Kazuyuki Doi

Two evolutionarily distant plant species, rice (Oryza sativa L.), a short-day (SD) plant, and Arabidopsis thaliana, a long-day plant, share a conserved genetic network controlling photoperiodic flowering. The orthologous floral regulators-rice Heading date 1 (Hd1) and Arabidopsis CONSTANS (CO)-integrate circadian clock and external light signals into mRNA expression of the FLOWERING LOCUS T (FT) group floral inducer. Here, we report that the rice Early heading date 1 (Ehd1) gene, which confers S

Rapid and cost-effective genotyping of large mapping populations can be achieved by sequencing a reduced representation of the genome of every individual in a given population, and using that information to generate genetic markers. A customized genotyping-by-sequencing (GBS) pipeline was developed to genotype a rice F2 population from a cross of <i>Oryza sativa</i> ssp. <i>japonica</i> cv. Nipponbare and the African wild rice species <i>O. longistaminata</i> While most GBS pipelines aim to anal

To fully exploit the genetic potential of African rice, Oryza glaberrima Steud., we aimed at developing a series of O. glaberrima introgression lines (GILs) in the back-ground of Japonica rice (O. sativa L. cv. Taichung 65). Each GIL carrying homozygous chromosome segments from O. glaberrima will be selected using RFLP markers. As a first step, an RFLP Iinkage map based on backcross population (BC1F1) was constructed. QTLs for two quantitative traits, male sterility and heading date, were invest

The era of the green revolution has significantly improved rice yield productivity. However, with the growing population and decreasing arable land, rice scientists must find new ways to improve rice productivity. Although hundreds of rice yield-related QTLs were already mapped and some of them were cloned, only a few were utilized for actual systematic introgression breeding programs. In this study, the major yield QTLs <i>Grain Number 1a</i> (<i>Gn1a</i>) and <i>Wealthy Farmer's Panicle</i> (<

DNA marker-assisted selection (MAS) has become an indispensable component of breeding. Single nucleotide polymorphisms (SNP) are the most frequent polymorphism in the rice genome. However, SNP markers are not readily employed in MAS because of limitations in genotyping platforms. Here the authors report a Golden Gate SNP array that targets specific genes controlling yield-related traits and biotic stress resistance in rice. As a first step, the SNP genotypes were surveyed in 31 parental varietie

A genetic resource for studying genetic architecture of agronomic traits and environmental adaptation is essential for crop improvements. Here, we report the development of a rice nested association mapping population (<i>aus</i>-NAM) using 7 <i>aus</i> varieties as diversity donors and T65 as the common parent. <i>Aus</i>-NAM showed broad phenotypic variations. To test whether <i>aus</i>-NAM was useful for quantitative trait loci (QTL) mapping, known flowering genes (<i>Ehd1</i>, <i>Hd1</i>, an

Molecular markers play a crucial role in the improvement of rice. To benefit from these markers, genotyping is carried out to identify the differences at a specific position in the genome of individuals. The advances in sequencing technologies have led to the development of different genotyping techniques such as genotyping-by-sequencing. Unlike PCR-fragment-based genotyping, genotyping-by-sequencing has enabled the parallel sequencing and genotyping of hundreds of samples in a single run, makin

RFLPs of 192 accessiens ef A-genome rice species were aRalyzed ORe plant vvas used to represent each accession assayed RFLPs were detected for the combinations of Dra 1-digested total DNA and tweRty-one sirgle-copy genomic cones A dendrogram was constructed using ePGAryiethd frrl a geRetic distaxceaxasscafhe A-geRmece speces based on RFLP analysis matched well with the conventional classcation The African annual species O gtaberrimct and O barthii were not clearly differentiated by RFLP loci whi

ABSTRACT Rapid and cost-effective genotyping of large mapping populations can be achieved by sequencing a reduced representation of the genome of every individual in a given population and using that information to generate genetic markers. A customized genotyping-by-sequencing (GBS) pipeline was developed to genotype a rice F2 population from a cross of Oryza sativa ssp. japonica cv. Nipponbare and the African wild rice species Oryza longistaminata . While most GBS pipelines aim to analyze main