RESEARCHERS at Mariano Marcos State University (MMSU) are using gamma irradiation to create new garlic varieties that could make Ilocos garlic more competitive against imports and help address the country’s supply gap.
Known locally as “white gold” for its distinct pungent aroma, Ilocos garlic remains a key crop in Ilocos Norte. According to Philippine Statistics Authority (PSA) data, the province accounted for about 74 percent of the country’s total garlic output in 2022.
Despite this, more than 90 percent of annual national demand is still met through imports, reflecting a wide difference between local production and domestic consumption.
To address the gap, the MMSU Garlic Research Center (GRC) has been testing mutation breeding through gamma irradiation.
In the study titled “Impact of gamma irradiation doses on early growth of Philippine garlic (Allium sativum L.) varieties,” five Ilocos varieties — Ilocos Pink, Ilocos White, Ilocos Tan Bolters, Mexican, and MMSU Gem — were exposed to controlled doses of gamma rays at the Philippine Nuclear Research Institute (PNRI), an agency under the Department of Science and Technolog (DOST).
The research was conducted by Jeremay Layaoen, Noralyn Legaspi, Raymund Julius Rosales, Dionisio Bucao, Micah Benize Gregorio-Balbas, and Clarita Palacio.
The study focused on early plant growth. The long-term objective is to produce, over several generations, new garlic lines with ideal size, shape, and the characteristic traits of Ilocos varieties.
Why use gamma irradiation
GRC Chief Noralyn Legaspi said conventional breeding methods used for rice, corn, and other vegetables do not apply to garlic because the crop is propagated through cloning, not true seeds. Without seeds, hybridization and cross-pollination cannot be done.
Gamma irradiation serves as a physical mutagen. Controlled doses of gamma rays pass through garlic clove cells and cause changes in DNA sequences. In succeeding generations, these changes may appear as new traits.
Because the specific traits that emerge cannot be predetermined, researchers screen large numbers of bulbs, select those with desirable characteristics, replant them, and repeat the process until the traits stabilize.
The project is now in its fourth generation of cultivation, or M4. At this stage, researchers have observed some bulbs that are larger than usual and some with no inner cloves — traits targeted for new Ilocos varieties.
These plants are referred to as “putative mutants.” Additional generations will be needed before the traits become stable enough for evaluation and possible registration as new varieties.
The process is also constrained by garlic’s short planting season, which limits how quickly new generations can be grown. Further replicated on-station and on-farm trials will be required to compare the experimental lines with existing varieties.
Industry challenges
Beyond breeding, researchers cited pests, diseases, and climate variability as major challenges to garlic production.
Bucao, who is also the MMSU Director of Research, said the center’s primary goal is to develop improved Ilocos garlic varieties resistant to major insect pests and diseases while maintaining productivity under changing temperature and rainfall patterns linked to climate change.
Bucao added that adopting improved production technologies has the potential to increase yields beyond current farmer averages.
For now, existing Ilocos varieties continue to compete with imported garlic in the market. The M4 generation results, according to GRC, provide foundational data that supports the ongoing effort to develop new varieties.
If stabilized and released, the new lines are intended to help increase local supply and reduce reliance on imports.
The work forms part of broader efforts by MMSU and partner institutions to strengthen the garlic industry in Ilocos Norte and contribute to national food security goals.