Identification of Bacterial Blight Resistance Loci in Rice (Oryza sativa L.) against Diverse Xoo Thai Strains by Genome-Wide Association Study

Bacterial leaf blight (BLB) is a serious disease affecting global rice agriculture caused by Xanthomonas oryzae pv. oryzae (Xoo). Most resistant rice lines are dependent on single genes that are vulnerable to resistance breakdown caused by pathogen mutation. Here we describe a genome-wide association study of 222 predominantly Thai rice accessions assayed by phenotypic screening against 20 Xoo isolates. Loci corresponding to BLB resistance were detected using >142,000 SNPs. We identified 147 genes according to employed significance thresholds across chromosomes 1–6, 8, 9 and 11. Moreover, 127 of identified genes are located on chromosomal regions outside estimated Linkage Disequilibrium influences of known resistance genes, potentially indicating novel BLB resistance markers. However, significantly associated SNPs only occurred across a maximum of six Xoo isolates indicating that the development of broad-spectrum Xoo strain varieties may prove challenging. Analyses indicated a range of gene functions likely underpinning BLB resistance. In accordance with previous studies of accession panels focusing on indica varieties, our germplasm displays large numbers of SNPs associated with resistance. Despite encouraging data suggesting that many loci contribute to resistance, our findings corroborate previous inferences that multi-strain resistant varieties may not be easily realised in breeding programs without resorting to multi-locus strategies

Přepínač osmimístný analogový pro 4 vodiče, připojitelný k PC prostřednictvím RS 232 : Analýza řešení a návrh

Import 20/04/2006Prezenční výpůjčkaFakulta elektrotechnická VŠB (Ostrava). Katedra elektroniky (454

Optimalizace odběrů a sazeb ze sítí NN u odběratelů kategorie MOO, MOP

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta elektrotechniky a informatiky. Katedra (451) elektroenergetik

Characterization of Myanmar Paw San Hmwe Accessions Using Functional Genetic Markers

Paw San Hmwe (PSM) rice has been cultivated in many areas of Myanmar for a long time. Strong aroma, good taste and its elongation during cooking are the key characteristics of PSM rice. Thirty-one PSM accessions were genotypically characterized, and their physical grain and cooking quality traits were studied. We used specific gene markers associated with aroma, apparent amylose content (AAC) and alkali spreading value to determine the alleles carried by different PSM accessions. The results revealed that six PSM accessions (PSM10, PSM12, PSM13, PSM21, PSM22 and PSM30) had a 3-bp insertion in Os2AP gene. Gel consistency (GC) allele was predominant among the PSM accessions for gelatinization temperature (GT), however, the phenotype observed was between low and intermediate GT because of the combination of the GC allele with the presence of low GT allele at heterozygous state from the other loci of the SSIIa gene. Intermediate to high AAC was observed among the PSM accessions corresponding to the haplotype identified for the single nucleotide polymorphism G/T and the (CT)n repeat in the Wx gene. The characterization and grouping data of PSM accessions posted benefits to Myanmar seed banks, and our results will help in maintaining the integrity of PSM rice variety