Analysis of Asian Rice (Oryza sativa) Genotypes Reveals a New Source of Resistance to the Root-Knot Nematode Meloidogyne javanica and the Root-Lesion Nematode Pratylenchus zeae

Abstract

<jats:p> The sedentary root-knot nematodes, Meloidogyne spp., and the migratory root-lesion nematodes, Pratylenchus spp., cause significant yield losses, particularly in aerobic and upland rice production systems. Recently, the Asian rice Oryza sativa accessions LD 24 and Khao Pahk Maw (KPM) were shown to be highly resistant to M. graminicola. In this study, we have analyzed the responses and broadness of resistance of these two rice genotypes to another root-knot nematode M. javanica and a root-lesion nematode P. zeae. The penetration as well as post-penetration development and reproduction of nematodes were compared including known susceptible and resistant genotypes. Our results indicate that the genotype KPM confers strong resistance to both M. javanica and P. zeae, while LD 24 was resistant to M. javanica and susceptible to P. zeae. Detailed observations revealed that similar numbers of M. javanica or P. zeae penetrated the resistant and susceptible hosts during early infection stages. However, the development and reproduction of both nematodes were arrested or reduced in resistant genotypes, implying that resistance occurs at the post-penetration stage. </jats:p>

Salicylic Acid, Jasmonate, and Ethylene Contribute to Rice Defense Against White Tip Nematodes Aphelenchoides besseyi

“…The number of nematodes in Tetep were significantly lower at all the time points as well as in 100 grains compared with Nipponbare, which indicates that the resistance in Tetep may be associated with the reduced numbers of invasion, development, and reproduction of A. besseyi . The same resistance mechanisms were also observed in previous studies on cultivars resistant to other nematodes ( Linsell et al, 2014 ; Khanam et al, 2018 ; Lahari et al, 2020 ; Nzogela et al, 2020 ).…”

Evolutionary Systems Biology Identifies Genetic Trade-offs In Rice Defense Against Above- and Belowground Attackers

“…However, the effects of KSL8 can be overridden in the presence of the immune receptor MG1, which is segregating among tropical japonica, indica, and aus cultivars, but not temperate japonica cultivars (Dimkpa et al, 2016; Wang et al, 2023). This intracellular NLR immune receptor was previously shown to confer strong resistance to the RKNs M. graminicola and M. javanica upon recognition of nematode attack through a hypersensitive response (Lahari et al, 2020; Wang et al, 2023). We found that rice cultivars carrying MG1 are strongly resistant to M. incognita as well, with nearly zero galling in cultivars LD24 and Khao Pahk Maw (two-tailed t-test relative to cv.…”