甘蔗种质资源自然条件下耐寒性评价

Evaluation on Cold Tolerance of Sugarcane Varieties under Field Conditions

为了解广西农业科学院甘蔗研究所种质资源圃(南宁)保存的400份甘蔗种质材料的耐寒性表现,在2008年初低温灾害的自然条件下,以蔗茎节间受害指数和节间生长点受害指数为基础,通过系统聚类方法将参试材料分为不同耐寒性表现类群。结果表明,2008年初的低温灾害属于阴雨霜冻类型,400份甘蔗种质材料可分为5个耐寒性表现类群,耐寒性强的材料有226份(56.50%),耐寒性较强的材料有103份(26.75%),耐寒性一般的材料有53份(13.25%),耐寒性较差的材料有7份(1.75%),耐寒性差的材料有7份(1.75%)。可构建甘蔗耐寒性指数(CTI):CTI=0.3×节间受害指数+0.7×节间生长点受害指数。节间生长点对低温伤害的敏感性高于蔗茎节间组织,建议作为耐寒性评价的重要指标之一;甘蔗耐寒性指数可以用于评价阴雨霜冻灾害下甘蔗种质材料的耐寒性。

An investigation was conducted in order to understand the cold tolerance of 400 accessions of sugarcane germplasm maintained in Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences at Nan- ning, China. Different cold tolerant groups were clustered based on internode and internode growing point injury in- dex by system clustering method during the extreme low temperature disaster in early 2008. The low temperature in early 2008 was a rainy frost type. The cold tolerance of 400 accessions of sugarcane germplasm could be divided in- to 5 groups, that is, strongest cold tolerance group, strong cold tolerance group, average cold tolerance group, poor cold tolerance group and poorest cold tolerance group, which include 226 （56.50%）, 103 （26.75%）, 53 （ 13.25% ） , 7 （ 1.75% ） and 7 （ 1.75% ） accessions of sugarcane germplasm, respectively. The Cold Tolerance Index （CTI） of sugarcane could be calculated as： CTI = 0.3 x internode injury index ＋ 0.7 x internode growing point injury index. The internode growing point was more sensitive than internode tissue for low temperature injury, and CTI could be used to evaluate the cold tolerance of sugarcane germplasm under rainy frost.