作 者 :庄瑶,孙一香,王中生*,杨琳璐,邓自发,姚志刚,安树青
期 刊 :生态学报 2010年 30卷 8期 页码:2173~2181
Keywords:Phragmites australis, ecotype, phenotypic variation, genetic variation, clonal diversity,
摘 要 :芦苇生态幅极广,适生于多种生境类型。不同的环境选择压力如水深、盐度、养分、气候等交互影响致使芦苇个体及种群间发生不同程度的分化和变异,形成了形态、生理或遗传上互有差异、异地性的不同生态型。尽管基于芦苇表型变异以及遗传变异进行生态型划分的研究已开展很多,但针对芦苇生态型变异规律及其可能的形成机制的认知仍存在较多分歧。在总结近年来有关芦苇生态型研究文献的基础上,通过对影响芦苇生态型变异的主要因素——环境因素和遗传因素的分析,以期为芦苇生态型的划分及其可能的形成机制提供新的研究思路。(1)空间尺度的选择应成为研究者分析、划分芦苇生态型的首要定位。在较大的地理空间尺度上,高度异质性的生境导致某些性状的变异式样具有相对的不连续性,可作为不同芦苇生态型鉴别与描述的主要依据;(2)在合理的尺度定位、取样设计和统计分析的基础上开展的表型变异研究,及进一步基于种群水平的分子标记研究(分子指纹特征或特有等位基因),可为芦苇生态型的鉴定、划分提供更为可靠的参考数据,并且可以甄别生境差异(环境响应)和遗传变异对芦苇不同生态型分化的贡献;(3)应同时进行不同生态型的特定性状与功能(株高、茎粗、生物量、生理抗逆性、水体污染物净化能力等)的定位,推动优良基因型的选育与扩繁。
Abstract:Phragmites australis (common reed) has a wide ecological amplitude, which enables it to tolerate many types of habitat. The interacting influences of different environmental selective forces, such as water depth, salinity, nutrients and climate, lead to differentiation and variation among reed clones or populations, and form various ecological types which differ in morphology, physiology or genetics. Although there are many studies on the division of reed ecotypes based on phenotypic variation and genetic variation, large disagreement exists on the variation patterns of the common reed ecotypes and variation driving mechanism. This article summarized the researches on reed ecotypes in recent years. We analyzed the main environmental and genetic factors which have influence on reed ecotypic variation. Our study provide basis for new classification of reed ecotypes and will inspire more studies to explore the possible mechanism for the ecotype variations. Specifically, we argue that the following principles should be adopt in order to better classify reed ecotypes: (1) The choice of spatial scale should be the first consideration of analysis and reed ecotypes classification. In large geographical space scale, a high degree of heterogeneity of habitat lead to a variation pattern of some traits with discontinuities, which are the main basis in identification and description of reed ecotypes; (2) It is important to carry out phenotypic variation research on appropriate scale and location, and use adequate sampling design, statistical analysis and molecular markers. Molecular fingerprint characteristics or specific alleles on the population level can provide more reliable references for the identification and classification of reed ecotypes, and determinate the relative contributions of habitat variance (environmental response) vs. genetic variation for the classification of different reed ecotypes; and (3) The specific traits and features of different ecotypes (height, stem diameter, biomass, physiological resistance, water purification ability of pollution, etc.) should be quantified simultaneously in order to promote breeding and multiplication of the superior genotypes.
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