Identification of Quantitative Trait Loci (QTLs) Controlling Heading Time in the Population Generated from a Cross between Oriental and Occidental Barley Cultivars (<i>Hordeum vulgare</i> L.)

Abstract

The present study was carried out to identify QTLs controlling heading time of barley. A total of 89 recombinant inbred lines (RILs) generated from a cross between the Oriental-type winter cultivar 'Azumamugi' and the Occidental-type spring cultivar 'Kanto Nakate Gold' were examined. Two field experiments consisting of one spring sowing and one autumn sowing and a greenhouse experiment under 24 h illumination were conducted. Two genes for the spring habit and five QTLs controlling heading time were identified. The two genes for the spring habit, sgh1 and Sgh2 were located on chromosomes 4HL and 5HL, respectively; four QTLs were mapped close to the heading time genes identified in the previous studies on chromosomes 1HL, 2HS, 2HL and 7HS; and one was a new QTL detected on chromosome 7H.

Detection of photoperiod responsive and non-responsive flowering time QTL in barley

“…qDHE.ak-7H was expressed in the Ppd-SV treatment, and thus is responsive to the lengthening of the photoperiod as spring advanced. The same QTL was also detected in a spring sowing of non-vernalized barley (Sameri and Komatsuda 2004), which indicates that its action is independent of vernalization. In the Ppd-SNV experiment, the flowering time of the 20 winter habit RILs was greatly delayed, and these were therefore eliminated from the QTL analysis.…”

“…Sameri and Komatsuda (2004) found a close linkage between sgh1 and e04m32.8. Here, the Ppd-SNV treatment detected a QTL lying close to vrn-H2.…”

“…Yin et al (2005) have similarly mapped a flowering time QTL to the terminus of chromosome arm 1HL in their Apex × Prisma mapping population. A further major QTL insensitive to photoperiod, believed to be Eam5, mapped close to Sgh2 (Vrn-H1) locus in all of the treatments except Ppd-10 h. As this QTL was also detected under natural day length conditions from a spring sowing (Sameri and Komatsuda 2004), the detection of this locus may have been thanks to the pleiotropic effect of Sgh2. Yasuda and Okinaga (1977) have shown that the effect of Sgh2 on flowering time depends on the genetic background of the cultivar.…”

Photoperiodic control of flowering in barley

“…Laurie et al (1995) reported that 4 genes and 8 QTLs were involved in controlling the timing of flowering in autumn-sowing, spring-sowing and glasshouse experiments using doubled-haploid (DH) lines developed from a cross between the winter barley variety Igri and the spring variety Triumph. Autumn-sowing and spring-sowing experiments using recombinant inbred lines (RILs) from the winter variety Azumamugi and the spring variety Kanto Nakate Gold identified a total of 7 QTLs (Sameri and Komatsuda 2004). Figure 1 shows the QTLs and the mapping of the positions of the photoperiodic and vernalization response genes of barley, according to Laurie et al (1995) and Sameri and Komatsuda (2004).…”

Barley and Wheat Share the Same Gene Controlling the Short Basic Vegetative Period

“…Franckowiak and Konishi (2002) identified the Eam6 locus on chromosome 2HS, which might be synonymous with the eps2 locus identified by Laurie et al (1995). Recently, a QTL on chromosome 1H was located at the interval between ABC261 and ABG055 markers controlling heading time from the Azumamugi (JP17209)  Kanto RIL population, which is supposedly closely linked or allelic to eam8 (Sameri and Komatsuda 2004;Sameri et al 2006). However, comparing our mapping results with the barley consensus map, ABC261 and ABG055 markers were not entirely consistent with the BVP-1 gene closely-linked markers in this study.…”