The Department of Agriculture (DA), together with the University of the Philippines-Natural Sciences Research Institute (UP-NSRI), is now conducting a study to examine the genetic diversity of upland rice in Arakan Valley, Cotabato.
Initiated by Dr. Juliet Bangi of UP-NSRI, the study seeks to determine the desirable rice gene characteristics through morphogenetic characterization and analysis of the genetic diversity of the indigenous upland rice in Arakan, which is considered as an upland “rice belt” where a number of indigenous variety of the grain are thriving.
“Understanding the structure and diversity of indigenous rice is needed by our scientists and researchers in the conservation and preservation of genetic resources that have potential uses for future breeding purposes,” Bangi said.
In the study, 14 indigenous upland rice were collected from local farmers.
These include Azucena, Dinorado, Malos, Magalitok, Kapalawan, Mubpon, Manisi, Bungulan, Kawilan, Malundiang, Sinulid, Ulipapa, Dabao, and Hinumay.
These were subjected to laboratory and greenhouse experiments to characterize their seeds and plant structure—including plant height, number of tillers per plant, number of days to flowering, number of panicles per plant, panicle length, and 1,000-grain weight.
Results showed that the indigenous upland rice is highly diverse with desirable characteristics. Among those studied, the tallest plants are the Azucena and Hinumay.
Meanwhile, Kawilan had the highest number of tillers per plant as well as the panicles produced, and the Malundiang had the earliest flowering period. Magalitok produced the longest panicle, and Ulipapa and Bungulan had the heaviest 1,000-grain weight.
In analyzing the genetic diversity of the rice varieties, the researchers used DNA markers. The study particularly used the simple sequence repeats (SSR), which are also called microsatellites.
Among DNA markers, SSRs are found to be the most efficient and cost-effective tool that can detect higher degrees of polymorphisms in rice, the study said.
The study also revealed that Malundiang and Ulipapa have 30 percent to 50 percent associated genes that possess the desirable qualities of being early-maturing and having high yield potential. Bungulan, Mubpon, Sinulid, and Mal-os have diverse genes, and are found to have desirable genetic make-ups based on their morphogenetic characteristics.
Bungulan, Manisi, Kapalawan, Magalitok, Sinulid, Mal-os, and Dinorado have varied and narrow genetic distance indicative of having distinct genes. With a dissimilarity index of 3.32, Kawilan and Kapalawan are upland rice with different genes.
“These reflect the diversity of the indigenous upland rice in the Arakan Valley Complex based on their genetic makeup, and those that were studied are part of the genetic pool of resources in the locality,” Bangi said.
She added that high-yielding varieties with promising potentials may emerge in the future as breeding efforts using indigenous upland rice results in the successful improvement of grain quality, resistance to pests and diseases, and reduction in the maturity period, among others.
“If effectively managed and used, they would be substantial in meeting the ever-increasing demand for food as the future unfolds,” the expert said.
Rice is and will always remain as one of the most important staple foods among Filipinos. For most of the country, it is the one thing that satisfies and completes our every meal.
However, the agriculture sector is continually faced by challenges brought about by factors that hinder rice production. These include climate change as well as the widespread infestation of pests and diseases, among others.
The Food and Agriculture Organization of the United Nations recognizes genetic diversity as the foundation of improving the genes of the crop and has become an integral part of the domestication and cultivation of crops.