The Pigment Distribution Regulation of the Natural Brown Cotton and Relations between Pigment Synthesis and Cotton Fiber Development

The pigment distribution regulation of the natural brown cotton was analyzed by observing the fiber of three cultivars,whose color had a different hue and saturation.It was found that the pigment distribution of middle-brown cotton was a basic type,which has four bands of color.The relationship of pigment distribution to pigment synthesis or cotton fiber development were studied by observing the fiber color dynamic development,the test of washing fiber by distilled water,determining of pigment content in the fiber and seeds coat.It is concluded colorless precursor of the pigment was synthesized in the seeds coat,and then the precursor was conveyed into fiber cell,where the precursor would be turned into brown pigment.And the link mode of the pigment to the fiber could be divided into two types according to the color fastness.The results supported the diffuse growth theory of cotton fiber elongation,and that diffuse growth was not a uniform continuance.The results also showed that the pigment content in fiber had obvious negative correlations to boll weight and fiber length.