Genomic Assisted Breeding of Climate-smart Rice Inbred and Hybrid Varieties
Jauhar Ali, International Rice Research Institute, Los Banos, Philippines
Abstract: Climate change would have a significant impact on food security and livelihoods of millions of rice farmers especially in Asia in the coming decades. Rice production and productivity need to be sustained and secured under harsher climatic conditions across all ecosystems. There is an urgent need to develop multiple stress tolerant inbred and hybrid varieties by exploiting the existing genomic resources especially from the primary genetic pools. Hybrid rice is one of the most viable technologies that ensure >20% increased productivity over the conventional inbred varieties both under favorable and unfavorable conditions. Combining the genomics and breeding technologies innovatively helped us to breed several climate-smart inbred rice varieties and a considerable number of parental lines for their exploitation of heterosis. Development and targeted deployment of climate-smart rice inbred and hybrids that could withstand major abiotic (i.e., severe drought, salinity, and flooding tolerances) and biotic stresses (i.e., blast, bacterial leaf blight, Tungro, brown planthopper (BPH) green leafhopper) could provide a kind of crop insurance to resource-poor farmers in Asia. At IRRI, selective introgression breeding is carried out by carefully identifying separate donor pool of lines into elite restorer, and maintainer backgrounds are providing a series of parental lines within a short span of five years. Both the donor and recipient pools are the whole genome sequenced, and the derived introgression lines could be exploited for detection of QTLs and genes for different target traits. Further, these targeted traits could be stacked by designed QTL pyramiding across different donor alleles in a common recipient parental background. This strategy not only allows QTL detection of different target traits but also augments the release of inbred varieties besides getting them incorporated into the heterosis breeding program. Based on a multi-location and multi-year study, the newly developed climate-smart inbred lines gave higher yields than inbred check cultivars under different stress conditions. We also identified several abiotic stress tolerant CMS, restorer, and pollen parents for the development of climate-smart rice hybrids. By this approach, we were successful to identify several hybrids that have the potential of being climate smart rice hybrids. Increased production and productivity through wide-scale adoption of climate-smart rice varieties would undoubtedly allow many rice growing countries to secure their food.
Bio: Jauhar, a hybrid rice breeder, has significantly contributed to the development of and capacity-building for global agricultural research. He has developed and characterized eight thermo-sensitive genic male sterile (TGMS) rice lines, for which he was awarded the Jawaharlal Nehru Award for outstanding PhD thesis research work. This work led to the discovery of the genetics of the TGMS gene and to knowing that ‘tg’ genes (tms4, tms8) were unique and could be exploited. Using these materials led to the development of several TGMS-based hybrids involving different centers.
Currently, Jauhar has taken up two-line hybrid rice breeding at IRRI on a strong footing to deliver the two-line hybrid rice technology in Asia. In addition, he had been instrumental to the development of the Green Super Rice breeding technology at IRRI, being the project leader and regional coordinator of the Green Super Rice (GSR) Project in Asia and Eastern and Southern Africa. Through this innovative approach, he has developed and released 22 rice varieties in Asia and nominated nearly 75 GSR cultivars into national cooperative yield trials. He connects genomic resources and tools to breed superior, high-yielding, multiple-stress–tolerant rice varieties and hybrids. As lead and regional coordinator, Jauhar leads the development and targeting of improved rice materials through systematic testing, adaptive trials, and varietal release for eight countries in Asia and five in Eastern and Southern Africa. Forty-two GSR inbreds and 22 hybrids have been released, whereas 134 are nominated for national yield trials. Jauhar has also established the IRRI-GSR breeding front in 2009 and produced more than 530 promising multiple-stress–tolerant materials shared with NARES partners, INGER, and MET. He has published more than 75 peer reviewed publications. He has also provided training to more than 2,100 researchers, especially on hybrid rice technology, seed production, and molecular breeding.
