[1] Penglai rice is a hybrid produced by crossbreeding between strains of the subspecies Oryza sativa subsp.

But japonica rice's sensitivity to day-length did not allow it to grow well in Taiwan's long hours of sunlight and subtropical climate.

[2][3] In 1921, Japanese researchers Eikichi Iso [ja], known as "father of penglai rice", and his colleague Megumu Suenaga (末永仁), known as "mother of penglai rice", began to crossbreed two strains of highland japonica rice, [4] the "Kameji" and the "Sinliki", eventually producing a hybrid "Taichung No.

[2] A mutation enabled the new cultivar to be insensitive to day-length, unlike its parental strains, allowing it to yield two harvests per year.

[6] [7] Most of the modern penglai rice varieties currently grown in Taiwan are descendants of T65.