蝉棒束孢显微形态变异式样

Micro-morphological variation pattern of Isaria cicadae

摘要:

[目的]揭示蝉棒束孢居群形态性状的变异式样。[方法]通过对15个居群，75个蝉棒束孢菌株17个显微形态性状的观察和测量，采用SAS 8.1软件对蝉棒束孢显微形态性状数据进行描述性、巢式方差和Q聚类分析，获得蝉棒束孢显微形态变异数据。[结果]蝉棒束孢具有大小两型分生孢子，产孢细胞的形态可分为葫芦状和瓶状2种类型；蝉棒束孢在PDA培养基中易形成数量众多的厚垣孢子，菌丝间多能形成融合菌丝，并可观察到少量的融合菌丝在厚垣孢子与菌丝间、产孢细胞间形成。描述性分析表明，蝉棒束孢居群17个形态性状的变异系数（CV）在13.07%-104.09%之间，在物种水平上表现出丰富的变异；巢式方差分析表明，蝉棒束孢显微形态性状在居群间平均方差分量占总变异的11.29%，居群内个体间平均方差分量占总变异的15.27%，菌株内观察值间平均方差分量占总变异的73.44%。[结论]蝉棒束孢菌株形态性状变异丰富，是形态性状变异的主要来源，蝉棒束孢居群显微形态性状不存在明显的地理相关性。

关键词:蝉花;居群;菌丝体;形态变异

Abstract:

[Objective] To reveal the morphological pattern of Isaria cicadae. [Methods] We observed 17 morphological characters and measured 75 strains of 15 populations in I. cicadae. Statistical analysis system (SAS) 8.1 was used to analyze the morphological data, the morphological pattern was analyzed in 15 populations of I. cicadae, using the descriptive statistical analysis, nested analysis and Q cluster analysis. [Results] Two types of asexual conidium (large and small conidium) were observed in I. cicadae. The gourd-shaped and bottle-shaped conidiogenous cells were observed in I. cicadae. Many chlamydospores of I. cicadae were easy to form in PDA medium. Many fusion hyphae were generated between hyphae, and some fusion hyphae between hypha and chlamydospore, the fusion hyphae between conidiogenous cells were also observed. The CV of 17 morphological characters was from 13.07 to 104.09% in I. cicadae, indicating an ample morphological diversity at the species level. The nested variation analysis of the 17 morphological characters indicated that about 11.29% of the variability was attributable to the differentiation among populations, the rest 15.27% of the variability was derived from individual strains, and the remaining 73.44% was resided in the observations in the same strain. [Conclusion] The phenotypic variation within strain was the main morphological variation of I. cicadae. The morphological characters had no significant relationship with geographical origin in I. cicadae.

Key words:Isaria cicadae;population;mycelium;morphological variation