直播早籼稻品种苗期耐冷性鉴定

Identification of Cold Tolerance of Direct Seeding Early Rice Varieties at Seedling Stage

以在江西地区大面积种植的45个早籼稻品种为材料,设置5℃、8℃、11℃、25℃(对照)4个温度处理,对幼苗的生物量、最长根长、茎基宽、根数、苗高、叶长、根系体积等指标进行观察,并应用主成分分析、模糊数学的隶属函数法和聚类分析法探讨了直播早籼稻品种苗期耐冷性的鉴定方法,并筛选出了耐冷性品种。结果表明;水稻苗期在遭遇低温后各项生长指标较正常温度(CK)明显下降,其中5℃处理下各指标变异系数均明显高于其他低温处理的,因此5℃适合作为耐低温性鉴定的温度;苗高和生物量最能代表早稻幼苗对低温的响应状况,可作为苗期耐冷性鉴定的评价指标;初步将供试早稻品种分为3类:第Ⅰ类包括五丰优623、湘早籼6号、淦鑫203等15个品种,为耐冷性品种;第Ⅱ类包括陵两优661、陵两优7717、陵两优0516等17个品种,为中等耐冷性品种;第Ⅲ类包括两优287、中嘉早17及株两优819等13个品种,为冷敏感品种。

In this study,45 early indica hybrid rice varieties in Jiangxi Province were used as experimental materials,and the low temperature stress treatments of 5℃,8℃,11℃,25℃(control)were set up at seedling stage.The biomass,root length,stalk diameter,root number,seedling height and root volume were observed.Principal component analysis,fuzzy membership function and cluster analysis were used to explore the evaluation methods of cold tolerance at seedling of direct seeding early rice and to screen cold tolerant varieties.The results showed that all indexes decreased after low temperature.Among the indexes,variation coefficient of 5℃ low temperature treatment was the largest,which indicated that 5℃ low temperature was more suitable for the selection of varieties with low temperature tolerance.The seedling height and biomass could be used as indicators of cold tolerance at seedling stage,and the tested varieties could be classified into three groups.The first category was composed of 15 varieties with strong cold tolerance(Wufengyou 623,Xiangzaoxian 6,Ganxin 203,etc.).The second category was composed of 17 varieties with medium cold tolerance(Lingliangyou 661,Lingliangyou 7717,Lingliangyou 0516,etc.).The third category was composed of 13 varieties with cold sensitive(Liangyou 287,Zhongjiazao 17,Zhuliangyou 819,etc).