GENETIC DIVERGENCE IN TOMATO

A set of fifty tomato genotypes comprising four wild collections and rest the common cultivars belonging to different geographical areas were evaluated for seventeen characters of which ten were quality attributes, to study the nature and extent of genetic divergence using Mahalonobis’s distance (D²) and canonical analysis.
Genotypes were grouped into sixteen clusters on the basis of the relative magnitude of D² values.
The four wild collections of which three belonged to Lycopersicon peruvianum and one to L. pimpinellifolium were grouped in three distinct clusters which were highly diverse from all other clusters comprising only the common cultivars.
Among the clusters including the cultivars, clusters comprising the pear shaped cultivars were disposed distinctly apart from the clusters including round fruited cultivars.
Canonical analysis well supported the group constellation derived by D² analysis.

Number of fruits per plant which was found to be the most important character in the primary axis of differenciation as evident from canonical analysis, might be the primary factor for species differenciation in this crop.
Similarly, shape index, the most important trait in the secondary axis of differentiation resulted the varietal differentiation in the species L. esculentum, Mill.

Cluster mean for different quality and other economic traits indicated appreciable amount of differences among the clusters for several characters.
A hybridization programme involving L. pimpinellifolium as one parent and the other parent from the clusters including large fruited cultivars viz.
F₁ – hybrid and Punjab Tropic have been suggested for the improvement of quality attributes in this crop.

Symposium on Quality of Vegetables

M.K. Bhattacharyya, K.S. Nandpuri, S. Singh

https://doi.org/10.17660/ActaHortic.1979.93.27