Genetic variation for fibre quality and yield related traits in coloured cotton genotypes

Cotton is the king of all natural fibres and the second most important oil seed crop, predominantly known as "kapas" in Pakistan. It is an important cash crop and plays a vital role in the economy of Pakistan with major share in foreign exchange earnings. Cotton is also present in various natural colours known as "Coloured Cotton", Coloured cotton has naturally pigmented fibres of brown, green, black, pink, blue and dirty white colour. Due to coloured fibre, it is getting importance in market. Research was designed to evaluate the potential of available coloured cotton germplasm for yield and fibre quality related traits. Eight genotypes were evaluated to find the variability using Randomized Complete Block Design with three replication in the Research area of the department of Plant Breeding and Genetics, University of Agriculture, Faisalabad in 2014. Estimated genetic association for yield and fibre quality related traits among eight coloured cotton genotypes was also studied. The data was recorded to find correlation among days to first bud, days to first flower, plant height (cm), monopodes per plant, sympodes per plant, opened bolls per plant, unopened bolls per plant, seed cotton yield (g), GOT (%), fibre length (mm), fibre strength (g/tex), fibre fineness (micronaire), elongation (%) and short fibre index (%). The analysis of variance revealed that the populations showed highly significant difference for the studied traits. Days to first bud had significant positive correlation with days to first flower, plant height and monopodial branches. Number of days to first flower per plant had significant positive correlation with plant height and short fibre index. Plant height showed significant positive correlation with number of sympodial branches, number of opened bolls, number of unopened bolls, seed cotton yield, fibre uniformity and fibre elongation. Number of opened bolls per plant had positive correlation with seed cotton yield, fibre strength and fibre elongation. Unopened bolls per plant had significant positive correlation with seed cotton yield and fibre elongation. Seed cotton yield showed positive correlation with fibre related traits. GOT had positive significant phenotypic correlation with fibre length in medium brown 1 and medium brown 2 genotypes. GOT had positive significant phenotypic correlation with fibre fineness in medium green genotype. Out of the fifteen, first three PCs exhibited more than 1 Eigen value. The PC1 have 56.17%, PC2 showed 17.73% and PC3 exhibited 12.15% variability. The characters like days to first flower, plant height, opened bolls per plant, seed cotton yield, GOT and fibre length contributed 73.91 % variability among two PCs. The result of the light microscopy revealed that the medium brown fibre (Khaki AARI) among colourd cotton had more twists that are why it has more fibre strength and fibre fineness.