Mass selection and individual plant selection as two breeding methods for improving lettuce (Lactuca sativa L.)‎

الملخص EN

Three field experiments were conducted in order to estimate the magnitudes of variability of some important characters of the “Balady” cultivar of lettuce and to study the efficiency of two cycles of mass selection and individual plant selection for two generations, as two breeding methods, on the studied economical characters.

Heritability percentages in broad sense and phenotypic correlation coefficients among all possible pairs, of the studied characters, were also estimated.

This study was carried out at the Experimental Station Farm (at Abies), Faculty of Agriculture, Alexandria University, during the three successive winter seasons of 2010/2011, 2011/2012 and 2012/2013.

The obtained results, generally, illustrated that the estimated coefficients of variability and ranges for all studied characters; reflected high and enough variability to suggest high possibilities of conducting successful and efficient selection to produce improved strains with better performances than the original population.

Generally, the results indicated clearly that the studied characters were improved through the two practiced breeding methods; mass selection and individual-plant selection; but, with different magnitudes among the characters and the used breeding methods.

The obtained results showed high heritability estimates, in broad sense, for the various studied characters.

Also, the estimated values for the correlation coefficients, between the different pairs of characters, were found to be either significant or highly significant with positive or negative signs, which may help in selecting desirable traits in lettuce breeding programs.

Accordingly, improving production of lettuce can be achieved through purification of already established cultivars and introducing improved strains through via both mass and individual-plant selection programs.