Development of TGMS lines for developing two-line rice hybrids for the tropics uri icon

abstract

  • A breeding program was initiated at the International Rice Research Institute (IRRI) in 1990 to develop thermosensitive genic male sterile (TGMS) rice lines for developing two-line rice hybrids for the tropics. The TGMS trait was transferred from a temperate japonica TGMS mutant, Norin PL 12, to indica and tropical japonica rice varieties using the pedigree selection procedure. Six new TGMS rice lines adapted to tropical conditions were developed which showed complete pollen and spikelet sterility when maximum temperature was higher than 30 degrees C 1-2 week after panicle initiation. However, up to 85.5% spikelet fertility was observed when these lines were exposed to 26-29 degrees C during the critical stage. Using two of these TGMS lines, some heterotic rice hybrids showing 1-1.6 t/ha higher grain yield than the inbred check varieties were identified in unreplicated observational yield trial conducted at IRRI. Two of the six two-line hybrids yielded significantly higher than the check variety in a replicated preliminary yield trial.

publication date

  • 2000
  • 2000