水稻不同种质苗期耐旱性综合评价

Comprehensive Evaluation of Drought Tolerance of Different Rice Germplasms at Seedling Stage

以国内外收集的20份优异水稻种质为试验材料,测定了对照和干旱胁迫处理下的水稻苗期苗总长、苗高、根长、茎叶鲜重、根鲜重、茎叶干重、根干重和根数共9个形态性状指标,运用差异显著性分析和相关分析分别探索处理间和指标间的相互关系,利用因子分析和聚类分析等研究水稻苗期耐旱性有效鉴定指标和筛选苗期耐旱水稻种质。结果表明:干旱胁迫处理与对照相比,越光、一味稻、JWR221和大珍稻等8份水稻种质不少于5个性状发生了改变(P<0.05);W0610、文长稻和秋田小町共3份种质4个性状发生了改变(P<0.05);黑糯1568、安多稻、龙锦1号和旱526等9份种质不少于5个性状未发生统计学意义上的改变。相关性分析共得到28个相关系数,其中在0.05水平上存在显著相关性的有9个,在0.01水平上存在显著相关性的有12个。因子分析提取了3个公因子,解释的累积方差贡献率达到88.157%。应用系统聚类方法将20份种质聚为3个组群,其中第Ⅱ组群属理想的苗期耐旱种质。根据公因子载荷矩阵耐旱性评价方法,20份水稻种质中龙锦1号、黑糯1568和淮稻9号苗期耐旱性强,其次是X2-5、旱526和安多稻,而大珍稻、一味稻和越光苗期耐旱性较弱。

The total seedling length, seedling height, root length, fresh weight of stem and leaf, fresh weight of root, dry weight of stem and leaf, dry weight of root, and root number of 20 excellent rice germplasm seedlings collected at home and abroad were measured under both control and drought stress. The relationships among these 9 morphological character indexes in different treatments were explored by using difference significance analysis and correlation analysis. The effective identification indexes for drought tolerance of rice seedlings and the screening of rice germplasms whose seedlings were tolerant to drought were studied by using factor analysis and clustering analysis. The results showed that: in comparison with the control, under drought stress, more than 5 characters of 8 rice germplasms(Yueguang, Yiwei, JWR221, Dazhen, etc.) were changed(P<0.05), four characters of W0610, Wenchang and Akita had changed(P<0.05), and over 5 characters of 9 rice germplasms(Heinuo 1568, Anduo, Longjin 1, Han 526 and so on) did not change at significant level. A total of 28 correlation coefficients were obtained through correlation analysis;among them, 9 and 12 correlation coefficients reached 0.05 and 0.01 significant level, respectively. Three common factors were extracted by factor analysis, and the cumulative variance contribution rate explained by them reached 88.157%. These 20 rice germplasms were clustered into three groups by using the method of systematic clustering, and the rice germplasms in group Ⅱ had an ideal drought tolerance at seedling stage. According to the drought tolerance evaluation method of common factor load matrix, among 20 rice germplasms, Longjin 1, Heinuo 1568 and Huaidao 9 had strong drought tolerance at seedling stage, followed by X2-5, Han 526 and Anduo, while Dazhen, Yiwei and Yueguang had weak drought tolerance at seedling stage.