Correlation and Heritability for Yield and Fiber Quality Parameters of Ethiopian Cotton (Gossypium hirsutum L.) Estimated from 15 (diallel) Crosses

Abstract

               Correlation and heritability estimates of the yield and the fiber or lint quality were determined using 15 F1 cotton hybrids obtained from a diallel cross made in the Werer Agricultural Research Center, in Ethiopia, in 2003. The results indicated that the seed cotton yield was highly genetically correlated to boll weight (r = 0.99**), lint yield (r = 0.88**) and lint index (r = 0.96**). The lint yield was highly correlated to lint percentage (r = 0.94**) and the number of seeds per boll (r = 0.96**). The results illustrated that a high lint percentage, more bolls per plant and a small seed size were positively correlated to high cotton lint yield.

               Fiber strength was highly correlated to all fiber quality parameters and positive correlations were found between staple length 2.5% (r = 0.99**) staple length 50% (r = 0.64**) and fiber strength. A positive correlation was also found between the fineness indicator (micronaire) and the uniformity ratio (r = 0.61**). However negative correlations were observed between fiber length and the fineness indicator (micronaire) (r = -0.86**), short fiber index (r = -0.85**) and uniformity ratio (r = -0.99**).

                Negative genetic correlation coefficients of lint percentage and lint yield with fiber strength were quite high (r = -0.99 and r = -0.96**, respectively), but they had a positive correlation with the fiber-fineness indicator or micronaire (r = 0.99** and 0.79**, respectively). The broad-sense heritability estimates of the yield and yield components were high for lint percentage (h² = 97%), lint yield (h² = 72%), lint index (h² = 79%) and seed index (h² = 86%). As they also had a strong relationship with other fiber quality parameters as well, they could be considered as indicators of the yield and fiber quality improvement in cotton.