叶片δ^(13)C与长期水分利用效率的关系

Relationship between foliar carbon isotope composition (δ^(13)C) and long-term water use efficiency (WUE_L).

该文测定并研究了不同水分处理下,不同黑杨无性系的长期水分利用效率(WUEL)、叶片δ^(13)C、光合作用、气孔及其相互关系.结果显示无性系间WUEL、δ^(13)C、光合作用、气孔都存在差异.4个水分处理下J2、J6、J7、J8、J9都是WUEL较优的无性系,同时它们的δ^(13)C高、净光合速率Pn和瞬时水分利用效率WUEi较高、气孔频度和气孔大小适中、上/下表皮气孔数目比大.气孔的差异是导致无性系间Pn和WUEi差异,并最终导致WUEL、δ^(13)C差异的关键因子.δ^(13)C和WUEL呈正相关,充分供水条件下相关性最好.

Foliar carbon isotope composition （δ^13C）, long-term water use efficiency （ WUEL）, photosynthesis, and stomata of different Populus deltoids clones were studied under different water treatments. The results showed that the differences in WUEL , δ^13C, photosynthesis and stomata among the tested clones were obvious. Under four water treatments, J2, J6, J7, J8, J9 were good clones in WUEL, with higher δ^13C, relative higher net photosynthetic rate （ Pn ）, instantaneous water use efficiency （ WUEi ）, optimal stomatal frequency and stomatal size, higher superior/inferior ratio. The stomatal differences might be a key factor, which leading to Pn and WUEi differences, and ultimately inducing WUEL and δ^13C differences. WUEL was positively related to δ^13C, and the best performance occurred under well watered treatment.