幼胚长度、2,4-D浓度、光强度等对花生体细胞胚发生的影响及高效再生系统的建立

Influence of Length of Immature Embryos Excised for Culture, Concentration of 2,4-D, Light Intensity and Other Factors on Somatic Embryogenesis and Establishment of a Highly Efficient System for Regeneration of Peanut Plantlets

花生幼胚在含 2 ,4 D的诱导培养基中 ,形成近球状的致密的胚性愈伤组织、杆状两极结构及子叶期体胚。继代培养也有体胚发生。光照明显抑制体胚发生类似于自然栽培的情况。成熟培养基中诱导体胚根、芽两极发育完全。光下 ,具有根、芽的体胚于再生培养基中长成小植株后移栽于盛沙土的盆中正常生长、结实。在较好的影响因素 (光照、幼胚长度、激素、切分方式、接种密度 )组合下 ,体胚发生频率达 75 %以上 ,每子叶形成体胚 3个以上。该体细胞胚高效再生系统与合子胚的发育相似 。

Regular formation of globular compact embryogenic callus with bipolar shaft and somatic embryos with diminutive cotyledons (Plate Ⅰ a～d) was induced from immature peanut embryos in induction media containing 2,4 D (Tables 1, 2). More somatic embryos were also formed during their subculture (Fig.2). Light substantially suppressed embryogenesis, a phenomenon similar to that observed under in vivo conditions. (Fig.3). In media for maturation, somatic embryos developed root and shoot apexes up to an advanced stage (Plate Ⅰ e～g). Somatic embryos with roots and shoots gave rise to plantlets in medium for regeneration under light (Plate Ⅰ h). The plantlets were then transferred into pots containing sand soil mixture and grew there healthily (Plate Ⅰ i), and eventually bore peanut pegs (Plate Ⅰ j). Appropriate combination of factors such as light intensity (Fig.3), length of immature embryos, 2,4 D concentration, treatment of cotyledons and inoculation density (Fig.1) brought about embryogenesis at 75% or higher percentage and more than 3.0 somatic embryos per cotyledon could be formed (Figs.1～3). Because of its similarity to zygotic embryo and high efficiency, the in vitro system is deemed a satisfactory system to be used as a receptor in genetic transformation and for embryo development research.