Study of phenological, morphological and phytochemical characteristics of cumin genotypes in Mashhad

  Cumin (Cuminum cyminum) is an economically important drought resistance medicinal plant of family Apiaceae. It is mainly cultivated in Iran, India, Syria, Pakistan and Turkey. It is widely used in foods, beverages and perfume and pharmaceutical industries. The mature dried fruit contain 2-5% essential oil(Gohari and Saeidnia, 2011, Li and Jiang, 2004). It is a monotypic species, phenotypic and genetic variability in cumin is also low(Bahraminejad, Mohammadi-Nejad, et al., 2011). This study was carried out at Research Station of the Agricultural Research and Education Center of Khorasan Razavi, Iran during 2012-2013 crop year. In this experiment, 24 cumin ecotypes were collected from different parts by the Natural Resources Genes Bank of Iran. In order to evaluate the morphological and phenological traits and also measuring essential oil percentage, yield and yield components of Cuminum cyminum for achieving superior germplasm. It was conducted in a randomized complete block design with three replications. Seed samples were first cultivated in the greenhouse and then transferred to the field and cultivated in drip irrigation conditions. According to the results, there was a significant variation (p≤ 0.05) among the genotypes in terms of traits including phenological characteristics (number of planting days to stem length of 41-28 days, 50% flowering 37- 57 days and maturity of 92-101 days) and morphological characters between the genotypes. The number of stem branches the genotypes was significantly (p ≤ 0.05) different (3.5-5.7). The observed differences in the yield components were: number of umbels per plant 8.7-8.5, number of umbellate in umbel 3-4, seeds in the umbellate 23-13, 1000-seed weight 2.8-4.2 g, total plant biomass as 6-22 g, the seed yield of each plant 2-8 grams, the essential oil percentage 0.99-3.11 and the essential oil yield 0.02-0.2 g/plant, which were significant at p ≤ 0.05. The results of Stepwise linear regression analysis showed that the plant biomass was the first trait that entered the regression model and justifies alone 51% of the variations in essential oil yield. Three more characters were entered to the regression model as 1000-seed weight, crown area and umbrellas per umbel and explained 60% of dependent traits (essential oil yield). In order to identify the direct and indirect effects of traits on seed yield, path-way analysis was performed based on the variables entered into the final regression stage. The number of branches and number of umbels per plant had the most direct effect on seed yield and essential oil PCA and cluster analysis were used to identify the distant among accessions. The first and second component in Cumin, justifies 71% of variations of the variables. Traits of plant cover, plant height, plant weight and essential oil percentage were the most important traits in cumin. the accessions located in cluster 1 were mainly originated from Markazi province, which had less essential oil yield. Traits of plant biomass, number of umbrellas, canopy cover and 1000-seed weight had the most direct effect on the essential oil yield of the plant. These traits were determined as a suitable criterion for determining the production ability of cumin ecotypes