QTLs associated with root traits increase yield in upland rice when transferred through marker-assisted selection
Altering root morphology of rice (Oryza sativa L.) cultivars could improve yields in drought-prone upland ecosystems. Marker-assisted backcross breeding was used to introgress four QTLs for root traits into an upland rice cultivar. The QTLs had previously been identified under experimental conditions in a different genetic background. The introgressed lines and the recurrent parent were grown for 6 years by resource-poor farmers in upland sites in Eastern India and yields recorded. In combination the QTLs significantly increased yield by 1 t ha−1 under relatively favourable field conditions. In less favourable trials, the QTL effects were not detected due to greater heterogeneity in soil–water availability in very low yielding environments and consequent yield variability. Root studies under controlled conditions showed that lines with the introgressions had longer roots throughout tillering than the recurrent parent (14 cm longer 2 weeks after sowing). Therefore, both improved roots and increased yield can be attributed to the introgression of QTLs. This is the first demonstration that marker-assisted backcross breeding (MABC) to introgress multiple root QTLs identified under controlled conditions is an effective strategy to improve farmers’ yields of upland rice. The strategy was used to breed a novel upland rice cultivar that has been released in India as Birsa Vikas Dhan 111.
- Mandal NP, Sinha PK, Variar M, Shukla VD, Perraju P, Mehta A, Pathak AR, Dwivedi JL, Rathi SPS, Bhandarkar S, Singh BN, Singh DN, Panda S, Mishra NC, Singh YV, Pandya R, Singh MK, Sanger RBS, Bhatt JC, Sharma RK, Raman A, Kumar A, Atlin G (2010) Implications of genotype × input interactions in breeding superior genotypes for favorable and unfavorable rainfed upland environments. Field Crops Res 118:135–144CrossRefGoogle Scholar
- Pinheiro JC, Bates DM (2004) Mixed-effects models in S and S-PLUS. Springer Science and Business Media, New YorkGoogle Scholar
- R Development Core Team (2012) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org/
- Steele KA, Singh DN, Kumar, R, Prasad SC, Virk DS, Gangwar JS and Witcombe JR (2002) Combining molecular marker technology and participatory techniques: a case study for drought-tolerant rice in eastern India II: Farmer evaluation of SLS-MAS bulks in participatory plant breeding. In: Proceedings of a DFID Plant Sciences Research Programme/IRRI Conference in breeding rainfed rice for drought-prone environments: integrating conventional and participatory plant breeding in South and Southeast Asia. IRRI, Los Banos, Laguna, Philippines, 12–15 March 2002, pp 20–22Google Scholar
- Verulkar SB, Mandal NP, Dwivedi JL, Singh BN, Sinha PK, Mahato RN, Swain P, Dongre P, Payasi D, Singh ON, Bose LK, Robin S, Chandrababu R, Senthil S, Jain A, Shashidhar HE, Hittalmani S, Vera Cruz C, Paris T, Hijmans R, Raman A, Haefele S, Serraj R, Atlin G, Kumar A (2010) Breeding resilient and productive rice genotypes adapted to drought-prone rainfed ecosystems of India. Field Crops Res 117:197–208CrossRefGoogle Scholar
- Witcombe JR, Joshi KD, Virk DS, Sthapit BR (2011) Impact of introduction of modern varieties on crop diversity. In: Lenne JM, Wood D (eds) Agrobiodiversity management for food security—a critical review. CAB International, Wallingford, pp 87–90Google Scholar