Importance To Citrus Growers Of Having The Citrus Genome

By: Robert “Bob” Rouse, PhD
Citrus Research Specialist
UF/IFAS/Southwest Florida Research & Education Center
 

The recent announcement by UF/IFAS that a group of international scientists lead by Florida researchers has sequenced the genome for two citrus varieties is a landmark event. The two varieties are sweet orange and Clementine mandarin. Having the complete genetic makeup of genes for citrus will advance the ability to manipulate the genes to solve many of the problems we encounter currently and those in the future. The possibilities include changing the gene expression for better disease and pest resistance including greening, improve performance on poor soils and salt tolerance, increased cold tolerance of the tree and fruit, lessen fruit blemishes, and reduce juice, fruit, and rind breakdown during storage. This is like having a map of the genetic makeup of citrus with markers at each of the points that determine some characteristic of interest. By changing or manipulating the genetic makeup at that point we could change the characteristic. Simply overstated, we may be able to make the albedo (inner white spongy part of the peel) and flavedo (outer colored peel) as hard as a baseball or increase the sugar content and make it sweet. A more practical thought would be to reduce creasing and splitting that occurs in stressed fruits under certain condition.