SCIENTISTS in Jamaica are leveraging crop mutation through gamma irradiation as a promising strategy to tackle crop scarcity, improve disease resistance, and boost the nation’s food security. Scientific Research Council (SRC) is leading this innovative research, with a focus on enhancing the resilience of key crops like ginger and yam.

Currently, SRC has narrowed down over 200 initial lines of ginger to around 20 which show promising resistance to Fusarium, a pathogen responsible for ginger rot. Dr Collin Scantlebury, team leader of biotechnology at SRC, explained that these lines exhibit “putative resistance” a term used to describe crops that have shown potential tolerance under controlled laboratory conditions. During testing, individual leaves from the ginger plants were exposed to the pathogen, and in the lines deemed resistant the infection was halted, preventing the disease from spreading. Yams are also undergoing similar research, with SRC developing over 50 new lines through mutation breeding.

“This is just some small changes in the DNA of the plant that are induced by the gamma irradiation,” Product Research and Development Manager Dr Ryan Francis told the
Jamaica Observer in an interview.

“The theory is that they may be all different. You’ve actually, by this treatment, tried to generate genetic diversity,” added Dr Scantlebury.

The driving force for this research stemmed from the severe decline in Jamaica’s ginger industry, largely caused by rhizome rot. In the 19th century Jamaica was one of the world’s leading ginger producers, but soil-borne diseases devastated the crop, leading to losses of up to 90 per cent of yield. With global demand for Jamaican ginger, known for its potent flavour, there was strong economic motivation to find a solution, prompting scientists to turn to crop mutation through gamma irradiation as a solution.

“We realised that we need to have a ginger plant that is tolerant; that means it can be affected but it will [still] produce the yield. Or better, a ginger line or a ginger variety that is resistant to the disease, which is a rhizome rot,” Francis explained.

Unlike many crops, ginger cannot undergo traditional crossbreeding because it is vegetatively propagated rather than grown from seeds, making it necessary to explore other methods for inducing genetic changes.

“There’s nothing to cross, so the only other way to effect genetic changes in the plant is to do something to induce the change in the chromosome. So, that is where the mutation comes in,” Dr Scantlebury added.

SRC then collaborated with International Atomic Energy Agency (IAEA) in Austria, where scientists adopted gamma irradiation technology and then started their mutation breeding programme in 2008. The research has now progressed from laboratory selection to the multiplication of mutated plants for field testing. The test fields are located in the same traditionally infected areas where ginger has been grown in the past. By comparing the performance of the new mutated ginger varieties to traditional ones, the researchers aim to prove that the new varieties can thrive in these disease-prone environments and produce viable yields. However, field trials present a significant challenge as, unlike lab tests, they require larger sample sizes to yield reliable results.

“We can’t conduct field trials with just a few plants — we need hundreds or even thousands,” Scantlebury explained to the Business Observer.

Testing 20 different varieties would require hundreds of blocks — each planted with multiple specimens — and careful logistical planning to ensure accurate results. This step marks a major milestone for SRC as the typical process for developing disease-resistant crops through mutation breeding takes between 5 and 10 years. SRC, now in its fifth year, is ahead of schedule, moving swiftly from lab tests to field trials. However, once these trials are complete they will need to be repeated over three cycles to ensure the varieties are strong and reliable under real world conditions.

“It is not a rushed process; it’s a process that we have to ensure that what we are releasing is what is expected, and therefore there’s a quality aspect to it as well,” Francis noted. “It’s not just the resistance; we want to ensure that this plant, the plant material, has that nice flavour. It is that quality that we started out with [which is the aim], plus it now has the resistance.”

In addition to disease resistance, gamma irradiation has the potential to shorten the maturation time of crops like yam and ginger. Traditionally, both crops take around nine months to mature, but the irradiation process might reduce that time. While the main focus of the research is to develop disease resistance and tolerance in yams and ginger, Francis revealed that gamma irradiation could also lead to the development of other beneficial traits.

“Because the technology of gamma irradiation is random, there can be additional traits that are beneficial,” he said. “At field trials we will select for those traits, and therefore we could have a yam variety that has both disease resistance and early maturity.”

Addressing concerns about the safety of consuming crops treated with gamma irradiation, Francis reassured that the process has been widely used for many years and that the safety of it is “well documented as the way forward with regards to food security”. As part of its public sensitisation efforts, Scientific Research Council (SRC) has incorporated public engagement into its project, with a communication strategy set to roll out closer to the release of the new ginger varieties — which it predicts will be ready to launch in four years, all being well. A key element of the strategy is working closely with farmers, who play a crucial role in the success of the project.

“We start with the farmers because, remember, they are the receivers. They have to have that buy-in to the planting material to produce it,” said Francis. “Without the farmers’ willingness to adopt the new planting material, the crop will never make it to market.”

The impact of this research could have far-reaching benefits, as the disease affecting ginger crops is not limited to Jamaica but is a global issue. The researchers anticipate that the outcomes of their work will be in high demand worldwide in the next two to three years.

“This can only be big things for Jamaica when we release that variety to the Ministry of Agriculture and then to the farmers,” said Francis.