不同烤烟品种叶片光合特性和相关酶活性的叶位差异性分析  

Difference among leaves located on different plant positions in photosynthetic properties and relevant enzyme activities in three tobacco cultivars

作　　者：苏贤坤[1] 陈松[2] 张国平[2] 

机构地区：[1]贵州省烟草科学研究所,贵州贵阳550003 [2]浙江大学农业与生物技术学院农学系,浙江杭州310029

出　　处：《浙江大学学报（农业与生命科学版）》2009年第5期537-542,共6页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：贵州省烟草公司科技资助项目(05-05)

摘　　要：以3个主栽烤烟品种为材料,分析植株不同部位叶片的光合作用、叶绿素荧光参数以及与碳氮代谢有关的硝酸还原酶(NR)和蔗糖转化酶(INV)活性,以明确烤烟不同部位烟叶品质差异的生理机制.结果表明:打顶至此后40 d内,净光合速率(Pn)、气孔导度(gs)、蒸腾速率(Tr)在3供试品种中均表现为上部叶显著大于下部叶,且随着生育进程而下降,但下降速度因品种和叶位而异;叶绿素含量(SPAD值)在各品种间差异显著,但均表现为上部叶大于下部叶,且在生育过程中呈下降趋势,品种K326在后期的下降幅度明显大于品种云85和云87;量子产量(Fv/Fm)在品种间差异明显,云87在后期下降快于其他2个品种,下部叶片在生育期间的差异大于上部叶片,表现为打顶后先增大,后期变小;硝酸还原酶活性在生育期间呈下降趋势,3个供试品种之间差异明显,以K326的NR活性最大;各品种的蔗糖转化酶活性在上、下部叶片之间存在着很大的差异,品种间以K326的差异最小.上述结果表明,烟叶光合特性和相关酶活性在不同叶位间存在着很大的差异,而这种差异程度因品种而异.Experiments were conducted to study the mechanism of the difference in quality formation among the leaves located on different plant positions by measuring photosynthetic rate（Pn）, chlorophyll fluorescence and activity of enzymes related to carbon and nitrogen metabolism, i.e. nitrate reductase （NR） and sucrose invertase （INV） using three tobacco （Nicotiana tabacum L. ） cultivars, namely K326, Yunyan 85 and Yunyan 87. The top leaves had higher NR activity, Pn, stomatal conductance and transpiration rate than base leaves, and all these parameters showed gradual decline with the growth. However, the declined extent varied with cultivar and leaf position, with top leaves being relatively slower, and cv. K326 remained the high values at late stage. Chlorophyll content （SPAD value） differed distinctly among the three tobacco eultivars and leaf positions, with K326 showing more rapid decline at late stage and top leaves having higher values than base ones. The difference in quantum yield （Fv/Fm） of chlorophyll fluorescence between top- and base leaves varied with leaf age, being smaller at early stage, larger at middle stage, and becoming smaller again at late stage. Yunyan 87showed more rapid decline in Fv/Fm than other two cultivars at late stage. NR activity declined during the growth and differed dramatically among the cultivars, with K326 being the highest. There was a marked difference in INV activity between top- and base leaves, and among the cultivars, with K326 being consistently higher than other two cultivars. The current results showed that there were the marked difference of photosynthetic properties and relevant enzyme activities among the leaves located on different plant positions, and the difference also varied with the cuhivars.

关 键 词：烤烟(Nicotiana tabacum L.) 叶位 光合作用 叶绿素荧光 品质 

分 类 号：S511[农业科学—作物学]