| Triticale(Triticosecale Wittmack) is a new type of synthetic crop which passes through intergeneric hybridization and chromosome doubling between wheat(Triticum) and rye(Se-cale). And it serves as grain, cash crop and fodder. As the advantage of good-quality, high-yield and strong-resistance, the super long stalk triticale has becoming the most popular forage grass in pasturing area. Xinjiang is a typical temperate continental climate and drought. The drought resistance character of triticale has been causing great concern, especially in XinJiang where has a large area of farmland. Although many studies have made a certain amount of progress about triticale, they have their limitations. For example, drought resistance is an important character of triticale, yet many researchers consider triticale without any consideration of its drought resistance mechanism. Selected 30 triticale materials for this experiment, including drought-related markers used in screening parents of different genotypes in order to screening identification of typical traits in drought period and their associated molecular markers. 3-leaf stage seedlings were treated through drought stress of 20% PEG-6000 treatment at different times with hydroponics, and screened related physiological and morphological indicators of drought, including electrical conductivity, malondialdehyde (MDA), water physiology, proline, top root ratio, leaf curl, the root proliferation and coleoptile long and so on. And select the appropriate drought resistance traits for screening of Simple Sequence Repeat (SSR) molecular markers. These studies play a great significant role for drought resistance breeding of triticale varieties.1. Research on drought resistance traits of triticaleRelative conductivity of leaves, MDA and proline concentration were increased with the extension of time in water stress, and declined with the extension of time in rehabilitation water. Relative conductivity and MDA were not fully recovered through rehabilitation water after a short period of time, but the proline was recovered fastly after rehabilitation water.Compared with the control, the materials have taken place the phenomenon in different degrees that coleoptile growth was inhibited and water content was reduced after drought stress with 20% PEG6000 in 72h, and leaf curling and root proliferation at different degrees were appeared in some materials. Compared with the control, the top root ratio was increased of majority material.The results showed that the indicators of electrical conductivity, water content, coleoptile length and root proliferation were changed significantly under the water stress condition. The above-mentioned targets of were not only significant differences among different materials, but also the relevance of indicators was significant differences among indicators. These typical indicators were fitted for drought resistance research for a period of triticale seedlings. In this experiment, the indicators of MDA, proline, leaf curling and top root ratio were more affected by other factors, and the law was difficult to grasp. So these indicators should not be alone as identification of indicators for drought resistance at the seedling stage.At the same time, drought resistance cluster analysis showed that the best material of drought resistance at seedling stage were 04 Chun H Xi 757-758,04 Chun H Xi 499-500,04 Chun H Xi 447-448,04 Chun H Xi 547-548,H05-5 and so on, the most sensitive materials were 04 Chun H Xi 147-148,04 Chun H Xi 799-800,04 Chun H Xi 513-514,04 Chun H Xi 729-730,04 Chun H Xi 415-416. Selected the drought resistance parents H05-5 based on the performance of drought resistance pattern from experimental field before experiment, that is, the 30th material is one of the best materials of drought resistance in 30 materials. Sensitive parents H04-7, that is, the 25th material is the moderate drought tolerance.2. Screening of drought-related SSR molecular markersSelected the coleoptile length after water stress (72h stress / CK) was used for screening related drought SSR marker.164 plants had 33.0% polymorphism between the drought resistance and sensitive parents in 497 wheats and rye of SSR primers in this experiment. the 164 primers throughout the A, B, R in each group of chromosomes except 4R and 7R. More distribution was chromosome 5A-16 specific primers, 2A chromosome-14 specific primers, 5B chromosome-15 specific primers, 1B chromosome-13 specific primers. The other chromosome was distributed in a range of 1-12 primers.Parent-specific primers were screened between the F2 population of H05-5 and H04-7 combination using of SSR-BSA method, and cfd25 and xbarc155 which linkaged 72hWS/CK coleoptile length quantitative trait loci were acquired. However, electrical conductivity did not screen to the relevant tag. |
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