Morphological and genetic diversity among blackberry accessions in Kenya

Horticultural crops’ morphological and genetic diversity are important components for cultivar development and a pre-requisite for cultivar improvement. This study is being conducted to determine the morphological and genetic diversity among blackberry (Rubus L sub-genus Rubus Watson) accessions in Kenya and their relationship with introductions using SSR markers with the aim of improving the crop for local use. Thirteen Simple Sequence Repeat (SSR) markers will be used to assess the genetic diversity among twenty blackberry accessions which will be collected from the Genetic Resources Research Institute (GeRRI) – Muguga and the field. Field collections will be made in Kericho, Nanyuki, Bomet, Baringo, Molo, Mau-Narok, Naivasha and Limuru. The study will be conducted at Egerton University Agricultural Experimentation Station Field 7, Njoro and KALRO Molo in a Randomized Complete Block Design replicated three times. Morphological traits will be phenotypically characterized using RosBREEDII Blackberry Standardized Phenotyping protocol and, thereafter, subjected to multivariate analysis to determine eigenvalues. All data collected will be subjected to Analysis of Variance (ANOVA), principal component analysis (PCA) and cluster analysis. Their means will be compared by Tukeys test at a=0.05. Genetic characterization will be based on Simple Sequence Repeat (SSR) markers analysis and genetic distances amongst all accessions will be based on Jaccard’s variability index. Results of this study are expected to provide useful information on the diversity of blackberry germplasm available and the possibilities of improving this fruit in Kenya.