Genetic diversity of Persian clover (Trifolium resupinatum) gene pools in National Plant Gene Bank of Iran

Iran and the east of Mediterranean area is the main center for genetic diversity of Persian clover (Trifolium resupinatum). To investigate the genetic diversity of Persian clover for primary (T. resupinatum), secondary (T. clusssi) and tertiary (T. fragiferum) gene pools, 359 accessions were evaluated in the field according to IPGRI descriptors in 2003. Days to flowering differed from, 22 to 100 days, 40 to 52 days, and 50 to 130 days for the primary, secondary, and tertiary gene pools, respectively. Thousand seed weight means were 1.15, 0.49, and 1.23 g in the primary, secondary, and tertiary gene pools, respectively. In T. fragiferum, mainly showed prostrate growth habit trait, one accession showed growth habit that could be used in the agronomic systems. Phenotypic variation (CV) and Shannon indices showed high levels of diversity for most of the traits. A positive linear relationship between stem length at the flowering as depended trait with growth habit and days to flowering traits expressed of 58.6% (r2=0.586) variation. Cluster analysis classified the gene pools in three groups. Landraces from primary gene pool appeared in the first cluster, whereas in the second cluster the wild germplasm of primary gene pool came together with secondary gene pool materials. Finally, the tertiary gene pool germplasms revealed in the third cluster. Existence of high levels of diversity in the primary, secondary and tertiary gene pools of Persian clover in National Plant Gene Bank of Iran can provide a potent germplasm for improvement of high potential Persian clover lines.