Role of Solanum dulcamara L. in Potato Late Blight Epidemiology
Golas, T.M. ; Weerden, G.M. van der; Berg, R.G. van den; Mariani, C. ; Allefs, J.J.H.M. - \ 2010
Potato Research 53 (2010)1. - ISSN 0014-3065 - p. 69 - 81.
infestans mont debary - nevado-de-toluca - phytophthora-infestans - natural occurrence - solanaceous hosts - western slopes - resistance - plant - inoculation - strains
Four sites with naturally growing Solanum dulcamara were surveyed during 2006 and 2007 for the presence of late blight. Despite 2 years of observations, no late blight was detected among natural populations of bittersweet. Nevertheless, repeated infections occurred on few S. dulcamara plants from a collection growing in a botanical garden in the same years. These plants were used to investigate the possibility of survival of the inoculum between seasons. In the respective years, a set of 21 and 52 S. dulcamara accessions inoculated with Phytophthora infestans under field conditions resulted in a wide range of responses to the disease. More susceptible reactions were found among genotypes collected at greater distance from commercial potato fields indicating the possibility of genetic selection caused by P. infestans. However, both scarceness of natural infections and no overwintering, suggest that bittersweet may not play a role in late blight epidemiology
Alteration of the genomic composition of Solanum nigrum (+) potato backcross derivatives by somatic hybridisation: selection of fusion hybrids by DNA measurements and GISH
Horsman, K. ; Gavrilenko, T. ; Bergervoet, M. ; Huigen, D.J. ; Tjin Wong Joe, A. ; Jacobsen, E. - \ 2001
Plant Breeding 120 (2001)3. - ISSN 0179-9541 - p. 201 - 207.
infestans mont debary - lycopersicon-esculentum - chromosome-number - alien chromosomes - rflp analysis - tuberosum - brevidens - tomato - identification - resistance
Fusion experiments were performed with a first (BC1-6738) and a second (BC2-9017) generation backcross hybrid of 6x Solanum nigrum (+) 2x potato somatic hybrids with potato cultivars. Because no progeny was obtained from the BC2 genotypes, alternative approaches were sought to overcome the sexual crossing barrier. Five potato genotypes, one of which contains the hygromycin resistance gene, were used in the fusion experiments. All vigorous regenerants were used for the estimation of nuclear DNA content using flow cytometry. Plants with a DNA content higher than that of the BC1-6738 or BC2 genotypes were considered potential somatic hybrids. Forty-nine potential somatic hybrids resulted from fusion experiments with BC1-6738, from which 20 grew vigorously in the greenhouse and flowered. After pollination with several 4x potato cultivars. eight genotypes produced seeded berries and five genotypes gave seedless berries. In addition. Il of these 13 somatic hybrids were selected for genomic in situ hybridization (GISH) analysis to determine their genomic composition. Nine had exactly or approximately the expected number of 36 S. nigrum and 60 potato chromosomes. In one genotype. only 22 instead of 36 S. nigrum chromosomes were found acid one potato chromosome was possibly missing. Only five potential somatic hybrids were detected among the 79 regenerants from BC2-9017 (+) 2x potato Fusion experiments that were analysed by flow cytometry. Two of these hybrids were rather vigorous and did flower, but pollinations with potato have not yet yet any berries.