鲜食蕉品种的高度不育性和多倍性制约了用传统育种方法培育生产实践中所需的新品种,建立稳定的胚性细胞悬浮系是香蕉生物技术育种的前提.以目前国内尚未建立该体系的鲜食蕉品种贡蕉(AA)未成熟雄花序的第1～15位花梳为外植体,对胚性细胞悬浮系的建立和植株再生体系进行了优化.结果表明,5～6个月的培养后可获得分生小球体和浅黄色、松散易碎的胚性愈伤组织.9μmol/L 2,4-D对外植体愈伤组织的诱导效果最好,诱导率为40.96%,胚性愈伤组织诱导率可达7.45%,其中5.79%的胚性愈伤组织来源于第6～12号位置的花梳.胚性愈伤组织悬浮培养后,通过3个月的筛选和继代培养,可得到均质的胚性细胞悬浮系.该培养体系合适继代周期为15d,继代时合适的起始接种量为每30mL培养基加2 mL PCVECS.培养6个月的胚性细胞在体细胞胚诱导培养基中培养15d后可见到白色半透明体细胞胚的发生,体细胞胚诱导率为280×103个/mL PCV.成熟体细胞胚的萌发率为17.28%,其中发育成正常的再生植株的百分率为14.16%.
Conventional breeding for dual resistance of disease and pest of Musa cultivars remains a difficult endeavor, as the plant is polyploidic and high in sterility. Biotechnological techniques, eg., genetic engineering, in vitro mutation breeding, or protoplast fusion, may overcome the difficulties and improve the germplasm. Establishment of a stable embryogenic cell suspension (ECS) is a prerequisite for any of the biotechnological breeding methods. In this study an embryogenic cell suspension was established from immature male flower of Musa acuminata cv. Mas (AA), a popular commercial variety of banana in the South East Asian region. After culture for 5～6 months on callus induction media, which consisted of MS salts, different concentrations of 2,4 dichlorophenoxyacetic acid (2,4 D), 4 1μmol/L biotin, 5 7μmol/L indoleacetic acid (IAA), 5 4μmol/L naphthaleneacetic acid (NAA), other vitamins, 87mmol/L sucrose, and solidified with 7g/L agarose,meristematic globules and yellow, friable embryogenic cultures were induced from the explants of 1～15 th row young floral hands of immature male flowers. Of the four treatments of 2, 4 D, 9μmol/L was the most effective on the callus induction, it transformed 40 96% and 7 45% of the cultivated male floral hands into callus and embryogenic callus respectively. The explants to produce highest frequency of the embryogenic calli were floral hands of 6 to 12th rows, which generated 5 79% of the embryogenic calli. Suspension cultures were initiated from these embryogenic calli in liquid medium supplemented with 4 5μmol/L 2, 4 D. After sieving selection of the cultures using a stainless steel metallic strainer with pore sizes of 154μm at 15day intervals for 3 months, homogeneous and yellow embryogenic cell suspensions, composed of single cells and small cell aggregates, were established. Based upon the growth quantity and growth rate of ECS, it was determined that the appropriate inoculum was 2 0mL PCV ECS/30mL medium in 100mL flask, and the appr
Chinese Journal of Biotechnology
banana, male inflorescences, embryogenic cell suspension, somatic embryo, plant regeneration