Characterization of Resistance to Major Tropical Root-Knot Nematodes (Meloidogyne spp.) in Solanum sisymbriifolium

Abstract

Root-knot nematodes (Meloidogyne spp.) are important contributors to yield reduction in tomato. Though resistant cultivars to common species (Meloidogyne arenaria, M. incognita, and M. javanica) are available, they are not effective against other major species of root-knot nematodes. Cultivars or lines of Solanum sisymbriifolium were examined to assess the presence and level of resistance to five major species: M. arenaria race 1, M. incognita race 3, M. haplanaria, M. javanica, and M. enterolobii. Differences in S. sisymbriifolium response to the nematode infection were apparent when susceptibility or resistance was classified by the egg counts per gram fresh weight of root and the multiplication rate of the nematodes. The cultivar Diamond was highly susceptible, Quattro and White Star were susceptible, while Sis Syn II was resistant to M. arenaria. Quattro, White Star, and Sis Syn II exhibited a moderate to high level of resistance to M. incognita but the nematode increased 2.5-fold from the initial population of the M. incognita on Diamond. All S. sisymbriifolium cultivars were highly resistant to both M. haplanaria and M. enterolobii, while highly susceptible to M. javanica. A microplot study under field conditions using Sis Syn II confirmed that M. arenaria, M. incognita, and M. haplanaria were not pathogenic on the plant. Likewise, an examination on cross-sections of galled root tissues confirmed the susceptibility and resistance of S. sisymbriifolium lines to Meloidogyne spp. Using S. sisymbriifolium as a resistant rootstock or a new source of resistance may result in the development of nonchemical and sustainable management strategies to protect the tomato crop.

Differences in parasitism of root-knot nematodes (Meloidogyne spp.) on oilseed radish and oat

“…The absence of nematodes and giant cells in the resistant cultivars may be attributed to inhibition of juvenile development in the root tissues. In contrast, the root tissues of susceptible oilseed and oat cultivars had several hypertrophied and multinucleated cells due to root-knot nematode development ( Cabasan et al, 2014 ; Hajihassani et al, 2020 ). Giant cells serve as an important source of nutrients for nematode growth and reproduction.…”

“…Cross sections 4 to 5 μm thick were prepared using a rotary microtome (RM2125 RTS, Leica Biosystems, Nussloch, Germany), and then mounted on glass slides. The sections were stained with Hematoxylin-Eosin (HE), evaluated microscopically at 40 to 100 × magnifications (Olympus BX43, Olympus, Tokyo, Japan) and images captured using a digital camera (Olympus DP73, Olympus, Tokyo, Japan) ( Hajihassani et al, 2020 ).…”

“…Least-squares means (LS-means) t -tests demonstrating if the mean was significantly different from 0 were used to determine whether the nematode Rf was different from 1 (the base 10 algorithm of 1 is 0). Therefore, single t -tests that showed the treatment mean was significantly different from 0 indicated that the Rf deviated significantly from 1 ( Hajihassani et al, 2020 ).…”

Recent Advances in the Development of Environmentally Benign Treatments to Control Root-Knot Nematodes

“…and the presence of mixed populations of different RKN species in the field ( Trudgill and Blok, 2001 ; Xiang et al., 2018 ). The use of Meloidogyne -resistant cultivars has been an effective management tool for RKN; however, not many resistant cultivars are commercially available, and resistance may be overcome by new emerging RKN species such as M. enterolobii ( Xiang et al., 2018 ; Hajihassani et al., 2019b ).…”

Solanum linnaeanum and Solanum sisymbriifolium as a sustainable strategy for the management of Meloidogyne chitwoodi

“…The most effective, environmentally friendly, and economical means of controlling Meloidogyne spp. is the use of resistant cultivars 10 . However, up to now, there are no potato cultivars resistant to RKN 9 .…”