| This paper studied the character of community structure in BT transgenic pest-resistance cotton, rule of pest occurrence, control effect to cotton bollworm by the pest-resistance cotton, rule of occurrence and transfer in difference field, technology about prevention and cure in BT transgenic pest-resistance cotton during 1998-2000. The main contents and conclusion are as follows:1. Investigated the species component in the BT transgenic pest-resistance field. 51 species of insect were found, 18 species more than that in common cotton field. Analysised relative abundance of category of insect community in BT transgenic pest-resistance cotton field. Cotton aphid, cotton spider mite, tobacco thrips, tobacco whitefly, and American leafminer. The amount of the other pest in BT transgenic pest-resistance cotton field went up while the amount of cotton bollworm community fell down. Among the natural enemy of the pest, relative abundance of genus such as ladybug, Chrysopas, spider etc kept ahead. The amount of predacity natural enemy increased than that in non-pest-resistance cotton field. Compare with the amount of non-pest-resistance cotton field, except the autoecious bee of aphis which had higher relative abundance, the abundance of other specious was lower.2. In accordance with the index number of the community character of insect community and species, such as richness, diversity, uniformety and so on, structure character of the time pattern of insect community in BT transgenic pest-resistance cotton field was studied. Result appeared that in BT transgenic pest-resistance cotton field, to the dominance of the pest and nautre enemy in different period , insects amount of dominant species increased or decreased alternatively.3. Space ecosphere, total space ecosphere, time ecosphere, width and superposition degree of time-space ecosphere of the mainly pest and nature enemy on the time sequence in BT transgenic pest-resistance cotton field werestudied. Result appeard that, on time sequence, ecosphere of pest and nature enemy in 33B cotton field was dynamic. With time passage, the width of ecosphere expanded or shrank. Pest and nature enemy had good in space.4. In accordance with the analysis and date of investigation on pest system of pest-resistance cotton, regulation of occurrence of cotton bollworm and pest in BT transgenic pest-resistance cotton field were studied.5. Through the study on control effect of BT transgenic pest-resistance cotton, there's indications that the capacity of pest-resistance remained difference among different apparatus. The order of the capacity of pest-resistance from strong to feeble was that: tender leaf, mature leaf, bud, flower(bell). To the different generation, the capacity of pest-resistance of the pest-resistance cotton diversity. The order of the capacity of pest-resistance from strong to feeble was that: second generation, third generation, fourth generation.6. In accordance with the inquisitional result of distributing of cotton bollworm in BT transgenic pest-resistance cotton and in other field, the quantity of the eggs in cotton field of second, third, fourth generation cotton bollworm account for 96.25%, 80.63% and 56.73% of total eggs. The quantity of cotton bollworm of each generation account for 39.13%, 36.59% and 5.16% of total cotton bollworm. This indicated that the quantity of eggs in the cotton field was large. And cotton was still the principal plant. Other field had become the principal base of cotton bollworm for cotton field.7. In accordance with the structure character and regulation of occurrence of pest and the analysis of anti-pesticide of the insect community in BT transgenic pest-resistance cotton field, combine with the experiment on protection and cure of pesticide, and the experiment of process term, the tactic of prevention and cure and competitive measure of prevention and cure of the pest in BT transgenic cotton field was brought forward.
|
PDF Full Text Request