两个黑麦品种种子萌发期和幼苗期耐寒性差异及其生理机制
Contrasting Cold Tolerance and Underlying Physiological Mechanisms in Two Rye Varieties during Seed Germination and Seedling Stages
杨朝伟 1安明珠 1任伟 1王丹 1孙伟红 1耿飞龙 1王显国1
作者信息
- 1. 中国农业大学草业科学与技术学院,北京 100193
- 折叠
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.
Abstract
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 pho-tosynthetic 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.
关键词
黑麦/种子萌发/幼苗生长/低温胁迫/生理机制Key words
Rye/Seed germination/Seedling growth/Cold stress/Physiological mechanism引用本文复制引用
基金项目
国家牧草产业技术体系建设项目(CARS-34)
出版年
2024
NETL
NSTL
万方数据