Evaluation of phenotypic diversity of the endangered orchid (Orchis mascula): Emphasizing on breeding, conservation and development

Abstract

The phenotypic diversity of the Iranian orchids has sharply decreased during the last 15 years and is currently threatened with local extinction and global climatic changes. Harvest of tuberous orchids has recently been raised in Iran owing to the high prices of orchid's tubers and international demand from neighboring countries. This has caused competition among orchid harvesters in the country so that the orchids are not even allowed to produce seeds. The present study was done aimed at protecting and identifying the phenotypic diversity within Orchis mascula genotypes in Abr forest, which is a natural habitat of Orchis mascula in Shahrood area, Northeast Iran. The morphological variability of 101 collected samples of early purple orchids was analyzed based on a total of 57 morphological traits. In terms of the quantitative traits, the highest and lowest coefficients of variation (CV%) were observed in the number of side tubers (200%) and petal length (14.43%), respectively. When it comes to the qualitative traits, the highest and lowest CVs were observed in lip color (70.90%) and the flower form on the stem (0%), respectively. Among the studied traits, 11 attributes showed a CV value of less than 20%. The highest positive correlations were observed between tuber fresh weight and tuber dry weight (r = 0.908). Applying principal component analysis (PCA) indicated three main components that explained 45.81% of the total variance. The clusters number four and seven could arguably be suitable sources of parents in breeding crosses for tuber fresh and dry weight traits. In summary, this study confirmed that Abr forest would be one of the rich diversity areas for Orchis mascula and our findings might be satisfactorily applied for breeding, conservation, domestication and development of new traits depending on different breeding purposes.