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Studies On Antibiosis Of Different Cotton Varieties To Apolygus Lucorum(Meyer-Dur)

Posted on:2011-04-18Degree:MasterType:Thesis
Country:ChinaCandidate:F M LinFull Text:PDF
GTID:2143330302955365Subject:Pesticides
Abstract/Summary:PDF Full Text Request
Area-wide cultivation of transgenic Bt cotton has effectively controlled the cotton bollworm Helicoverpa armigera with resulting reduction in the amount of insecticides used in cotton production. This lowered insecticide use has caused the population of the mirids increase, and the mirids is major pest insect on cotton in china. The mirids were ofen treated as a secondary with limited studies and inperfect control in china, the IPM of mirids were extremely urgent. In order to clarify the correlation of the resistance of cotton to Apolygus lucorum (Meyer-Dur) with the structure characteristics and biochemistry characteristics, and provide a base for developing intergrated management measures, we evaluated the resistance levels of different cotton varieties to A.lucorum in the field during 2008 and 2009, and measured the leaf thickness,the leaf epidermis thickness and the gossypol glands density of cotton leaves,the density of each trichome type,the trichom length on midrib and lamina of cotton leaves during different growing stage were explored in laboratory. Meanwhile, we detected content of nutrient (solube protein and solube sugar) and Secondary Substance (tannic,flavonoids and terpenoids).The main results were summarized as follows.1.The different cotton varieties show different resistance levels against A. lucorum, and Jinmian 26,Jifeng 989,Chang D,Yazhoumian show high resistance against to A. lucorum, while Liaoyangduomaomian,X033,Kelin 08-14 show sensitive. We established the method of evaluat resistance of cotton to A. lucorum, this provided gist for preparating resistance varieties.2.The density of each trichome type,the trichome length of cotton top leaves were significantly differed in seedling,budding and bolling stage among different varieties. The regression models about resistance index of cotton in relation to trichomes characteristics of cotton leaves were built. The trichome density of cotton leaves had a significant negative effect on host resistance to A. lucorum, while trichome type,trichom length were no-significantly correlation.3.The leaf thickness were significantly differed in seeding budding and bolling stage among different varieties;the leaf epidermis thickness of cotton leaves were significantly differed on seeding stage and bolling stage among different varieties, and indiffered on budding stage. The regression models about resistance index of cotton in relation to leaf thickness and lesf epidermis of cotton leaves were built. The epidermis thickness of cotton leaves in bolling stage had a significant positive effect on host resistance to A. lucorum, while leaf thickness and leaf pidermis thickness in seedling and budding stage were no-significantly correlation.4.The gossypol glands density of cotton leaves were significantly differed in seedling,budding and bolling stage among different varieties.The regression models about resistance index of cotton in relation to the gossypol glands density of cotton leaves were built. The gossypol glands density of cotton leaves in bolling stage had a significant positive effect on host resistance to A. lucorum, while the gossypol glands density in seedling and budding stage were no-significantly correlation.5.The content of solube protein of cotton leaves,buds and bols were significantly differed in seedling,budding and bolling stage among different varieties.The regression models about resistance index of cotton in relation to solube protein were built. The solube protein content of cotton had no significant effect on host resistance to A. lucorum.6.The content of solube sugar of cotton leaves in seedling stage and the bols in bolling stage were no-significantly differed, while the top leaves and buds in budding stage,the top leaves in bolling stage were significantly differed. The regression models about resistance index of cotton in relation to solube sugar were built. The solube sugar content of buds in budding stage had a significant positive effect on host resistance to A. lucorum,while solube sugar content of leaves in bolling stage negatively; the solube sugar content of leaves in seeding and budding stage,solube sugar content of bols in bolling stage were no significantly correlation.7.The content of tannic of cotton leaves,buds and bols were significantly differed in seeding budding and bolling stage among different varieties.The regression models about resistance index of cotton in relation to tannic were built. The contant of tannic of cotton leaves in budding stage had a significant positive effect on host resistance to A. lucorum,while leaves and buds in budding stage,leaves and bols in bolling stage were no-significantly correlation. 8.The content of flavonoids(rutin,catechin,isoquercitrin,quercetin) of cotton leaves,buds and bols were differed in seedling,budding and bolling stage among different varieties.The regression models about resistance index of cotton in relation to flavonoids were built. The content of rutin of leaf and bud in budding stage had significant positive effect on host resistance to A. lucorum, while the content of isoquercitri,quercetin and total flavonoids of bol in bolling stage negatively; other determined target were no significantly correlation.9.The content of terpenoids cotton leaves,buds and bols were differed in seedling,budding and bolling stage among different varieties;the total heliocide (include H1,H2,H3,H4)were contained higher in cotton leaf, and the content of gossypol in leaf increased along with cotton growing, while the content of gossypol in bud and boll were higher in leaf, and this say that terpenoids in different cotton varities or different tissue have different effect on the resistance of cotton to insect. The regression models about resistance index of cotton in relation to terpenoids were built. The content of total terpenoids,total heliocide of cotton leaves in seedling stage had significant positive effect on host resistance to A. lucorum, while other determined target were no significantly correlation.
Keywords/Search Tags:cotton, Apolygus lucorum, leaf structure characteristics, nutrient, secondary substance, resistance
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