Genetic manipulation of starch content in roots, on the phenology of cotton

Abstract

Breeding by recurrent selection for high and low starch content in roots of cotton (Gossypium hirsutum L.r. latifolium Hutch.) had profound phenological consequences. Earliness, the size of bolls and the yield of seed cotton per unit of leaf area are increased in the high starch line and decreased in the low starch. Number of branches, height of first fruiting node, height of plant, leaf area and number of bolls are decreased in high root starch and increased in low root starch. It seems that manipulation of root sink strength has affected carbohydrate partition and patterns of growth. The physiological and agronomical consequences of these modifications are discussed.