Browsing by Author "Pacheco Atariguana, Luis Daniel"

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    Capacidad hospedante de tres especies de solanáceas de la sección lasiocarpa al nematodo agallador de la raíz meloidogyne incognita
    (2023) Díaz Granda, Lourdes Elizabeth
    Root knot nematode M. incognita is one of the most dangerous and common species affecting Solanaceae family, including the naranjilla crop (S. quitoense). The objective of this work was to evaluate three species of Solanaceas as hosts (S. sessiliflorum, S. hirtum and S. quitoense) for an isolated of M. incognita in greenhouse. Plants of three species were planted in pots and each plant was inoculated with 2500 eggs and second stage juveniles (J2). Host suitability was assessed 80 days after inoculation. Initial inoculum was obtained from infested roots of S. quitoense plants collected in commercial naranjilla orchards. A completely randomized experimental design was used. The variables evaluated at 80 days after inoculation were: gall index (GI), nematode reproduction factor (RF), dry weight of the foliar area, plant height and stem diameter. All species were galled, but S. sessiliflorum and S. hirtum showed the least number of root knots with values of 33.73 and 34.73. Both were classified as resistant / hypersensitive with reproduction factors of 0.94 and 0.85 (RF> 1) respectively, while S. quitoense was susceptible with a value of 1.56. In terms of foliage yield (dry weight), plant height and stem diameter, S. sessiliflorum and S. hirtum showed a tolerance response in relation to S. quitoense.
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    “Determinación de la resistencia a Meloidogyne incognita, en tres especies de la sección Lasiocarpa: Solanum quitoense, Solanum hirtum y Solanum sp.”
    (2019-09-06) Pacheco Atariguana, Luis Daniel; Castro Quezada, Patricio Salvador
    The naranjilla crop has a great potential in Ecuador, due to its excellent organoleptic characteristics. Nevertheless, the crop has a high susceptibility to attack of nematode Meloydogyne incognita, sometimes occasioning the total loss of crop. This research was carried out under greenhouse and the objectives were: determine the resistance to Meloidogyne incognita, in three species of the Lasiocarpa section: S. quitoense, S. hirtum and Solanum sp; and, find RGAs and SSR molecular markers associated with resistance. For phenotypic analysis, a completely randomized design with five repetitions was used, and for molecular analysis the polymorphism based on absence or presence of amplification products was considered. Nematode inoculum was extracted from roots infected with naranjilla. For molecular analyzes, we used RGAs and SSR primers defined on homology regions for crop resistance genes previously identified. We found that for variables: accumulated biomass, population increase, incidence, index of knotty and severity, results showed highly significant differences between S. hirtum and Solanum sp. with respect to susceptible specie (S. quitoense) at 80 days of evaluation. Regarding the molecular markers, we found two pairs of primers that amplified in S. hirtum and S. quitoense: an RGA defined on an LRR domain and an SSR defined in pepper. No amplifications were obtained in Solanum sp. Furthermore, these primers were found to be polymorphic in the segregating population between S. quitoense and S. hirtum.