摘要
以贯叶金丝桃Hypericum perforatum种子为材料,设置不同温度及干旱条件下萌发试验,并于室温(25℃)下观察种子动态吸水规律。结果表明,贯叶金丝桃种子吸水率变化呈现出“快速(0~4 h)—缓慢(4~20 h)—饱和(20~30 h)”规律。随温度升高种子发芽起始时间提前,发芽率、发芽势、发芽指数、活力指数、根长、苗长等发芽指标呈先增后降趋势,且均在25℃时达最大值。随PEG浓度增加种子萌发质量降低,发芽启动时间延长,25%PEG抑制种子萌发。种子萌发期抗旱能力受温度影响,适宜温度25℃时种子抗旱性最强。温度对贯叶金丝桃幼苗胚根和苗长具显著调控效应。20℃处理下胚根与苗长达最大值;30℃高温显著抑制生长,15℃亦表现受限,随温度升高呈先促进后抑制趋势。研究表明,贯叶金丝桃种子浸泡20 h达到吸水饱和;种子萌发适宜温度为25℃,幼苗生长适宜温度为20℃;干旱承受PEG溶液浓度的阈值为25%;萌发适宜温度下种子抗旱性增强。
Seeds of Hypericum perforatum were germinated under factorial combinations of temperature(15-30℃)and osmotic stress(0-25%PEG-6000).Water-uptake kinetics at 25℃ displayed a triphasic pattern:rapid imbibition(0-4 h),deceleration(4-20 h)and saturation(20-30 h).Rising temperature shortened the lag phase and advanced germination onset;however,all germination metrics—percentage,energy,index,vigour,radicle and seedling length—reached maxima at 25℃ and declined sharply at 30℃.PEG-mediated drought progressively delayed and reduced germination,with 25%PEG imposing complete inhibition.Drought tolerance was temperature-dependent,peaking at 25℃.Radicle and seedling elongation were greatest at 20℃,significantly curtailed at 15℃and 30℃,indicating a stimulatory-to-inhibitory transition with increasing temperature.Thus,seeds achieve full hydration within 20 h;25℃is optimal for germination,whereas 20℃ best supports seedling growth.The osmotic threshold lies at 25%PEG,and drought resistance is maximised under the optimal germination temperature.
作者
刘媛媛
陈垣
郭凤霞
梁伟
阮梓涵
LIU Yuan-yuan;CHEN Yuan;GUO Feng-xia;LIANG Wei;RUAN Zi-han(College of Agriculture,Gansu Agricultural University/State Key Laboratory of Crop Science in Arid Habitat,Lanzhou 730070,Gansu China;College of Life Science and Technology,Gansu Agricultural University,Lanzhou 730070,Gansu China;Sichuan Kanghong Chinese Medicine Cultivation Co.Ltd.,Pengzhou 611930,Sichuan China)
出处
《亚热带植物科学》
2025年第3期284-291,共8页
Subtropical Plant Science
基金
校企合作企业项目“贯叶金丝桃新品种选育”(KHZZZZ20210730056/2021620005001562)。
关键词
贯叶金丝桃
吸水规律
温度
干旱胁迫
种子萌发
Hypericum perforatum
water absorption pattern
temperature
drought stress
seed germination
