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

Negin Hamidi,Abolfazl Hajihassani

doi:10.21307/jofnem-2020-043

Abstract

Oilseed radish and oat are cool season annual crops that are potentially used as “trap” or “biofumigant” crops for the suppression of plant-parasitic nematodes in soil. Cultivars of oilseed radish (Carwoodi, Cardinal, Final, Image, Concorde, Control, Eco-Till, Karakter and Cannavaro), white (Tachiibuki) and black (Pratex) oats were evaluated for their ability to reduce reproduction of three root-knot nematode species: Meloidogyne javanica, M. incognita race 3, and M. arenaria race 1. Nematode penetration and development were also evaluated using selected resistant and susceptible cultivars under greenhouse conditions. Root galling severity, number of eggs per gram of fresh root, and rate of reproduction varied among the cultivars in response to nematode infection. Oilseed radish cv. Carwoodi was resistant to M. javanica, whereas Karakter and Concorde were maintenance hosts allowing the nematode to maintain or increase its population on the plants. For M. incognita, Control and Carwoodi oilseed radish and Tachiibuki oat were resistant hosts. The cultivars that supported little reproduction of M. arenaria were Karakter and Carwoodi radish, and Tachiibuki oat. Comparable numbers of nematodes entered the roots of susceptible and resistant cultivars of oilseed radish and oat during early stages of infection. However, the development of the nematodes as evident from counting young and egg-laying females in roots were significantly decreased or inhibited in the resistant cultivars compared to the susceptible cultivars indicating that resistance occurs at post-infection stages. Histopathological examinations of galled-root tissues also revealed the susceptibility and resistance responses of selected cultivars of oilseed radish and oat to these nematode species.

Highlights

Oilseed radish and oat are cool season annual crops that are potentially used as “trap” or “biofumigant” crops for the suppression of plantparasitic nematodes in soil
Root galling severity on the oilseed radish and oat cultivars was in the range of 1.4 (Carwoodi oilseed radish) to 3.7 (Cannavaro radish) for M. javanica, 0.4 (Carwoodi) to 2.7 (Image radish and Pratex oat) for M. incognita, and 0.3 (Tachiibuki oat) to 3.3 (Eco-Till and Final) for M. arenaria
All three nematode species reproduced more on tomato than on the oat cultivars and most of the oilseed radish cultivars (Table 1)

Summary

Introduction

Oilseed radish and oat are cool season annual crops that are potentially used as “trap” or “biofumigant” crops for the suppression of plantparasitic nematodes in soil. Cultivars of oilseed radish (Carwoodi, Cardinal, Final, Image, Concorde, Control, Eco-Till, Karakter and Cannavaro), white (Tachiibuki) and black (Pratex) oats were evaluated for their ability to reduce reproduction of three root-knot nematode species: Meloidogyne javanica, M. incognita race 3, and M. arenaria race 1. Comparable numbers of nematodes entered the roots of susceptible and resistant cultivars of oilseed radish and oat during early stages of infection. Oleiformis), white (Avena staiva) and black oat (Avena strigosa) are cool season annual crops that can be grown in the fall and harvested in the spring in regions with mild winter temperatures These plant species are considered as potential “trap” or “biofumigant” crops for suppressing nematode populations in soil in an integrated program to lessen the use of fumigant nematicides. To avoid this, oilseed radish and oats cultivars that are resistant should be identified

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