Identification, regeneration and evaluation of agro morphological charactes of Alfalfa accessions in National Plant Gene Bank.

Alfalfa or green gold is the most important forage crops. Iran is the center of genetic diversity for alfalfa. To access to high yield cultivars or lines in the sustainable agriculture you have to use genetic resources. 435 accessions were planted in two years (1377 and 1378). Each accession was planted at two rows with 2 meter length. To identify taxa, herbarium samples were prepared from each accession. 332 accessions were identified as alfalfa (Medicago sativa), 44 accessions of annual medics and some species from other genera. Annual medics and 185 alfalfa accessions seeds were regenerated and transferred in to seed storage room. Agromorphological characters for Medicago species were characterized according to IPGRI descriptors. Statistical parameters such as dispersions and center tendency, and CV, Shannon index, correlation coefficient were calculated for each trait. Also cluster and factor analysis were done. In alfalfa accessions these results were determined: central leaflet area differed from 70 to 458 mm2. Days to 10% flowering after each cutting ranged from 17 to 40 days, this trait showed 23 days diversity, so it could be a good subject to breeding. Plant height at 50% flowering ranged from 20 to 73 cm. Most of alfalfa accessions were completely susceptible to alfalfa weevil, just one accessions was semi-susceptible to the pest. 1000-seed weight differed from 1.5 to 3.1 g. there was no correlation between this trait and central leaflet area, plant height at 50% flowering, leaf- stem ratio which are important traits in forage yield. The cluster analysis using each trait mean for provinces revealed four clusters. Northern provinces including Hamedan, Markazi, Kordestan, Zanjan, Tehran and Lorestan were grouped in the first and second clusters. The third and fourth clusters ---- contained--- central-southern provinces including Boosher, Fars, Esfahan, Yazd, southern Khorasan and Kerman. This result revealed that there is two gene pools for Iranian alfalfa: Southern and Northern gene pool. So this result in the breeding programs in alfalfa should be considered. The annual medics following results were determined. Most of annual medics were resistance or showed low susceptibility to alfalfa weevil. These accessions could be used in the alfalfa breeding programs for this character. Height of canopy ranged from 2 to 15 cm but the main stem length in some accessions were up to 30 cm. Hieght of canopy showed positive and significant correlation with seed / pod ratio and 1000-seed weight. However this character had a negative and significant correlation with pod spiness, pod form and days to plant death. All of annual medics shown determinate growth and noone was indeterminate. 100-pod weight ranged 1.55 to 29.8 g. Seed/ pod ratio differed 9.3% to 65%. Those accessions which had high seed/pod ratio could be used in breeding programs for seed production.