Breeding for qualitative and quantitative traits in pear - A review

Pear is a heterozygous perennial plant. Open pollination in pear has been reported to be better than controlled cross-pollination. Significant positive correlations were observed between increased inbreeding and improved flavour, grit and texture. Seedlings with ovate and ovate-elliptical leaves had the best fruit quality. The additive gene effects were predominant in the expression of fruit weight, fruit shape, ripening date and resistance to fire blight. Non-additive gene effects were predominant for total yield/plant, height, number of fruits/plant, number of branches/plant, number of locules/fruit and pericarp thickness. Heritability was higher for fruit weight and pH of the fruit juice; moderate for ripening period, fruit length, fruit diameter, fruit shape index, soluble solid content, grit content and skin russeting, while, flesh texture, flavour, appearance, flesh firmness, total weighted selection index and the weighted total score had relatively low heritability. General combining ability (GCA) were higher than specific combining ability (SCA) for number of branches/plant, average fruit weight, total soluble solids, acidity, height, number of fruits/plant, number of locules/fruit and total yield/plant, except pericarp thickness.