Dynamic quantitative trait loci (QTL) for plant height predict biomass yield in hybrid rye (Secale cereale L.)

摘要

The biomethane production from agricultural biomass will be a key component of the future energy mix. Rye (Secale cereale L.) is ideally suited for this purpose due to its high adaptability to a wide range of soils, weather and cropping conditions. Its high biomass yield is achieved with the lowest input of fertilizer and pesticides of all small-grain cereals. For the selection of cultivars with high kernel and biomass potential in the same breeding program, a prediction of biomass yield by indirect traits would increase the selection progress. To analyze quantitative-trait loci (QTL) for plant height in three developmental stages (BBCH 32, BBCH 51-55, BBCH 73) and biomass yield, 258 experimental rye hybrids were grown at three and four locations in Germany in 2011 and 2012, respectively. A genetic linkage map was constructed with 911 molecular markers. The QTL analysis identified a total of 18 QTL for plant height at the three assessment dates and of three QTL for dry matter yield at milk ripening. A major QTL on chromosome 2R explained 46, 12, and 25% of the total genetic variance for plant height at BBCH 51-55, BBCH 73, and for biomass yield, respectively. Furthermore, two large-effect QTL for plant height in two growth stages and dry matter yield were identified on chromosomes 3R and 5R. For eleven of the identified QTL in rye the respective QTL/genes on syntenic rice chromosomes were detected that could serve as candidate genes in follow-up experiments. A set of sequence-tagged site (STS) markers flanking the three QTL alleles for dry matter yield (QDmy-2R, QDmy-3R, and QDmy-5R) enables to the achievement of an indirect selection gain for biomass yield. This marker-assisted strategy allows for the screening of large hybrid rye populations already at early developmental stages without the resource-demanding harvest for biomass yield.