用-(13)C示踪研究CO_2浓度倍增对枸杞光合产物积累的影响  

Effect of doubled CO_2 concentration on accumulation of photosynthate in Lycium barbarum by ^(13)C isotope tracer technique

作　　者：石元豹[1,2] 曹兵[1] 宋丽华[1] 汪贵斌[2] 

机构地区：[1]宁夏大学农学院,银川750021 [2]南京林业大学南方现代林业协同创新中心,南京林业大学林学院,南京210037

出　　处：《农业工程学报》2016年第10期201-206,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(31160172,30860227)

摘　　要：CO2作为光合作用的底物,其浓度的高低直接影响植物光合作用能力的大小,为探究近年来大气CO2浓度升高对宁夏枸杞光合产物的影响,应用碳同位素示踪技术与开顶气室法,测定分析2种CO2浓度(倍增浓度(720±20)μmol/mol;对照(360±20)μmol/mol)处理下宁夏枸杞苗木各器官中光合产物积累与分配的差异。结果表明:CO2浓度倍增处理下,宁夏枸杞叶片净光合速率、胞间CO2浓度、气孔导度、水分利用效率均明显高于对照;在速生期,叶片蒸腾速率较对照显著降低,在生长后期没有差异。CO2浓度倍增处理下,未进行标记的宁夏枸杞各个器官的13C自然丰度值相对于对照均有不同程度的下降。13C标记90 d时,对宁夏枸杞各器官在24 h、48 h和7 d的δ13C值进行测定,并与未标记之前的δ13C值比较发现宁夏枸杞叶片δ13C值在24 h最大,根和茎δ13C值在标记结束后48 h最大,之后开始下降,根部δ13C值下降的幅度较小,光合产物总体呈现的是叶向茎,再向根部转移的规律。在CO2浓度倍增处理90和120 d时,宁夏枸杞δ13C值在枸杞根、茎和叶中均有不同程度的升高。处理90 d时δ13C值较对照增加的百分比分别为茎(65.53%)>根(27.39%)>叶(18.05%),120 d时为果实(145.04%)>叶(143.56%)>根(49.96%)>茎(43.26%)。因此大气CO2浓度倍增,增强了宁夏枸杞的光合能力,增加了光合产物在各器官中的积累,在速生期光合产物在茎中的增加比例最大,而生长后期则在果实和叶中的增加比例较大。As the substrate of photosynthesis, carbon dioxide concentrations play an important role in plant growth and accumulation and distribution of photosynthate. In recent years, atmospheric carbon dioxide concentration is rising and is predicted to continue to rise in the future. The impact of atmospheric CO2 concentration enrichment on plant has become aresearch hotspot. Lycium barbarum is one of Ningxia important economic tree species, and the Lycium barbarum industry development will increase farmers′ income. In this research, we studied differences of accumulation and distribution of photosynthate in different organs of Lycium barbarum with two levels, one is doubled CO2concentration（（720±20） μmol/mol）and another one is natural environment of atmospheric CO2concentration（（360±20） μmol/mol）. The field-based open top chambers system was used to simulate the CO132 concentration with two standards, and carbon isotope（C） tracer technique was used to trace the destination of photosynthetic product. The photosynthetic parameter was measured in two Lycium barbarum growth stage to determine difference photosynthetic ability between treated trees and a control, and the value of13 C was also measured to indicate the influence of doubled CO2 concentration on accumulation of photosynthate in Lycium barbarum. The results showed that the photosynthetic parameters included net photosynthetic rate, intercellular CO2 concentration, stomatal conductance and water use efficiency of Lycium barbarum under doubled CO2 concentration rose significantly compared with those parameters of the control. The leaf transpiration rate under doubled CO2 concentration in rapid growth stage（90 d） was significantly lower than the control, but no difference in later stage of growth（120 d）. Compared with the control, the13 C natural abundance of all the four different organs（root, stem, leaf and fruit） of Lycium barbarum of the doubled CO2 concentration treatment was decreased. After13 C isotope labeling, and compa

关 键 词：CO2 光合 作物 宁夏枸杞 13C示踪技术 光合产物 开顶气室 

分 类 号：S567.1[农业科学—中草药栽培]