提高木薯循环培养的次生体胚再生植株频率研究

IMPROVEMENT OF PLANT REGENERATION FROM CYCLIC SECONDARY SOMATIC EMBRYOS IN CASSAVA (MANIHOT ESCULENTA CRANTZ)

摘要:

用木薯成熟体胚子叶作外植体诱导次生体胚，接种7d或15d后分别在诱导培养基或成熟培养基中加入AgNO₃，可明显提高植株再生频率。前者可使体胚再生植株频率由对照的40．5％提高到58．1％；后者可使植株再生频率由对照的36．1％提高到61．3％。用ABA进行上述处理，效果更加显著。诱导期处理，可使植株再生频率由对照的40．5％提高到72．6％；成熟期处理，植株再生频率由对照的36．1％提高到81．3％。若诱导7d后，将2，4－D浓度由4．0mgL^-1降至2．0mgL^-1，并加AgNO₃，继续诱导15d，转到附加0．25mgL^-1ABA的成熟培养基中培养至30d，能极显著地促进体胚的发育和成熟，使植株再生频率达到一个相当高的水平，最高达95％，平均每个外植体产生的植株数达39．6个，分别相当于对照的2．38倍和2．46倍。

Abstract:

Cotyledons from mature embryos of cassava cultivar Nanzhi 188 selected from cultivar CM321 - 188, which was provided by CIAT (Centro internacional de Agricultura Tropical), were used as explants. AgNO₃ could obviously promote the plant regeneration frequency (PRF) in the induction medium (MS I) with 16 mg L^-1 AgNO3 added at the 7th day, and in maturation medium (MS II) with 20 mg L^-1 AgNO, added at the 15th day, the PRF being from 40.5% (control) to 58.1 %, and from 36.1 % (control) to 61.3%,respectively. 0.25 mg L-1 ABA adding to MS I and to MS II could markedly improve PRF by 32.1 % and 45.2%, respectively. An decreasing concentration of 2,4-D at 2.0 mg L^-1 plus 16 mg L^-1 AgNO₃ and 0.25 mg L^-1 ABA in combination signifcanlly improved somatic embryo maturation and promoted to form normal shoots, the highest PRF was 95%, and the number of plantlets produced reached 39.6 per explant.