Rosa multiflora ‘Ludiek’, a rootstock with resistant features to the root lesion nematode Pratylenchus vulnus

Abstract

Rootstocks of Rosa spp. recently developed at the Department of Horticulture of the Agricultural University of Wageningen were screened for their reaction to the root lesion nematode Pratylenchus vulnus and compared with current rootstocks. The newly developed rootstock Rosa multiflora cultivar ‘Ludiek’ proved to be a poor host for the nematode. In two consecutive tests the final P. vulnus population levels were significantly smaller under ‘Ludiek’ than under the cultivars Rosa hybrida ‘Motrea’, ‘Flora Dale’, and ‘Moonlight’, Rosa chinensis ‘Indica Major’, Rosa multiflora ‘Multic’, Rosa canina ‘Inermis’ and Rosa helenae. Flower production of R. hybrida ‘Motrea’ was significantly reduced when this cultivar was grafted on R. multiflora ‘Multic’, R. canina ‘Inermis’ and R. helenae rootstocks growing in soil containing P. vulnus compared with control plants growing in nematode free soil. However, no significant reductions were observed in the length of the primary shoots of cuttings of ‘Ludiek’ or the number of flowers or length of flower stalks of R. hybrida ‘Motrea’ when this cultivar was grafted on ‘Ludiek’ rootstocks growing in P. vulnus infested soil. Therefore, it may be concluded that the rootstock ‘Ludiek’ is tolerant to P. vulnus. Three root diameter classes were studied in R. hybrida ‘Motrea’ and R. chinensis ‘Indica Major’ and most P. vulnus were found associated with roots with a diameter less than 0.5 mm.