Features of crossing-over in virus-infected tomato

Abstract

Abstract:The evidence of increased crossing over rate in tomato hybrids infected with TAV (Tomato aspermy virus), PVX (Potato virus X), TMV (Tobacco mosaic virus), TMV+PVX indicates the recombinogenic effect of viral infection. Cytological studies of the early diakinesis in healthy and virus-infected tomato revealed significant changes in chiasma number and position. The most significant changes were established for bivalents with two interstitial chiasmata and with one terminal and one interstitial. The data obtained indicate redistribution of the chiasmata position and induction of additional exchanges. The virus-induced recombination is segment-specific and depends on the host plant genotype, virus infection and the interaction between them.

The Role of Viral Infection in Inducing Variability in Virus‐Free Progeny in Tomato

“…The modified numbers of recombinants were noted for genes located on chromosome 2, but not for those on chromosome 6. In line with Singh's evidence (Singh 1981) and our preliminary results (Chiriac et al 2006), the same chromosome responds differently to recombinogenic factors, and different chromosome segments respond in a different manner to the same factor.…”

“…The modified numbers of recombinants were noted for genes located on chromosome 2, but not for those on chromosome 6. In line with Singh's evidence (Singh 1981) and our preliminary results (Chiriac et al 2006), the same chromosome responds differently to recombinogenic factors, and different chromosome segments respond in a different manner to the same factor.Association between various traits is often an attribute of linkage between two or more quantitative trait loci: in that case recombination will bring about separation of desirable traits from the undesirable ones. Manifestation of this phenomenon of association between traits in a large number of crosses will be due to reduced crossing-over rates (Paterson et al 1990;Lippman and Tanksley 2001).…”

“…An increase in the proportion of univalents was observed for both hybrid and cultivar genotypes. Distinctive chromosome behavior during chromosome pairing was also evidenced in tomato plants infected with tomato aspermy virus or with TMV and PVX applied separately (Chiriac et al 2006).In conformity with some reports in the literature, it appears that, like other factors, viral infection can induce an increase in the incidence of recombination in the progeny of treated plants, thus manifesting meiotic stability (Lebel et al 1993;Puchta et al 1995;Ries et al 2000;Lucht et al 2002;Kovalchuk et al 2003;Filkowski et al 2004).The above led us to assume that the given combination of viruses or each of the viruses (Chiriac et al 2006) can modify recombination frequency in the d-aw segment. Similar results were obtained in the case of sorghum hybrids infected with the sugarcane mosaic virus (Stokes et al 1988).…”

“…The opportunity Role of Viral Infection in Inducing Variability 477 for shortening the breeding time and increasing the frequency of individual plants combining valuable traits can be realized through the use of factors increasing recombination frequency and spectrum (Schuermann et al 2005). Recently, viral infection has been found to be involved in the enhancement of mitotic (Kovalchuk et al 2003) and meiotic (Chiriac et al 2006) recombination, and their effects could persist in the subsequent untreated generation.In view of the above, the objectives of the present study were as follows:1. Evaluation of the effect of viral infection on the inheritance of quantitative traits (fruit weight, earliness, soluble solids content) in the progeny of plants infected with tobacco mosaic virus (TMV) and potato virus X (PVX); 2.…”

Genotoxicity of barley stripe mosaic virus in infected host plants

“…According to many reports, plant viruses are capable of inducing various genetic effects [36][37][38][39][40], including modification of the sister chromatid exchange rate [36,41]. SCE analyses have demonstrated the mutagenic effect of the bean common mosaic virus in bean plants that varies according to the stage of viral pathogenesis.…”