赣25个油茶优良品种的耐热性比较

Heat tolerance comparisons for 25 cultivars of Camellia oleifera

高温是影响经济林产品产量和质量的主要气候问题之一。为了探讨不同油茶Camellia oleifera品种的耐热性是否存在差异,以江西省林业科学院油茶种质资源圃25个油茶优良品种的叶片为材料,叶片分别经30 min的40,45,50,55,60和65℃高温处理,用电导法测定相对电导率并配合Logistic方程(y=k/(1+ae-bt)测定了其半致死温度(TL50)。根据半致死温度的高低把25个油茶品种分为3个类型:①TL50≥50℃(耐热型),其中有赣190,赣55,赣石84-3,赣447,赣71和赣无24;②45≤TL50<50℃(中间型),包括赣68,赣8,赣无11,赣兴46,赣无16,赣70,赣永5,赣77024,赣6,赣无12,赣无2,赣抚20,赣石83-4,赣无1;③TL50<45℃(感热型),包括赣无15,赣兴48,赣石83-1,赣石84-8,赣永6。水培条件下的大树枝条经过不同高温处理的形态特征变化和半致死温度结果一致。油茶的抗热性差异极显著(P<0.01)。

High temperature has been a major climatic issue affecting yield and quality of economic non-timber forest products. In order to identify the differences of heat tolerance among Camellia oleifera cultivars, the study was based on the leaves of 25℃. oleifera cultivars in the C. oleifera germplasm nursery in Jiangxi Academy of Forestry, which are respectively treated with the temperatures of 40, 45, 50, 55, 60 and 65 ℃ （control） for 30 min, and determined the semi-lethal temperatures （TL50） by conductivity method and logistic equation（y=k/（ l＋ae^bt） ）. According to the the semi-lethal temperatures, the 25 C. oleifera cuhivars were classified into three types： 1） TL50 ≥50 ℃ （heat-resistant type： 6 cultivars）, 2） 45 ℃ ≤TL50〈50℃（medium-re- sistant type： 14 cultivars）, and 3） TL50〈45℃ （heat-sensitive type： 5 cultivars）. These results showed im- portant differences in heat tolerance of C. oleifera cuhivars, which was similar to TL50 results for morphological characteristics of hydroponic cuttings at different high temperature stresses. The result will provide theoretical references for the study of heat resistance and directive breeding of C. oleifera. [Ch, 1 fig. 2 tab. 26 ref. ]