Physiological And Biochemical Study On Leaf Senescence In F₁ Hybrids Of A Male Sterile Line With Puriple Leaf Marker

With a variety Te You 63 as the control in the experiment, a male sterile line with purple leaf marker was used as the female parent, and crossed with wide compatibility line, indica rice, japonica rice and indica - japonica cross rice, respectively. Contents of the total chlorophlly, MDA and nutrient elements (N, P and K), and the ratios C/N and starch/soluble sugar, and the agronomic and economic characters of the FI hybrids were investigated at the flower and seeding stage to compare their senescence degree. The result were as follows:1) The contents of total chlorophyll and net photosynthetic rate in the functional leaves were obviously higher in the combinations of indica-jaonica hybrids and japonica rice than in the control (hybrid rice combination Teyou63); the ratio of chla/b was better than the control in some indica rice combinations and the contents of MDA in all indica rice combinations increase quickly.2) The contents of MDA in four types combinations, indica rice combination increase quickly, but japonica rice increase slowly. In all the combinations, the content of MDA in Hong S 5B8 increased mildly. The contents of the MDA in the combination of Hong S wide compatibilityline, Hong SXIL1018, Hong S 5B13 and Hong S 5B9 were higher than the control.3) All the combinations with purple leaf marker parent showed higher soluble sugar content in the FI leaves as compared with the control except Hong SxIL1018, and soluble sugar content in the F1 leaves decreased lowest at the seed-filling stage in all the combinations.4) Except for the Hong SxIL1018, there were no difference on the contents of starch in all combinations.5) The contents of N decreased and were higher than the control with the rice maturing. As to contents of N , there were larger different in Indica rice combination compared to the control, but no different in Hong SxIL1018.6) The combinations of indica-japonica hybrid rice showed higher C/N ratios than the others in the leaves and the ratios were higher than the control except for the Hong Sxminghui 63 and Hong SxxianB. Starch/soluble sugar ratios showed lower than the control in the leaves of hardly all combinations7) All the combinations with purple leaf marker parent were inferior to the control in the seed-setting percentage. Among them, the combinations of Hong Sx indica rice were much better than those of Hong Sx wide compatibility line. The combinations of Hong Sxwide compatibility line showed a bigger sink than then control, but the others showed very little difference. Except for the combination Hong Sx838 and Hong SxSBn, all the combinations lower than the control in the weight of thousand seeds.8) Hong Sx indica - japonica cross was the best idea combination in this test by it's syntheses characters.