南方型紫花苜蓿Millennium组织培养及其再生

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

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。

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.