The Taiwanese rice story
Rice, once our only staple food, and now one of many, can be made into a variety of cuisines, such as porridge, cooked rice, turnip cake, and, during the Dragon Boat Festival, zongzi, familiarizing itself with everyone.
Ever heard of “ponlai rice （蓬萊米）”, “zai-lai rice （在來米）”, and “glutinous rice (糯米)”? Have you ever wondered, what’s the difference between them?
Besides the shape of the grain, the biggest difference between ponlai rice (Japonica rice), zai-lai rice (Oryza sativa subsp. Indica), and glutinous rice, is its content of amylopectin, respectively. Starch can be categorized into amylopectin and amylose, with amylopectin being highly branched, able to bond with a large amount of water, producing a soft and sticky texture for cooked rice; so the more amylopectin in rice, the stickier it becomes. Zai-lai rice contains lesser than 80% of amylopectin, while glutinous rice has above 95%; that’s why cooked rice using zai-lai rice is dry and fluffy, suitable for making rice vermicelli, he fen （河粉）, uánn-kué（碗粿）, turnip cake, silver needle noodles, etc.; and glutinous rice-made cooked rice is very sticky, suitable for laba congee（臘八粥）, zongzi, Chinese sticky rice, tangyuan（湯圓）, and mochi（麻糬）. As for Ponglai rice, its amylopectin content is between zai-lai rice and glutinous rice, it’s stickiness and softness perfectly balanced! However amylose can be dissolved with one enzyme (alpha-amylase), while amylopectin requires two (alpha-amylase and beta-amylase), therefore making glutinous rice harder to digest, so it is advised not to eat too much!
The most bred species in Taiwan is Ponlai rice, making up around 93% of rice production; among Ponlai rice, the most popular strains are Taiken 9 （臺稉9號）, Tainung 71 （臺農71號，Yihchuan Aromatic Rice 益全香米）, Kaohsiung 139 （高雄139號）, Kaohsiung 145, and Taiken 16; the most widely cultivated is Tanan 11（台南11號）, with YunLin County, Changhua County, and Chiayi County being most prolific.
Rice is a tropical /subtropical crop, in the past it was believed that south China started growing rice around 6,000 to 7,000 years ago, but recent discoveries of ancient remains of rice cultivation were found in the Hu xi （虎溪） region, downstream of the Yangtze River, indicating that China’s rice cultivation may have begun 9,000 years ago. In the past scientists have been unable to verify whether Japonica rice and Oryza sativa subsp. Indica derived from the same ancestor, but with the findings of Japonica rice in Hu xi region, they are believed to have separate origins.
Although China’s rice cultivating history goes back 9,000 years, up until the Han dynasty, rice eating was still considered a privilege of the elite; only after the Three Kingdoms did the north start cultivating rice, and the south started applying some sort of aquaponics technique, keeping fish in the rice paddies.
The earliest discoveries of Taiwan’s rice cultivation goes back to the Dapenkeng Culture in Tainan, approximately 5,000 years ago, growing upland rice! Dutches introduced Oryza sativa subsp. Indica and water buffalo to Taiwan, and the immigrants from the Qing dynasty, besides introducing irrigation technology to Taiwan, they also brought different strains of Oryza sativa subsp. Indica from their hometowns.
During the time Taiwan was under Japan’s rule, the Japanese were not used to (or shall we say, dislike?) eating Oryza sativa subsp. Indica, and so they imported Japonica rice varieties from Japan. However, Japanese varieties are sensitive to daylength, so new variety was bred by Iso Eikichi （磯永吉，1886–1972） and his colleague Suenaga Hitoshi （末永仁）. They crossbred two varieties of Japanese rice, the “Kameji” and the “Shinriki”, successfully giving birth to a new kind of rice that adapted well to Taiwan’s climate and insensitive to daylength in 1929, called “ Taichung 65 (T65)”, named by the Taiwan governor “Ponlai rice”, which means “rice from Ponlai immortal island”, and the original breed of Taiwan’s “zai-lai rice”, meaning “local rice”. Affected by the Japanese, Taiwanese who used to eat Oryza sativa subsp. Indica fell in love with Ponlai rice!
Interestingly, neither Kameji nor Shinriki carries the daylength insensitivity gene. How come T65 became insensitive to daylength? This mystery was not solved until recently. When they sequenced T65 genome, they found a segment of gene coming from upland rice variety. It is this very chromosome segment making T65 insensitive to daylength.
