The Study On The Anti-senescence Physiological Characteristic Of Three Wheat Varieties With Translocation Chromosome 1RS/1BL And Countribution Of Their Functional Leaf To Yield

the yield of wheat, rice, maize as well as other crops has been significantly improved in these years, however, because of increaseing population in the globe , the crisis of food supplies is still finty. wheat is one of the most important grain crops in the world, which has high potential in improving its own yield. during the grouting period, the wheat yield declines serious because of the leaf senescence so as to shorten the photosynthesis days. therefore, it is the economical and effective method to improve the yield by the means of prolonging the green time during the grouting period so as to sostenuto transport photosynthesis production to grain.the 95%-95% of the wheat yield owes to photosynthesis. the functional leaf can contributes 80% to the grain yield, especially during the rear time of the procreation of the high-yield wheat. the flag leaf is the main constitutor on the top leaf of the wheat during the rear time of the procreation so that it is the great contributor to the photosynthesis of the top leaf .the anti-senescence wheat can keep green more days ,therefore, it is necessary to research on the correlation between the functional leaf of the top and the yield.The flag leaves of both keep-green wheat, ChuanNong18(CN18), ChuanNong12(CN12) and ChuanNong17(CN17), and common wheat MianYang11(MY11) are respectively clipped in different period after tasseling for the purpose of researching on the difference between the anti-senescence wheat and common wheat. the content of chlorophyll, the content of malondialdehyde(MDA), superoxide dismutase activity(SOD), Catalase acticity(CAT) of flag leaf, second leaf from top as well as third leaf from top, the 1000-grain weight under the condition of clipping the flag leaf of the CN18, CN12 ,CN17 and MianYang11(MY11) were measured in different periods. Results were shown as follows:1. CN18, CN12, CN17 can keep green more days after anthesis even approximately half of the whole plant can keep green when the wheats are of mature.2. it is shown that CN18, CN12, CN17 had higher abilities to eliminate the active oxygen and effectively restrain the oxidation of the cell membrane as well as prolong the senescence period of the crop by the means of measuring the SOD of the leaf in the different period after anthesis.3. it is shown that CN18, CN12, CN17 had higher abilities to resist the oxidation so as to lighten the contamination of the active oxygen by the means of measuring the CAT of the leaf in the different period after anthesis.4. it is shown that the cell membranes of the CN18, CN12 and CN17 were not seriously destroyed so it is significant to maintain the natural metabolizability of the cell by the means of measuring the MDA of the leaf in the different period after anthesis.5. CN18, CN12, CN17 can maintain high chlorophyll content after anthesis all the times so they had more time for photosynthesis and theirs grain had higher growth rate, therefore, CN18, CN12, CN17 had better 1000-grain weight, not the flag leaf but the second leaf from the top as well as the third leaf from the top had more contribution to the 1000-grain weight.6. "sink" was mostly the main reason for restricting the anti-senescence wheat to have much more high yield.The conclusions was drawn of this research as follows, CN18, CN12, CN17 can effectively resist the course of the senescence so as to have more time for photosynthesis, besides, the all functional leaf of CN18, CN12, CN17 had higher abilities to contribute to 1000-grain weight, However, from the 4th week after anthesis, the compensatory effect obviously declined mostly because of being restricted by the "sink", therefore, it is most significant to enlarge the "sink" of the anti -senescence wheat for the purpose of breeding the high yield even super high yield wheat.