Accelerating the development of new submergence tolerant rice varieties: the case of Ciherang-Sub1 and PSB Rc18-Sub1
Submergence is an escalating problem in many rice producing areas. A submergence tolerance gene, SUB1, derived from FR13A was previously introduced into six mega varieties through marker assisted backcrossing (MABC) with the final product selected at the BC2 or BC3 generation. Their phenotype was similar to the original varieties, but they could withstand complete inundation for up to 2 or 3 weeks. Several of these varieties have been released in South and Southeast Asia; nonetheless the development of additional submergence tolerant varieties is indispensable to provide farmers with diverse choices of varieties that are preferable for the local needs and to avoid ecological vulnerability due to planting only one variety across vast areas. To accelerate this effort, the SUB1 gene has now been introgressed into two new popular varieties from Indonesia and the Philippines, i.e. Ciherang and PSB Rc18, respectively, through MABC using only one backcross (BC1) with the previously developed IR64-Sub1 as the donor. Since this new donor is closely related to both recurrent parents, a more rapid MABC approach can be pursued due to the similarity of genetic backgrounds. Using this strategy, new submergence tolerant varieties Ciherang-Sub1 and PSB Rc18-Sub1 were developed in less than 2 years, presenting a promising approach to convert additional popular varieties in the future.
KeywordsRice (Oryza sativa) Submergence tolerance SUB1 One backcross strategy Ciherang-Sub1 PSB Rc18-Sub1
We thank J. Mendoza, E. Suiton, J. Borgonia, R. Formaran, G. Perez, R. Garcia, and N. Ramos from IRRI and S. D. Indrasari from Grain Quality Laboratory at ICRR for technical assistance. The work reported here was supported in part by a grant from the Japan Ministry of Foreign Affairs (MoFA) and the Global Rice Science Partnership (GRiSP). The work conducted in ICRR was supported by the ICRR budget implementation list (DIPA).
Conflict of interest
We declare that there is no conflict of interest.
- Iftekharuddaula KM, Newaz MA, Salam MA, Ahmed HU, Mahbub MAA, Septiningsih EM, Collard BCY, Sanchez DL, Pamplona AM, Mackill DJ (2011) Rapid and high-precision marker assisted backcrossing to introgress the SUB1 QTL into BR11, the rainfed lowland rice mega variety of Bangladesh. Euphytica 178:83–97CrossRefGoogle Scholar
- Juliano BO, Villareal CP (1993) Grain quality evaluation of world rices. International Rice Research Institute (IRRI), Manila, p 99Google Scholar
- Mackill DJ, Ismail AM, Singh US, Labios RV, Paris TR (2012) Development and rapid adoption of submergence-tolerant (Sub1) rice varieties. Adv Agron 115:303–356Google Scholar
- Septiningsih EM, Collard BCY, Heuer S, Bailey-Serres J, Ismail AM, Mackill DJ (2013) Applying genomics tools for breeding submergence tolerance in rice. In: Varshney RK, Tuberosa R (eds) Translational genomics for crop breeding: improvement for abiotic stress, quality and yield improvement, vol 2. Wiley-Blackwell, USA, pp 9–30CrossRefGoogle Scholar
- Singh S, Mackill DJ, Ismail AM (2014) Physiological bases of tolerance to complete submergence in rice involves other genetic factors in addition to SUB1. Ann Bot (in press)Google Scholar
- Zheng K, Subudhi PK, Domingo J, Magpantay G, Huang N (1995) Rapid DNA isolation for marker assisted selection in rice breeding. Rice Genet News 12:255–258Google Scholar