Mechanisms of <i>Oryza sativa</i> (Poaceae) resistance to <i>Tagosodes orizicolus</i> (Homoptera: Delphacidae) under greenhouse condition in Venezuela

Abstract

Abstract:Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundación Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundación Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata. Rev. Biol. Trop. 60 (1): 105-117. Epub 2012 March 01.

Micromorfología de la epidermis foliar de cultivares de arroz Venezolano (Poaceae) asociado con el daño mecánico de sogata Tagosodes orizicolus (Homoptera: Delphacidae)

“…El arroz (Oryza sativa L.) además de ser considerado el segundo cereal de mayor producción y consumo a nivel mundial, después del trigo, constituye la fuente alimenticia de mayor importancia por la superficie cultivada, incorporación de la población activa y aportes nutricionales (González et al, 2012). En Venezuela, el arroz constituye uno de los cereales más importantes en la dieta de los venezolanos y su cultivo es de gran importancia económica en las principales zonas agrícolas del país.…”