Investigation Of The Effect Of Arbuscular Mycorrhizal On Nutrients Absorption And Disease Resistance Of Watermelon

Wilt disease is soil-borne disease due to continuous cropping on watermelon.Disease frequency and disease index of watermelon wilt disease alleviated by arbuscular mycorrhizal(AM)colonization.It is unefficiency to colonize arbuscular mycorrhizal fungi to the field.This thesis will study the effect and mechanism of culturing arbuscular mycorrhizal seedling on nutrients absorption and disease resistance of watermelon.The main results are listed as followed:(1)Five basic media of rice husk,vermiculite,biochar,zeolite,and decomposed straw were used to study the mixing media of rice husk and vermiculite,biochar,biochar and vermiculite,decomposed straw,decomposed straw and vermiculite on seedling and its root growth of watermelon with or without AMF colonization.The results showed that five midia could culture arbuscular mycorrhizal seedling.The media of decomposed straw and mixed of decomposed straw and vermiculite were better,which biomass were higher than that growing in other media.The old leaf phosphorus content of watermelon mycorrhizal seedling was higher than that in non-mycorrhizal seedling.Compared to the mycorrhizal seedling cultured by decomposed straw,the root length,root surface area,root volume,root tip number,stem phosphorus content,and root phosphorus content increased significantly in the seedling cultured by mixing media of decomposed straw and vermiculite.In addition,the frequency,intensity,and arbuscular abundance were increased in mixing media of decomposed straw and vermiculite.(2)Compared to non-mycorrhizal seedling,phosphorus content in every sections and potassium content in old leaves of watermelon were increased by mycorrhizal colonization seedling on the condition of different organic fertilizer.Plant biomass improved by 42%by mycorrhizal seedling in straw manure application.(3)Frequency and index of watermelon wilt diseas decreased significantly by culturing arbuscular mycorrhizal seedling.Compare to non-mycorrhizal seedling,the frequency and index of watermelon wilt disease reduced by 20%and 39%by arbuscular mycorrhizal seedling,respectively.In addition,the frequency and index of watermelon wilt disease reduced by 27%and 45%by both infection of arbuscular mycorrhizal fungus and PGPR,respectively.Compared to non-mycorrhizal seedling,the chitinase activity in arbuscular mycorrhizal seedling was enhanced by 215%.The chitinase activity was improved by 222%in both infection of arbuscular mycorrhizal fungus and PGPR.On the condition of FON inoculation,compared to non-mycorrhizal seedling,the chitinase activity of watermelon increased by 51%in arbuscular mycorrhizal seedling.