Abstract: The browning and death of calli would reduce the efficiency of cotton plant regeneration and genetic transformation,and it was pivotal to inhibit the two peaks of browning and death of calli during cotton tissue culture to improve plant regeneration and genetic transformation efficiency.In this study, we analyzed subculture time, browning death degree, regeneration time and regeneration efficiency of calli of "Jihe 713"and "Coker 312" cultivars. The results showed that subculture time was able to regulate two peaks of browning and death of calli. To take an extended subculture time during the first PCD peak, subculture time interval 50 d can significantly reduce callus browning and death, increase the rate of callus embryogenesis and shorten the time of embryogenesis. To Take a shortened time of subculture during the second PCD peak, subculture interval 15d can significantly reduce the degree of browning and death, thereby increasing the plant regeneration rate and reducing the regeneration time of the plants. Regulation browning and death by callus subculture time will significantly improve the efficiency of genetic transformation in two cotton varieties, so as to help the gene function and genomics research in cotton.

Key words: Gossypium hirsutum L., calli tissue, program cell death, subculture time

摘要： 棉花组织培养中愈伤组织褐化常常严重影响植株再生的效率,如何解决棉花组织培养过程中愈伤组织和胚性愈伤组织首次继代的两次褐化死亡高峰，是关系到是否能够大幅度提高棉花植株再生和遗传转化效率的关键因素之一。本研究分析了冀合713和珂字312两品种愈伤组织的继代时间与褐化死亡程度、植株再生时间和再生率，结果表明继代时间对棉花愈伤组织两次褐化死亡高峰存在着显著调控作用。在第一次高峰发生时延长继代时间间隔到50 d，可以显著降低愈伤组织继续褐化死亡，提高胚性愈伤组织的发生率和缩短胚胎发生时间。在第二次高峰发生时缩短继代时间间隔为15 d，可以显著降低愈伤组织褐化死亡程度，从而增加植株再生率和缩短植株再生时间。通过继代时间间隔的调控，有助于提高两个棉花品种的转化效率，为棉花基因功能验证和功能基因组研究提供了保证。

关键词: 棉花, 愈伤组织, 细胞程序性死亡, 继代时间