| Locusta migratoria tibetensis Chen is one of China’s three major subspecies of migratory locusts, It had made a big damage to the agriculture and animal husbandry, caused serious economic loss. In China, the correlational studies for L. migratoria tibetensis Chen mainly focused on the biological, ecological characteristics, prophylaxis and control, In addition, there is few reported about L. migratoria tibetensis Chen.We made a systematic study on affects of low temperature and light stress on cold resistance of L. migratoria tibetensis Chen and the differences of discontinuous gas exchange cycle between L. migratoria tibetensis Chen and L. migratoria manilensis (Meyen), results as follows:1. The adults of L. migratoria tibetensis Chen and L. migratoria manilensis (Meyen) were significantly lower than their nymphs in standard metabolic rateThe standard metabolic rate of adult of L. migratoria tibetensis Chen and L. migratoria manilensis (Meyen) all significantly lower than their 4th instar nymphs and 5th instar nymphs.4th instar nymphs of L. migratoria tibetensis Chen were significantly higher than its 5th instar nymphs, but 4th,5th instar nymphs of L. migratoria tibetensis (Meyen) had no significant differences in standard metabolic rate. More energy was using to the growth and development in instar nymphs of L. migratoria tibetensis Chen and L. migratoria manilensis (Meyen). In DGC duration, L. migratoria tibetensis (Meyen) adult males and 5th instar nymphs had no significant differences; adult males and 5th instar nymphs were significantly higher than its 4th instar nymphs. In DGC duration, L. migratoria tibetensis Chen adult males and 5th instar nymphs were significantly lower than its 4th instar nymphs,5th instar nymphs were higher than adult males but had no significant differences. In IBD/DGCD, L. migratoria tibetensis Chen and L. migratoria manilensis (Meyen) adult males and 5th instar nymphs were significantly higher than their 4th instar nymphs, but L. migratoria manilensis (Meyen) adult males were significantly lower than 5th instar nymphs, L. migratoria tibetensis Chen adult males were significantly higher than 5th instar nymphs.2. L. migratoria tibetensis Chen increased the DGC frequency and IBD/DGCD to adapt to the hypoxic environment plateau environmentThere were no significant differences between three stages (ages) of L. migratoria tibetensis Chen and L. migratoria manilensis (Meyen) in SMR. DGC durations of L. migratoria manilensis (Meyen) adult males and 5th instar nymphs were 14.443min and 15.700min, L. migratoria tibetensis Chen adult males and 5th instar nymphs reduced DGC durations to 8.533min and 7.463min, that is to say L. migratoria tibetensis Chen increased the DGC frequency to absorb enough O2to adapt to the hypoxic environment. IBD/DGCD of L. migratoria tibetensis Chen adult males was 0.792, significantly higher than L. migratoria manilensis (Meyen) adult males 0.536, this indicated that it not only could adapt to strong sunlight and drought environments better, but also could compensate the water loss of increasing DGC frequency. Body weight did not influence the DGC durations and IBD/DGCD in each age of L. migratoria tibetensis Chen and L. migratoria manilensis (Meyen).3. Low temperature and short light stress made fat, glycogen, glycerin, mannito, trehalose, sorbitol, ALA, GLU, LYS and PHE of adult of L. migratoria tibetensis Chen significant accumulateThe fat content of L. migratoria tibetensis Chen body had the highest vaule in short light without cold-hardening treatments, in turn reduced from short light with cold-hardening treatments, natural temperature and light control treatments, long light without cold-hardening treatments to long light with cold-hardening treatments. Except short light with cold-hardening group and control group had no significant differences, other groups had significant differences. Long light and cold-hardening made fat resolve, short light made fat significant accumulate.The glycogen content had the highest vaule in long light without cold-hardening treatments; in turn reduce from control treatments, short light without cold-hardening treatments to long light with cold-hardening treatments, short light with cold-hardening treatments had the lowest vaule. Long light made the content of glycogen increase, cold-hardening made glycogen decrease.In the glycerin content, short light with cold-hardening treatments> long light with cold-hardening treatments> short light without cold-hardening treatments> control treatments> long light without cold-hardening treatments. Short light and cold-hardening made glycerin significant accumulate.Compared fructose content, except long light without cold-hardening treatments, other treatments had no significant differences. Long light without cold-hardening treatments and control treatments had no significant differences but was significantly lower than other treatments. Mannito, trehalose, sorbitol content all had the highest vaule in short light with cold-hardening treatments, the lowest vaule in long light without cold-hardening treatments. Short light and cold-hardening made mannito, trehalose and sorbitol significant accumulate.In amino acid content, ALA, GLU and LYS had a high content, and in turn reduced from short light with cold-hardening treatments, long light with cold-hardening treatments, short light without cold-hardening treatments, control treatments to long light without cold-hardening treatments; PHE in turn reduced from short light with cold-hardening treatments, short light without cold-hardening treatments, control treatments, long light with cold-hardening treatments to long light without cold-hardening treatments. Compared the content of 4 amino acids by significant analysis, we could see that each treatment had significant differences. Although LEU had ahigh content, but each treatment had no significant differences, other kinds of amino acid in treatments were basically the same, change is not obvious. Short light and cold-hardening made ALA, GLU, LYS and PHE significant accumulate.4. Composition of cold-tolerant substances in the body of L. migratoria tibetensis ChenThe low-molecular carbohydrate (Mannito, trehalose and sorbitol)-amino acid (mainly by ALA, GLU, LYS and PHE)-glycerin was the cold-tolerant substances in L. migratoria tibetensis Chen.5. Influence of low temperature and light stress on the cold-tolerant substances in L. migratoria tibetensis ChenThe content of cold-tolerant substances in L. migratoria tibetensis Chen with cold-hardening were significantly higher than short light stress, and both cold-hardening and short light stress had the highest content. The increased of cold-tolerant substances in L. migratoria tibetensis Chen was dominated by cold-hardening, and short light stress played a synergistic role. |
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