| Ensuring food self-sufficiency needs a certain amount of arable land as guarantee. Taking reasonable method to improve saline is an important way to increase the source of arable land. Wheat is one of the major food crops, and the annual account is more than half of the national grain reserve. Cultivation and promotion of salinity wheat is not only a long-term plan to improve the productivity of saline land, but also possible to solve the food problem in China. Saline tolerant wheats generally have strong growth potential and stress tolerance ability to promote the planting in saline areas. This is a challenge to select and train saltine tolerant wheat varieties, but molecular marker assisted breeding opened a new way to breed new germplasms.The experiments by anthrone - sulfuric acid, acidic ninhydrin method and pyrogallol were determined soluble sugar content, free proline content and SOD activity from 6 varieties of wheat which were suffered to salt-alkaliy stress of different concentrations. Through the difference of three physiological indicators, it reflects the impact of different kinds of wheat withstanded the salt-alkaliy stress followed as: 71-721> Cangmai 6005> Cangmai 6001> Qumai 12 >Fengyou 68> Tianyuan 1. There consistent with field results.On the basis of DNA extracted in the classic experiment of CTAB, this experiment reduced experimental procedures and adjusted the centrifugation speed and time. Besides that, there are PVP and Vc as stabilizers and antioxidants to prevent oxidation of DNA. The improved method is more practical, simple and time-consuming short. DNA extracted by this method is a higher purity, and fully meets the requirements of SRAP-PCR expansion, and strongly guarantees to carry out follow-up experiments.On basis of the orthogonal design, the best reaction system was established. And through some single-factor experiments, the SRAP-PCR reaction annealing temper was determined. The facts are as followed: Mg2+0.5 mmol·L-1, DNA 50 ng, dNTPs 0.4 mmol·L-1, primer concentration 0.6μmol·L-1 and Taq enzyme 1.5 U in the reaction system in which the total volume is 20μL. And the eventual reaction program was that: 94℃de- naturation 5 min; 94℃denaturation 1 min, 35℃refolding 1 min, 72℃extension of 1.5 min, 5 cycles; 94℃denaturation 1 min, 52℃refolding 1 min, 72℃extension of 1.5 min, 28 cycles; the last 72℃for 10 min, 4℃preservation.By single-factor experiment in agarose gel electrophoresis, some factors were optimized that the agarose gel concentration is 1.5%, the best time and voltage of electro- phoresis are respectively 1 h and 75 V.It analyzed salinity-tolerance of wheat by genetic markers of SRAP markers. Through selection of 81 primer pairs, there exist three SRAP markers which were closely related genes in the salt-tolerant wheat. It provides a fast and effective way for identification of salinity-tolerant wheat germplasm and can be used to breed salinity-resistance varieties of wheat in marker-assisted breeding process. It also lays a good foundation for salt-tolerant gene mapping, cloning and sequencing analysis for wheat.
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