低温胁迫下巴旦杏的形态生理变化及抗寒性研究

 莎车1号、英吉沙2号和莎车18号是新疆喀什地区巴旦杏的主栽品种。通过测定低温胁迫下细胞膜透性、叶绿素荧光参数的变化,对巴旦杏品种的抗寒性进行了比较研究,并进行了冻害分级。结果表明,随处理温度降低,相对电导率逐渐增加,枝条细胞膜受损程度在加重。引起巴旦杏品种低温伤害的临界温度范围为-24～-27 ℃,3个品种枝条半致死温度（LT50）分别为-24.9 ℃、-29.3 ℃、-27.7 ℃,英吉沙2号的抗寒性较强。随处理温度降低,巴旦杏枝条基础荧光（Fo）值逐渐上升,至某一温度达到峰值后开始下降,光系统（PSⅡ）最大光化学效率（Fv/Fm）值呈明显下降趋势。-24～-27 ℃左右的低温会造成PSⅡ结构的损伤,且品种抗寒性越差,PSⅡ结构受损越明显。综合分析结果表明,供试的3个巴旦杏品种中, 英吉沙2号抗寒性较强,莎车18号次之,莎车1号抗寒性较弱。

Morphological and Physiological Characteristics of Almond under Low Temperature Stress and Its Cold Resistance

Shache No.1,Yingjisha No.2 and Shache No.18 are the main cultivars of Almond in Kashgar region of Xinjiang,China.The permeability of plasma membrane and chlorophyll fluorescence of the different cultivars of Almond under different low temperature stress were measured to research characteristic changes and their cold resistance with the one year old dormant branches of the cultivars as tested materials.Results showed that the relative conductivity increased,and the damage to plasma membrane increased with decrease of temperature.The critical freezing temperature resulting in damage to the cultivars of Almond ranged from-24 ℃ to-27 ℃.The semilethal temperature of Shache No.1,Yingjisha No.2 and Shache No.18 were-24.9 ℃,-29.3 ℃,-27.7 ℃,respectively.The minimum fluorescence(Fo) of Almond increased firstly with decrease of temperature,and then decreased after reaching a peak value at typical temperature.The maximum photochemical efficiency(Fv/Fm) decreased evidently with decrease of temperature.The damage to photosystem Ⅱ(PSⅡ) could be induced by low temperature of-24~-27 ℃,and the weaker the cold resistance was,the obvious the damage was.Comprehensive analysis to these three cultivars of almond showed that Yingjisha No.2 had the strongest cold resistance,followed by Shache No.18,and the cold resistance of Shache No.1 was the worst.