Behavior of six rice varieties endowed with the rymv1-2 allele of resistance to rice yellow mottle in the irrigated rice ecology of Niger

Abstract

This study consisted of: (i) evaluating six varieties of irrigated rice, endowed with the resistance allele rymv1-2, under the agronomic conditions of Niger Republic, and by participatory varietal selection (PVS), (ii) identifying the preferred varieties of farmers, and (iii) determining the performance of improved lines. To achieve these objectives the improved varieties’ behavior towards the RYMV was first evaluated in the greenhouse and then their agronomic performance evaluations were conducted in multi-local trials. The results showed a biological diversity of Niger-RYMV, with the prevalence of a resistant breaking isolate (NG3) from the Toula perimeter. Five of the six improved varieties have good production potential and are adapted to the ecological and epidemiological conditions of the Niger Republic. Indeed, in addition to their high level of resistance to RYMV, the varieties ARC39-135-VL-5, ARC39-130-EP-4, ARC37-16-1-5-G, ARC39-145-E-P-3 and ARC 39-155-L-2 expressed the best agronomic characteristics with yields ranging between 6 and 9 T/ha vs 4 to 5 T/ha for the Kogoni 91-1 variety which is the most productive in the studied area. These high-potential varieties will help in the intensification of rice cultivation and rice yellow mottle disease control.