Morphological and molecular characterization of desi cotton (Gossypium herbaceum L.) landraces collected from different states of India

Abstract

Exploration missions were conducted to collect, characterize and conserve valuable landraces of desi cotton from the different States of India. Sixteen accessions of desi cotton (Gossypium herbaceum L.) collected from Gujarat and Tamil Nadu was characterized based on the morphological and also using Simple Sequence Repeats (SSR) markers. Improved cultivars, such as G.Cot-25, Jayadhar and DDhc-11 were used as standard checks. Morphological characterization for 18 qualitative and 12 quantitative characters underscores the variability found in the collected germplasm accessions. Diversity studies using morphological data grouped the accessions into three major clusters. Notably, a medium range of variability was observed for fibre length (18.31-23.74 mm), uniformity ratio (51.68-58.88 %), micronaire (3.10-5.62) and fibre strength (15.42-17.89 g/tex). Molecular genetic diversity among the collected desi cotton accessions was performed using 42 SSR primer pairs. Of these, 24 (57%) SSR primer pairs exhibited polymorphism. These primers produced a total of 49 alleles across all the collected accessions. The number of alleles per locus ranged from 2 to 3 with a mean of 2.04. The polymorphism information content (PIC) values ranged between 0.09-0.45 with a mean value of 0.29.The observed heterozygosity values for the marker loci varied from 0.0 to 0.63 with a mean value of 0.16 as against the expected values (0.10 to 0.53 with the mean of 0.36). Diversity analysis using SSR markers grouped the accessions into three major clusters.