摘要
【目的】探究油茶在干旱胁迫和复水处理下生长、光合作用及其他生理指标的变化规律,为油茶抗旱机制研究及抗旱品种选育提供参考。【方法】以江西油茶产区主推的3个品种‘赣兴48’‘赣无1’‘长林53’2年生油茶嫁接苗为试验材料,采用盆栽控水的方式进行干旱胁迫和复水处理,于干旱0、10 d和复水10 d时调查不同油茶品种的生长情况,并测定光合参数、叶片解剖结构及相关生理指标,运用主成分分析法和隶属函数分析法综合评价3个油茶品种的抗旱性。【结果】干旱胁迫下,各品种油茶植株均出现叶片卷曲、枝干下垂等萎蔫现象,叶片厚度(LT)、上下表皮厚度(UT、UCT)、组织结构紧密度(CTR)以及根系活力等均不同程度下降,角质层(LUT)明显增厚。其中,‘赣无1’的LT降幅最大(14.82%),‘长林53’ECT、SR的增幅最大,分别为29.44%、2.13%。与干旱0 d相比,干旱10 d后‘长林53’净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(G_(s))降幅最大,分别为64.15%、66.6%、65.32%;‘赣无1’的P_(n)、T_(r)、G_(s)的降幅最小,且显著高于其余品种。根据各品种的P_(n)、Ci、G_(s)在干旱过程的变化趋势,可知‘赣无1’和‘赣兴48’的P_(n)下降受气孔限制,而‘长林53’的P_(n)下降受非气孔因素影响。在生理特性方面,干旱胁迫导致根系活力和叶绿素(Chl)含量显著下降,叶片相对电导率(REC)和丙二醛(MDA)含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)等抗氧化酶活性、可溶性糖含量(SS)、可溶性蛋白含量(SP)以及脱落酸(ABA)含量明显增加。其中,‘长林53’MDA和SS含量增幅(19.85%、67.31%)且含量最高(120.82 nmol·g^(-1)、94.23 mg·g^(-1)),SOD含量增幅最大(40.21%),但含量最低(765.21μg·g^(-1));‘赣兴48’POD和ABA含量最高且升幅最大,分别提高了40.21%和11.77倍。复水10 d后,3种油茶幼苗的叶片解剖结构、Chl含量、POD活性、SOD活性、可溶性糖含量和MDA含量基本恢复到正常水平,根系活力出现超补偿效应,而叶片REC、可溶性蛋白和ABA含量整体仍显著高于正常水平。不同品种油茶光合特性的恢复程度出现差异,其中‘长林53’P_(n)、G_(s)、T_(r)仍显著低于正常水平,其余2种油茶的P_(n)、G_(s)、T_(r)基本恢复到正常水平。利用主成分分析得出各品种综合评价得分大小依次为:‘赣无1’>‘赣兴48’>‘长林53’。【结论】油茶幼苗具有一定的抗旱能力。在干旱胁迫和复水处理过程中,不同品种的油茶幼苗在生长、光合特性、生理指标中存在明显差异。通过各项指标综合评价得出:其中‘赣无1’抗旱性较强,其次为‘赣兴48’,‘长林53’的抗旱性较差。
【Objective】To explore the changes of leaf anatomy,photosynthetic characteristics and other physiological indexes of Camellia oleifera under drought stress and rehydration,so as to provide a reference for the study of drought tolerance mechanism and the breeding of drought-tolerant cultivars of C.oleifera.【Method】Three cultivars of C.oleifera‘Ganxing 48’,‘Ganwu 1’and‘Changlin 53’two year old seedlings which were mainly promoted in Jiangxi C.oleifera production area were used as experimental materials.Pot water control was used to simulate drought stress and rehydration test.The growth of C.oleifera,photosynthetic parameters,leaf anatomical structure and related physicochemical indexes of the three C.oleifera cultivars were measured at 0,10 days of drought and 10 days of rehydration,and the drought resistance of the three C.oleifera cultivars was comprehensively evaluated by principal component analysis and membership function analysis.【Result】Under drought stress,all cultivars of C.oleifera plants exhibited wilting phenomena such as leaf curling and branch drooping,leaf thickness(LT),upper(UT)and lower epidermal thickness(UCT),organizational tightness(CTR)and root vigor decreased to varying degrees,and the cuticle layer(LUT)increased significantly.Compared with the drought for 0 days,the net photosynthetic rate(P_(n)),transpiration rate(T_(r))and stomatal conductance(G_(s))of‘Changlin 53’decreased the most after 10 days of drought,which were 64.15%,66.6%and 65.32%,respectively.The decreases of P_(n),T_(r) and G_(s) of‘Ganwu 1’were the smallest and significantly higher than those of other cultivars.According to the variation trend of P_(n),T_(r) and G_(s) of each cultivar during the drought process,it can be seen that the P_(n),decline of‘Ganwu 1’and‘Ganxing 48’was limited by stomatal factors,while the P_(n),decline of‘Changlin 53’was affected by non-stomatal factors.In terms of physiological characteristics,drought stress led to a significant decrease in root vigor and chlorophyll(Chl)content,while leaf relative conductivity(REC),malondialdehyde(MDA)content,superoxide dismutase(SOD)and peroxidase(POD)activities,soluble sugar(SS),soluble protein(SP)content and abscisic acid(ABA)content increased significantly.Among them,the contents of MDA and SS increased(19.85%and 67.31%)and had the highest content(120.82 nmol·g^(-1) and 94.23 mg·g^(-1)),and the content of SOD increased the most(40.21%)but the lowest(765.21μg·g^(-1)).‘Ganxing 48’had the highest POD and ABA contents and the largest increases,increasing by 40.21%and 11.77 times.After 10 days of rehydration,the leaf anatomy,Chl content,POD and SOD activity,soluble sugar and MDA content of the three C.oleifera seedlings basically returned to normal levels,while the root activity showed an overcompensating effect,and the contents of REC,soluble protein and ABA in leaves were significantly higher than the normal levels.There were differences in the degree of recovery of photosynthetic characteristics of different cultivars of C.oleifera,among which the P_(n),G_(s) and T_(r) of‘Changlin 53’were still significantly lower than the normal levels,while the P_(n),G_(s) and T_(r) of the other two C.oleifera cultivars basically returned to normal levels.The comprehensive evaluation scores of each cultivar are as follows:‘Ganwu 1’>‘Ganxing 48’>‘Changlin 53’.【Conclusion】C.oleifera seedlings have a certain drought resistance.During the process of drought stress and rehydration treatment,there were obvious differences in the growth,photosynthetic characteristics and physiological indexes of different cultivars of C.oleifera seedlings.Through the comprehensive evaluation of various indicators,it was concluded that‘Ganwu 1’had strong drought resistance,followed by‘Ganxing 48’and‘Changlin 53’.
作者
叶甜甜
左继林
周文才
李晚根
黄建建
YE Tiantian;ZUO Jilin;ZHOU Wencai;LI Wangen;HUANG Jianjian(Jiangxi Academy of Forestry,Nanchang 330032,Jiangxi,China;Key Laboratory of Cultivation and Utilization of Oil Tea Resources in Jiangxi Province,Nanchang 330032,Jiangxi,China;Wanzai County Ecological Public Welfare,Wanzai 336100,Jiangxi,China)
出处
《中南林业科技大学学报》
北大核心
2025年第11期42-54,共13页
Journal of Central South University of Forestry & Technology
基金
江西省林业局油茶研究专项(YCYJZX〔2023〕121号)
江西省油茶种质资源库项目(20212BCD46002)。
关键词
油茶
干旱胁迫
复水处理
光合作用
生理响应
Camellia oleifera
drought stress
rehydration treatment
photosynthesis
physiological responses
