Abstract:

Thirty six japonica cultivars bred in Jiang-Huai area were categorized into three groups with semi-dense panicle, near-dense panicle and dense panicle by clustering analysis, based on panicle grain density. With the panicle type changing from thin panicle to semi-dense panicle and dense panicle the rice cultivars were changed as follows: total grain numbers and filled grain numbers per panicle, the diurnal yield were improved significantly while panicle numbers/m², 1000-grain-weight and the percentage of filled grains declined; plant height was increased, top three leaves became longer and wider, biological production per day was increased; the first and second branches of the panicle and grain density were increased; some values of physiological character were increased, such as nitrogen content and chlorophyll content of leaf, and nitrogen content of stem during heading and maturity stages; As to some grain quality characters, the rate of brown rice and head milled rice, chalkiness rate were decreased, gel consistency became rigid and protein content was increased.

Key words: Japonica cultivars, Panicle type, Agronomical character, Quality character, Analysis