Induction of Autotetraploidy and its effects on some morpho-physiological traits in some annual and perennial medics

Primary screening of original diploid species and induced autotetraploids after induction of single node cutting of three populations of perennial diploid Medicago sativa ssp caerulea: (Karaj1, Karaj2 and Tehran) and seven annual diploid alfalfa species: (M.lupulina, M.radiata, M.rijidula, M.truncatula, M.turbinata, M. noeana and M. minima) with four concentrations (0.10, 0.50, 1 and 2%) of colchicine counting the chloroplasts number in the stomata guard cells was done. The highest survivor rate and tetraploidy induction with average values of 80.2% and 74.3% were obtained in 0.10% colchicine concentration. Seeds of survived diploids, tetraploids and controls sown in pots in glasshouse experiment using completely randomized design with five replications in 2018 in Ahvaz, Iran. Data were collected for leaf length, leaf width, shoot and root length, seedling weight, shoot weight, root weight, branch number, leaf area index (LAI) and water use efficiency (WUE). Result of mean comparisons between three groups (2x, induced 4x and controls 4x), showed that both of tetraploids had significantly higher mean values for all of traits except leaf size and LAI than that for diploids. It was concluded that induced 4x had 25% and 38% lower values for Shoot and root length than 2x, respectively. In contrast, the induced 4x had 40%, 38%, 44%, 65% and 23% higher values than their 2x for seedling weight, shoot weight, root weight, WUE and branches number, respectively.