Identification And Evaluation Of Important Agronomic Traits On Some Rice Germplasm (Oryza Sativa L.)

Germplasm resources are the basic materials for plant breeding and genetic research. The identification and evaluation of the germplasm resources are one of the most important contents on the germplasm research. In this study it was identified the variation in some important agronomic traits of 1,466 rice (Oryza sativa L.) germplasm resources (808 indica rice, 658 japonica rice) from different countries and regions in during 2004 and 2005, including heading period (HP), full panicle stage (FPS), plant height (PH), panicle number per plant (PN), panicle length (PL), grain number main panicle (NGMP), seed setting rate(RSS), spikelet density (SD) 1,000-grain weight (1000GW), rate of brown rice (RBR) and resistance of rice bacterial leaf blight. The main results are decribled as follows1. There were to large extent variation in HP, FPS, and growth duration (from sowing to full panicle stage, DSFPS) among all indica or japonica rice resources evaluated. The HP and FPS of indica rice were mainly distributing between 7/26～8/14 (month/day, the same below) and 7/26～8/24, respectively, and HP and FPS of japonica rice mainly distributing between 7/26～8/24 and 7/26～9/8. There was an obviously different reaction to temperature and light between different indica and japonica rice varieties. Among these rice germplasm resources there are very profound genetic diversity in reaction to temperature and light, which provides favourable materials for futher research.2. The PH, PN, PL, NGMP, RSS, and 1000GW of indica rice were mainly distributing between 80～120 cm, 3～9, 19～29 cm, 80～240, 5～40%, and 18～30g, respectively, and the PH, PN, PL, NGMP, RSS, and 1000GW of japonica rice mainly distributing between 80～120 cm, 3～8, 15～25 cm, 80～200, 0～20%, and 19～31g. There was also an obviously variation of PH, PN, PL, NGMP, RSS, SD, 1000GW, and RBR between indica and japonica rice varieties, with the more than 20% of variation coefficients for these traits.3. There is a significantly difference in the resistances to bacterial leaf blight between indica and japonica rice varieties. Most of indica varieties identified were susceptible to the disease, and many japonica varieties identified more resistant. Most of resistant resources to bacterial leaf blight were foreign varieties or landraces. These excellent materials can be used for genetic study of resistance to bacterial leaf blight and breeding in rice. 4. Meanwhile it was found that there were 80 varieties with high resistance to bacterial leaf blight, e.g. IR1112-104, IR1561-228-3-2, Biguang, and Huangjinqing, and some multi-spike-type varieties with more than 10 of spikes, e.g. Guangcong, IR19784-9-2-1, Mayinl-1 and Aiganhuang, 137 of large-panicle-type varieties with more than 180 grains for japonica rice per panicle and 250 grains for indica rice, e.g. 1158-2, Gaomengya, Lijiangbeizigu, Yipiannian, and 29 of large-grain-type varieties with more than the 35g of 1000-grain weight, e.g. Cungu, Ruiyu406-23, Pangxiegu, Haohai. These especial materials with single or double excellent traits could be used in further genetic research and modern breeding in rice.