中国西南区野生芒居群表型变异研究

Phenotypic variation of wild Miscanthus sinensis populations from southwestern China

生物能源被认为是21世纪最有希望在解决能源危机方面有所作为的能源。芒植株普遍高大、生物质产量高、燃烧品质好,加之其分布广泛、抗逆性强、适宜在广袤的边际土地上种植,成为一种极为理想的生物能源植物。为探明中国西南区野生芒居群的表型多态性及表型变异规律,对37个野生居群材料的9个植物学形态特征及产量性状进行了研究。结果表明,11个表型性状在居群间的差异均达到极显著(P<0.01)水平,各性状特征在居群间存在广泛的变异,变异系数由大到小依次为单株产量干重、单株产量鲜重、分蘖数、旗叶长、旗叶宽、叶宽、茎节数、茎节长度、茎粗、株高和叶长。11个性状特征间存在显著的相关性,叶片长而且宽的芒,旗叶长而宽,植株高大,茎秆粗壮,分蘖较少,反之亦然。此外发现分蘖数、株高、叶长3项指标对芒单株产量存在显著正相关(P<0.01),是评价芒单株产量的3项主要指标。9个植物学形态特征可归成为4个主成分因子,累计贡献率达到82.551%,最大程度上反映了所有材料测定的表型特征。采用欧氏距离系统聚类法将37个芒野生居群依据9个植物学形态特征分为3类:植株高大叶片窄长型、植株高大叶片宽长型和植株低矮叶片窄短型。

Bioenergy is considered as the most promising energy source under the energy crisis in the 21st centu- ry. Miscanthus sinensis is a very good bioenergy candidate because of its high biomass, good burning quality, environmental tolerance, and tolerance of marginal land for growth. To investigate the phenotypic variation and relationships of different wild All. sinensis populations collected from southwestern China, a project was carried out to study nine botanical characteristics and yield characters of 37 wild M. sinensis populations. There were significant differences （P〈0.01） between populations in all characteristics studied. Abundant morpho- logical variation was detected in accessions of M. sinensis and their coefficients of variation were ranked as fol- lows： dry weight of individual plant （46.89%）〉fresh weight of individual plant （46.34%）〉tiller numbers （44.08%）〉flag leaf length （33.99%）〉flag leaf width （27.40%）〉leaf width （19.59%）〉internode number （18.76%）〉internode length （18. 49%）〉stem diameter （17. 89%）〉plant height （14. 64%）〉1eaf length （12.83%）. Phenotypic characteristics of M. sinensis were also significantly correlated. Those accessions with long and wide leaves were tall plants with longer and wider flag leaves, wider stems, but fewer tillers, and vice versa. In addition, the weight of individual plants was significantly correlated with tiller numbers, plant height, and leaf length which suggests that these characteristics should be improved and evaluated for future applications. Principal component analysis based on nine morphological characteristics showed that four princi- pal components reflected most of the plant phenotypic characteristics. Thirty-seven populations were divided into 3 categories based on Euclidean distance clustering analysis which included tall plants with long and narrow leaves, tall plants with long and wide leaves, as well as short plants with short and narrow leaves.