火力楠扦插苗与实生苗生长及光合生理特性分析

Analysis of Growth and Photosynthetic Physiological Characteristics of Michelia macclurei Seedlings and Cuttings

为探究火力楠扦插苗与实生苗间的差异,本试验以相同遗传基础来源优树种子培育的火力楠扦插苗和实生苗为研究对象,观测两种苗木之间的高径生长、生物量及光合作用参数、气孔密度、叶绿素含量的变化。结果表明:扦插苗高、地径、生物量增量均显著高于实生苗,但高径比小于实生苗,根冠比无明显差异。光合日变化趋势均表现为先上升后下降趋势,在早上10∶00时净光合速率(Pn)达最大值,但在光照最强的12∶00-14∶00时,扦插苗Pn大于实生苗。与Pn相类似,扦插苗蒸腾速率、气孔导度及胞间二氧化碳浓度大于实生苗,但水分利用效率无显著差异。通过显微观测,扦插苗与实生苗气孔密度无明显变化,但活体检测发现扦插苗叶片叶绿素含量偏高。研究认为,相较实生苗,火力楠扦插苗生长快、光合能力强,具有更强的环境适应性,生产应用潜力较好。

In this experiment,the cutting seedlings and seedlings of Michelia macclurei cultivated by seeds of superior tree species with the same genetic basis were taken as the research objects.The changes of height and diameter growth,biomass,photosynthesis parameters,stomatal density and chlorophyll content of seedlings two types of seedlings were observed to reveal the differences between cutting seedlings and seedlings of M.macclurei.The results showed that the height,ground diameter and biomass increment of cutting seedlings were significantly higher than those of seedlings,but the height-diameter ratio was smaller than that of seedlings,and there was no significant difference in root-shoot ratio.The diurnal variation of photosynthesis showed a trend of increasing first and then decreasing.The net photosynthetic rate(Pn)reached the maximum at 10 o'clock in the morning,but at 12-14 o'clock when the light was the strongest,the Pn of cutting seedlings was greater than that of seedlings.Similar to Pn,the transpiration rate,stomatal conductance and intercellular carbon dioxide concentration of cutting seedlings were higher than those of seedlings,but there was no significant difference in water use efficiency.Through microscopic observation,there was no significant change in stomatal density between cutting seedlings and seedlings,but in vivo detection showed that the chlorophyll content of cutting seedlings was higher.The results showed that compared with seedlings,the cutting seedlings of M.macclurei grew faster,had stronger photosynthetic capacity,stronger environmental adaptability and better production and application potential.