Caracterização da nematofauna em vinhedos no sul do Brasil e resistência a Mesocriconema xenoplax (Nematoda: Criconematidae) em porta-enxertos

Abstract

Numerous biotic factors interfere with grapevine productivity and causing considerable damage, especially plant parasitic nematodes. Thus, our objectives were: (i) to carry out a survey of the nematode community associated with vineyards of Santa Catarina and grape nurseries of the Rio Grande do Sul; (ii) to characterize the species of Meloidogyne, Mesocriconema and Pratylenchus associated to vineyards and grape nurseries of Rio Grande do Sul and Santa Catarina; (iii) to evaluate the genetic resistance of rootstocks of Vitis spp. to Mesocriconema xenoplax. The survey in Santa Catarina was carried out in 12 vineyards, in which Helicotylenchus, Mesocriconema, Xiphinema, Hemicycliophora, Tylenchus, Pratylenchus and Meloidogyne were identified. In the vineyards of the Rio Grande do Sul, 5 species of Mesocriconema (M. xenoplax, Mesocriconema spp 07, M. curvatum, M. rusticum and M. sphaerocephala) were identified in Santa Catarina, 4 species of Mesocriconema (M. xenoplax, Mesocriconema spp 07, M. curvatum, M. rusticum) and one species of Meloidogyne, M. javanica (Est J3). In relation to the nurseries, the genera identified were Meloidogyne, Pratylenchus, Mesocriconema, Helicotylenchus, Tylenchus, Xiphinema, Hemicycliophora, Dorilaimus, Paratrichodorus, Hoplolaimus. Among the species of Meloidogyne, we identified M. arenaria (Est A2), M. javanica (Est J3 and J2), M. incognita (Est I2), M. luci (Est L3) and M. morocciensis (Est A3). To our knowledge, this is the first record of M. luci associated with grapevine roots in the Brazil and elsewhere. In relation to Mesocriconema species, M. xenoplax and M. ornatum were identified in these samples. In relation to Pratylenchus, only P. brachyurus and P. zeae were observed for us. In order to evaluate the resistance of Vitis to M. xenoplax, an experiment was conducted with 12 cultivars (Chardonnay, IAC 313, Paulsen 1103, Harmony, K5BB KOBER, Niagara Rosada, Isabel, Magnolia, Salt Creek, R99, Gravcesc and VCR04-43) and five replicates. The inoculation was done with 500 specimens (Pi) per plant and, after 155 days, the roots weight, leaf weight, total chlorophyll, final population (Pf) and reproduction factor (FR = Pf/Pi) were evaluated. Significant reductions in leaf weight were observed in the cultivars Chardonay, VCR0443 and R99 (P<0.05). Gravcesc, VCR0443 and K5BB Kober showed significant reductions in root weight (P <0.05). Regarding the resistance, there were high values for resistance on Magnolia (FR <1.0).