31 research outputs found

    A microsatellite marker for yellow rust resistance in wheat

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    Bulk segregant analysis (BSA) was used to identify molecular markers associated with yellow rust disease resistance in wheat (Triticum aestivum L.). DNAs isolated from the selected yellow rust tolerant and susceptible F-2 individuals derived from a cross between yellow rust resistant and susceptible wheat genotypes were used to established a "tolerant" and a "susceptible" DNA pool. The BSA was then performed on these DNA pools using 230 markers that were previously mapped onto the individual wheat chromosomes. One of the SSR markers (Xgwm382) located on chromosome group 2 (A, B, D genomes) was present in the resistant parent and the resistant bulk but not in the susceptible parent and the susceptible bulk, suggesting that this marker is linked to a yellow rust resistance gene. The presence of Xgwm382 was also tested in 108 additional wheat genotypes differing in yellow rust resistance. This analysis showed that 81% of the wheat genotypes known to be yellow rust resistant had the Xgwm382 marker, further suggesting that the presence of this marker correlates with yellow rust resistance in diverse wheat germplasm. Therefore, Xgwm382 could be useful for marker assisted selection of yellow rust resistances genotypes in wheat breeding programs

    Anti-Apoptotic Machinery Protects the Necrotrophic Fungus Botrytis cinerea from Host-Induced Apoptotic-Like Cell Death during Plant Infection

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    Necrotrophic fungi are unable to occupy living plant cells. How such pathogens survive first contact with living host tissue and initiate infection is therefore unclear. Here, we show that the necrotrophic grey mold fungus Botrytis cinerea undergoes massive apoptotic-like programmed cell death (PCD) following germination on the host plant. Manipulation of an anti-apoptotic gene BcBIR1 modified fungal response to PCD-inducing conditions. As a consequence, strains with reduced sensitivity to PCD were hyper virulent, while strains in which PCD was over-stimulated showed reduced pathogenicity. Similarly, reduced levels of PCD in the fungus were recorded following infection of Arabidopsis mutants that show enhanced susceptibility to B. cinerea. When considered together, these results suggest that Botrytis PCD machinery is targeted by plant defense molecules, and that the fungal anti-apoptotic machinery is essential for overcoming this host-induced PCD and hence, for establishment of infection. As such, fungal PCD machinery represents a novel target for fungicides and antifungal drugs

    Selezione con marcatori molecolari per la resistenza a Sharka

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    La Sharka è una malattia virale molto grave che colpisce le drupacee come l’albicocco ed il cui agente eziologico è il Plum Pox virus (PPV). In albicocco si conosce un QTL maggiore per la resistenza localizzato nella parte alta del cromosoma 1 (regione PPVres). Precedenti studi hanno indicato che le cultivar resistenti al virus e i semenzali resistenti derivati da incrocio possono essere selezionati analizzando una serie di marcatori SSR presenti in questa regione. L’efficienza di questi marcatori per la MAS (molecular assisted selection) è stata verificata in un lavoro recentemente pubblicato sulla rivista Tree Genetics and Genomics (Decroocq et al 2014): l'analisi degli individui di 11 popolazioni segreganti per la resistenza al virus ha dimostrato che la selezione di nuovi genotipi basata solo sui marcatori associati alla regione PPVres non è completamente affidabile. La maggior parte degli individui resistenti al virus della Sharka ha mostrato effettivamente la presenza degli alleli associati alla resistenza mentre la totalità delle piante suscettibili che ne erano privi. Purtroppo però gli alleli associati alla resistenza erano presenti anche in un numero significativo di individui suscettibili . Si è avuto quindi conferma che nel genoma dell'albicocco sono presenti altri fattori o geni in grado di modulare l’azione del gene localizzato nella regione principale. L'identificazione di ulteriori marcatori in queste nuove regioni sarà importante per selezionare in modo inequivocabile le accessioni di albicocco resistenti a PPV. Questo è l'obiettivo del Progetto Europeo MARS (Marker Assisted Resistance to Sharka, https://www6.inra.fr/mars)
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