Dr. Dao Minh So and his team have successfully developed three varieties of colored rice: red, purple, and black. Among them, the red rice variety (SR20) boasts the highest yield of up to 8 tons per hectare, comparable to conventional rice.
Dr. So currently serves as the Head of the Crop Breeding Department at the Southern Institute of Agricultural Science and Technology (Vietnam Agricultural Science Institute). Along with his research team, he has spent nearly a decade selectively breeding three colored rice varieties: red (SR20), purple (SR21), and black (SR22) that meet criteria for purity, yield, disease resistance, and nutritional content. Currently, both SR20 and SR21 are registered for protection and circulation within the country.
Dr. Dao Minh So (right) at the 1-hectare experimental rice cultivation area in Cu Chi District, Ho Chi Minh City. (Photo: Ha An).
According to Dr. So, colored rice is characterized by the color of its husks, which contain nutrients beneficial for health, such as minerals, vitamins, and antioxidants. Colored rice can be processed into brown rice varieties suitable for dieters and individuals with chronic illnesses. However, a disadvantage of colored rice is its lower yield due to a lower chlorophyll content, which reduces its photosynthesis capability. Additionally, when cooked, it does not have the same stickiness as regular white rice, making it less desirable. The team has focused on overcoming these drawbacks. Dr. So noted that the price for this rice ranges from 50,000 to 100,000 VND per kilogram, catering to the diet market, indicating significant potential.
The team tested hundreds of crossbreeding methods over many years, spanning 8 to 10 generations, to select three colored rice varieties that met criteria for yield, nutritional content, and disease resistance. Dr. So emphasized that the selection process corresponding to the set criteria is considered the most crucial step, determining the success of creating new varieties. “A variety is considered pure when it meets uniform criteria for growth duration, height, flowering time… Characteristics like stickiness, softness, and aroma are mainly influenced by the genetic makeup of the variety,” Dr. So explained, noting that this process is the most time-consuming, labor-intensive, and costly aspect of breeding.
Black rice variety SR22 experimentally grown in Cu Chi. (Photo: Ha An).
For the SR20 variety, the harvest period is 90 to 95 days, yielding 5 to 8 tons per hectare, which is comparable to conventional rice. In terms of stickiness, SR20 has an amylose content (a component of starch) of 17 to 18%, placing it in the soft rice category. This variety has a low glycemic index, making it suitable for dieters and those looking to lose weight.
SR21 has a lower yield than SR20, producing about 4 to 6 tons per hectare with a harvest time of 100 to 105 days. According to the research team, SR21’s strong point is its fragrant aroma and low sugar conversion index, with grains measuring 8 mm in length, catering to current consumer preferences for rice.
The SR22 variety yields approximately 4 to 6 tons, with a harvest time of 95 days. One of its strengths is its high anthocyanin content, the highest among the three varieties. This compound helps support the body in combating oxidative cells and may aid in cancer prevention. “Anthocyanin is a substance found only in colored rice varieties,” stated Dr. So.
The three colored rice varieties developed by the team are suitable for various cultivation regions and exhibit resistance to common diseases such as blast, leaf blight, and brown planthopper. According to Dr. So, for white rice, harvesting occurs when the rice reaches 85% ripeness. In contrast, colored rice must be harvested when it is over 95% ripe to ensure it has fully accumulated color and nutrients.
The three colored rice varieties successfully bred by the research team. (Photo: Research Team).
According to the research team, these rice varieties can be expanded for commercial production. However, a leader of an agricultural export-import company in Ho Chi Minh City believes that colored rice is primarily suitable for dieters and those undergoing treatment. Therefore, the market share for colored rice in Vietnam is still limited, focusing on a small group, leading to low current consumption levels. “Although we have improved the yield, the most crucial factor for colored rice must be its softness and palatability to fit the preferences of consumers,” he stated.
