تنوع ژنتيكي در كلكسيون سورگون بانك ژن گياهي ملي ايران

Genetic Diversity in Sorghum Collection of National Plant Genebank of Iran

For genetic diversity study, 130 accessions of sorghum were evaluated in Karaj for two years (1998-99) under field conditions. Considerable diversity was observed in most of the traits. All of accessions were pigmented. Days to 50% anthesis ranged from 55 to 114 days and 58 to 150 days in the first and second years, respectively. Plant height at 50% flowering differed from 44 to 240 with a mean of 132.92 cm. Panicle exsersion showed all levels of diversity. Panicle shape and compactness showed ten levels of diversity. Panicle length ranged from 7 to 55 cm. The weight of 100 seed ranged from 1.01 to 5.07g with a mean of 2.7g. Multiple regression showed that 59% of variation of 100 seed weight included in grain covering, panicle exsersion, panicle compactness, and waxy bloom. Results of factor analysis showed that eight factors expressed 71.3% of total variations in the collection. The first factor consisted of days to 50% flowering, glume color, grain covering, grain luster, panicle length, stalk juices and juicy flavour accounted for 28.1% of variations. Provinces were divided into four groups by cluster analysis. Mazandaran, Golestan and Ilam accessions appeared at the first cluster, Tehran, Khorasan and Kerman accessions at the second cluster, Yazd, Isfahan and Fars accessions at the third cluster and Sistan and Balochestan at the fourth cluster. Sistan and Balochestan accessions in comparison with others, showed the least genetic similarity. Finally, due to the presence of high diversity in the collection, the sorghum collection can be used for different purposes in sorghum breeding.