Breeding for perennial growth and fertility in an Oryza sativa/O. longistaminata population uri icon

abstract

  • The development of perennial cultivars (CVs) of upland rice would give farmers a new tool to reduce soil erosion from hilly fields, thereby mitigating a problem of regional concern in Southeast Asia. Oryza longistaminata is an undomesticated, perennial, rhizomatous relative of domesticated Asian rice (Oryza sativa). Using five sets of 4 x 2 factorial mating designs, we crossed rhizomatous interspecific genotypes (lGs) from an interniated 0. sativaffi. longistandnata population with male-fertile IG selections from the intermated population, and with O. sativa CVs. Parents and progeny were planted in an upland field at IRRI using a randomized complete block design and evaluated for rhizome expression, survival after 1 year, vigor of the survivors, and yield. For the IG parents, rhizome expression was variable and penetrance of most genotypes was incomplete, but genotypes that demonstrated the potential for moderate rhizome expression had high penetrance (89% average). The CV parents yielded 11.0 g/plant on average but none produced rhizomes or survived I year. The IG parents averaged yields of 3.1 g/plant, 57% rhizonnatous and 36% survival. The IG/IG progeny averaged yields of 4.2 g/plant, 32% rhizomatous and 37% survival. The IG/CV progeny averaged yields of 6.0 g/plant, 18% rhizomatous and 16% survival. Nine IGAG progeny and six IG/CV progeny were rhizomatous, perennial, and yielded at least 5 g/plant, and five of these yielded more than 10 g/plant. For the IG parents and IG/IG progeny, rhizome presence and expression were positively associated with survival and vigor of the survivors. General combining ability effects were significant for percent survival and yield but not percent rhizomatous. Specific combining ability effects were significant for percent rhizomatous, percent survival and yield. By selecting female parents for long rhizomes and male parents for fertility, considerable gains in rhizome expression, survival and yield were made. The development of perennial upland rice CVs should be feasible via introgression of genes from O. longistaminata. (c) 2005 Elsevier B.V. All rights reserved.

publication date

  • 2006
  • 2006
  • 2006