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ARS Home » Pacific West Area » Wenatchee, Washington » Physiology and Pathology of Tree Fruits Research » Research » Publications at this Location » Publication #212052

Title: Md-ACS1 and Md-AC01 genotyping of apple breeding parents and suitability for marker-assisted selection

item Zhu, Yanmin

Submitted to: Eucarpia Fruit Breeding Symposium
Publication Type: Proceedings
Publication Acceptance Date: 6/12/2007
Publication Date: 3/7/2009
Citation: Zhu, Y., Barritt, B. 2009. Md-ACS1 and Md-AC01 genotyping of apple breeding parents and suitability for marker-assisted selection. Eucarpia Fruit Breeding Symposium. N/A.

Interpretive Summary:

Technical Abstract: Fruit ethylene production genotypes for Md-ACS1 and Md-ACO1 were determined for 60 apple cultivars/selections and 35 advanced breeding selections. Two alleles for each gene are commonly found in cultivated apple. Earlier studies showed that genotypes homozygous for the ACS1-2 allele produce less ethylene and have firmer fruit than ACS1-1/2 and ACS1-1/1 genotypes. ACO1 plays a minor role compared to ACS1, with homozygous ACO1-1 having lower ethylene production. In this study, it was shown that ACS1-2 and ACO1-1 homozygotes had firmer fruit at harvest and after 60 days of 0-1oC cold storage compared to other genotypes. The most desirable genotype, homozygous ACS1-2/2 and ACO1-1/1, was observed for the following 8 of 95 cultivars/selections: ‘Delblush’, ‘Fuji’, ‘Pacific Beauty’, ‘Sabina’ and 4 breeding selections. Cultivars/selections that were homozygous ACS1-2 but not ACO1-1 were ‘Ambrosia’, ‘Aurora Golden Gala’, ‘CrimsonCrisp’, ‘Gala’, ‘GoldRush’, ‘Huaguan’, ‘Pacific Rose’, ‘Pacific Queen’, ‘Pinova’, ‘Sansa’, ‘Sonja’, ‘Sundance’, ‘Zestar’ and 17 breeding selections. Cultivars with heterozygous ACS1-1/2 genotype were ‘Arlet’, ‘Braeburn’, ‘Cameo’, ‘Delicious’, ‘Delorgue’, ‘Empire’, ‘Enterprise’, ‘Ginger Gold’, ‘Golden Delicious’, ‘Granny Smith’, ‘Honeycrisp’, ‘Orin’, ‘Pink Lady’, ‘Silken’, ‘Suncrisp’, ‘Sundowner’, ‘Sunrise’ and 11 breeding selections. No cultivars were detected homozygous for both ACS1-1 and ACO1-1, or for both ACS1-2 and ACO1-2. This study is the first large scale allelic genotyping of both ethylene synthesis genes for a comprehensive set of apple breeding parents used in an ongoing breeding project. These data are also essential for informative selection of parent combinations for breeding low ethylene-producing apple cultivars for better storability.