Microsatellite mapping of the gene conferring compact spike in Japanese “Gumbai” landraces of common wheat (Triticum aestivum L.)

Abstract

The “Gumbai” wheat landraces of are a distinctive group of Japanese common wheat landraces. They originated in the Yamanashi region of Japan and are characterized by compact spikes, which were called “Gumbai” in the Japanese language. It is well known that the spikes of club wheat (Triticum compactum Host, 2n = 6x = 42, BBAADD genome) are governed by the dominant allele of the compactum (C) locus. We were interested to determine if the compact spike trait in “Gumbai” landraces is controlled either by the gene on chromosome 2D or by an orthologous gene. Five F₂ hybrid populations of ‘Novosibirskaya 67’ (N67)/“Gumbai” landraces segregated in 3 compact spike: 1 normal ratios. We tentatively designated the gene C _g (Compact spike of Gumbai) for “Gumbai” landraces. The C _g gene was not allelic to the C locus on chromosome 2D, or the Cp locus on chromosome 5A. In an F₂ population of N67/‘Nakate Gumbai’, there was linkage among C _g and microsatellite loci Xgwm47, Xhbg410 and Xhbg440. Deletion mapping, showed that Xhbg410 and Xhbg440 were located across bins 2BL-7 0.48–0.69 and 2BL-1 0.69–0.89. These results indicated that the C _g gene governing compact spike lies near breakpoint 0.69 in chromosome arm 2BL. The C _g gene was located in the orthologous region of a spike compactness QTL in chromosome arm 2AL of wild emmer.