Author
|
Submitted to: Proceedings Florida State Horticultural Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/9/2008 Publication Date: 3/13/2009 Citation: Niedz, R.P. 2009. In vitro germination of citrus seed to produce seedlings for genetic transformation. Proceedings Florida State Horticultural Science.121:148-152. Interpretive Summary: Citrus greening disease is the most serious citrus disease worldwide and has the potential to eliminate the Florida citrus industry, as it currently exists today. The disease is spreading through Florida and multifaceted research efforts to control the disease are underway. Genetically engineering citrus trees to make them resistant to citrus greening is one potential solution. However, genetic engineering of citrus is inefficient, or in the case of many mandarin and mandarin hybrids currently not possible. The objective of this study was to determine how to germinate large numbers of uniform seedlings in sterile culture tubes. Such seedlings are required as the starting material for genetic engineering. To overcome germination that is often erratic, nonuniform, and low, we tested a number of seed treatments for achieving good uniform germination. The seed treatments were applied to important sweet orange, grapefruit, and rootstock varieties. Technical Abstract: Seedlings germinated in vitro are commonly used as a source of explants for Agrobacterium-mediated transformation of citrus. Seed and seed treatments that result in rapid, uniform, and high percentage germination are preferred. A number of seed treatments including peeling, aeration, presoaking procedures, prehumidification, and sterilization procedures were used on Citrus sinensis ‘Hamlin’ seed. Germination curves were produced and percentage, rate, and uniformity for each treatment combination were estimated. Seed of additional citrus types including grapefruit, ‘Carrizo’ citrange, and H897 were tested using combinations of treatments that had the highest positive effect on germination. The importance of seed germination in the genetic transformation of citrus will be discussed. |
