提高西瓜离体培养植株再生效率的研究

本文以“京欣1号”母本和“伊选”西瓜4天苗龄子叶为外植体,研究离体培养植株高频率再生体系。结果表明：“伊选”子叶远轴端外植体的再生频率仅为10％,子叶近轴端外植体在5mg／LBA 0．1mg／L IAA的激素组合下植株再生频率为100％,平均每个外植体的丛生芽数在所有组合中最多,为10.3个;“京欣1号”母本子叶近轴端外植体在2mg／LBA 0．5mg／L IAA激素组合下植株再生频率为100％,平均每个外植体的丛生芽数在所有组合中最多,达6．9个。本试验条件下,子叶近轴端外植体接种4天即分化出不定芽,至再生苗的移栽仅需40天,在MS 0．1mg／L NAA的生根培养基上的生根率为97．3％,移栽成活率达98．5％。

Enhancement of plantlet regenerative efficiency of watermelon in vitro]

The purpose of this study was to enhance shoot regenerative efficiency of watermelon by optimizing culture parameters. Cotyledons at 4-day seedlings were explanted and cultured on MS medium supplemented with different combinations of hormones. In "Yixuan" cultivar, the plantlet regenerative frequency and shoots produced by per explant was as low as 10% and 0.4 respectively at all combinations tested when distal parts of cotyledons were inoculated. Whereas, maximum regenerative frequency of 100 percentage and 10.3 shoots regenerated from per explant were observed on MS medium supplemented with 5 mg/L BA and 0.1 mg/L IAA using basal parts of cotyledons as explants. Likewise, in "Jingxinmuben" cultivar, the highest regenerative frequency of 100 percentage and 6.9 shoots regenerated from per explant were obtained when proximal parts of cotyledons were cultured on MS medium containing 2 mg/L BA and 0.5 mg/L IAA. In the present study, adventitious buds were initiated after only 4 d in culture and intact plantlets were obtained in 40 d culture. This will facilitate quicker gene transformation and polyploidy induction of watermelon in vitro.