Sticky Rice

By Douglas C. Daly

May 5 2020

A couple of years ago I was asked by Michael Purugganan (Dean of Science at NYU) and Rod Wing (Director of the Arizona Genomics Institute) to help with a problem about the identity of rice. Both of them work on rice genomics, studying the genes of rice. NYU collaborates closely with NYBG on several large-scale genomics projects.

In order to study the genes of any species, researchers have to make sure they are referring to the correct plant, identified by the scientific name. Since 1928, two major lineages of rice have been known by the scientific names Oryza sativa subspecies indica (long grained rice), and subspecies japonica (short grained rice). Drs. Purugganan and Wing had been contacted by collaborators of theirs in China with a proposal to change the names to subspecies xian and geng, respectively. The collaborators had historical and cultural reasons for wanting to do so, as these names have been used for centuries in Chinese vernacular and references, albeit not in taxonomic references. They also asserted that indica and japonica were never validly published, which if that were the case could open the door for formal publication of xian and geng as the “official” names for scientific literature.

The question was, what should we call these two distinct kinds of rice? I obtained a copy of the original 1928 scientific publication of these names - which is in Japanese - and joined forces with NYBG’s in-house expert on botanical nomenclature, James Lendemer.  The botanical community follows strict rules for assigning scientific names, compiled in the International Code of Botanical Nomenclature. We were able to ascertain that key requirements for valid publication after 1958 - a diagnosis in Latin or English, and citation of specimens, including a type collection (primary reference collection) - would not apply to a publication from 1928. Conclusion: although the verdict might not be palatable for those who feel the traditional Chinese names should be acknowledged, the 1928 names stand. 

Ultimately, however, what matters most is that there are unique identifiers for these two rice lineages so that scientists can accurately refer to them in their research, and the rest of us know what we're eating!

A Closer Look