ABSTRACT
MADS-box genes interact with TB1 to regulate plant organ morphogenesis. In rice, OsMADS57 interacts with OsTB1 to control OsD14 transcription. In this study, we aimed to determine the relationships among these genes in barley. We identified a natural mutant of HvTB1 (tb1) formed by a C?A transition at position 230, which resulted in a premature stop codon. We cloned the HvMADS57 and HvD14 genes and studied their expression in the tb1 mutant. The results showed that HvMADS57 is a MIKCc -type MADS-box gene, and the expression levels of both HvMADS57 and HvD14 were significantly reduced in the tb1 mutant when compared to those in the wildtype gene. These results indicate that, HvMADS57 regulates plant growth and development by interacting with HvTB1 to suppress the transcription of HvD14 in barley which is similar to the relationships among the orthologs of these genes in rice.
ABSTRACT
Abstract Pre-harvest sprouting (PHS) is a major abiotic factor affecting grain weight and quality, and is caused by an early break in seed dormancy. Association mapping (AM) is used to detect correlations between phenotypes and genotypes based on linkage disequilibrium (LD) in wheat breeding programs. We evaluated seed dormancy in 80 Chinese wheat founder parents in five environments and performed a genome-wide association study using 6,057 markers, including 93 simple sequence repeat (SSR), 1,472 diversity array technology (DArT), and 4,492 single nucleotide polymorphism (SNP) markers. The general linear model (GLM) and the mixed linear model (MLM) were used in this study, and two significant markers (tPt-7980 and wPt-6457) were identified. Both markers were located on Chromosome 1B, with wPt-6457 having been identified in a previously reported chromosomal position. The significantly associated loci contain essential information for cloning genes related to resistance to PHS and can be used in wheat breeding programs.
ABSTRACT
The genetic diversity and phylogenetic relationships in the genus Secale L. (rye) was evaluated using 24 Secale cereale microsatellite (SCM) markers. The average polymorphism information content (PIC) value of each microsatellite locus in 30 Secale accessions evaluated was higher than that in 47 cultivated ryes (Secale cereale ssp. cereale). The mean genetic similarity (GS) index in Secale was lower than that in cultivated rye. The highest within-species GS index was observed for S. sylvestre and the lowest for S. strictum, whereas the highest between-species GS index was found between S. cereale and S. vavilovii and the lowest between S. sylvestre and S. cereale. There was no obvious difference in GS levels in the cultivated rye accessions from Asia, Europe, North America or South America. Cluster analysis indicated that all the Secale accessions could be distinguished by the 24 microsatellite loci. We also found that the S. sylvestre accessions were obviously divergent from the accessions of other species and that the S. vavilovii accessions were closely related to the S. cereale accessions. Our results also showed that S. strictum was heterogeneous and showed great within-species differences. The microsatellite-derived dendrogram faithfully reflected the phylogenetic relationships between Secale species but did not indicate a possible domestication process of the cultivated rye based on the geographical sources of the accessions.