Efficient utilization of plant genetic resources for nutrition and crop improvement requires systematic understanding of the important traits. Amaranthus species are distributed worldwide with an interesting diversity of landraces and cultivars whose leaves and seeds are consumed. Despite their potential to enhance food security and economic livelihoods, grain amaranth breeding to improve nutritional quality and adoption by farmers in sub-Saharan Africa is scanty. This study assessed the variation among 29 grain amaranth accessions using 27 phenotypic (10 morphological and 17 nutritional) characters and 16 random amplified polymorphic DNA (RAPD) primers. Multivariate analysis of phenotypic characters showed the first four principal components contributing 57.53% of observed variability, while cluster analysis yielded five groups at 87.5% similarity coefficient. RAPD primers generated a total of 193 amplicons with an average of 12.06 amplicons per primer, 81% of which were polymorphic. Genetic similarities based on Jaccard's coefficient ranged from 0.61 to 0.88. The RAPD-based unweighted pair group method with arithmetic mean dendrogram grouped the accessions into nine clusters, with the same species clustering together. RAPD primers distinguished the accessions more effectively than phenotypic markers. Accessions in the different clusters as obtained can be exploited for heterotic gain in desired nutritional traits.

Understanding the level and distribution of genetic diversity in African locust bean (Parkia biglobosa) would strengthen breeding and conservation programmes towards domestication and sustainable use of this species. Sixteen accessions of P. globosa were assessed for variability based on seed morphology, seed protein and DNA profiling. Significant variation in seed characteristics were observed across locations. Seed protein profiling by SDS-PAGE revealed homogeneity as most bands were found common in all accessions, indicating that the protein profiles are highly conserved. Protein profiling separated the 16 accessions into four major clusters at 0.93 similarity coefficient. Most accessions grouping into Cluster 1 had a similarity coefficient of close to 100% and were from the Derived Savanna suggesting the presence of duplicates. Accessions NH/2016/P14, NH/2016/P03 and NH/2016/P04 grouped into clusters II, III and IV; respectively. Sixteen RAPD markers generated a total of 256 bands of which 63.67% were polymorphic. Gene diversity ranged from 0.41 to 0.93 and Polymorphic Information Content (PIC) from 0.39 to 0.93. The RAPD-based dendrogram separated accessions into six groups at 0.68 similarity coefficient. Based on a polymorphic seed storage protein marker a genetically distinct accession NH/2016/P04 could be exploited for breeding purposes. The homogeneity of alleles and narrow genetic base as revealed by RAPD and SDS-PAGE analyses suggests possible loss of intraspecific genetic diversity. Thus, intensification of germplasm collections across the different agroecological zones and characterization using specific markers will give a better understanding of diversity of P. biglobosa in order to enhance selection towards conservation, breeding and sustainable utilization.

No abstract

No abstract

The experiment was conducted to evaluate variability estimates for yield contributing and nutritional traits in 60 tomato (Solanum lycopersicum L.) hybrids and their parents. The trial was laid out in alpha lattice design and data pertaining to 13 quantitative, six nutritional and four qualitative characters have been presented. The estimates of mean, range, phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) revealed significant phenotypic and nutritional variations among the genotypes for most of the characters under study. The principal component analysis showed that number of marketable fruits, number of non-marketable fruits, marketable yield, total yield, total number of fruits, number of fruits per cluster, fruit length and width, beta carotene, vitamin C, lycopene and acidity content contributed most to observed variations in the population. Five clusters were identified among the tomato population and they significantly associated with high nutritional content, high yield, yield contributing traits and fruit size related traits. For association among traits, moderate to very strong significant (P < 0.05) positive correlation was recorded for yield with number of branches (0.40), number of marketable fruit (0.84), number of non-marketable fruits (0.71), marketable yield (.98) and non-marketable yield (0.71). On the contrary, brix recorded weak negative significant correlation (-0.32) with non-marketable yield-while no significant association was observed between the agronomic and nutritional variables. Estimates of moderate to high heritability in the broad sense coupled with high genetic advance as a percentage of mean showed the feasibility of improving fruit nutritional quality, yield and yield contributing traits in this population through selection.