中文摘要：

本研究选用旱稻、R974//R974/东乡野生稻回交重组自交系及其亲本等66份水稻材料,进行苗期抗旱性鉴定及其综合指标筛选,测定了水分胁迫下最大根长、根基数、茎长、根干重、根鲜重、根系相对含水量、叶片相对含水量、卷叶级别及干旱反复存活率等9个性状。利用主成分分析和逐步回归分析法进行苗期抗旱综合评价,结果表明株系1949最为抗旱;回归分析和相关分析表明最大根长、根数、根鲜重和根系相对含水量对抗旱性影响显著,可作为苗期抗旱性鉴定综合指标。采用综合抗旱D值进行抗旱遗传分析,表明BILs群体的苗期抗旱性表现2对独立主基因＋多基因控制。结果可知,东乡野生稻可作为水稻抗旱遗传改良的宝贵资源。

英文摘要：

66 rice（ Oryza sativa L. ）materials, including four upland rice, the backcross inbred lines （BILs）de- rived from the combination R974//R974/Dongxiang wild rice（ Oryza rufipogon Griff. , Hereafter DXWR） ,and their parents ,were employed for evaluation of drought resistance and screening of drought resistance index at seedling stage. Nine traits were monitored for assessment of drought resistance, including maximum root length（MRL） , num- ber of root （ NR）, stem length （ SL）, dry root weight （ DRW）, fresh root weight （ FRW ）, root relative water content （RRWC） , leaf relative water content（ LRWC ） , level for rolling leaf（LRL） , and seedling survivability under repeat drought（SSRD） ,respectively. Comprehensive assessment of drought resistance based on the principal component a- nalysis（PCA） indicated the line 1949 showed the strongest drought resistance. Analysis on the stepwise regression e- quation and correlation demonstrated that MRL, RN, FRW, and RRWC significantly influenced the drought resist- ance, thus could be used as comprehensive index for identification of drought resistance at the seedling stage. The genetic mechanism of drought resistance at the seedling stage in the BILs population was controlled by two inde- pendent genes and polygenes, based on comprehensive drought resistance value （CDRV）. As a result, the DXWR could be precious resources for genetic improvement of drought resistance in cultivated rice.