Influence of Md-ACS1 allelotype and harvest season within an apple germplasm collection on fruit softening during cold air storage

• Published in: Postharvest biology and technology Vol. 44; no. 3; pp. 212 - 219
• Main Authors: Oraguzie, Nnadozie C., Volz, Richard K., Whitworth, Claire J., Bassett, Heather C.M., Hall, Alistair J., Gardiner, Susan E.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier B.V 01-06-2007; Elsevier Science
• Subjects: alleles; Apple population; apples; Biological and medical sciences; cold storage; cultivars; ethylene; ethylene production; firmness; Food industries; food storage; Fruit and vegetable industries; fruit quality; Fundamental and applied biological sciences. Psychology; genotype; germplasm; harvest date; Postharvest firmness; postharvest physiology; seasonal variation; Softening curves; Storage potential; storage quality; Postharvest firmness; Softening curves; Storage potential; Apple population; Cold; Fruit; Harvesting; Postharvest; Firmness; Air; Softening; Germplasm; Apple; Warehousing; Quality; Food preservation; Season
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2006.12.013

Previous studies have demonstrated a relationship between
Md-ACS1 allelotype and apple fruit softening at ambient temperatures. The present study was undertaken to further examine the influence of this allelotype (
-1/1,
-1/2 or
-2/2) and its interaction with harvest season (early or late) on changes in internal ethylene concentrations (IEC) and fruit softening during cold air storage. This was carried out by describing natural differences found among old apple cultivars/species and modern commercial cultivars. For late maturing cultivars,
Md-ACS1-1/1 was firmer at harvest than
Md-ACS1-2/2 with the heterozygote intermediate. However harvest firmness showed no differences among for the early season
Md-ACS1 allelotypes. The
Md-ACS1-2/2 allelotype had a slower rate of postharvest IEC increase and flesh softening compared with
Md-ACS1-1/1 and
-1/2 allelotypes, and late maturing cultivars had a slower rate of fruit softening than early maturing cultivars, which was independent of postharvest IEC. All three late season allelotypes and early season
Md-ACS1-2/2 were firmer after storage than early season
Md-ACS1-1/1 and
-1/2 allelotypes, reflecting differences in both harvest firmness and softening rates
. While cultivar variation in final firmness could be explained partially through
Md-ACS1-mediated postharvest ethylene increases and subsequent softening, much more variation was accounted for by their differences in harvest firmness. These results are discussed in relation to strategies for breeding cultivars with superior flesh textures that are maintained during storage.