Effects Of A Plant Immunity Regulator On Rice Yield And Disease Control

Controlling the harmful biological damage by improving the crops itself immunity is one of the most effective ways of the integrated plant disease management and the agriculture sustainable development. PDV, a 33-aa variant from 62-94 derived from modifying HpaGxooc produced by Xanthomonas oryzae pv. oryzicola, 3.63 kD in size, or 9.93 kD with His-tag, is a new type non-specificity plant immunity regulator with characteristics of small molecular weight, high activity, no side effect, can improve rice resistance against rice blast, rice blight and enhance defense ability to stem borer and hopper, ,suppress chlorophyll decompose, promote photosynthesis and growth, increase the crop yield. Our research report that using plant signal factor PDV as experimental biology preparation in 10 indica and japonica rice cultivars at Yunnan province to analyze its influence on rice productivity, controlling blast and leaf blight depending on different cultivars, using density or time, by three seasons experiment in three years. The results are as follow:1.Using PDV on the indica, japonica rice cultivar can increase grain yield in density scope 120u g/ml～1200u g/ml. In indica rice, spraying with PDV at the seedling stage and tiller initial period at 400u g/ml～800u g/m is best, but in Japonica rice at turning green later period and a beginning ear of time at 400u g/ml～800ug/m production increase effect is obvious. Compared with control the production increase scope is 8.4～23.4%2.Using PDV on the indica, japonica rice cultivar can obviously control rice blast and leaf blight. On the both the rice cultivars spraying PDV with 800u g/ml at beginning ear of time is suitable, but higher concentration (1200u g/ml) has no obviously effects on disease incidence and severity. On susceptive cultivar PDV has the same controlling disease effect comparing with agricultural chemicals. But on resistant or middle-resistant cultivar, PDV has no obvious effect on controlling disease.3.Using PDV on rice in the small plot indicate that on susceptive indica or japonica cultivar, PDV improves yield 7.1-13.6% compare with control, and have same yield comparing agricultural chemicals. The disease severity decrease about 4-8 fold compared with control, and have same effect with agricultural chemicals.