Wild Gossypium anomalum: a unique fibre fineness and strength

The improvement in textile spinning machinery has an important impact upon the entire cotton fibre business, particularly in the demand for high quality cot ton fibre. Genetic improvement of fibre quality traits, viz. length, strength, fineness, maturity and uniformity is vital to meeting the challenge of the textile industry. Amongst wild Gossypium L. species, the African Gossypium anomalum Waw. & Peyr. (In = 2x= 26; B1B1) produces cotton with good fibre strength and fineness coupled with resistance to pest and diseases. The seed hairs of Gossypium anomalum are short and non-convoluted and are fully thickened with secondary cellulose deposition, and possess low fibre weight due to thinness of wall. X-ray crystallography and crystallinity index studies showed that Gossypium anomalum has highest fibre strength with highest crystallinity index due to maximum cellulose deposition. Either inter se mating among selected BC1F1 plants or a second backcross of the elite plants to the cultivated parent was found effective in improving the recovery of desirable segregants. Intercrossing of plants selected in F2 or BC2 from large populations result in enhancement of variability and rapid accumulation of favourable genes for the improvement of biochemical traits, disease resistance and for developing germplasm pools. Examination of single plant for fibre weight and swollen hair diameter and pursuing selection for fineness with economic attributes is necessary to avoid loss of fibre strength and fineness during sub sequent generations. Intermating of several synthetic hexaploids increases the variability, fertility and re combination potential. Utilization of Gossypium anomalum to impart fineness (low fibre weight) with high maturity to Gossypium arboreum L. yielded com mendable results. If Bt gene is incorporated into this hybrid, it can be an excellent source of bollworm tolerance coupled with superior fibre properties and yield.