Breeding for drought resistance in West Africa upland and hydromorphic rice germplasm (Poster IX 7)

Jones Monty P., Audebert Alain. 1995. Breeding for drought resistance in West Africa upland and hydromorphic rice germplasm (Poster IX 7). In : Interdrought = [Intersécheresse]. Belhassen E., Schlicht F., Cuellar T., Lewicki S. Montpellier : INRA, Résumé, 1 p. InterDrought I. 1, Montpellier, France, 31 Août 1995/2 Septembre 1995.

Autre titre : Améliorer la résistance à la sécheresse dans le germplasm de riz d'altitude hydromorphe d'Afrique de l'Ouest

Résumé : Le riz cultivé en altitude et en conditions hydromorphiques en Afrique de l'Ouest est soumis à diverses périodes et intensités de sécheresse, responsable de perte de rendement. Une stratégie d'amélioration variétale pour la résistance à la sécheresse est développée par l'Association pour le Développement du Riz en Afrique de l'Ouest. La sélection récurrente est utilisée pour élever le niveau de résistance dans le germplasm de Oryza sativa et de O. glaberrima identifié comme tolérant. Des croisements entre ces 2 espèces ont pu être réalisés de façon satisfaisante. La culture d'anthères des F1 et F2 de ces croisements interspécifiques améliore le niveau de fertilité et accélère l'obtention de lignées homozygotes. Ces descendances montrent une certaine résistance aux stades végétatif et reproductif

Résumé (autre langue) : Rice grown in upland and hydromorphic conditions in West Africa can be subjected to varying degrees and durations of drought stress during the crop cycle causing yield reduction and sometimes total crop failure. Breeding for drought resistance in upland and hydromorphic rice germplasm is, therefore, a major activity at the West Africa Rice Development association (WARDA). WARDA's breeding strategy emphasizes the need to understand the mechanisms of drought resistance and studies in drought resistance were initiated in 1991. A methodology to screen for resistance to drought involving escape, avoidance and recovery mechanisms has been developed by WARDA and is being used to screen existing germplasm. A wide diversity of drought resistance and of other agronomic traits was observed in O.sativa and O.glaberrima germplasm. This provides a broad genetic base for the drought resistance studies. Varieties with high to moderate resistance from 0, sativa and O.glaberrima origin have been identified and are being utilized in the breeding program. Recurrent selection to upgrade the levels of drought and blast resistance in upland and hydromorphic rice varieties has been implemented and several promising selections have already been made from the inter-breeding populations. Considerable success has been made in the wide crossing program between O.sativa and O.glaberrima where backcrossing and embryo fescue has reduced spikelet sterility in the subsequent progenies. Anther culture of Fl and F2 progenies from the wide crossing program is also showing success in reducing sterility and in attaining rapid homozygous lines. These progenies are showing resistance at both vegetative and reproductive stages of growth, For example, there was a significant correlation between resistance scores after 21 days of moisture stress at the reproductive stage, and seedling vigor (r = 0.22, P < 001) at 30 days of moisture stress in the vegetative stage; and a highly negative correlation (r = - 0.391, P < O.OOl)between resistance in the reproductive stage and leaf-rolling ability.

Mots-clés Agrovoc : Oryza sativa, Oryza glaberrima, germoplasme, résistance à la sécheresse, riz pluvial, sélection récurrente, haplométhode, hybridation interspécifique

Mots-clés géographiques Agrovoc : Afrique occidentale

Classification Agris : F30 - Génétique et amélioration des plantes

Auteurs et affiliations

• Jones Monty P.
• Audebert Alain ORCID: 0000-0002-5822-7166

Source : Cirad - Agritrop (https://agritrop.cirad.fr/387716/)

Métriques

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