Rice Breeding Strategies in the Philippines

Rice is a major staple in the Philippines. The major goal of the rice sector in the country is to increase its productivity to meet the ever growing demand for rice. Breeding is one of the potential solutions to achieve rice self-sufficiency in the country. Rice variety development is led by research institutions such as PhilRice, IRRI, UPLB, and private companies and each adapts various breeding strategies. Rice variety normally takes 10-12 years of a journey from breeding to release and more than 300 varieties have been developed and released that were suited for various rice ecosystems. Sufficient varieties were available for production and this led to continuous in rice production for the past decade. However, yield increment has plateaued. To meet the increasing demand for rice, achieve self-sufficiency, and particularly, break the yield barrier (plateau) and achieve a leap in yield potential, breeding institutions particularly PhilRice should embrace new advances and technologies in rice breeding. The introduction of the concept of transforming breeding into a “factory line” type encouraging rapid generation advance, earlier multi-location trials, and increasing selection pressure, and employing genomic selection (GS) in handling a large quantity of materials/populations can improve breeding efficiency and outputs significantly

Molecular dissection of connected rice populations revealed important genomic regions for agronomic and biofortification traits

Breeding staple crops with increased micronutrient concentration is a sustainable approach to address micronutrient malnutrition. We carried out Multi-Cross QTL analysis and Inclusive Composite Interval Mapping for 11 agronomic, yield and biofortification traits using four connected RILs populations of rice. Overall, MC-156 QTLs were detected for agronomic (115) and biofortification (41) traits, which were higher in number but smaller in effects compared to single population analysis. The MC-QTL analysis was able to detect important QTLs viz: qZn5.2, qFe7.1, qGY10.1, qDF7.1, qPH1.1, qNT4.1, qPT4.1, qPL1.2, qTGW5.1, qGL3.1, and qGW6.1, which can be used in rice genomics assisted breeding. A major QTL (qZn5.2) for grain Zn concentration has been detected on chromosome 5 that accounted for 13% of R2. In all, 26 QTL clusters were identified on different chromosomes. qPH6.1 epistatically interacted with qZn5.1 and qGY6.2. Most of QTLs were co-located with functionally related candidate genes indicating the accuracy of QTL mapping. The genomic region of qZn5.2 was co-located with putative genes such as OsZIP5, OsZIP9, and LOC_OS05G40490 that are involved in Zn uptake. These genes included polymorphic functional SNPs, and their promoter regions were enriched with cis-regulatory elements involved in plant growth and development, and biotic and abiotic stress tolerance. Major effect QTL identified for biofortification and agronomic traits can be utilized in breeding for Zn biofortified rice varieties