Securing Food through Climate-Resilient Rice Varieties for Asia and Africa

Research efforts to cope with the climate change are currently being integrated into several national agricultural research programs globally. We highlight here the successful development of the climate resilient rice varieties and their deployment in the most vulnerable areas. We developed and distributed more than 240 multiple abiotic and biotic stress tolerant rice materials to Asia and Africa without compromising on grain yield and quality. Released 20 IRRI bred climate resilient materials and nominated 70 such cultivars into national cooperative yield trials within a short span of 7 years period. These varieties are now being cultivated to more than 2 million ha on a cumulative basis in Asia and Africa. BC₁F₂ populations derived from Huanghuazhan (HHZ), WTR1, TME80518 (recipient parents) and 16 donors at IRRI were screened simultaneously over three rounds for different abiotic and biotic stresses and normal irrigated condition that resulted in identification of 1333 (HHZ-ILs) + 2232 (WTR1-ILs) + 1408 (TME80518-ILs) trait specific introgression (ILs) and further by designed QTL pyramiding efforts developed 1280 HHZ-PDLs +850(WTR1-PDLs) pyramiding (PDLs) that were superior over tolerant checks respectively. QTLs governing complex traits (drought, salinity, cold) were identified by genome sequencing 495 ILs in HHZ background and tGBS for 575 ILs in WTR1 background. Newly developed three-yield barrier breaking and multiple stresses tolerant materials (GSR IR2-8-Y14-SU3-R2, GSR IR2-5-L10-Y1-Y2, and GSR IR2-1-R5-N1-Y3) are now being shared, which gave an average of 5.9% and 18.3% higher grain yield over the best hybrid check Mestiso 6 and NSIC Rc38 under MET respectively. Such high yielding materials would further augment the ongoing hybrid rice breeding program at IRRI by using them as parental lines. Success may be attributed to an innovative introgression breeding and designed QTL pyramiding efforts combined with appropriate cross-tolerance screening and selection techniques that tapped the hidden genetic diversity from a large number of donors into an adaptable varietal backgrounds like HHZ, WTR1 and TME80518.