东乡普通野生稻全生育期抗旱性鉴定

Drought-resistance Identification of Dongxiang Common Wild Rice(Oryza rufipogon Griff.) in Whole Growth Period

利用组合R974//东野/R974 BC1F5BIL群体,设水分胁迫和非胁迫两种处理,在全生育期测定了株高、单株分蘖数、单株有效穗数、穗长、穗实粒数、穗总粒数、着粒密度、千粒重、结实率、单株产量、叶片相对含水量、卷叶级别等12个与抗旱相关的形态及生理性状,其中单株产量对水分胁迫影响最敏感。通过各性状旱、水相对值对抗旱系数分别进行单因素逐步回归、通径、灰色关联分析,结果表明,叶片相对含水量、单株分蘖数、穗实粒数、千粒重、株高、单株有效穗数等6个性状与水稻抗旱性相关显著,可作为全生育期抗旱鉴定指标。利用模糊隶属函数法对入选性状的抗旱D值进行抗旱性综合评价,更表明上述性状作为水稻全生育期的抗旱鉴定指标是可行的。同时对5种抗旱性评价方法进行比较指出,抗旱指数是最合适的抗旱性直接评价方法。

The drought and scarcity of water resource are more and more serious, which restrict agricultural development, specially rice production in China. Dongxiang common wild rice distributed in the most north region all over the world contains plentiful genetic diversities and excellent genes encoding drought resistance, cytoplasm male sterility （ CMS）, cold tolerance, fertility restoration, and so on. Screening drought resistance of dongxiang common wild rice is important for breeding rice with drought resistance and creating new drought resistance resource in current cultivated rice. With the water stress and non-stress treatments designed, twelve morphological and physiological traits correlating with drought resistance were monitored in whole growth period for the back-cross inbred line population （R974//DongYe/R974） BC1F5, which were plant height （PH）, tillers number per plant （TNP）, effective tillers number per plant （ETNP）, spikelets per panicle （SP）, filled spikelets per panicle （FSP）, length of panicle （LP）, panicle density （PD）, 1000-grain weight （TGW）, seed setting rate （SR）, grain weight per plant（GWP）, leaf relative water content （ LRWC）, and level for rolling leaf （LRL）. GWP is the most sensitive trait that is influenced by drought. Single variable stepwise regression, path analysis, gray correlative analysis, and multiple partial correlations analysis were conducted between the relative value of various traits and drought resistance coefficient. The results showed that six traits including LRWC, TNP, ETNP, TGW, PH, and ETNP significantly influenced the drought resistance and could be the indices to identify the drought resistance in flee. The D value of six traits elected was comprehensively used to evaluate the drought resistance by subordinate function values analysis, the results showed six index traits were feasible to predict the drought resistance in rice for whole growth stage. Four different drought resistance evaluated methods were compared, which indicated the drought resistance index is the best one for drought resistance direct evaluating.