What question did this study set out to answer?

The aim is to identify rice lines with high paddy yield that also show tolerance or resistance to rice yellow mottle virus and iron toxicity.

June 1, 2026Open Access

Rainfed-lowland Rice (Oryza sativa) in Côte d’Ivoire: Eight Promising Lines Selected for High Paddy Yield and Resistance or Tolerance to Rice Yellow Mottle Virus and Iron Toxicity

KMKaridioula L Cl ment NGNoumouha EN Ghislain OAOUATTARA AdamaCentre National de Recherche Agronomique

Key Points

The aim is to identify rice lines with high paddy yield that also show tolerance or resistance to rice yellow mottle virus and iron toxicity.
Evaluated 44 African rice lines under field conditions and controlled greenhouse settings.
Utilized mixed models for trait analysis and Best Linear Unbiased Predictions (BLUPs) for deriving selection indices.
Conducted Principal Component Analysis (PCA) and hierarchical clustering for genotype grouping.
18% of the lines showed partial resistance to RYMV; 66% were tolerant and 95% moderately tolerant to iron toxicity.
Selected lines achieved yield advantages of 16-33% over the control line WITA 9, with production rates of 2.18-2.69 t/ha.
Eight elite lines were identified for their combination of tolerance and superior selection index values, enhancing breeding potential.

Abstract

Rainfed lowland rice productivity in Côte d'Ivoire is severely constrained by iron toxicity and Rice Yellow Mottle Virus (RYMV).This study aimed to identify high-performing lines combining high paddy yield with tolerance or resistance to both stresses.Forty-four African rice lines were evaluated through field screening under an iron toxicity hotspot, greenhouse RYMV screening and yield trials in an alpha-lattice (5 × 9) with three replications.Agro-morphological traits were analyzed using mixed models, and selection indices were derived from Best Linear Unbiased Predictions (BLUPs) weighted by breeding objectives.Results indicated 18% of lines were partially resistant to RYMV, 66% tolerant and 95% moderately tolerant to iron toxicity.Principal Component Analysis (PCA) and hierarchical clustering grouped genotypes into three clusters, with the high-yielding cluster showing substantial variability in yield components, facilitating multi-trait selection.Four lines (ART1475-B-B-B-1-3-1, ART311-B-78-1-7, ART1555-B-B-4-4 and ART1555-B-B-24-4) met breeding objectives, achieving 16-33% higher yields than WITA 9 and desirable phenological and morphological traits.Eight elite lines (ART1475-B-B-B-1-3-1, ART1567-B-B-2-4, ART1553-B-B-3-4, ART1553-B-B-12-4, ART1555-B-B-24-4, ART1555-B-B-4-4, ART311-B-78-1-7 and ART1544-B-B-12-4) combining superior selection index values with tolerance to both stresses produced 2.18-2.69t ha -1 (7-33% yield advantage).The four selected lines will be advanced for on-farm validation, while the eight top-performing lines, identified based on the selection index, will be utilized in breeding programs to enhance stress tolerance and yield potential of locally adapted rice varieties.

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