直播早籼稻品种苗期耐冷性鉴定与筛选

Identification and screening of cold tolerance of direct-seedling early rice cultivars at seedling stage

直播早稻易遭受低温危害,造成烂秧死苗。为降低低温冷害对直播早稻生产的威胁,以18个江西推广的早籼稻品种为材料,进行苗期低温(5.0℃)处理,筛选适合大规模推广种植的早籼稻耐冷性品种。结果表明,低温胁迫处理后,不同生长指标较正常温度(CK)均有所下降,其中存活率、地上部干重、根数、根系体积、叶面积的变异系数较大,变异系数依次为根系体积>存活率≥倒三叶叶面积>根数>倒一叶叶面积≥倒二叶叶面积>地上部干重;因子分析表明,存活率及地上部干重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;利用隶属函数法和聚类分析获得耐冷性较强的早稻品种6个,中等耐冷性品种6个,耐冷性较弱品种6个。

Direct-seedling early rice is vulnerable to hypothermia,causing the seedling to rot or die.To reduces low temperature stress and select cold tolerance rice varieties at seedling stage to be direct seeding in early season,pot experiment with 18 early rice varieties was conducted under differently artificial low temperature （5.0℃） treatment and normal temperature condition. The results showed that 18 early rice varieties low temperature treatment indexs lower than normal temperature condition. The variation coefficient of seedling livabilit,aboveground biomass,the neumber of roots,root number,root volume,leaf area were relatively large under low temperature treatment,root volume〉 seedling livabilit ≥ thir dleafunder the centralleaf area〉 root number〉 leafunder the centralleaf area ≥ second leafunder The centrallea area〉 aboveground biomass. Accoording to factor analysis method showed that livabilit and aboveground biomass played a major role. Six stronger cold tolerance varieties,six intermediate cold tolerance varieties and six weaker cold tolerance varieties were obtained by using the method of subordination function method and accumulation analysis.