Avanços na ciência e tecnologia agrícola

Abstrato

Assessment of Genetic Improvement in Grain Yield Potential and Related Traits of Kabuli Type Chickpea (Cicer arietinum L.) Varieties in Ethiopia (1974-2009)

Tibebu Belete, Firew Mekbib and Million Eshete

Kabuli type chickpea is the most important commercial crop in Ethiopia and worldwide. A set of experiment was conducted to estimate the progress made in improving grain yield potential of Kabuli type chickpea varieties and changes in agromorphological traits associated with genetic yield potential. The varieties were laid down in a Randomized Complete Block Design with three replications. The annual rate of increase in yield potential of Kabuli type chickpea was estimated from linear regression of mean grain yields of varieties on year of release was 8.42 kg ha-1yr-1 but this increment was not significantly different from zero. This revealed that chickpea breeders have made little/small efforts over the last 35 years to improve the yield of Kabuli type chickpea in Ethiopia. From the linear regression of hundred seed weight (HSW) against the years of release indicated that the annual rate of genetic gain was 1.00 g HSW-1 (8.96%) yr-1, reflected that a significant increase was recorded for this trait for the last 35 years of Kabuli type chickpea improvement program in Ethiopia. Hence, better genetic improvement was obtained from breeding for HSW than it was from breeding for grain yield in Kabuli type. In contrast, significant negative trend was observed in number of pods plant-1, seeds per pod-1 and seeds plant-1. The correlation coefficients showed that grain yield was significantly and positively correlated with primary branches plant-1, biomass yield and with all productivity traits. However, HSW which is the economical trait in Kabuli type chickpea showed significant negative association with secondary branches plant-1, pods plant-1, seeds pod-1 and seeds plant-1. Stepwise regression analysis revealed that most of the variation in grain yield was caused by biomass yield and harvest index.