Twenty landraces of common bean (Phaseolus vulgaris L .) from Sarconi and Rotonda two locations of Basilicata, a Southern Italy region, were screened for variation in seed storage proteins (phaseolin and phytohemagglutinin) by polyacrylamide gel electrophoresis (SDS/PAGE and IEF-SDS/PAGE) . No variation of the main seed protein fractions was observed within each landrace . Phaseolin patterns type C and T were exhibited from the landraces ; the type C resulted predominant with a frequency of 70% . Only the C type was observed for the landraces of Rotonda, T and C for those from Sarconi . Two variants were observed for the phytohemagglutinin by SDS-PAGE, one was common to eighteen landraces . However, these variants submitted to IEF-SDS/PAGE resulted similar to the type TG2 described by Brown . The importance to safeguard these landraces is stressed by the observation that the more spread commercial cultivars of common bean growing in Southern-Italy had a T phaseolin pattern . A reduction of C type diffusion could produce the loss a typical trait of common bean in Mediterranean regions .
Genetic relationships among 13 grasspea (Lathyrus sativus L.) landraces mainly collected in Southern Italy were assessed using agronomic traits, biochemical and molecular markers. Field trials were carried out in two locations and revealed a high influence of field locations on yield, but a low genotype 9 environment interaction. Despite this, the agronomic data obtained provided useful information for the choice of the best grasspea landraces for southern Italian marginal areas. Seed storage proteins utilised as biochemical markers were not able to detect polymorphisms, on the contrary both classes of molecular markers used i.e. AFLP and SSR, provided useful information on genetic variation and relationships among landraces. Even though the number of polymorphic fragments detected by AFLP technique was low, it was sufficient to discriminate all the accessions. The use of SSR to detect polymorphic sites in grasspea showed that most landraces were clearly grouped in two sub-clusters. One comprised two landraces from most northern localities, while all the other landraces were clustered together at a very narrow genetic distance.
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SNP-based genome scanning in worldwide domesticated emmer germplasm showed high genetic diversity, rapid linkage disequilibrium decay and 51 loci for stripe rust resistance, a large proportion of which were novel.
AbstractCultivated emmer wheat (Triticum turgidum ssp. dicoccum), one of the oldest domesticated crops in the world, is a potentially rich reservoir of variation for improvement of resistance/tolerance to biotic and abiotic stresses in wheat. Resistance to stripe rust (Puccinia striiformis f. sp. tritici) in emmer wheat has been under-investigated. Here, we employed genome-wide association (GWAS) mapping with a mixed linear model to dissect effective stripe rust resistance loci in a worldwide collection of 176 cultivated emmer wheat accessions. Adult plants were tested in six environments and seedlings were evaluated with five races from the United States and one from Italy under greenhouse conditions. Five accessions were resistant across all experiments. The panel was genotyped with the wheat 90,000 Illumina iSelect single nucleotide polymorphism (SNP) array and 5106 polymorphic SNP markers with mapped positions were obtained. A high level of genetic diversity and fast linkage disequilibrium decay were observed. In total, we identified 14 loci associated with field resistance in multiple environments. Thirty-seven loci were significantly associated with all-stage (seedling) resistance and six of them were effective against multiple races. Of the 51 total loci, 29 were mapped distantly from previously reported stripe rust resistance genes or quantitative trait loci and represent newly discovered resistance loci. Our results suggest that GWAS is an effective method for characterizing genes in cultivated emmer wheat and confirm that emmer wheat is a rich source of stripe rust resistance loci that can be used for wheat improvement.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-017-2957-6) contains supplementary material, which is available to authorized users.
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