人工群落光环境对海州常山生长与观赏品质的影响

Effects of Light Environment in Artificial Community on Growth and Ornamental Quality of Clerodendron trichotomum

以人工栽培群落为背景,研究不同光照条件对海州常山生长特性与观赏品质的影响。利用常用的测量方法测定海州常山的生长指标和观赏品质参数,并使用TPS-2便携式光合仪测定海州常山的光合作用,观察不同处理的光合特性。且借助光学显微镜(Olympus CX-31)×40倍下,用数码显微成像系统(Olympus DP-20)照相,用数码测距软件Motic Images Advanced 3.0标定,观察各光照条件下的气孔特性。结果表明:随着光照强度的逐渐降低,叶片有不同程度的减小,比叶面积升高;组织含水量升高,干重/鲜重下降,而叶绿素相对含量则先升高后下降,81%光照时达最大值;净光合速率、蒸腾速率、气孔导度均有较大程度的下降,胞间CO_2浓度升高;气孔大小、气孔密度均下降,气孔开度则先升高后下降,81%光照时达最大值。观赏品质也有很大不同,81%光照下始花期、小花初放期、盛花期均提前,开花时间最长,花序长度达最大值。随着光照强度的减弱,低于全光照44%后,花期明显延迟,观赏花期缩短,花序直径、单花序小花数量、总花序数量、花序长度均显著减少。因此,研究表明适当遮荫有利于促进海州常山的生长,提高其观赏品质,过度遮荫则会明显影响生长和观赏品质。

In artificial cultivation community, the effects of different light intensities on growth characteristicsand ornamental quality of Clerodendron trichotomum were studied. The growth index and ornamental quality ofClerodendrum trichotomum were measured using common measuring methods, and the photosynthesis wastested with TPS-2 portable Photosynthetic apparatus. By optical microscope（Olympus CX-31） ×40 times, thephotographs of the stomatal characteristics were taken with digital microscopic imaging system（DP- 20Olympus） camera, calibrated by digital distance software Motic Images Advanced 3.0. The results showed thatwith light intensity decreased, the leaf size decreased in different degrees, but the specific leaf area increased.Dry weight/ fresh weight decreased, while the relative content of chlorophyll increased first and then decreased,and reached the maximum under 81% sunlight. The net photosynthetic rate, transpiration rate and stomatalconductance decreased, but the intercellular CO2 concentration increased. Stomatal size and stomatal densitydecreased, the stomatal opening increased first and then decreased, and reached the maximum under 81%sunlight. Ornamental quality was also very different： under 81% sunlight, the initial stage of floret, initialflowering stage and the full bloom stage were advanced, and the inflorescence length reached the maximum.With the decrease of light intensity to less than 44% sunlight, the flowering period was significantly delayed,and the ornamental time was shortened. The diameter of inflorescence, the floret number of singleinflorescence, the total number of inflorescences and the length of inflorescence were significantly reduced.Consequently, the study illustrated that appropriate shading was conducive to promote the growth and theornamental quality of Clerodendrum trichotomum, but adverse effects would appear if the shading exceeded acertain degree.