Assessment of heterosis (F1) and inbreeding depression (F2) for some economic characters in upland cotton

Twelve parents in fourteen cross combinations were studied for heterosis in F1 and inbreeding depression in F2 populations for seedcotton yield, number of bolls per plant, ginning out turn %, staple length and uniformity ratio. Seedcotton yield and number of bolls expressed fair amount of heterosis, however, hybrids showing higher magnitudes of heterosis were generally associated with higher amount of inbreeding depression suggesting dominant genes functioning for these traits. Small amount of heterosis, lower magnitude of inbreeding depression for lint percent, staple length and uniformity ratio indicated that additive genes were responsible for the expressions of these traits. Hybrid vigor recorded in F1 in respect of seedcotton yield per plant ranged from 4.5 to 159.0 percent, whereas in bolls per plant, ginning out turn, staple length and uniformity ratio the range was 0 to 150.0, -1.5 to 11.7, 0.7 to 13.0 and -2.0 to 11.1% respectively.