1 Institute of Vegetables and Flowers,Chinese Academy of Agricultural Sciences,Beijing 100081,China;2 College of Agronomy,Yanbian University,Yanji 133002,Jilin,China;3 Shouguang Vegetable Research and Development Center, Chinese Academy of Agricultural Sciences,Shouguang 262704,Shandong,China
Abstract:In order to establish a high efficient watermelon cotyledon regeneration culture system,this paper took watermelon variety ‘Xiangxiu’of small fruit type as test material;selected cotyledon cultured under aseptic conditions for 4-5 days as explant;and studied the effects of exogenous hormones(6-BA, NAA,IAA and IBA)on the regeneration of watermelon cotyledons in vitro.Results showed that the optimal medium for inducing adventitious buds was MS + 2.25 mg · L-1 6-BA + 0.1 mg · L-1 NAA.The induction rate was 90.56%.The optimal medium for adventitious bud elongation was MS + 1.0 mg · L-1 6-BA + 0.50 mg · L-1 IAA.The optimal medium for rooting was 1/2MS + 1.0 mg · L-1 IBA.The rooting rate could reach 93.33%. The survival rate of regeneration seedling after acclimitation and transplant could reach 98.33%.It took about 63 days from cotyledon inoculation to acquisitio of transplantable regenerated seedlings.