人工脱水对闽楠种子萌发特性的影响  

Effects of Artificial Dehydration on Germination Characteristics of Phoebe bournei Seeds

作　　者：黄锦 张俊红[1] 童再康[1] 杨琪 Huang Jin;Zhang Junhong;Tong Zaikang;Yang Qi(State Key Laboratory of Subtropical Silviculture Zhejiang A&F University,Hangzhou 311300)

机构地区：[1]浙江农林大学省部共建亚热带森林培育国家重点实验室,杭州311300

出　　处：《林业科学》2025年第4期249-256,共8页Scientia Silvae Sinicae

基　　金：国家自然科学基金青年基金项目(32201581);浙江省“十四五”农业新品种选育重大专项(2021C02070-10)。

摘　　要：【目的】探究人工脱水对闽楠种子生活力和萌发特性的影响,为解析闽楠种子失活和萌发受限机理提供参考。【方法】通过人工脱水处理,分析含水量40%(未脱水)、30%(轻度脱水)、20%(中度脱水)和10%(重度脱水)4种不同含水量种子的生理、生化和基因表达等,揭示不同脱水程度对闽楠种子生活力和种子萌发率的影响。【结果】闽楠种子生活力随脱水加重先升高后降低,轻度脱水(30%含水量)的种子发芽率最高达93%,甚至高于未脱水种子。重度脱水(10%含水量)导致种子丙二醛(MDA)含量上升,随脱水加重种子膜脂质过氧化程度加剧;过氧化物酶(POD)活性随脱水加重先升高,种子含水量10%时大幅降低。当闽楠种子贮存在25℃高湿环境下,30%和40%含水量的种子发霉率约为58%,重度脱水种子全部发霉。对种子萌发关键基因表达分析发现,随闽楠种子萌发进程负调控转录因子PbABI3均下调表达;PbFUS3、PbLEC2基因在30%含水量种子的胚根萌发初期即显著上调表达,在40%含水量种子中表达未显著改变。【结论】闽楠种子不耐脱水,种子生活力随脱水加重先升高后降低,中度(20%含水量)或重度(10%含水量)脱水种子发芽率大幅降低。重度脱水时种子内POD活性降低并受到氧化损伤。闽楠种子含水量变化能够诱导体内抗氧化酶系统的活性改变,并通过调节种子萌发关键基因PbABI3、PbFUS3、PbLEC2特异性表达,影响种子萌发。【Objective】This study aims to explore the effects of artificial dehydration on the viability and germination characteristics of Phoebe bournei seeds,so as to provide basis for understanding the mechanism of seed viability reduction and germination restriction of P.bournei seeds.【Method】The physiological and biochemical characteristics as well as gene expression of seeds with four different water contents of 40%(no dehydration),30%(mild dehydration),20%(moderate dehydration)and 10%(severe dehydration)were analyzed through artificial dehydration treatment,to reveal the effects of different dehydration degrees on P.bournei seed viability and germination rate.【Result】It was found that the seed viability of P.bournei first increased and then decreased with the increase of dehydration.The germination rate of seeds with mild dehydration(30%water content)was up to 93%,which was even higher than that of non-dehydrated seeds.Severe dehydration(10%water content)led to the increase of malondialdehyde(MDA)content,indicating that the degree of seed membrane lipid peroxidation increased with the increase of dehydration.Peroxidase(POD)activity first increased with increasing dehydration,but decreased significantly when seed water content reached 10%.When P.bournei seeds stored in 25℃and humidity environment,mold rate of seeds with 30%and 40%water content was about 58%,while severe dehydrated seeds were all moldy.The expression analysis of key genes involved in P.bournei seed germination showed that the negative regulatory transcription factor PbABI3 was down-regulated during seed germination.The expression of PbFUS3 and PbLEC2 genes was significantly up-regulated at the early stage of radicle growth in seeds with 30%water content,but not in seeds with 40%water content.【Conclusion】P.bournei seed does not tolerate dehydration,the viability of seeds increases first and then decreases with increasing dehydration.The germination rate of moderately dehydrated(20%water content)or severely dehydrated(10%water content)s

关 键 词：闽楠 种子萌发 脱水耐性 基因表达 

分 类 号：S718.3[农业科学—林学]