小果型西瓜离体诱导四倍体的初步研究

目的]为小果型西瓜三倍体的育种奠定基础。方法]以二倍体小果型西瓜优良自交系MH-39-1的子叶为外植体进行离体诱导四倍体的研究。结果]100 mg/L秋水仙素处理子叶的不定芽分化率达66.7%,平均分化不定芽6.7个。400 mg/L秋水仙素处理的四倍体诱导率为20.0%。秋水仙素处理12 h的不定芽分化率为83.3%,处理48 h的不定芽分化率为16.7%。秋水仙素处理24~36 h的四倍体诱导率为16.7%。4.0 mg/L 6-BA处理的不定芽分化率为83.3%,1.0 mg/L 6-BA处理的不定芽分化率为58.3%。再生芽在4种生根培养基上的生根率均在90%以上,在不添加植物生长调节剂的培养基上再生苗的平均生根数仅为6.5条,添加NAA的培养基上再生苗的平均生根数在10条以上,但根短而粗。结论]初步确定秋水仙素离体诱导小果型西瓜四倍体的适宜浓度和处理时间为400mg/L和24 h。

Preliminary Study on the Induction in vitro of Tetraploid Mini-watermelon

Objective] The study aimed to lay a foundation for breeding the triploid mini-watermelon.Method] With the cotyledons of good inbred line MH-39-1 in diploid mini-watermelon as explants,the induction in vitro of tetraploid mini-watermelon was studied.Result] The differentiation rate of adventitious buds from its cotyledons treated with 100 mg/L colchicine was up to 66.7% and the average number of adventitious buds differentiated from its cotyledons was 6.7.The induction rate of tetraploid in treatment with 400 mg/L colchicine was 20.0%.The differentiation rate of adventitious buds was 83.3% in treatment with colchicine for 12 h and 16.7% in treatment with colchicine for 48 h.The induction rate of tetraploid in treatment with colchicine for 24-36 h was 16.7%.The differentiation rate of adventitious buds was 83.3% in treatment with 4.0 mg/L BA and 58.3% in treatment with 1.0 mg/L BA.The rooting rates of regenerated buds on the 4 rooting media were higher than 90%,the average rooting number of regenerated seedlings on the media without plant growth regulator was only 6.5,that on the media with NAA was more than 10 and the roots were short and thick.Conclusion] It was preliminarily determined that the suitable concn.and treatment time for inducing tetraploid mini-watermelon in vitro with colchicine were 400 mg/L and 24 h.