Responses of Rice Mini-Core Collection Accessions to Damage by <i>Diatraea saccharalis (Fabricius)</i> Stem Borer

Abstract

This st udy aimed to observe the response of 32 rice accessions to attack of sugarcane borer ( Diatraea saccharalis Fabr., 1794). Twenty larvae were placed on the leaf sheaths of rice plants. At 30 days after infestation, the rice plants were cut at ground level and taken to the laboratory to analyse the signs o f b orer attack, external and internal diameter of the stem and weight of surviving larvae. The results of the morphological traits of the rice plant, response of the plant to insect attack and development of the sugarcane borer larvae indicated a genotypic variation. The accessions that most favored larval survivals were IRAT 124 and MEARIN. Larvae with highest weight (0.0643 g) were found in IAPAR L 99-98 and the largest internal diameters of the rice stem (5.65 mm) were found in LAC 12. These accessions (IRAT 124, MEARIN, IAPAR L 99-98 and LAC 12) remained morphologically grouped with IAC 47, cultivar susceptible to sugarcane borer. The most tolerant materials based on the ability to produce new tillers after larval infestatio n were BR IRGA 417 and MTU 15. The results of this study indicate that all the morphological traits were able to separate the accessions of rice into different groups in relation to resistance to the sugarca ne borer D. saccharalis. These materials can be used as donor sources in pre-breeding for genetic resistance to sugarcane borers.