Assessment of Variability in Morphological and Genetic Traits Among Nine Local Cultivars and One Wild Accession of Tomato (Solanum Lycopersicum L.) Using SSR Markars in Adamawa State, Nigeria (Published)
Variability is necessary in any crop breeding program. Morphological and genetic variability among ten local cultivars of Solanum lycopersicum (Linn.) in Adamawa State Nigeria was studied. The study was aimed at assessing the morphological and genetic variability and smilarities and elucidating on phylogenetic relationship of these local tomato cultivars. Two morphological traits, fruit size and fruit weight were utilized followed by ten SSR marker analysis to investigate their genetic diversity. Eight out of the ten primers representing (90 %) were polymorphic representing loci. The most variable mean across the morphological traits was obtained for fruit weight with a mean square value of 7122.88, while the least variable mean was recorded for fruit size with a mean square value of 321.66. There was significant positive correlation between fruit size and fruit weight per cultivar and fruit size positively correlated with fruit weight per plant and across the ten cultivars (r = 0.92). Total of (31) alleles were recorded and the mean number of alleles per locus was 0.2580. The lowest number of bands across genotype was three and the highest number of bands across genotypes was seven. The PIC value of SSR markers obtained ranged from 0.35 to 0.77 with the average number of polymorphic bands per primer being 23.72. While clustering among local cultivars of Adamawa tomato using the unweighted pair group method with arithmetic mean analysis (UPGMA), the clustering was not related to the geographical locations where seeds were collected. It can therefore be inferred that tomato accession (Tt001) with large number of fruits per truss having small sized fruits and tomato cultivars (Tt009 and Tt010) which on the other hand recorded high figures with regards to morphological traits, and clustered closely based on molecular analysis may hybridize into a better cultivar.
Keywords: Solanum lycopersicum., alleles, molecular markers, morphological parameters