Sources of root-knot nematode (Meloidogyne enterolobii) resistance in sweetpotato genotypes

Abstract

The root-knot nematode (RKN) Meloidogyne enterolobii is gaining importance all around the world, including Brazil, damaging sweetpotato genotypes with known resistance to other RKN species, making it challenging to generate new resistant genes. This study aimed to assess the levels of resistance of 10 advanced sweetpotato cultivars to this nematode species. Two experiments were carried out in 2018/2019 and 2021/2022 seasons, under greenhouse conditions in Brasília-DF, Brazil. A completely randomized block design with six replicates of one plant/plot/treatment was used. The gall index (GI) and egg mass index (EMI) in the root system of each plant, the number of eggs and juveniles per gram of root with galls (NERG), and the nematode reproduction factor (RF) were determined. M. enterolobii resistance is present within three of the evaluated clones: BGBD 1399, MD 1609024, and MD 1610036, therefore demonstrating their potential as sources of resistance genes to assist breeding efforts to release cultivars, and help to reduce the impact and spread of this RKN.

Growth, Physiological, and Biochemical Variations in Tomatoes after Infection with Different Density Levels of Meloidogyne enterolobii

“…According to Collettetal et al [ 4 ], the impacts of M. enterolobii might manifest as a reduction in both the quality and quantity of crops. The observable symptoms occurring above ground level include stunted growth, chlorosis, and wilting [ 5 ]. Conversely, below ground level, notable symptoms manifest as galls on the root system, which may exhibit significant size and abundance [ 6 ].…”