【目的】分析1年生白桦(Betula platyphylla)无性系幼苗RBCS1A、RBCS3B、GO、RCA基因表达量和光合速率、蒸腾速率、气孔导度、瞬时水分利用效率、胞间CO₂浓度、羧化效率与苗高、地径的相关性,探索基因表达量和光合参数对白桦无性系幼苗生长初期的影响。【方法】在白桦双列杂交子代林中选择6株成熟的树木进行组织培养,随后将其扩繁为6个无性系,对1年生白桦无性系幼苗的生长量与光合参数和4个与光合作用相关的基因表达量进行测定分析。【结果】6种不同基因型白桦无性系幼苗的生长量与光合参数及基因表达量间差异显著(P<0.05);光合参数间表现出了密切的相关性,其中净光合速率与瞬时水分利用效率、蒸腾速率、气孔导度、羧化效率显著正相关(P<0.05)。RBCS1A的表达量与RBCS3B显著正相关,RBCS1A的表达量与RCA显著正相关,GO基因的表达量与RCA显著负相关(P<0.05)。基因表达量与植物的蒸腾速率、净光合速率、瞬时水分利用效率及气孔导度间均表现出了显著相关性(P<0.05),但基因表达量和光合参数与白桦幼苗的苗高、地径相关性未达到显著水平(P>0.05)。【结论】1年生白桦不同无性系幼苗4种基因的表达量和6种光合参数间差异显著,并且表现出了密切的相关性,但与苗高、地径相关性不显著。说明在白桦幼苗生长的初期,4种基因的表达量和6种光合参数并不能够显著地影响白桦无性系幼苗的生长。

【Objective】 We analyzed the relationship among RBCS1A, RBCS3B, GO and RCA gene expression in one-year-old white birch clone seedlings and photosynthetic rate, transpiration rate, stomatal conductance, instantaneous water use efficiency, intercellular CO₂ concentration, carboxylation efficiency, seedling height, and ground diameter of seedlings. Moreover, the effects of gene expression and photosynthetic parameters on the initial growth of birch clone seedlings were preliminarily explored. 【Method】 Six mature trees in a diallel cross progeny forest of white birch were cultured and propagated as six clones, and growth, photosynthetic parameters and expression of four photosynthesis-related genes in one-year-old white birch clone seedlings were determined and analyzed. 【Result】 There were significant differences in growth, photosynthetic parameters, and relative gene expression in seedlings of six different genotypes of white birch clones (P < 0.05). A significant correlation between photosynthetic parameters was observed, and the net photosynthetic rate was significantly positively correlated with instantaneous water use efficiency, transpiration rates, stomatal conductance, and carboxylation efficiency (P < 0.05); the relative expression of RBCS1A was significantly positively correlated with RBCS3B. The relative expression of RBCS1A was significantly positively correlated with RCA, and the relative expression of the GO gene was significantly negatively correlated with RCA (P < 0.05). A significant correlation between the relative gene expression and the plants’ transpiration rate, net photosynthetic rate, instantaneous water use efficiency, and stomatal conductance was observed (P < 0.05); however, the difference between the relative gene expression and photosynthetic parameters was not significantly correlated with the plant height and ground diameter (P < 0.05). 【Conclusion】 The expression levels of four genes and six photosynthetic parameters of different one-year-old white birch clone seedlings were significantly different and showed strong correlations, however, the correlation between the seedling height and ground diameter was not significant. This showed that in the early stage of birch seedling growth, the expression of the four examined genes and six photosynthetic parameters did not significantly affect the growth.