Ideotype of apples with resistance to storage diseases

Abstract

Upon the completion of a three-year evaluation of natural occurrence of storage diseases within a range of cultivars or advanced selections and a simultaneous assessment of their other characteristics, an apple ideotype has been proposed that could be used in breeding of new cultivars resistant to these diseases. The ideotype combines the potential of apples for long-term storage with higher skin thickness and toughness, a lower production of ethylene, a higher natural content of calcium, a higher content of total phenolic compounds and antioxidant capacity, a higher flesh firmness, and a higher acidity of juice expressed in pH values. For some of these characteristics, threshold values have been suggested in the paper. The genotypes preselected according to these criteria should be chosen on the basis of the final screening with Pezicula alba inoculum test. The result of the inoculation test should be equal to or better than the standard cultivar Gala. Future research is required to determine the feasibility of the ideotype in routine breeding programs.

Trends in Fruit Breeding

“…The most important post harvest physiological disorders seen are internal breakdown problems in stone fruit (Crisosto et al 1999 ; 1 Trends in Fruit Breeding Peace et al 2006 ;Ogundiwin et al 2007Ogundiwin et al , 2009 ) and bitter pit and superfi cial scald in pome fruit (Blazek et al 2007 ;Pesis et al 2009 ) . Work has begun to identify the genotypic variation that promotes resistance of cultivars to these disorders (Crisosto et al 1999 ;Trivedi et al 2010 ;Volz et al 2006 ) , although, due to the diffi culty of these evaluations, work is now focused on parental material and advanced selections.…”

Impact of harvesting time and fruit firmness on the tolerance to fungal storage diseases in an apple germplasm collection

“…So far, no major genes providing resistance against the storage diseases have been identified but quantitatively inherited traits associated with chemical contents, fruit texture, structure of the fruit epidermis and ripening behavior may affect the ability of different cultivars to withstand fungal attacks (Prusky et al, 2004;Blazek et al, 2007;Nybom et al, 2008;Johnston et al, 2009). Positive effects of increased firmness and less softening due to calcium spraying, have been documented in a series of pre-and postharvest treatments of apple fruit, indicating that fungal decay caused by P. expansum, Botrytis cinerea and Glomerella cingulata can be significantly reduced (Conway et al, 1991;Sams et al, 1993;Conway et al, 2002).…”

A comparison of apple cultivars regarding ethylene production and physico-chemical changes during cold storage

“…The ideal apple for long-term storage combines higher skin thickness and toughness with a lower production of ethylene, which slows the softening of fruit (Blažek et al 2007). Apples are climacteric fruits, characterized by a burst of ethylene production during ripening.…”

“…In addition, the skin also helps to protect against apple storage diseases (Homutová, Blažek 2006;Blažek et al 2007). Water vapour presents about 90% of all weight losses, although the cultivars behaved differently: Golden Delicious Reinders, Resista and Rubinstep lost 93 to 114 mg/day of water, and Meteor and Topaz lost 60-65 mg/day.…”

“…A wide range of factors influence the resistance of apple cultivars to storage diseases (Blažek et al 2007), particularly the presence of phenolic compounds, skin thickness and its resistance to mechanical damage. This study used discriminant analysis to compare the performance of five different apple cultivars during cold storage, by measuring the production of ethylene and other, non-volatile compounds, changes in firmness of tissues and weight loss.…”