摘要
针对构树幼苗抗逆性的性别差异影响种群密度、种群性比等特征,而实生苗难以区分性别的问题。以盆栽构树(Broussonetia papyrifera)雌雄扦插幼苗为材料,设轻、中、重度干旱处理60d后,测定叶片性状、光合色素组成、光合参数等等指标,分析干旱强度对幼苗光合作用影响的性别差异。结果表明:(1)干旱对构树幼苗光合叶面积影响有显著性别差异(P<0.05),雌株通过减少叶片数,雄株通过缩小单叶面积、增加叶片厚度应对干旱,雌株光合总叶面积显著低于雄株(P<0.05);(2)干旱显著影响幼苗光合色素组成与含量(P<0.05),干旱对色素含量影响顺序为Caro>Chla+b>Chla>Chlb>Chla/b,雌株Chla与Chla+b显著大于雄株(P<0.05),Chlb、Caro含量和Chla/b无性别差异(P>0.05);(3)干旱显著影响光合参数(P<0.05),轻度干旱利于Pn和Gs,中度干旱利于Tr与Ci,重度干旱抑制了光合作用,性别对光合参数有显著影响(P<0.05),影响顺序为Tr>Pn>Ci>Gs,雄株现实Pn大于雌株,而潜在Pn小于雌株。综上,雌雄幼苗采取不同的光合叶面积、光合色素、光合速率调整策略应对干旱,雄株光合能力强于雌株。
It is difficult to identify the gender of dioecious seedlings,and the population characteristics are easily affected by the gender differences of seedling stress resistance.The male and female cuttings of Broussonetia papyrifera were treated for 60 days at mild,moderate and severe drought respectively,and leaf characteristics,photosynthetic pigments and photosynthetic parameters were measured to analyze the gender differences of the effects of drought intensity on photosynthesis of seedlings.The results showed that:(1)There was a significant gender differences in drought stress on the photosynthetic leaf area of the seedlings(P<0.05).The female plants responded to drought by reducing leaves number and the male plants by reducing single leaf area and increasing leaf thickness,but total photosynthetic leaf area of female plants was significantly lower than that of male plants(P<0.05).(2)Drought stress significantly affected the composition and content of photosynthetic pigment in seedlings(P<0.05),and the order was Caro>Chla+b>Chla>Chlb>Chla/b.Chla and Chla+b content of female plants were significantly higher than those of male plants(P<0.05),but there were no gender differences in Chlb,Caro content and Chla+b(P>0.05);(3)Drought stress significantly affected photosynthetic parameters of seedlings(P<0.05),and mild drought was beneficial for Pn and Gs,moderate drought was beneficial for Tr and Ci,severe drought inhibited photosynthesis.Gender had significant influence on photosynthetic parameters(P<0.05),the order of the influence was Tr>Pn>Ci>Gs.The actual Pn of male plants was higher than female plants,while the potential Pn was lower than that of female plants.In conclusion,male and female seedlings adopt different strategies of adjusting photosynthetic leaf area,pigment and photosynthetic rate to cope with drought and the photosynthetic capacity of male plants was stronger than that of female plants.
作者
苟蓉
游明鸿
白史且
刘金平
曾晓琳
GOU Rong;YOU Minghong;BAI Shiqie;LIU Jinping;ZENG Xiaolin(Key Laboratory of Southwest China Wildlife Resources Conservation(Ministry of Education),China West Normal University,Nanchong 637002,China;SichuanAcademy of Grassland Sciences,Chengdu 611731,China)
出处
《四川林业科技》
2020年第6期1-7,共7页
Journal of Sichuan Forestry Science and Technology
基金
四川省科技计划(2019YFN0022)
四川省植物资源共享平台(TJPT20160021)。
关键词
构树
雌雄异株
干旱
光合作用
扦插苗
Broussonetia papyrifera
Dioecism
Drought
Photosynthesis
Cuttage
