Effects of different hormone ratios on callus induction of four explants of Medicago archiducis-nicolai
[Objective]To identify the optimal regeneration conditions for different explants of Medicago archiducis-nicolai.[Method]Seeds of M. archiducis-nicolaiwere used as the starting materials. MS medium (0.8％ agar+3％ sucrose) was selected as the basic medium for the experiment. Callusinduction and redifferentia-tion were tested on cotyledons,petioles,stems and leaves using varioustypes and concentrations of growth regulators.[Result]The induction rate of explants,from highest to lowestwas as follows:stem>petiole>leaf>cotyledon. The browning rate of explants,from highest to lowestwas as follows:stem<leaf<petiole<cotyledon. The most suitable condition for callus induction in true leaves was 1.5 mg/L 2,4-D+0.1 mg/L KT+MS+0.8％ agar+3％ su-crose,with the induction rate of 78％ and the browning rate of 8％. The best condition for callus induction in cotyle-donspetiole and stem was 1.5 mg/L 2,4-D+1.0 mg/L KT+MS+0.8％ agar+3％ sucrose,with the stem show-ing the highest callus rate at 96％ and no browning,petioles with a callus rate of 92％ and a browning rate of 2％,and cotyledons with a callus rate of 60％ and a browning rate of 4％. The condition of 0.3 mg/LNAA+mg/LKT+MS+0.8％ agar+3％ sucrose was the most suitable for inducing embryogenic callus from cotyledons and petioles. For true leaves,the best condition was0.3 mg/L NAA+1.0 mg/L 6-BA+MS+0.8％ agar+3％ sucrose,while for stem,it was 0.3 mg/L NAA+0.5 mg/L KT+MS+0.8％ agar+3％ sucrose.[Conclusion]All four types of explants were capable of producing callus,which could then be induced todifferentiate into somatic embryos. Among the four explants,stems had the highest callus induction rate and the lowest Browning rate,making them the most suitable explants for regeneration.
万方数据
维普
