Natural Diversity in Stomatal Features of Cultivated and Wild Oryza Species.

Background: Stomata in rice control a number of physiological processes by regulating gas and water exchange between the atmosphere and plant tissues. The impact of the structural diversity of these micropores on its conductance level is an important area to explore before introducing stomatal traits into any breeding program in order to increase photosynthesis and crop yield. Therefore, an intensive measurement of structural components of stomatal complex (SC) of twenty three Oryza species spanning the primary, secondary and tertiary gene pools of rice has been conducted.

The Development and Characterization of Near-Isogenic and Pyramided Lines Carrying Resistance Genes to Brown Planthopper with the Genetic Background of Rice ( L.).

The brown planthopper (BPH: Stål.) is a major pest of rice, , in Asia. Host plant resistance has tremendous potential to reduce the damage caused to rice by the planthopper.

Novel cis-acting regulatory elements in wild Oryza species impart improved rice bran quality by lowering the expression of phospholipase D alpha1 enzyme (OsPLDα1).

Rice bran oil is good quality edible oil, rich in antioxidants and comprised typically of oleic-linoleic type fatty acids. However, presence of a highly lipolytic enzyme Phospholipase D alpha1 (OsPLDα1) increases free fatty acid content in the oil which further leads to stale flavor and rancidity of the oil, making it unfit for human consumption. In this study, we compared the upstream regions of OsPLDα1 orthologs across 34 accessions representing 5 wild Oryza species and 8 cultivars, to uncover sequence variations and identify cis-elements involved in differential transcription of orthologs.

Production and cytological characterization of a synthetic amphiploid derived from a cross between and .

Kotschy ex Steud. (BB, 2 = 24) is a wild species of rice that has many useful agronomic traits. An interspecific hybrid (AB, 2 = 24) was produced by crossing and variety Punjab Rice 122 (PR122, AA, 2 = 24) to broaden the narrow genetic base of cultivated rice.

Potential of Oryza officinalis to augment the cold tolerance genetic mechanisms of Oryza sativa by network complementation.

Oryza officinalis is an accessible alien donor for genetic improvement of rice. Comparison across a representative panel of Oryza species showed that the wild O. officinalis and cultivated O.

High-resolution genetic mapping of a novel brown planthopper resistance locus, Bph34 in Oryza sativa L. X Oryza nivara (Sharma & Shastry) derived interspecific F population.

A BPH-resistant locus designated as Bph34 identified in Oryza nivara acc. IRGC104646 on long arm of chromosome 4 using high-resolution mapping with 50 K SNP chip. BPH resistance contributed by locus showed dominant inheritance in F and F.

The Evolutionary Basis of Naturally Diverse Rice Leaves Anatomy.

Rice contains genetically and ecologically diverse wild and cultivated species that show a wide variation in plant and leaf architecture. A systematic characterization of leaf anatomy is essential in understanding the dynamics behind such diversity. Therefore, leaf anatomies of 24 Oryza species spanning 11 genetically diverse rice genomes were studied in both lateral and longitudinal directions and possible evolutionary trends were examined.

Evolutionary dynamics of an ancient retrotransposon family provides insights into evolution of genome size in the genus Oryza.

Long terminal repeat (LTR) retrotransposons constitute a significant portion of most eukaryote genomes and can dramatically change genome size and organization. Although LTR retrotransposon content variation is well documented, the dynamics of genomic flux caused by their activity are poorly understood on an evolutionary time scale. This is primarily because of the lack of an experimental system composed of closely related species whose divergence times are within the limits of the ability to detect ancestrally related retrotransposons.

New insights into Oryza genome evolution: high gene colinearity and differential retrotransposon amplification.

An approximately 247-kb genomic region from FF genome of wild rice Oryza brachyantha, possessing the smallest Oryza genome, was compared to the orthologous approximately 450-kb region from AA genome, O. sativa L. ssp.

Doubling genome size without polyploidization: dynamics of retrotransposition-driven genomic expansions in Oryza australiensis, a wild relative of rice.

Retrotransposons are the main components of eukaryotic genomes, representing up to 80% of some large plant genomes. These mobile elements transpose via a "copy and paste" mechanism, thus increasing their copy number while active. Their accumulation is now accepted as the main factor of genome size increase in higher eukaryotes, besides polyploidy.

The Oryza bacterial artificial chromosome library resource: construction and analysis of 12 deep-coverage large-insert BAC libraries that represent the 10 genome types of the genus Oryza.

Rice (Oryza sativa L.) is the most important food crop in the world and a model system for plant biology. With the completion of a finished genome sequence we must now functionally characterize the rice genome by a variety of methods, including comparative genomic analysis between cereal species and within the genus Oryza.

Influence of different Oryza cultivars on expression of nifH gene pools in roots of rice.

Cultivation-independent studies suggest that roots of rice (Oryza sativa) are colonized by a diverse community of nitrogen-fixing bacteria. Here we report for the first time mRNA-based profiling of nitrogenase (nifH) genes, to study the impact of lowland-rice genotypes at the cultivar level on the functional diversity of root-associated diazotrophs. Root RNA extracts from all plants contained nifH mRNA at levels detectable by reverse transcription polymerase chain reaction (RT-PCR).

The oryza map alignment project: the golden path to unlocking the genetic potential of wild rice species.

The wild species of the genus Oryza offer enormous potential to make a significant impact on agricultural productivity of the cultivated rice species Oryza sativa and Oryza glaberrima. To unlock the genetic potential of wild rice we have initiated a project entitled the 'Oryza Map Alignment Project' (OMAP) with the ultimate goal of constructing and aligning BAC/STC based physical maps of 11 wild and one cultivated rice species to the International Rice Genome Sequencing Project's finished reference genome--O. sativa ssp.

Identification and mapping of the QTL for aluminum tolerance introgressed from the new source, Oryza Rufipogon Griff., into indica rice (Oryza sativa L.).

This study was conducted to identify and map the quantitative trait locus (QTL) controlling Al tolerance in rice using molecular markers. A population of 171 F(6) recombinant inbred lines (RILs) derived from the cross of Oryza sativa (IR64), the Al susceptible parent, and Oryza rufipogon, the Al tolerant parent, was evaluated for Al tolerance using a nutrient solution with and without 40 ppm of active Al(+3). A genetic map, consisting of 151 molecular markers covering 1,755 cM with an average distance of 11.