Heritability of fruit shape in pears

Heritabilities for each of three different height and width ratios describi ng fruit shape were estimated from measurements on a population of seedling s comprising 17 families of European and Asian pear parentage in the HortRe search pear cultivar breeding programme. In families with European cultivar s as parents, the pyriform curvature in the upper, or stem end, half of the fruit was also quantified and heritabilities estimated. Heritabilities were computed using parent-offspring regression and from con sideration of the variance components. Heritabilities estimated from parent -offspring regression were generally high and higher than those estimated f rom variance component analysis, although within the limits of error. Herit ability estimates for the height:maximum width ratio were > 0.5 by both met hods of estimation indicating that fairly rapid genetic gain could be expec ted.