Dissection and cytological mapping of barley chromosome 2H in the genetic background of common wheat

Abstract

We used gametocidal (Gc) chromosomes 2C and 3CSAT to dissect barley 2H added to common wheat. The Gc chromosome induces chromosomal breakage resulting in chromosomal aberrations in the progeny of the 2H addition line of common wheat carrying the monosomic Gc chromosome. We conducted in situ hybridization to select plants carrying structurally rearranged aberrant 2H chromosomes and characterized them by sequential C-banding and in situ hybridization. We established 66 dissection lines of common wheat carrying single aberrant 2H chromosomes. The aberrant 2H chromosomes were of either deletion or translocation or complicated structural change. Their breakpoints were distributed in the short arm (2HS), centromere (2HC) and the long arm (2HL) at a rough 2HS/ 2HC/2HL ratio of 2:1:2. We conducted PCR analysis of the 66 dissection lines using 115 EST markers specific to chromosome 2H. Based on the PCR result, we constructed a physical or cytological map of chromosome 2H that were divided into 34 regions separated by the breakpoints of the aberrant 2H chromosomes. Fortyseven markers were present in 2HS and 68 in 2HL. We compared the 2H cytological map with a previously reported 2H genetic map using 44 markers that were used in common to construct both maps. The order of markers in the distal region was the same on both maps but that in the proximal region was somewhat contradictory between the two maps. We found that the markers distributed rather evenly in the genetic map were actually concentrated in the distal regions of both arms as revealed by the cytological map. We also recognized an ESTmarker or gene-rich region in the 2HL interstitial region slightly to the telomere.

Correlating the Genetic and Physical Map of Barley Chromosome 3H Revealed Limitations of the FISH-Based Mapping of Nearby Single-Copy Probes Caused by the Dynamic Structure of Metaphase Chromosomes

“…Our study on cytological mapping of barley chromosome 3H revealed a discrepancy between the genetic and physical positions of the analyzed single-copy sequences, in line with previous data [Sorokin et al, 1994;Künzel et al, 2000;Serizawa et al, 2001;Künzel and Waugh, 2002;Joshi et al, 2011]. In distal regions, long genetic distances translated into short physical distances, indicating hot spots of recombination.…”

New Aneuploids of Common Wheat

“…8.4 ). The Gc system was successfully applied to produce dissection lines of various alien chromosomes in common wheat, such as barley chromosomes (2H, Joshi et al 2011 ;3H, Sakai et al 2009 ;4H, Sakata et al 2010 ;5H, Ashida et al 2007 ;7H, Masoudi-Nejad et al 2005 ), rye 1R chromosomes (Tsuchida et al 2008 ;Gyawali et al 2009Gyawali et al , 2010 and rye B chromosomes (Endo et al 2008 ). All possible kinds of rearrangements of alien chromosomes have been obtained (Fig.…”

Dissection of barley chromosomes 1H and 6H by the gametocidal system

“…Using the Gc system, Endo and his colleagues have dissected the barley chromosomes in the addition lines of common wheat (Shi and Endo, 1997, 1999, and constructed cytological maps for five barley chromosomes using various DNA markers: 2H with ESTs (Joshi et al, 2011), 3H with ESTs (Sakai et al, 2009), 4H with ESTs (Sakata et al, 2010), 5H with ESTs (Ashida et al, 2007), 7H with AFLPs and STSs (Serizawa et al, 2001), 7H with AFLPs and SSR (Masoudi-Nejad et al, 2005), and 7H with ESTs .…”