Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Genetic Controls of Apple Fruit-Specific Auxin
2013 Annual Report


1a.Objectives (from AD-416):
1. Phenotyping fruit maturation and ripening behaviors including fruit firmness, crispness, ripening season, fruit size, and storability for 6-8 cultivars and selected seedlings in Pink Lady x Honeycrisp progeny, in a developmental stage-specific fashion. 2. Characterizing expression patterns of 20-25 previously identified candidate genes, implicated in plant hormone biosynthesis, transport and response by qRT-PCR method and analyzing their association with the specific traits of apple fruit ripening pattern and quality attributes.


1b.Approach (from AD-416):
Apple fruit ripening behaviors and fruit quality attributes including ripening season, fruit firmness and fruit size will be characterized for selections in a "Pink Lady x Honeycrisp” progeny. Documents Trust with WA Tree Fruit Research Commission. Log 40944.

The expression patterns of 20-25 previously identified candidate genes, implicated in plant hormone biosynthesis, transport and response will be analyzed by qRT-PCR method. Association of expression with the specific traits of apple fruit ripening pattern and quality attributes will be assessed. Formerly 5350-43000-005-23T (7/10).


3.Progress Report:

This serves as a final report for project 5350-43000-006-12T which expired 4/30/2013. This project relates to objective 1 of the associated in-house project which seeks to identify factors that influence postharvest fruit quality and development of market limiting physiological disorders. Plant hormones are the major regulators on apple fruit ripening and quality. Understanding specifics of plant hormone regulation of apple fruit quality and ripening patterns is a necessary step in developing molecular tools for genomics assisted breeding. This study analysis characterized expression of apple genes related to auxin biosynthesis, transport and response during apple fruit maturation. Fruit Maturity-dependent transcription profiles of eight genes showed temporal and spatial transcript abundances were regulated in a genotype-specific manner; furthermore, the correlating expression patterns and potential crosstalk between genes of auxin and ethylene signaling may control apple cultivar-specific fruit ripening season. The results may provide a means to develop genetic markers indicative of fruit ripening patterns.


Last Modified: 10/25/2014
Footer Content Back to Top of Page