Study On Differences Of Characters In Rice Varieties And Their Relations To Yield

Study on Differences of Characters in Rice Varieties and Their Relations to Yield Postgraduate: Wang Jiangang Supervisor: Professor Wang Yulong Abstract Hydroponical experiment was carried out with 41 Indica rice varieties and 40 Japonica rice varieties to investigate the aboveground and underground characters of high yield rice varieties and the relationships between root characters and yield and its components. The main results showed as follows: (1) There were significant differences of every character of lndica rice varieties and Japonica rice varieties. The maximum/minimum of aboveground characters ranged from 1.47?2.03 and underground characters ranged from 1.52?.70 in Indica rice varieties. The maximum/minimum of aboveground characters ranged from 1.70?.38 and underground characters ranged from 1.59?.97 in Japonica rice varieties. (2) The yields of both Indica and Japonica rice varieties were classified into six types (A.. B.. C.. D.. E.. F) from high to low by cluster analysis. The average yield of Indica rice varieties of type A,B,C,D,E,F was 10007. 9, 8593. 2, 7224. 3, 6250, 5580. 4, 4289. 8kg昲m2 respectively; The average yield of Japonica rice varieties of type A,B,C,D,E,F was 7572. 2, 6394. 2, 5645. 3, 4725. 1, 3786. 8, I 2258. 7kghm72 respectively. (3) The main characters of high yield Indica rice varieties were as follows: the number of spikeletes per ear and per unit of area and the sink capacity per unit of area were great and seed setting percentage was high. the main characters of high yield Japonica rice varieties were as follows: the number of ear and spikeletes and sink capacity per unit of area were great and seed setting percentage was high. (4) Biomass production.. biomass production before head and after head.. Economic co-efficient were all great with both high yield lndica rice varieties and 73 Japonica rice varieties. (5) In high yield Indica rice varieties ,There were more roots per plant ;the length of root per unit and per plant were great The root activity per dry-weight and per plant were high and the activity absorb area of root per plant was big. In high yield Japonica rice varieties, The number of root per plant.. dry-weight of root per plant and length of root per plant and length of the longest root were great;root activity per dry-weight and per plant were high.. the absorb area and activity absorb area of root per plant were big. (6) Positive linear correlation was observed between the number of spikeletes per ear an4 per unit of area ~ seed setting percentage .. the sink capacity per unit of area and yields in Indica rice varieties. Positive linear correlation was observed between the number of ear spikeletes and sink capacity per unit of area-, seed setting percentage and yields in Japonica rice varieties. Positive linear correlation was also observed between Biomass production.. biomass production before head and after head.. Economic co-efficient and yields in both lndica rice varieties and Japonica rice varieties. (7) length of root per unit and per plant.. the absorb ar...