Wednesday, August 10, 2016
Georgia Ballroom (Sheraton Hotel Atlanta)
Peaches are of considerable interest as an alternative crop for those hard hit in the Florida citrus industry, yet their temperate origins have challenged their production in a subtropical climate. Apart from various pests and diseases that reduce tree longevity and fruit quality, accumulating inadequate chill units for uniform bloom is a major challenge. Most of Florida’s chill hours are accumulated in December and January, but in recent years accumulated chilling units continue to decline. Hydrogen cyanamide (HC) is widely used around the globe where mild winters prevail and where there are insufficient accumulated chill units. Timely application of HC can enhance uniform bloom and leaf emergence, increasing labor efficiencies; however many growers have induced significant crop injury because the timing for different fruit crops is not well defined. The molecular mechanism of how HC works is still poorly understood and in order to find transcriptional pathways associated between dormancy release and HC application in peaches we analyzed the vegetative and reproductive buds of peach The objective of this study is to identify gene expression triggered by HC application.‘TropicBeauty’, a low-chill peach cultivar was sprayed with 1% hydrogen cyanamide (BudPro, Green Trees & Plants II, LLC, Marietta, GA USA) when pollen grains translucent. Single tree replicates were sprayed with HC and compared with control plants that were unsprayed controls. Vegetative and floral buds were collected from 4 branches per tree before application and then 1,3 and 7 days after application. RNA isolation was performed to carry out cDNA synthesis for real time PCR (RT-PCR). Ten genes involving dormancy release, cold regulation genes, and abscisic acid related genes were targeted for gene expression studies. These genes may play a role in dormancy release of buds due as a result of the hydrogen cyanamide treatment based on our observation that treated plants had both early uniform bloom and vegetative budburst approximately 30 days after HC application, whereas control trees that got inadequate chilling had a prolonged bloom, uneven leaf emergence and fruit ripening.