QTL mapping and introgression of yield-related traits from Oryza glumaepatula to cultivated rice (Oryza sativa) using microsatellite markers

Abstract

Rice ( Oryza sativa) cultivar development currently faces the task of overcoming yield plateaus, which is difficult due to the narrow genetic base of breeding programs. Oryza glumaepatula is a diploid wild relative of cultivated rice, native to Central and South America, and is therefore a potential source of alleles of agronomic importance to rice breeding programs. We studied 11 agronomic traits in BC(2)F(2) families of the interspecific cross Oryza sativa x O. glumaepatula. Transgressive lines which are almost isogenic to the elite recurrent O. sativa parent were identified for most of these traits. Quantitative trait locus (QTL) analysis was performed by single-point and interval mapping using a molecular map based on 157 microsatellite and STS markers. Marker regions accounting for 14.5 to 72.9% of a phenotypic variation trait were identified in 9 of the 12 rice chromosomes. Positive QTL effects from O. glumaepatula were observed in chromosomal regions associated with tillering and panicle-number traits.

Molecular Mapping of QTLs for Drought Related Traits at Seedling Stage under PEG Induced Stress Conditions in Rice

“…Though the landrace is agronomically unattractive, the results suggested to contribute favorable alleles for 65.86% of the QTLs, by enhancing the level of tolerance to drought through various seedling indices. These findings are in agreement with those of earlier workers many who had detected QTLs with trait value enhancing alleles in agronomically phenotypically inferior parental sources in rice [53][54][55]. McCouch and Doerge (1995) [56] have identified more than 50% of the QTLs for root morphology in the RIL population of the cross CO39/ Moroberekan and all the alleles that had positive effect were from Moroberekan, the japonica donor parent.…”

Yield QTL analysis of Oryza sativa x O. glumaepatula introgression lines

“…Transgressive segregants were previously reported in interspecific populations using O. glumaepatula as the donor parent (Brondani et al, 2002). The same fact was observed when other wild species of Oryza were used as recurrent parents, such as O. rufipogon and O. glaberrima (Bimpong et al, 2011).…”

“…However, some transgressive BC 2 F 2 families were observed, with higher number of tillers and panicles than that of cultivated parent Cica-8. Families showing transgressive segregation for the number of tillers and panicles were previously reported in interspecific populations derived from O. sativa BG90-2 x O. glumaepatula RS-16 cross (Brondani et al, 2002;Rangel et al, 2005). Panicle number and tiller number are important yield-related traits in rice, since they affect plant architecture, spikelet number, and biomass production (Peng et al, 1999).…”

“…It grows along riverbeds and margins or as isolated populations, in lowland conditions, far from the rivers (known as marshy valleys), in which case it has a behavior typical of weeds or colonizing plants (Brondani et al, 2001). Oryza glumaepatula has been extensively studied (Vaz et al, 2009), due to its close genetic relationship to cultivated rice and, especially, because it has the potential to successfully transfer favorable yield-related alleles, promoting positive increases in cultivated rice architecture and grain yield (Brondani et al, 2002;Rangel et al, 2005). Oryza glumaepatula has been used as allele donor to elite lines (O. sativa) from the Brazilian rice breeding program since 1996 (Brondani et al, 2001).…”

“…Furthermore, a limited genetic pool reduces the possibility of additional selection gain in breeding programs (Rangel et al, 1996). Wild relatives of rice comprise an important gene pool that can be used in breeding programs as a source of new genes and alleles of economically important traits, such as resistance to diseases, tolerance to environmental stresses, and yield (Brondani et al, 2002;McCouch et al, 2007;Swamy & Sarla, 2008;Bimpong et al, 2011).…”