南方型紫花苜蓿Millennium组织培养及其再生

以南方型紫花苜蓿Millennium种子发育5~7 d无菌苗的子叶、下胚轴为外植体,对紫花苜蓿愈伤组织诱导和植株再生进行了研究。结果表明,在愈伤组织诱导中,下胚轴为最佳外植体材料,出愈率随着2,4-D质量浓度的增加呈明显的升高趋势,最佳愈伤组织诱导培养基为2,4-D 2 mg/L+6-BA 0.5 mg/L,诱导率达到100%。紫花苜蓿诱导最佳愈伤组织的分化培养基为MS+KT 1.0 mg/L+NAA 0.05 mg/L,下胚轴愈伤组织分化率达到58%,子叶愈伤组织分化率达到40%。将苗切下转接到1/2 MS+20 g/L蔗糖质量浓度时,培养6 d即可诱导生根,诱导生根率达到100%,完成植株再生仅需60~70 d。成功地建立了南方型Millenni-um紫花苜蓿子叶和下胚轴的离体培养再生途径,并获得了再生植株。

Tissue Culture and Regeneration of the Southern Type Medicago sativa L .CV. Millennium

Cotyledon and hypocotyl of 5～7 d germinated seedlings were used to study callus induction and plant regeneration in Medicago sativa L .CV. Millennium. The results showed that hypocotyl was the optimal explant material in callus induction,callus induction rate was evidently enhanced with the increased concentration of 2,4-D. The effective medium for inducing callus was 2,4-D 2 mg/L+6-BA 0.5 mg/L,the inducing rate was 100%. The selected optimum medium was MS+KT1.0 mg/L+NAA 0.05 mg/L,the differentiate ratio from cotyledon and hypocotyl of Millennium alfalfa was 40% and 50%,respectively. When the young plants were cut and transferred to the 1/2MS+20 g/L sucrose medium,roots could be induced after 6 d,root inducing rate was 100%. The period of regeneration was only 60～70 days. These results indicated that the plant cotyledon and hypocotyl regeneration systems of southern type alfalfa have been successfully established and the regenerated plant was obtained.