Physiological and biochemical changes associated with cotton fiber development. VIII. Wall components

Fibers of three cotton cultivars (Gossypium hirsutum L.) H-4, H-8 and (G. a rboreum) G. Cot-15, which shows variation in staple length were analyzed fo r growth in terms of fiber length and fresh and dry mass. From the growth a nalysis cotton fiber development is divided in four distinct phases i.e. (i ) initiation (ii) elongation (iii) secondary thickening and (iv) maturation . Rate of fiber elongation and rate of water content shows close parallelis m. Highly esterified and less esterified pectic fraction along with high an d low molecular weight xyloglucan fractions were estimated from fiber walls of all the three cotton genotypes. Xyloglucans were fractioned in to high and low molecular weight by alkali treatment, 1 M and 4 M KOH respectively. Xyloglucan content shows inverse correlation with fiber elongation. Role o f water content and wall components in determination of staple length in co tton genotypes is discussed.