Genetic analysis of presence and absence of lint and fuzz in cotton

Cotton fibre mutants that were fuzzless and/or tintless were crossed with each other and a normal genotype (fuzzy, linted) to produce F-2 and BC1 generations. F-2 segregation ratios from the cross of fuzzless-lintless x fuzzy-linted, for fuzzy-linted, fuzzless-linted and fuzzless-lintless were 45 : 15 : 4. From the cross of fuzzless-lintless x fuzzy-linted. the F segregation ratios were 9 : 39 : 16 whereas the BC1F1 segregation ratios from the F-2 backcrossed to fuzzless-lintless were 1 : 3 : 4. These data suggest that the presence or absence of lint and fuzz are controlled by the interaction of four gene loci on non-homologous chromosomes. We designate these loci as N-1, N-2 Li-3 and Li-4. where N-1 N-1 confers the presence of fuzzy, N-2 N-2 confers inhibition of fuzzy initiation and development. and duplicate gene pairs, Li3Li3 and Li4Li4, determine the presence of lint. Homozygosity for li(3)li(3) and li(4)li(4) might also inhibit fuzz from development. In other words, they were recessive epistatic to fuzz genes.