黄河下游湿地芦苇形态变异研究

STUDY ON MORPHOLOGICAL VARIATION OF PHRAGMITES AUSTRALIS IN THE YELLOW RIVER DOWNSTREAM WETLAND

以水盐为主导生态因子 ,分析了黄河下游湿地芦苇 (Phragmitesaustralis)种群形态变异的水平与格局。对基径、株高、叶长、叶宽、节间长、节间数和穗长 7个形态特征在 15个种群中的变异分析表明 :种群内个体间形态差异极显著 ,7个形态特征在种群内的变异系数从大到小依次为节间长 (0 .2 846 )、叶宽 (0 .2 5 36 )、穗长 (0 .2 44 9)、叶长(0 .2 0 85 )、基径 (0 .1875 )、节间数 (0 .176 3)、株高 (0 .16 5 7) ;7个形态特征在种群间的变异度从大到小依次为株高、叶长、节间长、叶宽、基径、节间数、穗长 ,但种群间形态的显著差异主要存在于滨州种群 (BZH)、淡水种群 (ZHG、DPH、NYH ,土壤总盐度 <0 .1% )、盐生种群 (HS0 1、HS0 2、HS0 3、HS0 4、HS0 5、DWL、KD、GD、LZH、LJ、DLH ,土壤总盐度 >0 .3% )之间 ,在来自相似生境的种群间形态差异普遍不显著 ;7个形态特征均与水盐联合影响因子显著相关 ;以形态特征为基础的聚类分析将研究的 15个种群分为显著不同的 3类。因此 ,根据黄河下游湿地芦苇形态变异规律和分化特点 ,建议将该地区芦苇分为盐生芦苇、淡水芦苇、巨型芦苇 3个形态类型。

In this paper, the level and pattern of morphological variation of Phragmites australis in the Yellow River downstream wetland has been studied when water and salinity were considered as dominant ecological factors. A total of 14 populations from estuary to inland along the Yellow River and one freshwater population from Nanyang Lake were selected for study. The basal diameter, height, leaf length and width in the middle of stem, internode length in the middle of stem, internode amounts and panicle length of 30 plants from every population were recorded and analyzed. Results showed that the decreasing arrangement of CV (Coefficient of variation) within population of 7 morphological characters was from internode length in the middle of stem (0.284 6), leaf width in the middle of stem (0.253 6), panicle length (0.244 9), leaf length in the middle of stem (0.208 5), basal diameter (0.187 5), internode amounts (0.176 3) to height (0.165 7). The variability of 7 morphological characters among populations was arranged decreasingly from height, leaf length in the middle of stem, internode length in the middle of stem, leaf width in the middle of stem, basal diameter, internode amounts to panicle length. Distinct morphological differentiation was observed mainly among BZH population, freshwater populations and saltwater populations, and all 7 morphological characters were significantly correlated with the combined factors of water and salinity. According to the pattern of morphological differentiation, the P. australis populations in investigated area could be divided into three ecotypes, including saltwater reed, freshwater reed and giant reed.