不同激素配比对矩镰荚苜蓿4种外植体愈伤组织诱导的影响

Effects of different hormone ratios on callus induction of four explants of Medicago archiducis-nicolai

【目的】筛选出矩镰荚苜蓿(Medicago archiducis-nicolai)最佳外植体及最佳再生条件。【方法】以矩镰荚苜蓿种子为材料,选择MS(含0.8%琼脂+3%蔗糖)为基本培养基,添加不同种类及浓度配比生长调节剂对矩镰荚苜蓿子叶、叶柄、茎、叶片进行诱导愈伤和愈伤再分化。【结果】外植体诱导率由高到低依次为:茎>叶柄>真叶>子叶,外植体褐化率由高到低依次为:茎<真叶<叶柄<子叶;在1.5 mg/L 2,4-D+0.1 mg/L KT+MS+0.8%琼脂+3%蔗糖条件下最适合真叶诱导愈伤,诱导率为78%,褐化率为8%;1.5 mg/L 2,4-D+1.0 mg/L KT+MS+0.8%琼脂+3%蔗糖最适合子叶、叶柄、茎诱导愈伤,在此培养基中,茎的出愈率为96%,褐化率为0,叶柄的出愈率最高,为92%,褐化率为2%,子叶的出愈率为60%,褐化率为4%;在0.3 mg/L NAA+1.0 mg/L KT+MS+0.8%琼脂+3%蔗糖条件下最适合子叶、叶柄诱导胚性愈伤;在0.3 mg/L NAA+1.0 mg/L 6-BA+MS+0.8%琼脂+3%蔗糖条件下最适合真叶诱导胚性愈伤;在0.3 mg/L NAA+0.5 mg/L KT+MS+0.8%琼脂+3%蔗糖条件下最适合茎诱导胚性愈伤。【结论】4种外植体均产生愈伤组织,且进一步诱导愈伤组织可分化形成体细胞胚。4种外植体中,茎的愈伤诱导率最高,褐化率最低,为最佳外植体。

【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.