🍇 Akitsu 21

Akitsu 21 is a Japanese table grape selection, an interspecific hybrid of the American Steuben with Muscat of Alexandria. Its name is the line number of the Japanese fruit tree institute NIFTS (now part of NARO) at Akitsu. Akitsu 21 became one of the parents of Japan's best-known table grape, Shine Muscat, which was crossed in 1988.

In a paper by NARO breeders (Yamada and co-authors, 2008), Akitsu 21 is described as a diploid hybrid of Steuben (Vitis labruscana) and Muscat of Alexandria (Vitis vinifera). It had fairly large berries, some tolerance to the main grape diseases in Japan, and firm, crisp flesh. VIVC gives this pedigree according to the breeder, without verification by markers, and does not state the berry colour.

According to VIVC, two varieties descend from Akitsu 21. Shine Muscat is a cross with the European Hakunan: the seedling was selected in 1997, tested from 1999 as Akitsu 23 at 30 locations across the country, released in 2003 and registered in 2006 under Japan's Seed and Seedlings Law as No. 13891. The second offspring is the dark-berried Oriental Star (Akitsu 21 × Ruby Okuyama), crossed in 1989.

Why it matters to you. If you have tasted Shine Muscat, a large yellow-green grape with crisp flesh and a muscat flavour, part of its pedigree comes from Akitsu 21: through it the variety carries the American Steuben line. So this little-known selection explains how a Japanese grape combined European and American traits.