低温胁迫对扁桃优株生理特性的影响

Effect of Low Temperature on Physiological Characteristics of Almond Strains

以2个扁桃优株(先锋一号、桃巴旦)后代叶片为试验材料,设置5个温度水平(4(CK)、2、0、-2、-4℃)和4个处理时间(1、2、3、4 h),探究低温处理期间2个扁桃优株膜结构稳定性、过氧化物酶活和渗透调节物质含量的变化,以期筛选出抗寒性较好的优株,为扁桃实生后代优株选择提供帮助。结果表明,在同一低温-4℃胁迫处理下,先锋一号的后代的相对电导率、丙二醛含量、过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性、多酚氧化酶(PPO)活性随处理时间延长均呈先降后升的趋势,桃巴旦的后代的相对电导率、丙二醛含量则呈递增趋势,在-4℃、4 h处理下达到最大值,桃巴旦后代的可溶性蛋白、可溶性糖、脯氨酸、SOD活性、苯丙氨酸解氨酶(PAL)活性随处理时间延长呈先降后升的趋势。在相同时间4 h处理下,先锋一号的后代的脯氨酸含量随着胁迫温度降低总体呈下降趋势,在-2℃、4 h处理下降幅最大;桃巴旦的后代的丙二醛、可溶性糖、脯氨酸含量、SOD活性含量随着胁迫温度降低总体呈上升趋势,其中脯氨酸含量和SOD活性在-4℃、4 h处理下增幅最大。桃巴旦后代的抗寒性显著优于先锋一号后代,其后代可以耐受更低的温度(-4℃)和更长时间的低温。桃巴旦后代的抗寒性突出,在实际生产中可作为优良砧木。

In this study,with two almond strains(Xianfeng 1,Taobadan)offspring leaves as test material,five temperature level(4(CK),2,0,-2,and-4℃)and 4 processing time(1,2,3,and 4 h)were set to explore during the low temperature treatment,membrane structure stability,change of peroxidase activity and osmotic material content of the two almond strains,in order to screen out the strains with better cold resistance,provide help for selcection of almond offspring strains.The results showed that under the same low-temperature stress treatment of-4℃,the relative conductivity,malondialdehyde content,activity of peroxidase(POD),superoxide dismutase(SOD),and polyphenols oxidase(PPO)of Xianfeng 1 offspring all decreased first and then increased with the extension of treatment time.The relative conductivity and malondialdehyde content of the Taobadan offspring showed an increasing trend,reaching the maximum values under the treatment of-4℃and 4 h.The content of soluble protein,soluble sugar,and proline,the activity of SOD and phenylalanine ammonia lyase(PAL)of Taobadan offspring decreased first and then increased with the extension of treatment time.At the same time of 4h treatment,the proline content of Xianfeng 1 offspring showed a trend of overall decrease and the decreasing range was the highest under the treatment of-2℃and 4 h.The content of propanondialdehyde,soluble sugar,and proline,the SOD activity of Taobadan offspring showed a trend of overall incrase and the increasing range of the proline content and the SOD activity was the highest under the treatment of-4℃and 4 h.The cold resistance of Taobadan offspring was significantly better than that of Xianfeng 1.The Taobadan offspring could be tolerate to lower temperature(-4℃)and longer duration.Therefore,the Taobadan offspring had the outstanding cold resistance and could be used as the excellent stock in production.