Field selection on several rice varieties for resistance to bacterial leaf blight strain IV and VIII

• Published in: Buletin Plasma Nutfah Vol. 17; no. 2
• Main Author: Silitonga T.S
• Format: Journal Article
• Language: English; Indonesian
• Published: 2011
• Subjects: Disease resistance; Oryza sativa; Selection; varieties; XANTHOMONAS ORYZAE
• ISSN: 1410-4377

Bacterial leaf blight (BLB) on rice (Oryza sativa) caused by Xanthomonas oryzae pv. oryzae (Xoo) is the major obstruction for rice production. Powerful strategy to control BLB is generally conducted by planting resistant plant. Meanwhile, the main way to explore germplasm as the source of resistance gene is conducted by selection a wide rice varieties. Field selection for resistance to BLB on 150 rice-varieties (BB-Biogen collection) was conducted in 2009 in Cianjur. Three leaves and flag leaves of individual hills at vegetative and flowering stage were inoculated by clipping the leaf tip with scissors which had been connected with a suspension bottle of bacterial cells (10 at the power of 9-10 at the power of 10 cells/ml) of the isolates which represented bacterial groups (strain) N and VIII, respectively. Each plant was inoculated with one race. Two weeks after inoculation, length of the lesion developed on the inoculated leaf was measured, as an index of severity of infection by BLB. This experiment was treated as factorial randomized completed block design (two factor-with 3 replications, respectively). The resistance reaction to strain IV and VIII was observed as the variable tested, while the factors measured consists of plant-varieties and two bacterial strains. The results showed that 11 varieties with a resistance-reaction to Xoo strain IV, in which 5 varieties poses a consistent resistance-reaction, i.e: Pulu Bolong, Pelopor, Gombal, Barito and Kapuas. While resistance-reaction to Xoo strain VIII obtained only one variety: IR42 (score-1), while 17 others showed intermediate resistance (score-3).