عنوان مقاله [English]
Introduction: Allium is one of the greatest genera in Amarylidaceae family with more than 900 species distributed in northern hemisphere from temperate region to tropical and subtropical areas. There are more than 135 Allium species in Iran, many of which have the ornamental potential and can be exploited in floriculture industry. Northeast of Iran with more than 35 species especially in Razavi and North Khorassan provinces is regarded as one of the main centers of diversity of Alliums. The species of Allium have the great potential to be used either as cut flower and potted plant or as outdoor plant in urban landscape. There are indeed a rich germplasm of Allium in Iran with diverse characteristics of flower colour, size and form. For the utilization of the wild species, it is necessary to identify and fully assess their main morphological and phenotypic characteristics as the initial step. Morphological markers are one of the commonly used tools which are applied in phenotypic evaluation, taxonomic classification and collection management of plant species. The aim of present study was to evaluate morphological traits and genetic diversity of some of the native Allium species of Razavi khorassan in Iran.
Materials and Methods: In this study the Allium species were collected from diverse regions of Khorassan, Iran and were cultured as a collection in Research Center for Plant Sciences (RCPS) of Ferdowsi University of Mashhad in a completely randomized block design. Following the establishment of the Allium species, 29 qualitative and 13 quantitative traits were recorded during the growing season in two successive years. Analysis of variance and comparison of all traits were performed using JMP8 software and simple correlation and factor analysis was calculated using SPSS software. Principal component analysis as well as maximum variance was also performed on the collected data.
Results and Discussion: The results exhibited that the species and genotypes were significantly different in their morphological characteristics. Some of the traits like scape length, leaf colour, flower diameter and length and width of perianth were more diverse among the species and consequently were considered as the most discriminating traits whereas some qualitative traits like perianth segment form, ovary form and perianth tip form remain uniform amongst the species. There are number of studies indicating the existence of high genetic diversity in phenotypic characteristics of some species of Allium like garlic, onion and shallot .The traits having the higher coefficient of variance bring the opportunity for the wider range of selection. Correlation analysis revealed the significant correlations among some of the studied traits. High positive correlation observed among leaf length with scape length, scape diameter with perianth length, leaf width with scape diameter and scape diameter with flower diameter. In garlic, similar positive correlation was reported on leaf length and width with scape length. Considering the quantitative traits, various parameters like environmental conditions are also effective in correlation between traits along with the corresponding genetic controlling. Factor analysis is used to identify the most important factors involving in discriminating among the species and genotypes. Based on the results, the 42 morphological characters were classified into five main factors which could justify 91.62% of total variance. Characters like inflorescence diameter, scape diameter, flower form, pedicel length, filament length and ovary and style length were placed in the first factor and expressed 30.03% of the variation. The second factor that could explain 24.9% of variation was included scape form and length, leaf length and pedicel colour. The selected discriminating traits of this study were similar to the ones of Allium roseum which had been earlier introduced by Zammuri et al (2009). The first two factors explained the highest amount of diversity while the 3rd to fifth factors could define 16.10%, 12.265% and 9.19% of variance, respectively. Traits like scape length, leaf form and colour and inflorescence diameter are amongst the main factors for the selection of ornamental plants.
Conclusion: In overall, substantial valuable information obtained for some of the native species of Alliums of Iran for the first time. This information can help in selection of desired species for specific landscape designing however characterization of the native germplasm can also be a very beneficial task in future breeding program as well as the conservation strategies for preserving the endangered species.