1a. Objectives (from AD-416):
Postharvest harvest CO2 injury is a recurring physiological disorder in many apple cultivars. Available evidences suggest that the condition of pre-harvest factors and postharvest regime can contribute to the development of this disorder. To gain the insight of how environmental and genetic factors influence the occurrence of this economically important postharvest disorder, transcriptome changes will be characterized to identify the aberrant gene expression under different pre-and postharvest conditions. Through the identification of potential genes and pathways inciting this disorder, the goal is to develop better prediction and prevention tools and management strategy.
1b. Approach (from AD-416):
Whole transcriptome sequencing method will be utilized to identify the global gene expression patterns on samples with various maturity and duration of postharvest storage and regimes. “Golden Delicious”, which is prone to the development of CO2 injury, will be used as model. Fruits from two different orchards at different location will be sampled from pre- and post-harvest stages, at different storage regimes for transcriptome analysis. Two orchards, one was previously classified with high tendency of CO2 injury incidence, will be selected for sampling. The detail of horticultural practice in two orchards such as application of chemical and/or nutrients application as well as microclimate parameter will also be taken into account when data are analyzed.
3. Progress Report:
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. Postharvest CO2 injury is a recurring physiological disorder in many apple cultivars. Fruit harvested at several times during maturation on the tree were placed in storage under conditions that promote or avoid CO2 injury. Tissue samples for gene expression analysis were collected after several storage durations. CO2 injury during storage occurred on fruit stored in 1% oxygen with 5% CO2, with or without a pre-storage treatment that inhibited fruit ripening. Tissue samples are currently being analyzed for gene expression.