16个建兰品种叶片解剖结构研究

兰属植物是市场上流行的观赏花卉,其中建兰具有极高的观赏价值。目前,因建兰叶片极易染病,导致其观赏价值大幅下降,因此,本研究对16个建兰（Cymbidium ensifolium）品种的叶片气孔和横切结构进行测定,探究叶片微观结构间的差异,以期为建兰叶片功能性状研究及病虫害防治提供参考依据。利用NIS-Elements D软件对叶片表皮气孔进行测量,观测指标包括气孔器的长轴、短轴、气孔面积和气孔密度,发现建兰的气孔主要集中在下表皮,16个品种中仅‘大青’‘锦旗’2个品种上表皮有少量的气孔分布;利用NIKON数码荧光显微镜、光学数码成像系统和NIS-Elments D软件在20倍镜下对叶片的中脉长轴、中脉短轴、上表皮厚、下表皮厚、叶片厚和叶肉厚进行观测,采用SPSS软件对实验数据进行方差分析和多重比较分析。结果表明：16个建兰品种的叶片微观结构之间存在显著差异,其中建兰‘大青’的气孔密度、中脉长轴和中脉短轴最大,分别为125.19个/mm²、439.14 μm和403.51 μm。气孔密度最小的是‘朝阳三星’‘玉女素’和‘八宝奇珍’,分别为52.70、60.48、61.54个/mm²。中脉长轴与中脉短轴最小的品种是‘十三太保’和‘大凤素’,分别为147.63 μm和125.93 μm。而‘复兴奇蝶’的叶片厚度最大,为528.29 μm,叶片厚度最小的品种是‘桃腮素’,为100.32 μm。通过对16个建兰品种叶片解剖结果的相关性分析发现,气孔面积与气孔其他参数均呈极显著正相关,叶片厚度与上表皮厚度以及叶肉厚度均呈极显著正相关,而叶肉厚度与气孔面积是研究建兰非生物胁迫的重要指标。本研究可为筛选优异的建兰种质资源、新品种选育及其非生物胁迫研究提供参考。

Leaf Anatomical Structure of 16 Cymbidium ensifolium Varieties

Orchid is one of the most popular flowers in the market, among which Cymbidium ensifolium has a very high ornamental value. The leaves of C. ensifolium are very susceptible to diseases, which decreases the ornamental value of C. ensifolium significantly. The research explored the differences between the leaf microstructures of 16 varieties of C. ensifolium through measuring the stomatal and cross-sectional structures of them. Stomata on the epidermis of the blade was measured using Nis-Elements D software, including the long axis, short axis, stomatal area and stomatal density of the stomatal apparatus. The stomata of C. ensifolium was mainly concentrated in the lower epidermis, and only two cultivars, C. ensifolium ‘Daqing’ and ‘Jinqi’, had a small amount of stomata on the upper epidermis. Transection structure of the leaf was observed and measured under 20x microscopy by using NIKON digital fluorescence microscope and optical digital imaging system and NIS-Elments D software, including the length of midrib, width of midrib, thickness of upper epidermis, thickness of epidermis, thickness of epidermis, thickness of leaf and thickness of mesophyll. SPSS statistics software was utilized to analyze the variance and multiple comparisons of the experimental data in this study. Experiment results indicated that there were significant differences in the leaf microstructures of the 16 varieties of C. ensifolium. Among them, ‘Daqing’ had the largest stomatal density, midrib long axis and midrib short axis, which was 125.19 pcs/mm², 439.14 μm and 403.51 μm, respectively. The smallest stomata density was from ‘Zhaoyang Sanxing’, ‘Yunvsu’ and ‘Babao Qizhen’, which was 52.70 pcs/mm², 60.48 pcs/mm² and 61.54 pcs/mm², respectively. Varieties with the smallest long axis and short axis of the midrib were ‘Shisan Taibao’ and ‘Dafengsu’, which was 147.63 μm and 125.93 μm respectively. ‘Fuxing Qidie’ had the largest leaf thickness at 528.29 μm, and the variety with the smallest leaf thickness was ‘Taosaisu’, which was 100.32 μm. Through the correlation analysis of the anatomical results of the leaves of the cultivars, It was found that only the stomatal area had a very significant positive correlation with other parameters, and the leaf thickness was extremely significantly positively correlated with the thickness of the upper epidermis and the thickness of the mesophyll. This experiment could provide reference for screening excellent germplasm resources of C. ensifolium breeding of new varieties and research on abiotic stress.