Submitted to: Journal of Crop Production
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2002
Publication Date: 9/20/2004
Citation: Panta, G.R., Rowland, L.J., Arora, R., Ogden, E.L., Lim, C. 2002. Inheritance of cold hardiness and dehydrin genes in diploid mapping populations of blueberry. Journal of Crop Production. 10:37-52.
Interpretive Summary: An important problem in the blueberry industry is the need to develop more cold hardy blueberry varieties. Consequently, our laboratory has been studying the genetic control of cold hardiness (CH) in blueberry. Previously, we identified three abundant proteins that are induced during cold acclimation and levels are closely associated with CH levels. These proteins, known as dehydrins, are induced by cold and drought stress are good candidates for controlling CH in blueberry. The present study reports on progress made to isolate and map the dehydrin genes of blueberry utilizing populations comprised of individuals that have a range of CH levels. Specifically, we (1) determined CH levels for a portion of the blueberry mapping populations, (2) analyzed the data genetically, and (3) used the sequence of a clone of one of the 3 major blueberry dehydrins to map a dehydrin gene in the population. Results indicate that (1) the parents differed significantly in terms of CH levels as expected, (2) CH levels of offspring were skewed more toward the cold sensitive parent, indicating that CH is a partially recessive trait, and (3) the dehydrin gene mapped to linkage group 12 of the current map. Identification and mapping of genes associated with CH will benefit scientists developing more effective strategies for increasing CH of blueberry varieties.
Technical Abstract: Although development of cold hardiness (CH) is an integral part of the life cycle of woody perennial plants, studies on its genetic control are scarce. A better understanding of the genetic control of CH would be valuable for developing more effective strategies to increase CH and, hence, climatic adaptation of woody perennial crops. In blueberry, three major dehydrins of 65, 60, and 14 kDa have been found to increase with cold acclimation and decrease with deacclimation. Efforts are underway to isolate and map the dehydrin genes of blueberry utilizing blueberry populations that segregate for CH in order to determine if the dehydrin genes map to QTLs controlling CH. CH levels were determined for a portion of the blueberry mapping populations (derived from interspecific hybrids of Vaccinium darrowi Camp and V. caesariense Mackenz.) using a laboratory controlled freeze-thaw regime, followed by visual assessment of injury to floral buds. As expected, the V. darrowi and V. caesariense parents were found to differ significantly in terms of CH levels (LT50s of -13C and -20C, respectively). Mean CH level of F1s (-14.7) was skewed more toward the V. darrowi parent and was significantly different from the V. caesariense parent, suggesting that CH is a partially recessive trait. The sequence of a 2.0 kb cDNA clone, which encodes the 60 kDa blueberry dehydrin, was used to map a dehydrin-related gene to current linkage group 12 of the V. caesariense testcross population.