Establishment Of In Vitro High Efficient Regeneration System Of Cowpea (Vigna Unguiculata L. Walp.) And Screening Test For Its Resistance To Kanamycin

In this paper, cv. Cheng-jiang VⅡof cowpea(Vigna unguiculata L.Walp.) was selected as material. We had studied the effect of many factors on cowpea tissue culture and established a stable and high-efficiency plant regeneration system. The effect of different concentrations of kanamycin on shoots induction from cotyledonary node explants of cowpea had also been researched. All the achievements provided an academic prerequisite for genetic transformation researches of cowpea. The main results were as following:(1) The primary leaves and stems explants could only induce callus, the regeneration capacity of primary leaves were very low, the highest rate of callus induction was 5.53%, the regenerated callus and the explants could turn brown easily on the subculture medium, the stems had higher potential of callus induction, the highest rate of callus induction was 81.23%, the best medium was MSB5 (MS salts+B5 vitamins)+1.25 mg.L-1 6-BA+0.2 mg.L-1 IBA, and the stem was the best explants for callus induction of cowpea;(2) The cotyledons and cotyledonary nodes explants could induce shoots directly, the highest rate of shoot induction were 28.57%and 100%respectively, the highest mean number of shoot were 3.47 and 4.47 respectively, the best medium for shoots induction was MSB5+1.25 mg.L-1 6-BA, the addition of 0.2 mg.L-1 IBA was no significant effect on shoots induction, and cotyledonary nodes were the best explants for shoots induction.(3) TDZ at lower concentrations could fast induce shoots from cotyledonary nodes, TDZ at higher concentrations could aging the explants, the best shoots induction medium was MSB5+0.3 mg.L-1 TDZ+0.0/0.2 mg.L-1 IBA.(4) The addition of KT was no significant effect on shoot elongation, cutting off the initial shoots was favored to the elongation of secondary shoots, the best medium for elongation was the basal medium;(5) The shoots could root easily at different concentrations of IBA and the rooting rate of different treatments could reach 100%, the roots in medium supplemented with 0.5 mg.L-1 IBA were more vigorous than others;(6) Addition of appropriate concentrations of 6-BA in germination medium could improved the regeneration from cotyledonary nodes, the best preconditioning concentration was 3 mg.L"1 and up to 4 mg.L"1 would suppress the induction of shoots;(7) The presence of cotyledons could significantly improve the mean number of shoots, however, the number of cotyledons was no effect on shoots number, the highest number of shoots was 7.83;(8) Cotyledonary node explants armed with the axillary meristem and had high resistance to kanamycin, the shoots could regenerate mostly on the screening medium supplemented with different concentrations of kanamycin, the concentration at 90 mg.L' could bleach the regenerated shoots at 100%after three weeks of culture.