摘要
以白BK-1黑麦和冬牧70黑麦为供试材料,对种子萌发期和幼苗期黑麦的耐寒性进行了比较,探究了黑麦幼苗应对低温胁迫(4℃)的生理机制。结果表明,白BK-1在低温下种子发芽率、发芽势、根长、芽长和幼苗生物量等指标均优于冬牧70,耐寒性强于冬牧70。低温胁迫损害了黑麦叶肉细胞光合组织,净光合速率大幅度下降,白BK-1净光合速率降低幅度较小,且恢复生长后净光合速率恢复较高。随着胁迫时间的延长,黑麦叶片叶绿素含量呈先增后减的趋势,叶绿素a/b降低。低温胁迫下黑麦叶片丙二醛含量增加,白BK-1叶片中丙二醛含量增幅较小。随着低温胁迫时间的增加,黑麦叶片渗透调节物质含量增加,抗氧化酶活性先升高后降低。白BK-1黑麦通过维持较高的净光合速率和抗氧化酶活性,加速积累可溶性糖、脯氨酸以降低低温胁迫造成的损伤。
This study investigated the physiological mechanism underlying cold resistance differences between two rye(Secale cereale)cultivars,White BK-1 and Dongmu-70,during seed germination and seedling stages.The results showed that seed germination rate,germination potential,root length,stem length,and seedling biomass were all significantly greater in White BK-1 compared to Dongmu-70 under cold stress(4℃),indicating superior cold tolerance.Low temperature exposure resulted in damage to photosynthetic tissues within rye mesophyll cells,leading to a significant decrease in net photosynthetic rate(Pn).White BK-1 exhibited a smaller reduction in Pn and a faster recovery rate after stress alleviation.Chlorophyll content in rye leaves initially increased with prolonged cold stress,followed by a subsequent decline.Additionally,chlorophyll a/b ratio decreased under cold conditions.Malondialdehyde(MDA)content increased in rye leaves under cold stress,but to a lesser extent in White BK-1.Exposure to cold stress triggered the accumulation of osmotic regulators in rye leaves,while antioxidant enzyme activity exhibited a biphasic response,initially increasing and then declining.White BK-1 displayed a more robust response to cold stress by maintaining higher levels of soluble sugars and proline accumulation,as well as sustaining greater Pn and antioxidant enzyme activity.
作者
杨朝伟
安明珠
任伟
王丹
孙伟红
耿飞龙
王显国
YANG Chaowei;AN Mingzhu;REN Wei;WANG Dan;SUN Weihong;GENG Feilong;WANG Xianguo(College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China)
出处
《中国草地学报》
CSCD
北大核心
2024年第6期1-9,共9页
Chinese Journal of Grassland
基金
国家牧草产业技术体系(CARS-34)。
关键词
黑麦
种子萌发
幼苗生长
低温胁迫
生理机制
Rye
Seed germination
Seedling growth
Cold stress
Physiological mechanism
