摘要
以杜梨(Pyrus betulaefolia Bunge.)和豆梨(Pyrus calleryana Decne.)2a生实生苗为材料进行盆栽控水试验,对持续性梯度干旱胁迫处理下梨砧木幼苗生长、叶片光合特性及色素含量、叶绿素荧光特性的变化进行研究,为梨树苗期栽培管理和耐旱砧木的选育提供理论参考。结果表明:干旱胁迫使梨砧木新梢相对生长量下降,生长速率减缓,杜梨受胁迫的影响程度明显小于豆梨。2种砧木幼苗净光合速率(Pn)均在干旱胁迫下逐渐下降,不同程度干旱处理间下降趋势存在差异,豆梨在中度和重度干旱处理45d时Pn值分别下降44.81%和78.04%,而杜梨则分别下降了36.8%和74.5%。叶绿素含量在干旱胁迫下呈现相似变化规律。杜梨和豆梨在干旱条件下的最大光化学效率(Fv/Fm)、实际光化学量子效率(ΦPSⅡ)、光化学猝灭系数(qP)和电子传递效率(ETR)均呈下降趋势,最小初始荧光(F0)和非光化学猝灭系数(NPQ)均显著增加,在45 d时轻度、中度、重度干旱分别使杜梨的NPQ值提高21.7%、42.7%和68.9%,而豆梨提高12.0%、42.4%和53.0%。可见,水分亏缺使梨砧木叶片叶绿素含量降低,叶片发生了光抑制,光系统Ⅱ(PSⅡ)受到破坏,光合作用明显减弱,从而抑制新梢枝条生长。但杜梨相较于豆梨能够更有效地保护光合机构,以应对胁迫对其的破坏。
The two-year-old seedlings of Pyrus betulaefolia Bunge and Pyrus calleryana Decne were used as materials to conduct potted water control tests,the change characteristics of the growth,photosynthesis,the contents of chlorophyll and carotenoid,chlorophyll fluorescence parameters were studied,this wouldlay foundation for pear seedlings cultivation and drought-tolerant rootstocks breeding.The results showed that the relative growth and the new shootsgrowth rate of pear rootstocksdecreased under drought stress,P.betulaefolia Bunge was less affected by stress than P.calleryana Decne.The net photosynthetic rate(P n)of the two kinds of rootstocks gradually decreased under drought stress,and there were significant differences among different drought treatments.The Pn value of P.calleryana Decne decreased by 44.81%and 78.04%after 45 days under treatments of moderate and severe drought respectively,while that of P.betulaefolia Bunge decreased by 36.8%and 74.5%respectively.There was a consistency between the change trend of chlorophyll content and net photosynthetic rate.The maximum photochemical efficiency(Fv/Fm),actual photochemical quantum efficiency(ΦPSⅡ),photochemical quenching coefficient(q P)and electron transport efficiency(ETR)of both P.betulaefolia Bunge and P.calleryana Decne decreased,the minimum initial fluorescence(F0)and non-photochemical quenching coefficient(NPQ)significantly increased.At 45 days,the NPQ value of P.betulaefolia Bunge increased by 21.7%,42.7%,68.9%,while P.calleryana Decne increased by 12.0%,42.4%,53.0%under the mild,moderate and severe drought stress respectively.Therefore,the chlorophyll content reduced,the leaves of the pear rootstocks were photoinhibitedand the photosystemⅡ(PSⅡ)was destroyed in case of water deficit,the photosynthesis of both the leaves of Pyrus betulaefolia Bunge.and Pyrus calleryana Decne seedlings were obviously weakened,and the shoot growth were inhibited.However,damages caused by stress,photosynthetic apparatus in P.betulaefolia Bunge could be protected more e
作者
解斌
李俊豪
赵军
朱霄飞
李六林
XIE Bin;LI Junhao;ZHAO Jun;ZHU Xiaofei;LI Liulin(College of Horticulture,Shanxi Agricultural University,Taigu Shanxi030801,China;Agricultural Service Center of Bieqiao Town,Liyang Jiangsu213321,China;Qixian Service Center for Fruit Tree Industry,Qixian Shanxi030900,China)
出处
《西北农业学报》
CAS
CSCD
北大核心
2019年第5期753-761,共9页
Acta Agriculturae Boreali-occidentalis Sinica
基金
山西省重点研发计划(农业)(201703D221015-1,201703D221015-2)~~
关键词
梨砧木
干旱胁迫
生长
光合作用
叶绿素荧光参数
Pear rootstock
Drought stress
Growth
Photosynthesis
Chlorophyll fluorescence parameters
