Effects Of The Ester Compounds On Physiological Characteristics And Soil Micro-ecology In Grafted Watermelon

Watermelon (Cirrullus lanatus) belongs to Cucurbitaceae (Cucurbitaceae) watermelon (Citrullus), annual herbaceous vine, is an important economic crop in China. But due to the watermelon growing area, especially the cultivated area under greenhouse condition, and waterme Ion prone to continuous cropping obstacles. Studies have shown that allelochemicals the accumulation will lead to continuous cropping obstacle of watermelon. In actual production, people use grafting to alleviate Autotoxicity of watermelon. Some research pointed out that the grafted watermelon root exudates in the change of material, change of watermelon allelopathy, alleviate the continuous cropping obstacle. Therefore. the subject of allelochemicals on Grafted Watermelon composition, selection of DOP, DIBP. Allelochemicals in order from watermelon and grafted watermelon growth, angle of physiological characteristics and soil biochemical properties revealed esters compounds allelopathic substances of grafted watermelon watermelon and mechanism and grafting to alleviate the mechanism in watermelon autotoxicity and lay a theoretical basis for the further improvement of grafted watermelon yield increasing mech anism. The research results are as follows:(1) Two substances are of watermelon seedlings \"low to promote high suppression\" allelopathy characteristics of DOP best promote the concentration of watermelon seedlings is the tendency for 0.1/L, DIBP best promote concentration is the tendency for 0.05/L, the concentration in greater than 1 tendency when L have inhibition; Two substances under the treatment of SOD, POD, CAT activity in 5 d,10 d all have varying degrees of increase, of which 10 d promote the strongest, in dealing with 15 d, SOD, POD. CAT activity decreased significantly, the MDA content significantly increased when dealing with 15 d:DOP, DIBP processing makes the pro content increased to different extent, DOP d 15 pro content increased significantly under the handle, DIBP 10 d under the treatment of pro content increased significantly. Watermelon leaf pro content increased with the increase of the concentration of rising; A high concentration of ester compounds material after processing, the watermelon leaf antioxidant enzyme activity, plant growth is restrained.(2) Under different concentrations of DOP, DIBP processing watermelon leaf chlorophyll a and chlorophyll b content of chlorophyll a/b have a certain degree of increase:Under the DOP, DIBP processing, from the roots of watermelon and grafted watermelon stomatal conductance, intercellular CO2 concentration and improve, show that ester compounds can promote watermelon photosynthetic efficiency, one of the grafted watermelon three indicators are higher than the root watermeion. suggests that under the action of ester compounds are material, grafted watermelon photosynthetic efficiency than those from the roots of watermelon.(3) Under the DOP, DIBP processing, from the roots of watermelon and grafted watermelon and Fo a certain degree of rise, since the root watermelon Fv/Fm decline and were lower than control. Fv/Fm of grafted watermelon are processed with DOP, DIBP concentration increases the trend of first increased and then drop, show that in low concentration of ester compounds are material, under the action of grafted watermelon original light energy conversion rate is higher than the root watermelon. Deal with the low concentration of DOP, DIBP make the root, grafted watermelon NPQ has a certain degree of decline, but when the concentration>tendency for 0.5/L, NPQ to rise significantly, that sense of appropriate concentration of ester compounds material can reduce watermelon for heat dissipation, improve the energy conversion rate. When the concentration of DOP, DIBP treatment tendency for 0.05/L, the root of watermelon, grafted watermelon qP have dropped significantly, the electron transfer rate ETR also decreased significantly, showed that excess fatty acid esterification feeling make PSII reaction center of excitation can increase the degree of reduction of QA, results in the decrease of ETR. electron transport activity decline.(4) With the increase of concentration of DOP. DIBP, grafted watermelon soil is increased after the first reduction in the number of bacteria and actinomycetes, fungi number first decreases after increasing. Soil catalase, sucrase, protease activity change rule first increases then decreases, urease activity of a certain degree of increase. Under the DOP, DIBP treatment, grafted watermelon number of bacteria and actinomycetes were higher than the self-rooted watermelon, fungi amount is lower than the watermelon. Grafted watermelon soil catalase, urease. sucrase, protease activity were higher than the self-rooted watermelon.