Screening Of Drought-resistant Salt-tolerant Maize And Research On RAPD Markers

The maize is the second food crop in Xinjiang. With the adjustment of agricultural structure in our country and Xinjiang, the livestock husbandry has already become the center of the agriculture in Xinjiang, thus the needs of maize are increasing. Xinjiang is one of the main droughty areas, the erosion of sand and salt soil are serious. However, the maize in growth stage needs large amount of water, and maize is very sensitive to salt-stress. Drought and salt soil have become the main factors which limited maize products and growing areas. Breeding new varieties of drought-resistant and salt-tolerant maize is a main pathway in reduction of stress. The main contents and results of this thesis are as following:1. Maize inbreeds of 14 varieties were treated with NaCl solutions and PEG-6000 solutions of different concentration, their drought resistance and salt tolerance during seedling emergence stage were analyzed. The result indicated that inbreed XS-28,XS-K had strong tolerance to drought and salt.2. Phylogenetic relationship of 21maize inbreeds has been identified by using random amplified polymorphic DNA (RAPD) markers. 14 primers were selected to analyze these inbreeds, and 132 DNA bands were amplified, 100 of which (75.76%) were polymorphism. According to the RAPD data, the genetic similarities of 21 inbreeds ranged from 0.52 to 0.94. According genetic similarity values, the dendrogram was constructed for them. The inbreeds could be divided into four clusters.3. RAPD analysis were studied among F₂ segregated population originating from a cross between maize inbreed XS-28 (drought-resistant and salt-tolerant) and XS-D (drought-sensitive and salt-sensitive). The four DNA pools (drought-resistant DNA pool, drought-sensitive DNA pool, salt-tolerant DNA pool, salt-sensitive DNA pool) had been constructed by the method of BSA. Primer S101 and S426 could amplify 3 identical polymorphic RAPD markers between drought-resistant pool and drought-sensitive pool. Primer S101 could amplify one identical polymorphic RAPD marker between salt-resistant pool and salt-sensitive pool.