荔枝胚性愈伤组织诱导和离体保存条件的筛选

Induction and screening of in vitro conservation conditions of embryogenic callus of Litchi chinensis

对影响荔枝(Litchi chinensis Sonn.)胚性愈伤组织诱导的因素(防褐化剂种类、花期、荔枝品种以及外植体取材部位)进行了比较研究,并对其离体保存条件进行了筛选。结果表明,在愈伤组织诱导培养基(含2.0 mg.L-12,4-D、0.5 mg.L-1NAA、30 g.L-1蔗糖和6 g.L-1琼脂的MS培养基,pH5.8)中添加防褐化剂水解乳蛋白(0.4g.L-1),可使花药胚性愈伤组织的诱导率达到20.51%;以茎段、叶柄和幼叶为外植体,不能诱导出胚性愈伤组织,而采用花药和幼果培养,可诱导出胚性愈伤组织,其中,第1期雄花花药是最适宜的培养材料,胚性愈伤组织的诱导率可达20.11%;荔枝不同品种间幼果的胚性愈伤组织诱导率存在差异,品种‘及第’的诱导率最低。在15℃条件下,将荔枝胚性愈伤组织保存在添加20 g.L-1甘露醇的保存培养基(含1.0 mg.L-12,4-D、30 g.L-1蔗糖和6 g.L-1琼脂的MS培养基,pH5.8)中,保存效果最佳,可将继代时间延至100 d。

The influence factors in induction of embryogenic callus of Litchi chinensis Sonn.,including anti-browning agent,flowering stage,cultivar and explant type,were compared and studied,and the in vitro conservation conditions of embryogenic callus were screened.The results show that when adding 0.4 g·L^-1 lactoalbumin hydrolysate in the induction medium（MS medium containing 2.0 mg·L^-1 2,4-D,0.5 mg·L^-1 NAA,30 g·L^-1sucrose and 6 g·L^-1agar,pH 5.8）,the induction rate of embryogenic callus from anthers can reach 20.51%.The embryogenic callus can be induced from anther and young fruit but not from stem segment,petiole and young leaf.Anther of male flower at first stage is the best explant,and the induction rate reaches 20.11%.The induction rates of embryogenic callus from young fruit of different cultivars of L.chinensis are various,and among them,the induction rate of cultivar ＇Jidi＇ is the lowest.Conservation effect of embryogenic callus is the best in the conservation medium（MS medium containing 1.0 mg·L^-1 2,4-D,30 g·L^-1sucrose and 6 g·L^-1agar,pH 5.8） added with 20 g·L^-1 mannitol under 15 ℃,and the subculture time of embryogenic callus can be prolonged to 100 d.