Inheritance of resistance to rice yellow mottle virus disease in selected rice cultivars in Uganda

Abstract: 
Rice yellow mottle sobemovirus (RYMV) has been identified as the most destructive viral disease in lowland and upland rice. In this study, the mode of inheritance of resistance to a prevalent RYMV strain in Uganda was determined for five resistant lines (upland NERICAs 8, 11, 12, 13 and Gigante (an O. sativa lowland variety). These resistant lines were crossed with four susceptible lines (lowland NERICAs 4, 6, 10 and IR64 (an O. sativa lowland variety)) in a full diallel mating design. Segregating F2 progeny were planted in both field and screenhouse in an α- lattice design, and inoculated by standard mechanical procedures. GCA effects were significant (P<0.001), and were larger than SCA effects. Both the field and screenhouse experiments strongly expressed genotype differences. GCA, SCA and reciprocal effects were significant (P<0.001) in both experiments. The narrow sense coefficient of genetic determination based on genotype means was relatively high in both screenhouse (76%) and field (84%) experiments. These results suggest that additive gene effects were more important than non-additive effects, and that selecting as early as F2 or F3 generations can be effective. However, reciprocal effects showing a consistent tendency of F2 progeny to reflect the resistance level of the female parent indicates the need for careful choice of male and female parents in hybridization programs to achieve RYMV resistance in the offspring.
Rice yellow mottle sobemovirus (RYMV) a été identifié comme la maladie virale la plus destructive du riz de plaine et de montagne. Dans cette étude, le mode de la transmission de la résistance à la contrainte de RYMV en Ouganda a été déterminé pour cinq lignées résistantes (NERICAs de montagne 8, 11, 12, 13 et Gigante, une variété de plaine ) croisées avec quatre lignées sensibles ( NERICAs de plaine 4, 6, 10 et et une variété de plaine O. sativa IR64) dans une complëte conception joignante de diallële. La progéniture F2 de séparation a été examinée en utilisant des procédures mécaniques standard d’inoculation dans le champ et d’observation avec des expériences conçues comme trellis-α. Les effets du GCA étaient significatifs (P<0.001) et hauts par rapport aux effets du SCA. L’expérience sur le terrain était plus favorable pour exprimer la performance du génotype comme démontré par un coefficient de variance experimentale C.V. bas et une erreur expérimentale. SCA et les effets réciproques étaient significatifs (P<0.001) dans l’expérience sur le terrain. L’héritabilité étroite était significative (P <0.001) dans des expériences d’observation (76%) et sur terrain (84%). Ces résultats suggèrent que les effets additifs de gène aient été plus importants et un sélectionneur puisse accomplir le progrès par le choix dans la génération F2 ou F3. Les effets réciproques significatifs suggèrent le besoin pour des choix appropriés des parents mâle et femelle dans des programmes d’hybridation pour la résistance de RYMV impliquant ces cultivars.
Language: 
Date of publication: 
2010
Country: 
Region Focus: 
East Africa
University/affiliation: 
Collection: 
RUFORUM Conferences and Workshops
Licence conditions: 
Open Access
Access restriction: 
Form: 
Printed resource
Publisher: 
Extent: 
469-474
Notes: 

About the RUFORUM 2010 Biennal Conference
"The 2010 RUFORUM Biennial Conference was the second in the series. The main objective of the Biennial conferences is to provide a platform for agricultural research for development stakeholders in Africa and beyond to actively exchange findings and experiences, while at the same time learning lessons towards improving performance of the agricultural sector and ultimately people’s livelihoods. The biennial conference is RUFORUM’s most comprehensive meeting for the diversity of stakeholders in agriculture. It is especially dedicated to graduate students and their supervisors, grantees in RUFORUM member universities and alumni. It is a platform for peer review, quality control, mentorship, networking and shared learning. This record contains an extended abstract accepted under the theme of Plant Breeding"