光质对棕色棉纤维色素形成的影响

采用红、黄、蓝紫、白(对照,透明膜)滤光膜对棕色棉棉铃进行套袋处理,研究光质对棕色棉纤维色素合成的前体物质及色素合成相关酶活性的影响.结果表明:不同光质处理对纤维中总黄酮、总酚、缩合单宁含量和苯丙氨酸解氨酶(Phenylalanin ammonia-lyase,PAL)活性均具有一定的影响.不同光质处理使棕色棉纤维发育前期的可溶性缩合单宁含量发生明显变化,表现为:红光＞自然光(对照)＞黄光＞蓝紫光；而不溶性缩合单宁含量以红光处理的最高.棕色棉纤维发育不同时期纤维的总黄酮、总酚、缩合单宁、PAL与棕色棉色素含量的相关分析结果表明,总黄酮与色素含量呈显著负相关,总酚、缩合单宁与色素含量呈显著正相关,且缩合单宁合成对色素含量的直接作用最大,表明缩合单宁可能是棕色棉色素合成的直接前体物质.

Effect of Light Quality on Pigment Formation in Brown Cotton Fiber

The aim of this study was to determine the effects of light quality on pigment formation and enzyme activity in cotton fibers. The different light qualities were achieved by covering cotton bolls with different colored film filters (red, yellow, blue-violet, and white). The contents of flavonoids, total phenols, and condensed tannins, and phenylalanine ammonia lyase activity were affected by different light qualities. The different light qualities could be ranked, in terms of their effects on the content of soluble condensed tannins in fiber, as follows: red light>control>yellow light>blue-violet light. The highest content of insoluble condensed tannin in cotton bolls was those treated with red light. A correlation analysis showed that both phenols and condensed tannin contents were positively correlated with fiber pigmentation. The flavonoid content was negatively correlated with fiber pigmentation. Condensed tannins are the direct precursors of the brown pigment in cotton bolls.