1,720,975 research outputs found
Molecular genotyping of “Rizor” and “Holly” rhizomania resistances in sugar beet
No full textRhizomania is the most damaging and widespread disease of the sugar beet crop and is caused by Beet necrotic yellow vein virus vectored by the fungus Polymyxa betae. The only disease man- agement tool used is resistant varieties. In the last 30 years, ‘‘Rizor’’ and ‘‘Holly’’ (Rz1) resistances have been the most widely used. Despite the lack of information, a common origin for both types of resistance was hypothesized by some breeders. The aim of this study was to assess the phylogenetic relationship between Rizor and Rz1 by means of SNP analysis. Fifty leaf samples of each were genotyped with a fingerprinting panel of 192 SNPs, using the QuantStudio 12K Flex system coupled with Taqman OpenArray technology. Analysis of molecular variance and principal coordinate analysis confirmed that Rizor and Rz1 cannot be distinguished as separate sources of resistance
Sugar beet resistance to rhizomania: state of art and perspectives
No full textThe productivity of sugar beet is strongly limited by several biotic stresses, among them rhizomania (induced by Beet necrotic yellow vein virus, BNYVV) which causes yield losses of 20–50% or more. The only way to control this disease is the use of resistant varieties. Sources of resistances have been found in the ancestor of the cultivated beets Beta vulgaris L. ssp. maritima (L.) Arcang. Rz1 is the major resistance gene present within commercial sugar beet varieties. This resistance was recognized as monogenic and dominant. Experimental evidence highlighted that Rz1 originated from sea beets belonging to Munerati’s genetic pool. The development of molecular markers linked to Rz1 allows the use of marker assisted selection (MAS) to introgress this gene into pollinator lines, to assess the trueness of hybridity and to remove off-type individuals. MAS speeds variety development and reduces production costs guaranteeing at the same time a high qualitative standard in variety development. Recent studies have shown an emergence of new BNYVV strains with increased virulence that could overcome Rz1 resistance. Therefore, exploitation of new genetic sources of resistance and the pyramiding of several resistance genes into new breeding lines is becoming a main priority for sugar beet breeding companies to maintain an adequate resistance level to rhizomania
Recenti Acquisizioni in tema di Diagnosi,terapia e Prevenzione delle Epatiti Acute ad Etiologia Virale.
No full textCaratterizzazione genetica di popolazioni italiane di scazzone. (Cottus gobio L., 1758).
No full textDeterminazione di caratteri morfofisiologici della radice legati alla produttività in barbabietola da zucchero
No full textThe origin of rhizomania resistance in sugar beet
No full textn the last 35 years, breeding has greatly reduced the damages caused by rhizomania in sugar beet crops. After the first encouraging results using the Alba genotypes, the cultivar Rizor represented a substantial step forward and has given good yield improvement in diseased fields in many parts of the world. The original variety and subsequent improved versions continued to offer good performances for about a decade, after which it was surpassed by other hybrids derived in part from the Rizor itself. Further progress in terms of sugar production became possible in 1986, when the Holly monogerm lines were released in USA and Europe. In spite of the incomplete information about the genealogy of the first resistant materials, many evidences and the molecular analyses on the different genotypes suggest a possible common progenitor and lineage. The resistant cultivars have kept the yield at an adequate level, allowing cultivation to continue in countries where the disease has reached epidemic proportions. The case of rhizomania resistance in sugar beet can therefore be considered as one of the most important achievements in plant breeding
Genetic variability in morpho-physiological traits in sugar beet
No full textVariability in root morpho-physiological traits (root elongation rate and sulfate uptake rate) involved in the plant response to water-nutritional stress was highlighted in six sugar beet genotypes characterized by different root yield. The above traits, evaluated on sixteen-day-old seedlings grown in hydroponics, were significantly correlated with root yield. Furthermore, under field conditions, the sugar beet genotype (ISCI 6) characterized by the highest root yield and therefore root elongation rate and sulfate uptake rate with respect to the lowest (ISCI 1), showed higher root length density (RLD) and leaf relative water content (RWC). The association of these morpho-physiological traits might be considered determinant of sugar beet productivity under conditions of water-nutritional stress
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