黄土高原三种耐干藓营养繁殖的季节差异及机理

Seasonal differences in vegetative regeneration of three desiccation-tolerant mosses in the Loess Plateau and its mechanism

苔藓植物在园林绿化、水土保持等方面的应用日益增加,目前藓类植物营养繁殖的影响因素鲜见报道,限制了其应用研究。本研究以黄土高原常见的耐干藓(扭口藓、土生对齿藓、短叶对齿藓)为对象,研究了3种藓春、夏、秋、冬季营养繁殖能力(以活力指数表征)差异及其叶绿素、可溶性糖、可溶性蛋白质、丙二醛(MDA)含量等生理指标变化,探索了耐干藓营养繁殖的季节差异与其生理特征之间的关系。结果表明:1)藓类繁殖具有明显的季节差异,3种藓夏季活力指数均低于其他3个季节,平均较秋、冬、春季分别下降56.1%、48.4%、10.1%;相同季节的活力指数具有明显的年际变化。2)3种藓繁殖能力具有明显的种间差异,以短叶对齿藓最高,扭口藓最低,且后者的繁殖能力季节和年际变化最大。3)3种藓不同季节生理特征差异显著,其中夏季MDA含量高于其他季节,可溶性糖和可溶性蛋白质含量低于其他季节。4)耐干藓的营养繁殖季节变化主要与可溶性糖含量有关。本研究明确了藓类营养繁殖能力随季节变化的规律,指出可溶性糖含量是影响藓类营养繁殖的关键因素,可为藓类植物保护和人工培养提供科学依据。

Bryophytes have been used in many fields,such as landscaping and soil and water conservation.How-ever,few studies focused on moss regeneration and its influencing factors,which retards the application study.Three common desiccation-tolerant mosses(Barbula unguiculata,Didymodon vinealis,and Didymodon tectorum)in the Loess Plateau region were collected across four seasons.We measured vigor index of new shoots,representing vegetative regeneration capacity,and physiological indices,which included the contents of chlorophyll,soluble sugar,soluble protein and malondialdehyde(MDA),to determine seasonal differences in regeneration capacity and physiological characteristics of the three mosses,as well as their relationships.The results showed that,1)vegetative regeneration of mosses showed significantly seasonal differences.The vigor index of the three mosses in summer were the lowest,averagely decreased by 56.1%,48.4%,and 10.1%compared with that in autumn,winter,and spring,respectively.The vigor index of the three mosses in the same season showed interannual variation.2)There were considerable differences in the regeneration capacity of mosses across species.D.tectorum and B.unguiculata had the highest and lowest vigor indices,respectively.In terms of regeneration capacity,B.unguiculata had the largest seasonal and interannual variations.3)The physiological characteristics of mosses had seaonal variations.The mosses collected in the summer had the highest MDA content but the lowest contents of soluble sugar and soluble protein.4)Seasonal variations in desiccation-tolerant moss regeneration were mostly due to soluble sugar.Our results showed seasonal variations of vegetative propagation capacity,and highlighted the role of soluble sugar as a critical factor influencing vegetative propagation of mosses.These findings could provide scientific support for moss protection and artificial cultivation.