Chromosomal intervals responsible for tissue culture response of wheat immature embryos

To study the genetic mechanism underlying the tissue culture response (TCR) of immature embryos, callus induction and regeneration were performed in two separate trials using the recombinant inbred line (RIL) derived from a cross of Nanda2419 with Wangshuibai. In the first trial, immature embryos were collected from plants grown in the greenhouse in the winter of 2005; while in the second trial, immature embryos were collected from donor plants grown in the field during the growing season. Through whole genome screening, seven chromosome regions conditioning percent embryos forming embryogenic callus (PEFEC) and one conditioning percent callus pieces regenerating plantlets (PCRP) were detected. These QTLs were distributed on chromosomes of homoeologous groups 2, 3, 5 and 7. Among all, QPefec.nau-3B.2, QPefec.nau-7D, and QPcrp.nau-3A were consistently identified. The relationship of these identified wheat TCR QTLs with those of other cereal crops has been evaluated. PCR markers linked to TCR QTLs would facilitate germplasm identification, marker-assisted evaluation and utilization of these QTLs.