Interaction between genetic regions responsible for the starch properties in non-glutinous rice varieties in Hokkaido, Japan.

Starch properties are the major determinants of grain quality and food characteristics in rice ( L.). Understanding the interactions between genetic regions responsible for starch properties will lead to the development of rice cultivars with desirable characteristics.

encoding a chromatin remodeling factor, is a killer causing hybrid sterility between rice species and .

The genetic mechanisms of reproductive isolation have been widely investigated within Asian cultivated rice (); however, relevant genes between diverged species have been in sighted rather less. Herein, a gene showing selfish behavior was discovered in hybrids between the distantly related rice species and . The selfish allele in the locus impaired male fertility, discriminately eliminating pollens containing the allele from in heterozygotes (/).

Genetic region responsible for the differences of starch properties in two glutinous rice cultivars in Hokkaido, Japan.

Starch properties are major determinants of grain quality and food characteristics in rice ( L.). Control of starch properties will lead to the development of rice cultivars with desirable characteristics.

A novel genotype DATTO5 developed using the five genes exhibits the fastest heading date designed in rice.

The optimization of heading date is a key aspect for maximizing grain productivity in cereal crops including rice. The combinations of genes for heading date, a quantitative trait, are a major driver in the wide adaptability of cultivated rice worldwide. Here, we identified a novel QTL, (quantitative trait locus for days-to-heading on chromosome 3), for early flowering time in the F population derived from a cross between Hoshinoyume (HS) and Daichinohoshi (DH) among local rice populations with extremely early heading date.

Introgression of the chromosomal region with the Pi-cd locus from Oryza meridionalis into O. sativa L. during rice domestication.

The genotype of the Pi-cd locus found in blast-resistant rice variety Kitakurin, which is a cultivated rice from Japan belonging to Oryza sativa japonica, is identical to that of its wild relative O. meridionalis. Crop domestication from wild relatives to cultivated species has encompassed significant phenotypic changes.

Establishment of adaptability to the northern-limit of rice production.

The domestication of cultivated crops from their wild relatives narrowed down their genetic diversity in a bottleneck effect. Subsequently, the cultivation areas of crops have expanded all over the world into various environmental conditions from the original area along with human migration after domestication. Here, we demonstrated the genetic changes in the adaptation of rice to Hokkaido (41°2-45°3N latitude), Japan, from the tropics of their origin in Asian cultivated rice, Oryza sativa L.

Colocalization of QTLs for hull-cracked rice and grain size in elite rice varieties in Japan.

The control of insects that consume cereal grains is important for the production and storage of grains. Hull-cracked rice, which has splits in the hull, becomes more susceptible to insects both in the paddy field and during storage. The development of varieties with a low frequency of hull-cracked rice is the most economical and effective strategy to avoid insect damage and the environmental risks from agricultural chemical entering rice grains.

The superwoman1-cleistogamy2 mutant is a novel resource for gene containment in rice.

Outcrossing between cultivated plants and their related wild species may result in the loss of favourable agricultural traits in the progeny or escape of transgenes in the environment. Outcrossing can be physically prevented by using cleistogamous (i.e.

Genome-wide association mapping focusing on a rice population derived from rice breeding programs in a region.

Plant breeding programs in local regions may generate genetic variations that are desirable to local populations and shape adaptability during the establishment of local populations. To elucidate genetic bases for this process, we proposed a new approach for identifying the genetic bases for the traits improved during rice breeding programs; association mapping focusing on a local population. In the present study, we performed association mapping focusing on a local rice population, consisting of 63 varieties, in Hokkaido, the northernmost region of Japan and one of the northern limits of rice cultivation worldwide.

Genetic shift in local rice populations during rice breeding programs in the northern limit of rice cultivation in the world.

The rapid accumulation of pre-existing mutations may play major roles in the establishment and shaping of adaptability for local regions in current rice breeding programs. The cultivated rice, Oryza sativa L., which originated from tropical regions, is now grown worldwide due to the concerted efforts of breeding programs.