| Locusta migratoria tibetensis Chen is a branch of Orthoptera Locust (Acridoidea),a new subspecies named by Chen Yonglin in 1963.As its main food on plants of Gramineae,a serious reduction in production of grasses and highland barley took place in Tibet,Qinghai Yushu and Western Sichuan plateau every year.Presently,some scholars have done abundant researches on the ecology,biological nature and many other aspects of L. migratoria tibetensis,but they haven't analyzed or comment on the process of adaptability of the L. migratoria tibetensis in different environment,the distinguishing feature of adaptability of differentiation and some other important ecological problems.In order to probe the change situation of dynamical equilibrium of free radical in prosopon of the adult L. migratoria tibetensis,evaluate the adaptation response of it under the environmental stress and provide evidences for the analysis of the specific geographical distribution of it,we studied the temperature,the photoperiod and the light wavelength on the L. migratoria tibetensis's feeding and growth, anti-oxidative enzymes activity,soluble protein content and MDA which is the production of lipid peroxidation,and discussed the influence of the environment on its growth and development,we also studied how did it adapt to the change of the environment with its anti-oxidation system. Results as follows:1. Effects of environmental stress on the food intake and growthof L. migratoria tibetensis adultsThe growth and metabolism of the L. migratoria tibetensis have conspicuous temperature dependence,manifested as the trend that the food consumption, relative growth rate (RGR),eatable consuming rate(ECI) and eatable translating rate(ECD) increase as the temperature rises under 5-35℃,however,the reaction efficiency of approximately digestive rate(AD) reduces as the temperature rises.35℃is the best temperature for L.migratoria tibetensis's growth and digestion.Under the photoperiod stress,with the scale of 16L:8D,the food consumption is maximum,and for the female,it's the best photoperiod condition of growing,but with the scale of 12L:12D for the male.In terms of food consumption and energy conversion,8L-16L light can maintain good metabolic balance of L. migratoria tibetensis.Uv radiation significantly increases food consumption and RGR of adult L. migratoria tibetensis, manifested as follows:uvb treatment> uva treatment> visible light treatment>darkness treatment. Compared with darkness treatment,uv radiation can significantly increase ECI and reduce AD of L. migratoria tibetensis,but no significant influence on ECD.2. Effects of environmental stress on antioxidase activity in different parts of L.migratoria tibetensis adultsSOD(superoxide dismutase), POD(peroxidase) and CAT(catalase) under low and high temperature stress have different degrees,but at 45℃,the three kind of enzymatic activities all decrease significantly,even lower than CK.There is little remarkable relation between different photoperiod and the generation.The clear of ROS inside the L.migratoria tibetensis,manifested as the fact that the 3 kind of antioxidant enzyme activity change inconspicuously as the variation of the lighting duration. The influence of uva and uvb both within 24h and 72h on SOD activity inside the adult L. migratoria tibetensis is bigger than visible light. POD and CAT activity under 3 kind of wavelength treatment increase as the lighting time increases,especially,the impact of uvb on these two enzymatic activity is bigger than uva and visible light,manifested as follows:uvb treatment> uva treatment> visible light treatment. The test showed that oxidases change accordingly as the temperature and uv stress increase,and under the synergistic effect,oxidases resist against the damage of the organism by increasing active oxygen content.3. Effects of environmental stress on the soluble protein contents in L. migratoria tibetensis adultsThere is a notable difference between the sum and the contrast of the solved protein in L. migratoria tibetensis which under thermal threaten,except for the maximum 120.51mg·g-1 in female digestive tract under 45℃high temperature threaten,the female body wall,the male body wall and the male digestive tract all reach the maximum 170.54,158.21 and 115.55 mg·g-1 respectively under 5℃temperature stress.Under the photoperiod stress,compared with CK,the soluble protein content inside the adult L. migratoria tibetensis doesn't change significantly.Uv can greatly significantly increase the soluble protein content,and it is related to irradiation time.The test shows that the adversity stress makes L. migratoria tibetensis produce abundant stress protein.4. Effects of environmental stress on MDA content in different parts of L. migratoria tibetensis adultsMDA content inside the adult L. migratoria tibetensis under low and high temperature stress has different degree of increasing compared with CK.The content of MDA in female body wall,the female digestive tract,the male body wall and the male digestive tract all respectively reach the maximum in 5℃, they are 0.63,0.58,0.60和0.55nmol·g-1 FW. Under the photoperiod stress, MDA content under LD(long photoperiod) and SD(short photoperiod) treatment is conspicuously higher than that under MD(12L:12D) treatment. The optical wavelength indicated that uva and uvb can cause MDA content of the body wall to increase conspicuously, and there exists time effect on induction of lipid peroxidation.The content of MDA in female body wall,female digestive tract,male body wall and male digestive tract are separately reach the maximum 0.72,0.88,0.66和0.94 nmol/min/mg under uvb72h,uva72h,uva72h and uvb72h. The result shows that environmental stress can induce the L. migratoria tibetensis's lipid peroxidation reaction to cause degree of effect and time effect. Even though it has the protection of antioxidant system, partly damage can be still caused. |
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