Study On Physiological Effects Of Feeding On Different Varieties Of Tea Tree On Ectropis Oblique Prout And Gut Endogenic Fungi Of The Caterpillar

Ectropis oblique Prout, a primary pest of tea, periodically appears in our country’s major tea areas, seriously affecting both the quality of tea and the growth of tea trees. By testing the growth and development, the related physiological indicators, the nutrients and secondary metabolites, and the activities of defense enzymes and the abilities of producing intestinal fungal enzyme for the Ectropis oblique Prout larvae which grew in six cultivars of tea trees including Shangmeizhou, Quntizhong, Huangdan, Funyunliuhao Fudingdabai and Tieguanyin, this study explored the Ectropis oblique Proul’s defense and adaptation to tea trees, and summarized the relevant factors those affect the growth of the Ectropis oblique Prout, providing a basis for its biological control. The main results are as follows:1) Ectropis oblique Prout growing in Shangmeizhou has the shortest developmental period, the largest feeding area, the heaviest and longest body, and the highest survival rate, while the pupation rate of larvae and the emergence rate of pupa have no significant regularity; the relative growth rate, the relative feeding rate and the approximate digestibility, similar to the results of the feeding area, the body weight and the body length, reach the peak in the period of 2nd-3rd instar. and the largest ratio is for Shangmeizhou. while the smallest for Tieguanyin; the food conversion and utilization, which gradually increase along with the larvae’s instar. reach the largest at the end of the fifth instar. while the relative metabolic rate decreases.2) The higher water content and polysaccharide content are more suitable for insect growth, while the higher amino acids content, polyphenols content, caffeine content and flavonoid content are not; Shangmeizhou’s result differs significantly from others":its amino acids content and polyphenols content are the highest in the leaf; and the lowest in the feces, the larvae have a better adaptation to Shangmeizhou.3) The changes of the four kinds of defense enzymes. PPO. SOD, POD. CAT, have no certain regularity, but each enzyme varies significantly at different time; according to the overall change in four kinds of defense enzymes, the PPO and CAT in larvae of Shangmeizhou reach the maximum when defense enzyme makes the maximum effect, indicating that the Shangmeizhou larvae’s defense and adaptation are the strongest.4) One kind of fungus which can produce polyphenol oxidase, named WY-22, is isolated from the gut of Ectropis oblique Prout in Shangmeizhou. Based on morphological and molecular biology internal transcribedspacer (ITS) sequences, the strain WY-22 is identified as Basidiomycetes Cerrena sp. By optimizing medium components and liquid fermentation condition for polyphenol oxidase production through single-factor and orthogonal experiment, the WY-22’s activity of producing polyphenol oxidase increases by 11.749 times.