The adaptability of long-winged and short-winged strains to high and low temperatures was analyzed by comparing the survival rate,developmental duration,fecundity and supercooling point.【Results】The fecundity of the female adults of the long-winged and short-winged strains of SBPH was significantly lower than that of the wild population at 25,30 and 35℃,and there was no significant difference in the fecundity between the short-winged and long-winged strains.The fecundity of the female adults of the short-winged or long-winged strain at 25℃was not significantly different than that at 30℃,but the fecundity of the female adults of the wild population at 25℃was significantly higher than that at 30℃.At 35℃,the short-winged and long-winged strains hardly produce nymphs.The nymphal survival rate at 25℃was similar among the short-winged strain,long-winged strain and wild population.But at 30℃,the nymphal survival rate of the short-winged strain was significantly lower than that of the wild population,and there was no significant difference in the nymphal survival rate between the short-winged and long-winged strains.At 35℃,the nymphs of the short-winged and long-winged strains only survived to the 3rd instar,but the nymphs of the wild population could survive to the 5th instar.The nymphal duration of the short-winged strain at 25℃was significantly shorter than that of the wild population,but did not differ from that of the long-winged strain.At 30℃,however,the nymphal duration of the short-winged strain was significantly longer than those of the long-winged strain and the wild population.The survival days of the 3rd-4th instar nymphs of the long-winged strain were not different from those of the short-winged strain and the wild population at 5℃.The mortality rates of nymphs of the long-winged strain and the short-winged strain after exposure to-20℃for 10 min showed no significant difference,but were significantly higher than that of the wild population.The supercooling points of adults were not significantly different among the short-winged strain,long-winged strain and wild population.However,the supercooling point of the 5th instar nymphs of the short-winged strain was significantly higher than that of the wild population,but showed no significant difference from that of the long-winged strain.【Conclusion】The adaptability of the long-winged and short-winged strains of SBPH to high and low temperatures is similar but lower than that of the wild population.The nymphal development of the short-winged strain of SBPH is slower than that of the long-winged strain under conditions of high temperature.