棉花组织培养中异常苗的发生与转化

研究了棉花 (Gossypium hirsutum L.)组织培养中异常苗发生的类型、规律、影响因素及转化为正常苗的途径及技术。结果表明 ,在棉花组织培养中异常苗发生的频率极高 ,且形式多样 ,大体可分为生长点异常苗、叶片异常苗、胚轴异常苗、联体苗、丛生叶苗、单叶苗、玻璃化苗、白化苗、褐化苗和重新愈伤化苗等 1 0类。其中生长点异常苗和叶片异常苗最为常见。影响异常苗形成的因素很多 ,其中主要有外植体种类、培养基组成、培养方式和培养时间。有的异常苗来源于畸形胚 ,有的异常苗由正常苗转化而来。在合适的条件下异常苗可转化为正常苗 ,但不同培养基对异常苗转化为正常苗的影响不同 ,且不同基因型的异常苗转化为正常苗的能力也有差别。此外 ,从外界调控机制与棉花培养细胞的内在发育机制的相互作用方面讨论了造成棉花组织培养异常苗发生的原因 ;并讨论了降低异常苗产生频率的技术途径和异常苗存在对棉花组织培养的影响

DEVELOPMENT OF ABNORMAL PLANTLETS AND THEIR NORMALIZATION DURING COTTON TISSUE CULTURE

There was a high frequency in the occurrence of abnormal plantlets during cotton (Gossypium hirsutum L.) tissue culture.Their patterns,ways of development and effected factors,and the technique of their normalization were studied.Based on their morphologic characters,they could be classified into ten kinds,viz.growing point abnormal plantlets,cotyledon ,hypocotyl ,united ,fasciculated ,single leaf ,albino ,vitreous ,browning ,and callus forming plantlets.The growing point and the cotyledon abnormal plantlets, which were more commonly seen and were effected by multiple factors, are mainly influenced by the kind of explants,the medium composition,the method and time of culture.The abnormal plantlets could either developed from abnormal embryos or transformed from normal plantlets.Under suitable culture condition reversion of abnormality to normal was possible,however such normalization varied with different genotypes and media.The authors point out the interaction of external regulation and intrinsic developmental mechanism as the main factor causing the accurrence of abnormal plantlet and also discuss the technical procedures of reducing the occurrence frequency of such abnormal plantlets which greatly impact cotton tissue culture.