野牛草成熟胚植株再生及其影响因素研究

Plant regeneration from mature embryo of Buffalograss and its influencing factors

以野牛草Buchloe dactyloides成熟胚为外植体,对外植体灭菌方式及影响成熟胚再生的因素进行了研究.结果表明:70%酒精处理60 s,75% NaClO溶液(原溶液含有效氯为7%～10%)处理30 min,污染率最低为0.59%.6-BA 0.1 mg/L,2,4-D浓度增至3 mg/L时,愈伤组织诱导率达最高,为80.27%,但愈伤组织结构疏松、呈水渍状.附加5 mg/L硝酸银(AgNO3)或硫代硫酸银(STS)时,愈伤组织诱导率略有降低,愈伤组织结构紧密且表面有颗粒状突起,当AgNO3或 STS浓度为10 mg/L以上时,均不利于愈伤组织的诱导.愈伤组织继代培养过程中,3/4倍MS大量元素用量、聚乙烯吡咯烷酮(PVP) 200 mg/L、维生素C(Vc )200 mg/L及水解酪蛋白(CH) 1 000 mg/L可减轻愈伤组织褐化程度.不同诱导培养基所获得的愈伤组织与其植株再生能力有关,以不加任何植物生长调节剂的MS培养基(MS0)为分化培养基,仅在附加STS的诱导培养基中所得的愈伤组织能够形成再生植株,再生率为10%.

The factors influencing callus induction, plant regeneration from mature embryo of buffalograss and the explant sterilization were studied. The optimal method to obtain the sterile explant is that mature embryo was dipped in 70% ethanol for 60 s, then it was soaked in 75% diluent of NaClO for 30 min, in which 7%~10% chlorine is availed. The callus was induced easily in Murashige and Skoog (1962) (MS) basal medium supplemented with 1.5~3 mg/L 2,4-D. And the callus induction rate reaches to 80.27% with 3 mg/L 2,4-D, but the callus structure is loose. While the quality of the callus cultured in the induction medium with 5 mg/L silver nitrate (AgNO 3) or silver thiosulfate (STS) is better than others. The ingredients in the subculture medium such as three-quarter dosage of macro elements of MS, Polyvinylpyrrol idone (PVP)200 mg/L, vitamin C(Vc) 200 mg/L as well as CH 1000 mg/L mitigated the degree of callus browning, although no significant difference was detected. Plant regeneration of buffalograss was obtained from the callus initiated on the medium containing STS, and the regeneration rate reaches to 10%.