Inzatsu 131

Inzatsu 131 (印雑131), more formally 静印雑131 (Shizu-Inzatsu 131), is not a named, registered cultivar in the way Sofu or Fujikaori are. It is a breeding line: a single tea plant selected in 1944 at Shizuoka’s prewar tea experiment station from a natural, open-pollinated seedling of imported Assam (var. assamica) stock. It missed Japan’s cultivar naming and registration system entirely — that system only began in 1953, nine years after this line already existed — so it carries no Cha Norin number and no Plant Variety Protection Act registration, and it is identified only by its station selection number to this day. Its significance is not as a tea sold widely under its own name, though a little still is, but as a parent: it is the documented, shared source of methyl anthranilate, a grape- and jasmine-like aroma compound essentially absent from ordinary Japanese tea, which it passed on to two better-known cultivars bred from it in opposite directions — Sofu and Fujikaori.

Lineage

• Manipur No. 5 ♀ — an Assam (var. assamica) mother tree grown at the Shizuoka station from seed Maruo Fumio brought back from Assam in 1922. It was one of roughly ninety numbered Assam introductions planted at the station from that expedition; Inzatsu 131 grew from a seed harvested off this particular tree.
• Pollen parent — not recorded. The seed that became Inzatsu 131 was the product of a natural cross, not a controlled one, and no source consulted here identifies the tree that supplied the pollen. It was presumably a Japanese (var. sinensis) tree growing nearby at the station, which is what makes Inzatsu 131 a hybrid rather than a pure Assam introduction.

Inzatsu 131 is therefore neither a controlled cross in the manner of Sofu and Fujikaori, nor a landrace selection from a Japanese seed stand in the manner of Yabukita: it is an individual selected, in 1944, from an open-pollinated population grown from foreign seed — one known parent, one unknown. Its own descent is well documented by comparison with what came after it. Sofu (Yabukita ♀ × Shizu-Inzatsu 131 ♂, registered 2005) and Fujikaori (Shizu-Inzatsu 131 ♀ × Yabukita ♂, registered 1996) are reciprocal crosses of the same two parents, bred independently — Sofu at the national station in Kanaya, Fujikaori privately in Fujieda — and both inherited its floral aroma. NARO’s own genetics research (see History, below) additionally names two unnamed breeding lines, Kanaya No. 22 (金谷22号) and Miyazaki No. 24 (宮崎24号), as further descendants of Inzatsu 131 confirmed to carry the same aroma compound, though neither has been released as a named cultivar. A handful of other names circulate in less rigorous secondary accounts as further “children” of Inzatsu 131 — Kondowase (近藤早生) is one, and a single blog account also links a strain called Kurasawa (くらさわ, given there as Shizu-7111) to it as the parent of the cultivar Kôshun (香駿) — but neither claim is corroborated by a primary source consulted here and both should be treated as unconfirmed.

History

An Assam expedition, 1922

In 1922, Maruo Fumio (丸尾文雄), a researcher in the Shizuoka Agricultural Research Center’s tea department, was sent to India, Sri Lanka and Java to collect tea genetic material — part of a broader early-twentieth-century effort by Japan’s tea authorities to widen the genetic base of domestic cultivars beyond the varieties then in use. He brought back Assam-type seed of the “Manipuri” variety; Maruo himself did not survive the trip, dying of a tropical disease on the way home in Taiwan. The seed did arrive, and was sown at the Shizuoka station as a series of individually numbered trees, one to ninety.

Selection under Arima Toshiharu, 1944

In 1944, a seedling grown from a seed of tree “Manipur No. 5” was selected as an Assam–Japanese hybrid with distinctive qualities and given the station’s own designation, Shizu-Inzatsu 131. Its development is credited to Arima Toshiharu (有馬利治, 1912–1999), who had been responsible for black-tea cultivar breeding at the Miyazaki research station from 1938 before transferring to Shizuoka in 1942 to continue cultivar work there. Besides Inzatsu 131, Arima is credited with the station’s “7000 series” of Yabukita-derived breeding lines, including Shizu-7132 and Shizu-7166 (later named Yamakai). He left the station in 1960.

Early station documents, as summarised in a later account, describe the new line plainly: a “very hasty cultivar, not very resistant to cold and diseases, having a very special perfume, and adapted to the production of sencha and tamaryokucha.” Despite Inzatsu 131’s Assam ancestry — the type usually favoured for black tea — Arima judged it primarily as a green-tea cultivar, and reportedly saw particular promise in it for kamairicha (pan-fired tea). This ran against the tea industry’s prevailing direction at the time, which was consolidating around Yabukita; Inzatsu 131’s aroma was considered too unusual, and it was largely passed over.

A parent more than a product

By the late 1950s, Inzatsu 131 had found modest, localised uptake among a small number of Shizuoka growers making kamairicha, among them the father of Koyanagi Tsutomu in Fujieda — the same Fujieda lineage later responsible, through Koyanagi Mitsuyoshi, for co-breeding Fujikaori using Shizu-Inzatsu 131 as seed parent. Separately, in Nearai (Hamamatsu), a grower named Tarui — reportedly among those who had worked directly with Arima — took up Inzatsu 131 for steamed green tea, including fukamushi (deep-steamed) sencha, a use it is still put to by his family’s tea garden today. Sofu, bred the other way round from the same two parents, followed later at the national tea research station in Kanaya. This record has not directly consulted the fullest existing account of Inzatsu 131’s history, a dedicated 2014 book by Iida Tatsuhiko (飯田辰彦 『印雑一三一 我、日本茶の「正体」を究めたり！』, みやざき文庫110); the narrative above follows a summary of it published by the blog Japanese Tea Sommelier.

The methyl anthranilate discovery

In the early 2000s, NARO researchers working at the Kanaya and Makurazaki tea stations identified the compound behind the floral aroma of the new cultivar Sofu as methyl anthranilate (methyl 2-aminobenzoate), an ester associated with grape and jasmine notes that had not previously been reported in any Japanese tea cultivar. Sofu’s pollen parent, Shizu-Inzatsu 131, was found to contain the same compound, as was Fujikaori — confirming Inzatsu 131, not either Yabukita parent, as its source. A 2004 follow-up study mapped the trait to a single locus, provisionally named Mat, linked to the RAPD marker TRWO-03S at a genetic distance of about 2.1 cM; it segregated 1:1 in an F1 population from the Yabukita × Shizu-Inzatsu 131 cross. Shizu-Inzatsu 131’s own genotype at this locus was determined to be heterozygous (Mat/mat), against Yabukita’s homozygous recessive (mat/mat) — the aroma behaves as a simple dominant trait inherited from the Inzatsu 131 parent regardless of which side of a cross it sits on, which is exactly what allows both Sofu and Fujikaori to carry it despite being reciprocal crosses. The same NARO study also detected methyl anthranilate in two further, unnamed breeding lines descended from Inzatsu 131 through regional adaptation trials — Kanaya No. 22 and Miyazaki No. 24 — and, separately, in two materials with no pedigree link to Inzatsu 131 at all (“MAKURA1” and “Ak1699”), indicating the compound has turned up more than once in Japanese breeding material, though Inzatsu 131 remains the only documented source behind Sofu and Fujikaori specifically. An English-language paper covering this work, published in the Japan Agricultural Research Quarterly, states independently that Shizu-Inzatsu 131 “was selected from a natural cross population of the clonal strain introduced from Assam” and that it “is derived from a cross between var. assamica and var. sinensis” — corroborating the historical account above from a peer-reviewed source.

Characteristics

No formal characteristic sheet exists for Inzatsu 131 of the kind published for registered cultivars — it was never trialled or registered as one — so the record here is thinner and older than for Sofu or Fujikaori. Early Shizuoka station documents describe it as early-budding (“very hasty”) with weak resistance to both cold and disease; no source consulted gives a day-count relative to Yabukita or breaks disease resistance down by pathogen. Two general studies on Assam variety breeding utility from the same research-station tradition (both 1966) — not specific to Inzatsu 131, but describing var. assamica material generally — note poor rooting from cuttings, sparse side branching, oversized mature leaves, and weak cold hardiness as typical Assam-parent traits in this breeding programme; these are consistent with, though not direct evidence for, Inzatsu 131’s own recorded weaknesses.

The cup is where Inzatsu 131 is remembered. Its aroma — the same methyl anthranilate later identified and named in its descendants — is sweet, floral and unusual, described by one taster who brews it as fukamushi sencha as “bewitching,” spicy and intoxicating, set against a savoury counterpoint of cooked green vegetables, with soft rather than aggressive astringency and enough character to sustain four or five infusions; no umami-forward character is reported, and a hot brewing temperature (around 80°C) is recommended to bring the aroma out rather than emphasise sweetness. It is processed today across most of the range open to a green- and black-tea-capable cultivar: regular-steamed sencha, deep-steamed (fukamushi) sencha, kamairicha, and black tea are all currently sold under the Inzatsu 131 name by at least one specialist single-cultivar retailer, though volumes are small and cultivation remains confined to a handful of growers in Fujieda and Hamamatsu. It is, in practice, better known today through the two cultivars bred from it than as a tea in its own right.