Microsatellite mapping of the loci for false glume and semi-compact spike in Triticum L.

The “false glume” is an extra glume between the glume and lemma of the outer florets of each spikelet. The “false glume” phenotype was found in tetraploid wheat Triticum durum Desf. (2n = 4x = 28, genome BBAuAu) ‘Sharik’ and a Chernobyl radio mutant (‘UKR-1’) of hexaploid wheat T. aestivum L. (2n = 6x = 42, genome BBAuAuDD). The spikes of Sharik and UKR-1 were semi-compact; suggesting homoeoallelism or allelism at the false glume and semi-compact spike loci, which are specific to diploid wheat T. sinskajae A. Filat. et Kurkiev (2n = 2x = 14, genome AmAm). The objective of this study was to map the novel mutant genes for false glume and semi-compact spike in T. aestivum, T. durum and T. sinskajae, and to assess homoeologous relationship in genus Triticum L. by using molecular markers. It was evident that the gene false glume (fg) and semi-compact spike genes were linked in the F2 of UKR-1/T. aestivum ‘Novosibirskaya 67’, F2 of Sharik/T. durum ‘LD222’ and F2 of T. sinskajae k-48993/T. monococcum L. (2n = 2x = 14, genome AmAm) CItr 13962. The segregation analyses confirmed that the semi-compact spike locus (sc1) in Sharik was allelic to the sc1 locus in UKR-1, whereas neither loci were allelic to the C locus on chromosome 2D or the Cp locus on chromosome 5A. The sc1 gene and fg gene were bracketed by Xgwm372 and Xgwm312 in the F2 of Sharik/LD222, and by Xgwm372 and Xwmc644 in the F2 of UKR-1/N67. The sog gene for semi-compact spike of T. sinskajae, and fg genes were bracketed by Xgwm558 and Xwmc644 in the F2 of k-48993/CItr 13962. It was concluded that the semi-compact and spike false glume genes in T. sinskajae, T. durum and T. aestivum were determined by homoeoalleles in the short arm of chromosome 2A.