African pear fruit (Dacryodes edulis) is a highly sought for multipurpose agroforestry tree species that has the potential for both local and international trades, Nigeria is among the leading producer of the fruit, but its pattern and extent of its genetic variability is currently unknown. Hence, a study was carried out to determine the pattern and extent of genetic variability and interrelationships among 13 morphological traits of African pear fruit accessions. The experiment was laid in a Completely Randomized Design in 5 replications. Data collected on number of leaf production, leaf length, leaf breadth, leaf length/breadth ratio, internode distances, plant height, collar diameter, fresh leaf weight, fresh stem weight, fresh root weight, dry leaf weight, dry stem weight, dry root weight and biomass accumulation were subjected to Analysis of Variance. Treatment means were separated using Duncan’s Multiple Range Test at 5% probability level. Results showed significant (p<0.05) differences among the D. edulis genotypes for most of the traits evaluated indicated variation in the performance of the genotypes and pattern of clustering indicated that there was no association between eco-geographical distribution of genotypes and genetic diversity. PCA revealed that fourteen axes accounted for 100% of the variations observed while the first five axes contributed 73.23% of the total variation observed. The first axis accounted for 25.61% of the total variation while the second and third accounted for 15.43 and 15.01%, respectively. The fourth axis contributed 9.82% of the total variation while the fifth axis contributed 7.36% of the total variation. Significant phenotypic and genotypic correlations were observed between most of the plant characters evaluated and biomass accumulation which is an indication that the phenotypic association will be a good index for the genotypic association.
Study of genetic variability for morphological traits in bread wheat across sowing dates
