Genetic variation and heritability of agro-morphological and phytochemical traits in Iranian saffron (Crocus sativus L.) populations

Saffron is highly valued for its unique aroma, taste, colour and medicinal properties. Iran is known, as one of the most important saffron producing countries but the genetic variability present in crocus in Iran is currently unknown. The main objectives of our research were: (1) evaluate phenotypic diversity among Iranian saffron populations; (2) compare phytochemical content between populations originating from different ecological areas: (3) determine possible correlations between phytochemical content and morphological traits; (4) identify yield-related traits for use in clonal selection programs and (5) estimate the broad sense heritability (h(b)(2)) for the traits evaluated. In this study a combined analysis of variance was used to evaluate eight Iranian populations of Crocus sativus over a two-year period. The investigated characters were leaf number per plant, leaf length, flower number per plot, dry stigma weight per plot, spathe number and the content of crocins, picrocrocin and safranal. Statistical analysis showed that population had significant effect on most morphological parameters except leaf length and spathe number. Also it had significant effect on all phytochemical contents. Duncan's multiple range tests showed that populations were significantly different for most evaluated traits. Simple correlation analysis showed that dry stigma weight had significant and positive correlation with leaf number, flower number, picrocrocin and safranal (r=0.954, 0.998, 0.830 and 0.881, respectively). The estimates of broad sense heritability were higher for flower related traits (h(b)(2) = 0.76 - 0.99). Cluster analysis did not reveal a clear relationship between diversity pattern and geographical origin. (C) 2010 Elsevier B.V. All rights reserved.