Candidate Genes within Tissue Culture Regeneration QTL Revisited with a Linkage Map Based on Transcript‐Derived Markers

Abstract

ABSTRACTGreen plant regeneration from tissue culture is under the genetic control of multiple genes. Candidate genes for regeneration have been identified in multiple species using quantitative trait loci (QTL) and microarray analyses, and some of these genes have been verified as improving regeneration through transformation. Multiple studies have located QTL for regeneration from barley (Hordeum vulgare L.) tissue cultures, but these studies have been based on restriction fragment length polymorphism markers that do not provide information on candidate genes. A recent transcript‐derived marker barley map based on expressed sequence tags was used to locate QTL for barley green plant regeneration and identify candidate genes. Quantitative trait loci analysis identified four significant regions, on chromosomes 2H, 3H, 6H, and 7H, in places where QTL were previously identified. An additional four regions were suggestive for green and/or albino plant regeneration on chromosomes 1H, 3H, 4H, and 5H. Examination of transcript‐derived markers at the QTL peaks showed that many genes identified as important for regeneration in other species were located in these QTL peaks, including a gene for ferredoxin‐nitrate reductase and genes involved in hormone response and synthesis, cell division and the cell cycle, chloroplast development, and transcription factors. Identifying these genes allows manipulation to better understand the processes involved in regeneration from barley tissue cultures.