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Grafting Induced Biological Variation In Cucumis Sativus L. And It’s Distant Hybridization

Posted on:2017-05-09Degree:MasterType:Thesis
Country:ChinaCandidate:X S GuanFull Text:PDF
GTID:2283330485966936Subject:Pesticides
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Grafting technique is widely used in agriculture and forestry, especially in the cultivation of cucurbitaceae vegetables. It is mainly used to increase crop yield, improve fruit quality, and enhance crop resistance to the biotic or abiotic stresses. However, with the deepening of research, researchers found that genetic material had been exchanged between scion and stock, and it can induce mutations in plants. This has brought new ideas for traditional breeding. In this experiment, cucumber (Cucumis sativus Linn, as the scion) and pumpkin(Cucurbita moschata Duchesne, as the rootstock) were used to explore grafting induced cucumber compatibility of distant hybridization and the effects of reproductive organ in biology, and then we provided basic theories for grafting induced breeding. The main results were as follows:1. Through the analysis of cucumber fruit setting rate by hydridization and selfing, we found that the new characteristics of the grafted seedings combined with delayed pollination technology could break the barrier of distant hybridization incompatibility effectively before fertilization in scion. The fruit rates and operational ease of three pollination methods were comprehensively compared and analyzed, the best pollination was 8h-after-pollination.2. To study the fruit of positive and negative crossing, it was found that only when the pollen consistent with the rootstock, the orthogonal crossing fruit could be seen. The fruit rate of positive crossing was higher than the negative crossing; The development process in fruits of distant hybridization was almost the same with selfing fruits after pollination. The single fruit weight was not obvious difference between distantly hybridized with self hybridized, but they were more higher than those of self root; but distant hybridization did not get any true hybrid seeds.3. Through the morphological analysis of cucumber reproductive organ by multiple grafting, we found that multiple grafting could induce some degree of cumulative effects. In three times of grafted cucumber scions, the peduncle length-, petal length, total length and weight of male flowers were significantly higher than self root seedlings; and in the full bloom, the pedicel length、petal length、and total length of female flowers were significantly greater than self root seedlings; and the ovary length of two times grafting was significantly shorter than self root seedling, and the ovary length of one time grafting was the most shortest.4. Grafting could enhance the resistance of pollen germination in higher or lower temperature. Under 12 hour treatment at 4℃,10℃,28℃,30℃ and 35℃, the pollen germination rate of grafted group was significantly higher than of control group; but there was no significant difference between grafting and control at 40℃, the germination rate was almost 0%. With the increasing times of grafting, the pollen germination percentages were increased at 10℃ or 35℃.5. Salt tolerance and vigor of cucumber seeds was induced intensification by grafting. Under NaCl stress, the germination potential, germination rate and germination index of one time grafted cucumber were higher than that of self root. The order by root length of cucumber seedlings was G03> G02> G01, and the order by numbers of lateral root and stem length is G03> G02> G01 under low concentration of salt stress. But, there was no obvious difference in high concentration. Under no NaCl stress, the germination potential and germination index of one time grafted cucumber seeds were significantly higher than that of self root, which increased by 13.33% and 12.09%, respectively; but the final germination rate was no difference. The germination potential, germination rate and germination index of two times grafted seeds were significantly higher than that of self root seeds, which increased by 26.40%,3.34% and 16.03%, respectively.
Keywords/Search Tags:grafting, cucumber, distant hybridization, biology, salt tolerance
PDF Full Text Request
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