Assessment of genetic divergence in diploid cotton (Gossypium arboreum L.) germplasm using fibre quality traits

Abstract

Cotton is one of the most important crops among natural fibres. Fibre quality determines the spinning ability, which is negatively correlated with yield and yield-contributing traits. Limited efforts have been made to improve fibre quality and yield in diploid cotton. Therefore, screening a large panel of germplasm lines can help identify genotypes with better fibre quality and yield. We evaluated 712 desi cotton genotypes for fibre quality traits. The genotypes showed a significant difference for all the traits, suggesting considerable variability for fibre quality improvement. Fibre length and strength showed high phenotypic and genotypic coefficients of variation. Heritability was high for fibre strength, length, and elongation. Fibre length and strength were positively correlated; however, micronaire was negatively correlated with these two traits. Superior accessions were identified for fibre length (11), strength (20), uniformity (7), and elongation (25) among genotypes. Most of the desi lines (71%) had medium micronaire values. Twenty accessions identified were ideal for spinning, showing the fibre strength-to-length ratio of one. Cluster analysis based on Euclidean distance grouped all 712 accessions into four major clusters. Principal component analysis biplot revealed that accessions AC3418, 360-SP1, AC3522B, Kanpur A, Gao16CB-9, and AC3370 were genetically diverse. The superior accessions for fibre quality identified in this study are potential lines for the diploid cotton improvement programme.

Morphological characterization of Gossypium arboreum germplasm using qualitative descriptors

“…The trait petiole pigmentation recorded the lowest diversity index (3.532), followed by leaf nectaries (3.640) and leaf pubescence (3.742). As indicated by this trend, lower indices discriminated against genotypes in a greater order than other variables (Fig.5) Manivannan and Waghmare (2020). andRathinavel (2018) used clustering analysis for grouping cotton genotypes.…”

Assessment of production potential of long-linted Gossypium arboreum L. genotypes under different sowing times

“…The area under G. arboreum in India reduced from 65% of the total cotton area in 1947 to 17% in 2000 to around 3% a decade after the introduction of Bt hybrids (Blaise et al 2020;Kranti 2015;Narayanan et al 2014). Gossypium arboreum has the ability to provide resistance against insect pests and diseases, can withstand moisture stress, needs less nutrients and is suitable for erratic, less rainfall and marginal soils (Sankaranarayanan et al 2010;Iqbal et al 2019). Despite these advantages, this species is not currently preferred by farmers due to their small boll size and poor locule retentivity (Venugopalan et al2016).…”