Mapping of loci involved in quantitatively inherited resistance to the potato cyst-nematode Globodera rostochiensis pathotype Ro1

Abstract

We report the identification and mapping of two quantitative trait loci (QTLs) of Solanum spegazzinii BGRC, accession 8218-15, involved in resistance to the potato cyst-nematode Globodera rostochiensis pathotype Ro1, by means of restriction fragment length polymorphisms (RFLPs). For this purpose we crossed a susceptible diploid S. tuberosum with the resistant S. spegazzinii, and tested the F1 population for resistance to the Ro1 pathotype. Since the F1 segregated for the resistance, the S. spegazzinii parent was concluded to be heterozygous at the nematode resistance loci. For the mapping of the resistance loci we made use of RFLP markers segregating for S. spegazzinii alleles in the F1. One hundred and seven RFLP markers were tested in combination with four different restriction enzymes; 29 of these displayed a heterozygous RFLP pattern within S. spegazzinii and were used for mapping. Analysis of variance (ANOVA) was applied to test the association of the RFLP patterns of these markers with nematode resistance. Two QTLs involved in disease resistance to Globodera rostochiensis pathotype Ro1 were identified and mapped to chromosomes 10 and 11 respectively.

Nematode Pathogenesis and Resistance in Plants

“…Severa1 dominant or semidominant resistance genes have been identified and mapped to chromosomal locations or linkage groups (Table 1). For other sources of resistance, inheritance is polygenic or in some cases recessive (Trudgill, 1991;Kreike et al, 1993;Faghihi et al, 1995;Wang and Goldman, 1996). In some cases, polygenic resistance has been resolved into major genes, which are genetically dominant, and minor genes, which may modulate the response (Kreike et al, 1994;Webb et ai., 1995).…”

Quantitatively-inherited resistance toGlobodera pallida is dominated by one major locus inSolanum spegazzinii

“…The RFLP markers that were used in this study and the RFLP analysis have both been described earlier by Kreike et al (1993).…”

Potato resistance to quarantine diseases

“…Феномен HR описывается как инкапсуляция питательной клетки растения, в которую внедрилась личинка нематоды, слоем некротических клеток с последующей дегенерацией питающего синтиция в течение недели (Rice et al, 1985). Большинство известных QTL локусов устойчивости к цистообразующим нематодам детерминируют частичную устойчивость к одному или более патотипам (Kreike et al, 1993(Kreike et al, , 1996Caromel et al, 2005).…”