Difference Of Physiological Index In Indica Rice(Oryza Sativa L.)Varieties And Its Effect On Yield

This study was carried out in Yangzhou, China in 2002, and 108 indica rice varieties from domestic and foreign countries, which were developed in different years, were solution-cultured. The physiological index including chlorophyll a, chlorophyll b, soluble protein, Z+ZR in flag leaf and in root were measured to analyze the relationship between physiological index and panicle weight, sink potential and yield and to understand the physiological index of high-yielding indica rice varieties and its effect on yield. Result showed as follows:(1) Significant variation of Chlorophyll content, chlorophyll a/b in flag leaf and soluble protein, Z+ZR both in flag leaf and in root at heading among the tested varieties were observed. The ratio of maximum/minimum of Chlorophyll content, chlorophyll a/b in flag leaf , soluble protein and Z+ZR in peak leaf and root was 2.06, 4.14, 2.53, 3.67, 13.14 and 13.33, respectively.(2) Significant variations of panicle weight existed in the different types of, the average weight of single panicle for 6 types was 0.98 g, 1.43 g, 1.78 g, 2.30 g, 2.91 g, 4.37 g , respectively. In the varieties with larger panicle weight, the Chlorophyll content, soluble protein in flag leaf were higher, while the chlorophyll a/b, soluble protein and Z+ZR in root were lower at heading stage, and the contrary result was observed in varieties with low panicle weight. No close correlation between single panicle weight and Z+ZR in flag leaf was found in this study.(3) Sink potential varied significantly among 6 types, and the average sink potential was 469.10, 633.34, 774.54, 953.55, 1165.06, 1 460.46 g.m-2, respectively. In the varieties with larger sink potential , the Chlorophyll content, soluble protein and Z+ZR in peakleaf were higher, while the chlorophyll a/b, soluble protein and Z+ZR in root were lower at heading stage, and the contrary result was observed in varieties with lower sink potential.(4) Significant variations existed hi the different types of yield ,the average yield was 321.42, 470.90, 633.97, 830.13, 1021.57, 1282.72g/m2, respectively. In the varieties with high-yielding, the Chlorophyll content, Chlorophyll b content, soluble protein and Z+ZR in peak leaf were higher, while the chlorophyll a/b , soluble protein and Z+ZR in root were lower at heading stage; whereas the contrary result was observed in varieties of low-yielding type.(5) In tested indica rice varieties, the content of Z+ZR closely correlated with the content of soluble protein, Chlorophyll, Chlorophyll b, Chlorophyll a/b in flag leaf. With the content of Z+ZR increased, the content of soluble protein, Chlorophyll and Chlorophyll b in peak leaf increased significantly, whereas the Chlorophyll a/b content significantly decreased.