山茶属植物叶片δ^(13)C和δ^(15)N与养分含量及光合作用的关系

Leaf δ^(13)C and δ^(15)N in relationship with nutrients and photosynthesis of different Camellia species

以11个山茶属植物为试材,测定其叶片稳定碳氮同位素比率(δ13C和δ15N)、光合参数(净光合速率、气孔导度、蒸腾速率、胞间CO2浓度、水分利用效率)以及叶片C、N、P和K元素含量等指标,分析叶片δ13C和δ15N与光合参数、养分含量之间的关系。结果表明:11个山茶属植物δ13C值在-26.38‰^-29.44‰之间,其中多齿红山茶显著高于其它10个物种;δ15N在-3.01‰~4.27‰之间,其中以攸县油茶最高,石果红山茶最低;普通油茶净光合速率最高,是其它10个茶属植物种的124%~496%;11个山茶属植物叶片C含量在47.72%~53.07%之间,叶片N、P含量分别以攸县油茶和普通油茶最高,各物种叶片K含量差异不大;叶片δ13C与C和大量元素含量、光合速率均呈负相关关系,其中与N、P含量以及胞间CO2浓度呈极显著负相关,与水分利用效率呈正相关;δ15N与N、P含量显著正相关,与K含量显著负相关,与光合参数呈正相关,与水分利用效率呈负相关。

Using 11 Camellia plants as test materials, stable carbon and nitrogen isotope ratios （δ^15N and δ^13C）, photosynthetic parameters （Pn, Gs, Tr, C8 and WUEi） and contents of C, N, P and K in leaf were determined and the relations among leaf δ^13C, δ^15N, photosynthetic parameters and nutrients contents were analyzed. The results showed that the δ^13C values of 11 Camellia species were between -26.38 ‰ -29.44 ‰, of them, the δ^13C value of C. polyodonta was significantly higher than those of other 10 species, and δ^15N values were between -3.01‰- 4.27‰ , of them, the δ^15N value of C. yuhsienensis was the highest while the lowest value was observed in C. lapidea; Net photosynthetic rate of C. oleifera was 124%-496% of those of other 10 species; Leaf carbon content of 11 Camellia species were between 47.72% - 53.07%, leaf N, P contents of C. yuhsienensis and C. oleifera were the highest respectively, and K content in leaves showed little difference among the plant species; Leaf δ^13C showed a negative correlation with macro-elements, C content and photosynthetic rate, and showed significantly negatively correlated with N, P content and intercellular CO2 concentration, while positively correlated with water use efficiency; δ^15N was positively correlated with N, P content significantly and positively correlated with photosynthetic parameters, while significantly negatively correlated with K content and was negatively correlated water use efficiency.