加勒比松、湿地松苗期生长及叶绿素荧光特性

以加勒比松(Pinus caribaea)16个种源、湿地松(P.elliottii)4个种源2.5 a生营养袋苗木为材料,定期开展生长调查,于2016年7—8月、2017年2月开展叶绿素荧光参数的测定,分析加勒比松、湿地松针叶叶绿素荧光参数对树种、种源、不同测量时间的响应.结果表明,不同种源加勒比松/湿地松的株高、地径生长均存在显著差异(P<0.01);测量时间与树种对最大PSⅡ的光能转换效率(Fv/Fm)有显著影响(P<0.01),二者互作效应不显著,与7、8月相比,测量值均在第2年2月显著提高;两个树种的实际量子产量(ΦPSⅡ)、光化学淬灭(qP)与表观量子传递速率(ETR)对测量时间的响应模式相反;加勒比松与湿地松叶绿素荧光参数受种源影响不显著;相关性分析表明,加勒比松与湿地松的株高和地径生长与2月Fv/Fm、PSⅡ有效光化学效率(Fv′/Fm′)测量值呈一定的负相关关系;高光强抑制了湿地松、加勒比松的叶绿素荧光参数,但抑制效果与生长无明显相关关系;低温造成的胁迫主要抑制了加勒比松的光化学反应,并与其生长表现有一定的负相关关系.可考虑将2月份测量的叶绿素荧光参数作为加勒比松耐寒个体的筛选指标.

The Growth and Chlorophyll Fluorescence Characteristics of Pinus caribaea and P. elliottii at the Seedling Stage

The nutrition pot experiments of Pinus caribaea and P. elliottii (PEE) were conducted to assess the response of chlorophyll(Chl) fluorescence parameters to different provenances and measured time. The materials were potted seedlings from 16 P. caribaea provenances and 4 PEE provenances. The growth of the seedlings and the Chl fluorescence parameters were measured in July and August 2016 and February 2017, separately. The result showed there were significant differences among seedlings of different provenances in height and diameter (P<0.01). The measured time and species had a significant effect on the value of the PSⅡmaximal photochemical efficiency (Fv/Fm), while the interaction effect was not significant. The Fv/Fm was higher in February 2017 than in July 2016 and August 2016; the response models of measured times of two species were opposite in the effective quantum yield (ΦPS Ⅱ ), the photochemical quenching coefficient (qP) and the apparent electron transport rates (ETR). The Chl fluorescence parameters of two species were affected by the measured times rather than provenances. The growth had a negative correlation with Fv/Fm and Fv′/Fm′ in February 2017 in examined seedlings according to the correlation analysis. The Chl fluorescence parameters of P. caribaea and PEE were inhibited by high light intensity, which might not affect the growth. The Chl fluorescence parameters in P. caribaea were also inhibited by low temperature, which might be related to growth. The Chl fluorescence parameters of P. caribaea in February 2017 might be indicators of chilling tolerance among P. caribaea individuals.