Morphological and agronomical characterization of beef type tomato hybrids

Abstract

Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops and agro-morphological characterization has a key role in the development of new varieties. In this study, 228 samples of the tomato hybrid type “Beef” (Solanum lycopersicum L.) were characterized by comparing with 11 standard varieties based on 24 quantitative traits and 2 qualitative traits to reveal the phenotypic diversity by using conventional descriptors proposed by IPGRI (1996) and UPOV (2011). A significant level of variability was found in most of the traits studied among the genotypes in two locations. A high level of broad-sense heritability (H2) was detected for many traits such as the number of fruits, firmness, immature fruit color, stem length up to the first inflorescence, total height, and number of days to the first flowering in both locations. There was a highly significant positive correlation among the color values (L*, a*, b*, c*, h*) but no positive correlation between a* and h*. Number of locule had a positive correlation with fruit width and fruit weight, and a positive correlation was determined between fruit length and pericarp thickness in both locations. While fruit weight had a highly significant negative correlation with the number of fruits and number of flowers, there was a highly significant negative correlation between the number of locules and the fruit length-to-width ratio in both locations. Results of PCA showed that PC1 and PC2 accounted for around 15.6% and 13.7% of total variation and 13.8% and 11.8% of total variation for Location 1 and Location 2, respectively. The first five principal components accounted for around 54.2% of the total variation for Location 1 and 48.2% of the total variation for Location 2. Cluster analysis grouped the 239 genotypes under six cluster groups for Location 1 and seven cluster groups for Location 2. Results of the cluster analysis revealed that Cluster 3 for Location 1 and Cluster 2 for Location 2 had prominent genotypes for some of the agronomically important traits like yield. The results showed that present phenotypic diversity could be useful in the selection of best-performing genotypes, which would be important candidates for the beef red tomato market in the spring season.