A rapid technique for assessing the resistance of families of potato seedlings to potato leaf roll virus

High Levels of Heritable Resistance to Potato Leafroll Virus (PLRV) in Solanum tuberosum subsp. andigena

“…Here, the GCA component of variation was found to be highly signifi cant in a diallel mating design of andigena cultivars, indicating the importance of additive gene eff ects in the resistance to PLRV infection in S. tuberosum subsp. Several advantages have been attributed to the shaking inoculation technique for infecting seedlings applied in this study: (i) because seedlings are small, they quickly become completely invaded by the virus causing symptoms similar to those of secondary infection; (ii) it is more eff ective than hand transfer, because aphids are less disturbed; (iii) coeffi cients of variability have been smaller than those obtained under natural fi eld exposure due to a more even distribution of aphids which insures a more uniform exposure; and (iv) inoculum pressure (the number of viruliferous aphids to be applied) can be better controlled (Chuquillanqui and Jones, 1980;Rizvi 1982). Therefore, this resistance may be fi xed in a breeding program, provided parents are carefully selected based on their resistance performance as clones.…”

“…47, MAY-JUNE 2007 to the plant's production of toxins, volatile repellants, or even to the presence of nonglandular-type trichome or hairs (Jayasinghe, 1990). Current availability of standardized greenhouse experiments that allow controlled inoculation of plants with PLRV via viruliferous aphids, combined with enzyme-linked immunosorbent assay (ELISA), is eff ective for the identifi cation of genotypes exhibiting resistance to PLRV and of more-resistant progenies (Chuquillanqui and Jones, 1980;Solomon-Blackburn et al, 1994). Current availability of standardized greenhouse experiments that allow controlled inoculation of plants with PLRV via viruliferous aphids, combined with enzyme-linked immunosorbent assay (ELISA), is eff ective for the identifi cation of genotypes exhibiting resistance to PLRV and of more-resistant progenies (Chuquillanqui and Jones, 1980;Solomon-Blackburn et al, 1994).…”

“…Seedlings were inoculated by shaking PLRV-infected plants of the susceptible cultivar Flor Blanca, heavily infested with M. persicae, over the trays as evenly as possible (Chuquillanqui and Jones, 1980). Twenty days after sowing, 60 seedlings of each progeny were transplanted to Jiff y-7 pellets (Jiff y Products, Shippegan, NB) arranged in groups of 20 seedlings per tray, and set according to the experimental design.…”

Introgression of the Rl adg allele of resistance to potato leafroll virus in Solanum tuberosum L.

“…These results show that despite the adequate number of aphids per plant, escapes may have occurred, which is a relatively common situation in artificial inoculations, reinforcing the usefulness of the marker for the selection of clones that are resistant to PLRV. In addition, Chuquillanqui and Jones (1980) commented that the technique of transferring aphids from inoculum plants to the treatment with a brush disturbs the aphids, and/or leads to the fatigue of the operator. In the present work, about 4000 aphids were manipulated at each inoculation (totaling approximately 17000 aphids).…”

Recent advances in breeding potatoes for disease resistance

“…In the plant, the virus is restricted to the phloem tissue (Weidemann and Casper, 1982). Resistance to infection by PLRV is quantitatively inherited and methods have been described to select at the seedling stage (Chuquillanqui and Jones, 1980). Minor genes for resistance are probably derived from S. demissum and S. acaule (clones from family MP144.335 and clone MP144.1016/10 have been good donors of such genes; Ross, 1986).…”