不同种源红椿苗期生长及光合特性比较

Comparison of the Growth and Photosynthetic Characteristics of Toona ciliata Seedlings from Different Provenances

以不同种源1年实生苗为试验材料,通过测量其生长及光合特征,比较不同种源间差异,为种源评价和筛选提供理论基础。结果表明,不同种源间生长特征存在显著差异,如种源LZ的株高达143.43cm,而种源JG的株高仅为47.50cm,WY的地径超过JG地径73.60%以上,种源间变异丰富;不同种源光合特征变化规律存在差异,日变化曲线峰值大小差异明显,最大净光合速率(P_(nmax))在10~14μmol·m^(-2)·s^(-1)之间;单一的光合参数与生长的相关性往往没有达到显著水平(P>0.05),不过光饱和点(LSP)和P_(nmax)与生长均呈正相关,而补偿点(LCP)和暗呼吸速率(R_d)与生长均呈负相关,这在一定程度上反映了较强的光适应性和光合潜力,较高的弱光利用效率和低呼吸消耗有利于红椿生物量积累和植株生长。可见,红椿不同种源间苗期生长生理特征差异明显,遗传多样性丰富,种源LZ和WY选育潜力巨大。

One year old Toona ciliata seedlings from different provenances were used as the materials, tO study the growth and photosynthetic characteristics were measured to provide a theoretical basis for the e- Valuation and selection of provenances. The results showed that there were significant differences in growth traits among different provenances （P〈0.05）, the height of the seedlings from LZ was the highest about 143.43 cm,but the height from JG was only 47.50 cm,the diameter from WY was 73. 60% more than JG, the genetic resources of provenances were very rich. There were some differences in the photosynthetic characteristics among provenances, the peaks of curves changed significantly different, the maximum net photosynthetic rate （Pnmax） was from 10 μmol · m- 2 . s-1 to 14 μmol · m 2· s-1. There was no significant correlation between growth characteristic and single photosynthetic characteristic （P〈0.05）, but the P and LSP were positively correlated, the LCP and Rd were negatively correlated. The results indicated that strong light adaptability and potential photosynthesis, as well as strong low-light use efficiency and low consumption were conducive to plant growth and biomass accumulation. It was concluded that significant differences existed in the growth and photosynthetic characteristics of T. ciliata from different prove- nances,genetic diversity was rich in provenances,and the LZ and WY had a great development value.