Pathogenicity of the root-lesion nematode, Pratylenchus zeae, on rice genotypes under different hydro-ecologies in Tanzania

Abstract

Summary The root-lesion nematode, Pratylenchus zeae, is commonly found in upland rice fields. To measure the impact of the nematode on rice production, a screenhouse experiment was conducted using two farmer-adapted Oryza sativa cultivars, ‘Supa’ (‘SurinamV-880’) and ‘SARO-5’ (‘TXD 306’), under flooded, upland and drought water regimes imposed at 7 days post-inoculation of mixed-stage nematodes (200, 500, 1000, 3000 and 10 000 plant−1). Growth and yield parameters were recorded, and the experiment was terminated after 5 months. ‘Supa’ was shown to be resistant to P. zeae, while ‘SARO-5’ was susceptible. Pratylenchus zeae reduced the growth and yield of both cultivars, though more for ‘SARO-5’ than for ‘Supa’. Yield decreased with increasing final nematode densities. Pratylenchus zeae reproduction was highest at 200 and 500 inoculum levels and under upland water conditions. The yield of ‘SARO-5’ was greater than that of ‘Supa’ under flooded conditions and with no or 200 and 500 nematode inoculum levels, but with high P. zeae inoculum ‘Supa’ yield was better than ‘SARO-5’.

Population dynamics of Meloidogyne graminicola in soil in different types of direct-seeded rice agroecosystems in Hunan Province, China

“…The results of our pot experiment were consistent with those of the paddy field investigation, both of which prove that field water is closely related to the reproduction of nematodes and that low soil moisture is conducive to the reproduction of nematodes. The importance of the water regime to nematodes has also been illustrated in several other reports ( Cabasan et al, 2017 ; Nzogela et al, 2019 ; Soriano et al, 2000 ; Win et al, 2013 ). Previous studies have reported that nematodes of M. graminicola lay eggs inside the root cortex, and hatched J2 can be released into the soil or remain within the gall to migrate and reinfect the same or adjacent roots by establishing new feeding sites ( Mattos et al, 2019 ; Kyndt et al, 2012 ; Rao and Israel, 1973 ).…”

Responses of nematode abundances to increased and reduced rainfall under field conditions: A meta‐analysis

“…Soil nematodes are semiaquatic animals that rely on water films or water-filled soil pores for movement; hence, changes in water availability are likely to affect their activity in the short term and nematode abundances and community composition in the longer term (Nzogela et al, 2020). A recent global survey of nematode trophic groups showed that nematode abundances are positively correlated with mean annual precipitation, at least when other factors, such as soil carbon (C) and nutrients, are not limiting abundances (van den Hoogen et al, 2019).…”

Molecular identification of root-lesion nematodes, Pratylenchus spp. in agricultural crops from Costa Rica

“…The results from this research could have implications for nematode management because both crops are common in Guanacaste. Therefore, the presence of this crops permits the reproduction and survival of the nematode species and might reduce the positive impact of the sugar cane/rice rotation system (Nzogela et al, 2020;Santos et al, 2012). P. zeae has been associated with significant yield reduction in sugarcane and rice crops (Namu et al, 2018;Nzogela et al, 2020;Singh et al, 2020).…”

“…Therefore, the presence of this crops permits the reproduction and survival of the nematode species and might reduce the positive impact of the sugar cane/rice rotation system (Nzogela et al, 2020;Santos et al, 2012). P. zeae has been associated with significant yield reduction in sugarcane and rice crops (Namu et al, 2018;Nzogela et al, 2020;Singh et al, 2020). The genetic heterogeneity shown within the P. zeae populations from Costa Rica is consistent with previous reports (Carta et al, 2001;Mwamula et al, 2020;Subbotin et al, 2008), and supports that P. zeae could be a species complex.…”