Genetic variability and association of yield and its related traits in korarima (Aframomum corrorima (Braun) Jansen)) germplasm under jimma condition, southwestern Ethiopia

Abstract

Information on genetic variability for yield and related traits is prerequisite for further improvement of any crops. Currently, under Ethiopia korerima improvement project, large numbers of korarima accessions are collected from different major growing regions of Ethiopia by Jimma Agricultural Research Center (JARC). As far as the variability and association among characters in these accessions of korarima is concerned nothing has been done. Therefore twenty five korarima (Aframomum corrorima) germplasm accessions were tested using simple lattice design at Jimma Agricultural Research Center in 2011/12.Data were recorded on 21 characters with the objective of estimating the extent of variation and correlation between pairs of characters. Analysis of variance revealed that there was significance difference among the genotypes for the characters studied except internodal length, seed weight and dry matter content. High phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) recorded for bearing tiller, leaf area, and ash and crud fiber content. High heritability coupled with high genetic advance as percent mean were estimated for plant height, bearing tiller, number of capsule per plant, diameter of fresh and dry capsule, ash, crud fiber and oleoresin content; moderate heritability values coupled with higher genetic advance were observed for total tiller, length of fresh capsule, weight of dry capsule, length of dry capsule, volatile oil and crud fat content. This indicates that these characters could be improved through selection. Yield per plant had positive and significant association with total tiller, bearing tiller, number of leaves per stem, number of capsule per plant, weight of fresh capsule and length of dry capsule both at genotypic and phenotypic level of significance: indicating the possibility of correlated response to selection. Genotypic path analysis showed that, number of capsule per plant exerted maximum direct effect on yield .This justifies the correlation explains true relationship and direct selection through this traits will be effective. Diameter of dry capsule, total tiller, weight of dry capsule and length of fresh capsule also has positive direct effect on yield. Cluster analysis revealed that the 25 korarima germplasm were grouped in to four clusters. Distance among these clusters is significantly different for all the cluster combination. This indicates that there is an opportunity to bring about improvement through hybridization of germplasm from different clusters and subsequent selection from the segregating generations. Principal component analysis indicated that six principal components explained about 80.51% of the total variation. Differentiation of germplasm into different cluster was because of cumulative effect of number of characters. The present study generally implied the presence of significant genetic variability among the tested genotypes. Thus, there is an excellent opportunity to bring about improvement through direct selection and hybridization which involves crossing of genotypes from different clusters. This finding, being the result of one year and one location, it is recommended that the experiment should be repeated at more location and years with more germplasm to confirm the these results.