Alspach & Oraguzie-Genetic parameters of fruit quality in apple

New Zealand Journal of Crop and Horticultural Science abstracts

Estimation of genetic parameters of apple (Malus domestica) fruit quality from open-pollinated families

P. A. Alspach

The Horticulture and Food Research
Institute of New Zealand Ltd
Nelson Research Centre
P.O. Box 220
Motueka, New Zealand
email: palspach@hortresearch.co.nz

N. C. Oraguzie

The Horticulture and Food Research
Institute of New Zealand Ltd
Hawke’s Bay Research Centre
Private Bag 1401
Havelock North, New Zealand

Abstract Variance components of Julian harvest date, fruit weight, and eight sensory fruit traits (amount of over-colour, russet, firmness, crispness, juiciness, acidity, sweetness, and astringency) were estimated on two of the four initial sublines of the Apple Genetics Population in New Zealand. The sublines, both established at three sites, consisted of 119 and 50 families with sufficient fruiting trees, and had a median of c. 40 trees/family. These families were derived from open-pollinated seed from apple cultivars (Malus domestica Borkh.), as well as crab apples (Malus spp.) from a number of countries. Fruit weight was taken as the mean of six fruit, and sensory traits were scored on a 0 (no detectable presence) to 9 (full expression) scale by a pair of assessors in one laboratory. Additive and variance stabilising (AVAS) transformations were performed for scored traits before analysis. Genotype-by-environment interaction variance was less than half that among families. Heritability estimates of harvest date and fruit weight were high (>0.70), but those of the sensory traits were, at most, moderate (russet 0.35-0.54 and firmness 0.26-0.59). Estimates from the two sublines were in broad agreement, and exclusion of the crab apple families generally made little difference to the estimates. Phenotypic and genetic correlations were similar, and mostly below 0.3 in magnitude (median magnitude 0.12).

Keywords AVAS; coefficient of relationship; fruit breeding; fruit quality; heritability; Malus

H02030 Received 22 April 2002; accepted 26 August 2002; published 9 December 2002
New Zealand Journal of Crop and Horticultural Science, 2002, Vol. 30: 219-228
0014-0671/02/3004-0219 $7.00 © The Royal Society of New Zealand 2002

PDF file of entire paper: Print-quality (126K) | screen-quality (87K)

This year's abstracts | Journal home page | All abstracts | Publishing home page