Pyramiding of drought yield QTLs into a high quality Malaysian rice cultivar MRQ74 improves yield under reproductive stage drought.

Noraziyah Abd Aziz Shamsudin,Anitha K Raman,Ma Teressa Sta Cruz,Nitika Sandhu,Wickneswari Ratnam,Arvind Kumar,B P Mallikarjuna Swamy

doi:10.1186/s12284-016-0093-6

Noraziyah Abd Aziz Shamsudin, Anitha K Raman + Show 5 more

Open Access

https://doi.org/10.1186/s12284-016-0093-6

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Abstract

BackgroundWith the objective of improving the grain yield (GY) of the Malaysian high quality rice cultivar MRQ74 under reproductive stage drought stress (RS), three drought yield QTLs, viz. qDTY2.2, qDTY3.1, and qDTY12.1 were pyramided by marker assisted breeding (MAB). Foreground selection using QTL specific markers, recombinant selection using flanking markers, and background selections were performed in every generation. BC1F3 derived pyramided lines (PLs) with different combinations of qDTY2.2, qDTY3.1, and qDTY12.1 were evaluated under both RS and non-stress (NS) during the dry season (DS) of 2013 and 2014 at IRRI.ResultsThe GY reductions in RS trials compared to NS trials ranged from 79 to 99 %. Plant height (PH) was reduced and days to flowering (DTF) was delayed under RS. Eleven BC1F5 MRQ74 PLs with yield advantages of 1009 to 3473 kg ha−1 under RS and with yields equivalent to MRQ74 under NS trials were identified as promising drought tolerance PLs. Five best PLs, IR 98010-126-708-1-4, IR 98010-126-708-1-3, IR 98010-126-708-1-5, IR 99616-44-94-1-1, and IR 99616-44-94-1-2 with a yield advantage of more than 1000 kg ha−1 under RS and with yield potential equivalent to that of MRQ74 under NS were selected. The effect of three drought grain yield QTLs under RS in MRQ74 was validated. Under NS, PLs with two qDTY combinations (qDTY2.2 +qDTY12.1) performed better than PLs with other qDTY combinations, indicating the presence of a positive interaction between qDTY2.2 and qDTY12.1 in the MRQ74 background.ConclusionDrought tolerant MRQ74 PLs with a yield advantage of more than 1000 kg ha−1 under RS were developed. Differential yield advantages of different combinations of the qDTYs indicate a differential synergistic relationship among qDTYs.

Highlights

With the objective of improving the grain yield (GY) of the Malaysian high quality rice cultivar MRQ74 under reproductive stage drought stress (RS), three drought yield quantitative trait loci (QTLs), viz. qDTY2.2, qDTY3.1, and qDTY12.1 were pyramided by marker assisted breeding (MAB)
Selection of the donor and recipient parents Three drought yield QTLs (qDTYs) were pyramided by marker assisted QTL pyramiding into the high quality rice cultivar MRQ74 from Malaysia
Three drought-tolerant improved lines developed at International Rice Research Institute (IRRI), namely IR 84984-83-15-18-B, IR 7729814-1-2-10, and IR 81896-B-B-195 were used as donors for QTLs qDTY12.1, qDTY2.2, and qDTY3.1, respectively

Summary

Introduction

With the objective of improving the grain yield (GY) of the Malaysian high quality rice cultivar MRQ74 under reproductive stage drought stress (RS), three drought yield QTLs, viz. qDTY2.2, qDTY3.1, and qDTY12.1 were pyramided by marker assisted breeding (MAB). With the objective of improving the grain yield (GY) of the Malaysian high quality rice cultivar MRQ74 under reproductive stage drought stress (RS), three drought yield QTLs, viz. The expansion of rice growing areas and the adoption of high-yielding semi-dwarf varieties are important factors that contribute to increased rice production. Drought poses a threat in the need to increase the global production of rice by 70 % in the 35 years in order to meet the growing food demand (Cooper and Hammer 1996). Most of this increase has to come from rainfed lowland and upland rice ecosystems.

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