[Unpad Media Channel] The cultivation of tomatoes in Indonesia is considered promising, but it still encounters many problems. One of which is that the fruits do not last long and quickly become spoiled if kept at room temperature. Tomatoes not lasting long may cause losses for both the seller and consumer.
This concern motivated a professor from the Department of Agricultural Cultivation at Unpad’s Faculty of Agriculture, Syariful Mubarok, S.P., M.Sc., PhD, to undertake genetic and cultivation engineering on tomato plants.
The research was a continuation from Syariful’s studies when taking his Doctoral program at University of Tsukuba, Japan, in 2013. As part of a team, Syariful selected samples mutated by the SIETR gene, a gene related with the role of the ethylene hormone.
Ethylene itself is a hormone found in plants which can accelerate the ripening process of fruits. However, if not controlled properly, it can also accelerate the fruits’ deterioration.
Through the research done by the team from University of Tsukuba, it was found that a few tomato mutations, namely SIETR1-1, SIETR1-2, SIETR4-1, and SIETR5-1, are less sensitive toward the effects of ethylene. Syariful then tried to develop his own hybrid. As a result, the mutant tomatoes affected by SIETR1-1 and SIETR1-2 gained the advantage of having a longer shelf life.
After his success in Japan, Syariful’s promotors gave him the freedom to develop the research further in Indonesia. When he arrived in Indonesia, Syariful continued his research on long-lasting tomatoes and adapted it to the climate of Indonesia.
“In Japan, the hybrid tomatoes experienced longer shelf life of up to 5 days longer. After we developed it further here using the same genetic material, we produced hybrid tomatoes whose shelf life lasted up to 8 days longer, 25 for the NIL (Near Isogenic Line) generation, and whose nutritional value and postharvest quality did not show any difference,” he explained.
Syariful explained that with a longer timespan, damage to tomatoes on the postharvest process can be reduced. For sellers, this is sure to be beneficial. The sellers can sell their tomatoes for longer since they do not deteriorate easily.
“For consumers, when they buy the tomatoes, even without storing them in coolers, the tomatoes can last longer at room temperature compared to other tomatoes,” said Syariful.
Seedless Tomatoes
Aside from longer lasting tomatoes, Syariful and his team from Unpad’s Faculty of Agriculture works in collaboration with University of Tsukuba in developing research on seedless tomatoes. There is a reason as to why he chose to develop that type of tomato.
“We are developing seedless tomatoes to deal with problems with cultivating tomatoes at high temperatures,” said Syariful.
He explained that, at high temperatures, the process of forming fruit on tomato plants can become halted. This is caused by the sterility of the pollen which can cause fertilization to fail, automatically resulting in the fruits not being formed. “As a result, production can be diminished,” he added.
This process usually happens when tomatoes, especially beefsteak tomatoes, are planted on low-lying areas or areas with high temperatures. Because of that, so far, beefsteak tomatoes can only be produced optimally when planted on highlands or areas with low temperatures.
Through their research, Syariful and his team tried to apply engineering on the plants and on the cultivation process so the beefsteak tomatoes, which are usually planted in the highlands, can be cultivated in areas with high temperatures. Seedless tomatoes were a result of engineering which allowed tomatoes to grow without fertilization.
In the research, Syariful and his team tried to grow two tomato plants mutated with iaa9-3 and iaa9-5. The growing process was done at normal temperatures, as a control group, and at high temperatures reaching 45 degrees Celcius. In this temperature, normal tomatoes cannot produce a fruit. Meanwhile, the iaa9-3 and iaa9-5 tomatoes succeeded in producing fruits.
Aside from that, the development of seedless tomatoes is also focused on increasing the sweet taste of the fruit. Syariful explained that tomato seeds are usually covered in gel. This gel is what usually causes the tartness in tomatoes which consumers may not like as much.
Should the gel reduce because of the lack of seeds, the taste will predictably become sweeter compared to regular tomatoes.
The other advantage of seedless tomatoes is the color which is more red. This is caused by seedless tomatoes having higher lycopene compared to long lasting tomatoes.
Aside from developing long-lasting tomatoes and seedless tomatoes, Syariful is also developing hydroponic technologies for tomato plants, specifically beefsteak tomatoes.
The technology currently developed is that of NFT (Nutrient Film Technique) and fruit pruning, both in an effort to produce large-sized fruits. He is also developing methods to increase the sweetness and nutritional value of tomatoes utilizing engineering on the use of fertilizers as well as on the plant hormones.
“The technology for cultivation is still focused on increasing the yield, but we are trying to figure out the use of cultivation technology to improve the sensory qualities and nutritional value of the tomatoes, as well as its function as a functional food,” Syariful added. (arm/ICP)*
