盐胁迫下杨树质外体离子对气体交换参数的影响(英文)  

Effects of Apoplastic Ion Contents in the Tender Stems of Two Populus Cultivars on Gas Exchange Parameters Under Salt Stress

作　　者：马金龙[1,2] 姜国斌[3] 姚善泾[1] 金华[3] 

机构地区：[1]浙江大学化学与生物工程系,杭州310027 [2]大连民族学院生命科学学院,大连116600 [3]大连民族学院环境与资源学院,大连116600

出　　处：《林业科学》2013年第7期40-47,共8页Scientia Silvae Sinicae

基　　金：National Natural Science Foundation of China(30872004);Fundamental Research Funds for the Central Universities(DC12010305,12010204)

摘　　要：利用微透析技术,研究盐胁迫下吴屯杨和小胡杨嫩茎质外体中离子的动态变化对气体交换参数的影响。杨树嫩茎质外体离子采用微透析与原子吸收联用进行监测,同时采用Li-6400便携式光合仪进行气体交换相关参数的测定。盐胁迫下,2个杨树品种嫩茎质外体中Na+积累的程度不同,吴屯杨经过一段时间后能够自我调节,减少Na+含量,而小胡杨质外体一直积累Na+,从而造成细胞的渗透胁迫,抑制植物生长;随着盐处理时间的增加,2种杨树K+浓度基本呈现下降的趋势。吴屯杨在100mmol·L-1NaCl胁迫早期光合受抑制的主要原因是非气孔限制,后期是气孔限制;而小胡杨光合受抑制的主要原因是气孔限制。对Na+浓度、K+浓度、Ca2+浓度、Na+/K+、Pn进行相关性分析发现,2个杨树品种Pn均与Na+浓度和Na+/K+比值呈显著的负相关,与K+浓度呈极显著的正相关。以Pn为因变量,以Na+,K+,Ca2+浓度和Na+/K+为自变量,进行多元线性逐步回归分析得统计方程,其中只有Na+/K+对Pn的相关系数有显著意义,方程中只有Na+/K+进入方程,其他3个离子都被剔除。盐胁迫下,吴屯杨耐盐性强于小胡杨,统计方程说明盐胁迫下杨树嫩茎质外体离子变化和光合作用存在共线性关系,且Na+/K+对Pn有显著的线性关系。In this paper we investigated effects of apoplastic ion dynamic changes in the tender stems of Populus wutunenses and ＂P.simonii×P. euphratica＂×P. sp. on gas exchange parameters under salt stress. The apoplastic ions were monitored by microdialysis and atomic absorption, and the gas exchange parameters were determined with a portable photosynthesis system. The net photosynthetic rates （Pn） of the two poplar cultivars all decreased with increasing salt-treated duration. The stomatal conductance （Gn） and intercellular CO2 concentration （Ci） of P.×wutunenses increased and then decreased, whereas its stomatal limitation （Ls） exhibited a contrary changing trend. The Gn and Ci of ＂P. simonii×P. euphratica＂×P. sp. gradually reduced, whereas its Ls increased gradually. The results indicated that the photosynthetic inhibition of P.×wutunenses under the stress of 100 mmol·L^-1 NaCl resulted from non-stomatal limitation and stomatal limitation successively, whereas that of ＂P. simonii×P. euphratica＂×P. sp. resulted from stomatal limitation throughout the entire experiment. PnS of the two poplar cultivars were negatively correlated with Na^＋ concentration and Na^＋/K^＋ ratio significantly, however were positively correlated with K^＋ concentration extremely significantly. A multiple linear stepwise regression analysis was performed with Pn as the dependent variable, and Na^＋, K^＋, Ca2＋ concentrations and Na^＋/K^＋ as the independent variables. Pn was only significantly correlated with Na^＋/K^＋ aomg those independent variables. P.×wutunenses was more salt-tolerant than ＂P. simonii×P. euphratica＂×P. sp. under salt stress. The statistical equation showed that apoplastic ion contents in the tender stems of poplar cultivars were collinearly correlated with their photosynthesis performance under salt stress.

关 键 词：盐胁迫 杨树 质外体 离子 光合作用 

分 类 号：S718.43[农业科学—林学]