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Effects of Trichlorfon on Reproduce Biology and the Esterase Activity of Pardosa Pseudoannulata

Author: ZhangZuZuo
Tutor: ZhuWeiPing；WangZhi
School: Hunan Agricultural University
Course: Cell Biology
Keywords: Trichlorphon Pardosa pseudoannulata growing development reproduction Acetylcholinesterase Carboxylesterase
CLC: S481
Type: Master's thesis
Year: 2009
Downloads: 25
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Abstract

A long-term and frequent use of organophosphorus pesticide has destroyed the function of pest ecological adjustment and broken the balance of ecosystem, so the ecological control was given more attention.. Pardosa pseudoannulata is a dominant spider in the rice field and of great significance in pest control. Thus, in this paper the effect of trichlorfon, a kind of organophosphorus pesticide, on the esterase activity and Pardosa pseudoannulata’s growth, development and reproduction at different developmental stages was studied by the way of raising drosophila under trichlorphon and using them for spider feeding. And a theoretical basis was provided for the reproductive biology of Pardosa pseudoannulata and the potential of insects-control’s maximization. The main results are as follows:1. Through the study of Pardosa pseudoannulata’s the insect-control power under trichlorfon with different concentration, the results show that the power arrives at its peak when the concentration is 1:10500.2. The growth and development of Pardosa pseudoannulata were obviously inlluenced by trichlorphon. The results show that the spiderling period was longer for 8 to 32 days within which the duration is longer in the 1st to the 3rd instar, and shorter in the 4th to the 8th instar. Spiders fed drosophila which sprayed by pesticide have faster growth and weight gain than those which are not after the 3rd instar.3. By spectrophotometry and acid base titration, the effect of trichlorfon on protease and lipase activities of Pardosa pseudoannulata at different developmental stages was researched. The results showed that the low-dose trichlorfon could enhance the activity of digestive enzyme in spiders. This activation promoted digestion, which was good for their growth and development.4. Through the method of anatomy and histological sections, the ovarian development was studied. According to the morphology of nuclei, nucleoli and the vitelline accumulation, the oocyte dvelopment was divided into four phases:the oogonium phase, the oocyte phase during yolk synthesis, the premature stage and the mature stage. Because of the trichlorphon, the ovary’s length and width of spiders as well as their egg length were smaller than those without the influence of pesticide. Besides, the former have less ovum and significant atrophyofovary with weaker recovery capability after spawning.5. The effect of pesticide on the fecundity of Pardosa pseudoannulata was studied. The spiders’reproduction was restrained by pesticide to some degree. It is found that one egg sac of the female spider has 118.2 eggs on average which is less than 132.2 eggs of the control group. As for the ovipositing, hatching and survival rate in the 1st instar, the former are 75.1%,75.8%and 73%, which was lower percentage than the latter with 76.6%, 80.5% and 81%.6. The effects of the pesticide on activity of acetylcholinesterase(AChE) and carboxylesterase(CarE) in Pardosa pseudoannulata at different developmental stages were systemically studied by spectroscopy. In the 2nd and the 6th instar, the activity of AChE in the adult female spider are 2.471 nmol·mg~-1·min~-1,5.352 nmol·mg~-1·min~-1, 4.529 nmol·mg~-1·min-~l and are weaker than 3.178 nmol·mg~-1·min~-1,6.259 nmol·mg~-1·min~-1,5.404 nmol·mg~-1·min~-1 of the control group. As for the CarE in this period, the former were 4.295 nmol·-mg~-1·min~-1,6.435 nmo·mg~-1·min~-1,4.342 nmol·mg~-1·min~-1 and were stronger than that of the latter with 3.069 nmol·mg~-1·min~-1, 4.546 nmol·mg~-1·min~-1,3.387 nmol·mg~-1·min~-1. In the whole development process of Pardosa pseudoannulata, the specific activity of these two kinds of enzyme was the highest at their 6th instar body. The result indicated the spiders fed drosophila may raise the resistance to some pesticides.7. The method of differential centrifugation was used to separated the subcellular structure of Pardosa pseudoannulata and the distribution of AChE and CarE in the subcellular structure of Pardosa pseudoannul at different development stages was studied. Results showed that AChE was mainly distributed in cell nucleus, cell debris, mitochondrion and microsome in the form of membrane-bound protein. CarE in the cytoplasm soluble in the form of state solution. Both of them would distribute differently under the effect of trichlorphon. The percentages of AChE specific activity of membranous structure in the 2nd instar under pesticide compared with those under no pesticide are 84.9% and 89.8%, while 87.7% and 90.2% in the 6th instar,88.2% and 89.8% in the female adult. The percentages of CarE specific activity of cytosol fraction in the 2nd instar were 52.4%and 43.6%, while 50.6% and 45.6% in the 6th instar,51.5% and 44.7% in the female adult.8. The vertieal slab polyacrylamide gel electrophresis technology was used to study the esterase isoenzymes of Pardosa pseudoannulata at different developmental stages under pesticide and no pesticide. The results suggested that there were significant differences existed at different development stages. The number of band patterns was the biggest in the 6th instar with a trend of less-more-less. The trichlorphon also increased the concentration of enzyme and its belt.

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