摘要： 旨为分析不同西瓜品种在发芽期的耐冷特性、苗期的生长特性、光合作用及生理生化方面的差异,筛选出西瓜耐冷性的综合鉴定指标和鉴定方法,为实际生产上选育耐冷性的西瓜种质资源提供依据。通过对12份西瓜材料进行耐冷性比较,初步筛选出3个耐冷性不同的西瓜材料,对这3个材料进行低温处理。结果表明:不同处理时间下,各品种的冷害指数有差异。通过测定处理6 d和8 d时的冷害指数,得出各品种耐低温性强弱,从中选出耐低温性品种红野一号、中等耐低温性品种抗病苏蜜和冷敏感品种橙兰。15 ℃低温条件下,耐冷性品种红野一号的发芽率、相对发芽率、胚根长及相对胚根长最高。15 ℃可作为西瓜种子发芽期耐低温性鉴定的适宜温度;种子的始发芽日期、相对发芽率、相对胚根长可作为西瓜芽期耐低温鉴定指标。三叶一心的西瓜幼苗低温处理后,植株的生长量降低,光合速率下降,植株叶片的酶活性增加,MDA含量上升,各指标的变化幅度与低温处理强度及品种自身耐冷性相关。得出植株的株高、叶面积、株鲜质量、根干质量、净光合速率(Pn)、Chl a/b比值、MDA含量的变化幅度可作为西瓜耐低温品种筛选的鉴定指标。

关键词: 西瓜, 低温, 生长指标, 光合参数, 生理生化指标

Abstract: 12 different genotypes of watermelon seedings were studied in low temperature stress treatment,and selected three different cold tolerant watermelon materials.The cold tolerance of 3 watermelon materials seeds during the germination were analyzed with five different temperature, study of low temperature,weak light resistance in watermelon seedings and the change of growth characteristic,photosynthesis and physiological and biochemical characteristics under low temperature,to develop an efficient,comprehensive appraisal index and evaluation method for cold-resistance watermelon,the purpose of this study was to provide theoretical basis for the actual production breeding for low temperature,weak light watermelon germplasm resources.The results showed that the chilling injury index of each genotype was different under different processing time.It is concluded that each type of cold resistance strength through the determination of chilling injury index in 6 and 8 days treatment,and choose Hongyeyihao as cold tolerant germplasm,moderately cold resistance varieties gerplasm Kangbingsumi and cold sensitive germplasm Chenglan.Under 15 ℃,Hongyeyihao germination rate,relative germination rate,length of radicle and relative radicle were the highest,15 ℃ can be used as a watermelon seed germination period of low temperature resistance identification of appropriate temperature; Date of the beginning of seed germination and relative germination rate,relative radicle length can be used as a watermelon bud good low temperature resistance appraisal indicators.After low temperature treatment,plant growth,photosynthetic rate decreased,the enzyme activity of leaves increased,MDA content increased,the change range of each index associated with varieties of low temperature treatment intensity and its cold resistance.Plant height,leaf area,plant fresh weight,root dry weight,the leaf net photosynthetic rate(Pn),Chl a/b ratio,MDA content as watermelon varieties of resistance to low temperature screening appraisal indicators.

Key words: Watermelon, Low temperature, Growth index, Photosynthetic parameter, Physiological and biochemical indicators

中图分类号: 

• S651.01