Allohexaploid, PTT03084

Abstract

Result showed that 12 lines were more resistant to brown planthopper than Suphanburi 1, the standard resistant variety. Yield trial and some agronomic characterization of these lines were conducted. Six of eleven lines of these polyploids rices showed non-significantly higher yield than Khao Dawk Mali 105, the standard variety. They were PTT03084-5, PTT03084-7, PTT 03084-8, PTT03084-9, PTT03084-10 and PTT03084-6 that produced 450, 411, 402, 401, 398 and 397 kg/rai, respectively, while Khao Dawk Mali 105 yielded 395 kg/rai. Physical and chemical properties of these lines showed the same quality as Khao Dawk Mali 105. Identification of molecular markers using AFLP and Cytogenetics study for polyploid rice, from interspecific hybridization between cultivated rice Khao Dawk Mali 105 and wild rice Oryza minuta GS. 8173 was conducted. Eight of ten primers was appeared the same banding, as to parents. Chromosome numbers of polyploid rice was examined through root tip. It was found that the chromosome numbers of this polyploid rice was 6X=72. In 2006 we conducted the intra-station yield trial at Pathumthani Rice Research Center and after that repeated testing for resistant to brown planthopper of the polyploids lines with Khao Dawk Mali 105 as standard variety and Pitsanulok 2 as resistant variety. The reactions of these lines showed moderately susceptible to this important insect dued to changing the source of insect population in the test.