Evaluation of the durability of the Barley yellow dwarf virus-resistant Zhong ZH and TC14 wheat lines

Abstract

Serial passage experiments (SPE) of a Barley yellow dwarf virus-PAV (BYDV-PAV) isolate were performed on Zhong ZH and TC14 wheat lines to evaluate the durability of their resistance to BYDV. At different passage numbers (from the 2nd to the 114th), biological properties of the produced isolates were recorded either by monitoring infection percentages and virus titers of the first 3 weeks of viral infection or by measuring their impact on yield components. Statistical analyses using the area under pathogen progress curves and the area under concentration progress curves demonstrated that these two resistant lines induce, after only a few passages, a selection of variant(s) with significantly modified infection abilities. Isolates resulting from SPE performed on these lines induced important decreases of yield components. These results indicate that the use of Zhong ZH and TC14 lines in BYDV-resistant breeding programmes should be approached with caution.

Effect of passage of a Potato virus Y isolate on a line of tobacco containing the recessive resistance gene va 2 on the development of isolates capable of overcoming alleles 0 and 2

“…Thus, a single passage of SON41 on a va 2 background led to the production of virulent PVY populations overcoming both alleles 2 and 0 of the va gene. Such a rapid adaptation phenomenon to a resistance source has already been demonstrated in serial passages experiments for numerous plant viruses (Fargette et al 2002;Chain et al 2007) in which resistance breaking viral variants were obtained after a few passages. Moreover, a cooperative phenomenon in the acquisition of the ability to overcome allelic series of a recessive resistance gene has been suggested for the PVY/pvr2 (pepper) pathosystem.…”

“…However, the va gene does not stop viral infection of plants but limits cell to cell movement of viral particles during the infection of the host (Acosta-Leal and Xiong 2008) and reduces the development of vein necrosis symptoms induced by PVY on tobacco leaves (Verrier and Doroszewska 2004). The intensive use of these genetic resistance sources (alleles of the va gene) induces selection pressures leading to the possible emergence of variants putatively more virulent and/or aggressive than the parental viral entities (Pelham et al 1970;Fargette et al 2002;Chain et al 2007). Isolates of PVY virulent to va resistance have been previously described Piccirillo and Piro 1986;Verrier and Doroszewska 2004) confirming that PVY is able to overcome the resistance conferred by this gene.…”

A newCapsicum baccatumaccession shows tolerance to wild-type and resistance-breaking isolates ofTomato spotted wilt virus

“…The TBR isolate accumulated more in the susceptible Negral than in the resistant PI-159236 suggesting that the acquisition of overcoming resistance conferred by gene Tsw did not suppose a fitness cost for TSWV (at least for these host genotypes) as reported for other plant viruses (Jenner et al, 2002;Desbiez et al, 2003), although there are also several cases with no fitness cost associated to resistance breakdown (Sorho et al, 2005;Chain et al, 2007).…”

Reduced BYDV–PAV transmission by the grain aphid in a Triticum monococcum line

“…Resistance sources to BYDV-PAV multiplication have been found in perennial Triticineae (genera Thinopyrum and Lophopyrum) and transferred to bread wheat genotypes. The resulting wheat lines are partly resistant, but have been shown to quickly induce the selection of virus variants with increased infection abilities (Chain et al 2006).…”