双单倍体南瓜后代子叶离体再生植株研究

【目的】探索一种快速扩繁南瓜双单倍体植株的技术，以扩大双单倍体植株的数量，提高其育种效率。【方法】以双单倍体南瓜后代子叶为外植体，在MS培养基中分别添加不同质量浓度的6-BA（1.0，4.0 mg/L）和NAA（0.05,0.1,0.2,0.5,1.0 mg/L），筛选最佳组合；在此基础上，继续添加不同质量浓度的2,4-D（0.5,1.0,1.5,2.0 mg/L），筛选3种激素的最佳组合。在MS＋6-BA 4.0 mg/L＋NAA 0.2 mg/L的不定芽诱导培养基上，研究其对不同苗龄子叶的诱导效果。将不定芽接种在含不同质量浓度NAA (0.05, 0.1, 0.2, 0.5 mg/L)的MS生根培养基上，比较生根率和根系生长势。【结果】在诱芽培养基中，添加2种激素时，以6-BA 4.0 mg/L＋NAA 0.2 mg/L的MS培养基诱导率最高，为66.67％，分化系数为3.89；添加3种激素时，以6-BA 4.0 mg/L+NAA 0.2 mg/L＋2,4-D 1.5 mg/L的MS培养基诱导率最高，达80.95％，分化系数为4.12。当子叶展开后苗龄为3 d时，不定芽诱导率相对较大，为77.42％。不定芽在MS+0.1 mg/L NAA培养基上生根效果最好，根系生长健壮，生根率达100%。【结论】双单倍体南瓜后代子叶离体再生的适宜激素质量浓度组合为MS＋6-BA 4.0 mg/L+NAA 0.2 mg/L+2,4-D 1.5 mg/L；以展开后3 d苗龄的子叶作为外植体诱导效果最好；MS+0.1 mg/L NAA是不定芽诱导生根的最适培养基。

Study on in vitroregeneration of double haploid plants offspring of pumpkin(Cucurbita moschata Duch.) with cotyledon explants

【Objective】We explored a highly efficient plantlet regeneration technology on double haploid plants of pumpkin to get a great quantity of double haploid plants to promote the efficiency in pumpkin breeding.【Method】Taking the cotyledon of double haploid offspring of pumpkin as the explants,we inoculated on several types of MS-based media which were added 6-BA(1.0,4.0 mg/L) and NAA(0.05,0.1,0.2,0.5,1.0 mg/L) in different concentrations to select the optimal concentration combination;Based on this,we continued to study adding different concentrations of 2,4-D(0.5,1.0,1.5,2.0 mg/L),and screen three hormone optimal combination.The effect of the different ages of cotyledon explants in MS+6-BA 4.0 mg/L+NAA 0.2 mg/L adventitious bud inductive medium was studied.Adventitious buds were inoculated on MS medium supplement with different concentrations(0.05,0.1,0.2,0.5 mg/L) of NAA.The condition of rooting rate and growth vigour of root was analyzed.【Result】In the bud induction medium,adding two hormones MS+6-BA 4.0 mg/L+NAA 0.2 mg/L induced the highest rate 66.67%,and the differentiation coefficient was 3.89;Adding three kinds of hormones MS+6-BA 4.0 mg/L+NAA 0.2 mg/L+2,4-D 1.5 mg/L induced the highest rate of 80.95%,differentiation coefficient was 4.12.Adventitious bud induction rate was bigger,77.42%,when the age of cotyledon was 3 days after unfolding.The effect of adding 0.1 mg/L NAA in MS medium on rooting culture was better,the root can grow strongly,rooting rate of adventitious bud reached 100%.【Conclusion】The suitable hormone concentration combination for in vitro regeneration of the cotyledon of double haploid plants offspring is MS+6-BA 4.0 mg/L+NAA 0.2 mg/L+2,4-D 1.5 mg/L.3-day-old cotyledon after unfolding as the explants expresses the best induction effect.MS+0.1 mg/L NAA is the suitable medium for root induction.