Molecular Characterization and Genetic Analysis of Nutritional Components of Philippine Indigenous Pigmented Rice Germplasm

Rice is a staple food for more than half of the world's population, with more than 90% of rice being consumed in Asia. Pigmented rice, such as black and red rice is traditionally used for food for special occasion. The consumption of pigmented rice is rapidly growing along with the increasing interest in health-promoting functional food. Pigmented rice contains high level of phytochemicals such as anthocyanin, flavonoids and vitamin E. Antioxidant activity of these phytochemicals helps to scavenge radical oxygen species (ROS) in human cell, thus decrease the risk of degenerative diseases such as cancer, high cholesterol and cardiovascular disease. Since the price of pigmented rice is more than twice that of white rice and the potential of pigmented rice in international market is large, growing pigmented rice as an alternative to or together with white rice will give higher income for Philippines farmers.

Currently, the Genetic Resources Division of the Philippine Rice Research Institute (PhilRice) has more than 800 accessions of pigmented rice collected from various regions of the Philippines. These rice accessions may have nutritional and therapeutic components that can be utilized in the breeding and development of new varieties of pigmented rice, but their potentials has not yet been explored.

Through this project the Philippine Rice Research Institute (PhilRice), the National Institute of Agricultural Botany (NIAB) and the International Rice research Institute (IRRI) will collaborate to screen and characterize Philippine indigenous pigmented rice germplasm to discover those pigmented rice accessions that can be utilized as new donors for pigmented rice breeding. PhilRice and NIAB will characterize the variation in agro-morphological traits, grain quality, nutritional composition, seed coat colour, antioxidant activity and phytochemical properties (anthocyanins, flavonoids) in the pigmented rice germplasm. In addition, IRRI will determine the genetic diversity of pigmented rice germplasm through SNP genotyping using Illumina Infinium 6K chip. Based on this phenotype and genotype data we will select a Core collection of pigmented rice accessions.

This Core collection will represent different classes of morphological traits, grain quality, nutritional value, antioxidant activity, phytochemical profiles and genetic subgroup. This Core collection will be used for a thorough study of the antioxidant components within pigmented rice using HPLC and Liquid Chromatography/Mass Spectrometry (LC/MS) analysis at NIAB. The genetic basis of the known and potentially novel antioxidant components will be undertaken through a genome-wide association screen (GWAS).

Based on the results from the GWAS analysis we will choose several rice accessions that can be utilized as donors. We will identify single nucleotide polymorphisms (SNPs) that are closely associated with the phytochemical having high antioxidant activity and develop trait specific SNP markers for marker-assisted selection. SNP markers have the advantage in that they can be used in high-throughput systems, having fast turnaround times and therefore enable breeders to select desirable plant materials in a shorter time.

NutrientRice will accelerate the utilization of untapped genetic value within traditional pigmented rice varieties in the Philippine. The knowledge, resources and tools generated will enhance the world competitiveness of Philippine traditional rice, increase farmers' income and ultimately provide increased consumer access to healthy pigmented rice.

This project will increase consumer and producer awareness of the health benefits of pigmented rice. Breeders would gain insights into how to design a breeding programme specifically in consideration of bran pigmentation for healthier rice production. The outcome of this study can guide the breeders in choosing suitable materials for developing rice varieties with therapeutic potential. Improved, high-yielding pigmented rice varieties would improve production for Filipino farmers, both for the home and export markets.

Scientists in the field of food science, chemistry, genetic resources, veterinary medicine and other related areas will gain knowledge from the information that will be generated within NutrientRice. Pigmented rice varieties with therapeutic activity can be used as base ingredients by food technologists, processors and pharmaceutical companies for the development of antioxidant supplements and functional foods. Findings of this study can be used as the basis by pharmaceutical companies who are engaged in the marketing and commercialization of natural antioxidant supplements and functional foods.

The development of improved pigmented rice varieties with therapeutic activity could be utilized by food processors and technologists in the formulation of functional foods for disease prevention and management. Development of such products would enhance the economic value of our traditional rice varieties, which in turn would provide additional income to rice farmers and millers.