hinshu.jp The family trees of Japanese crop varieties
Text size

Home Rice

Tochiginohoshi

Parents: Tochigi No.11 (seed parent) and Nasuhikari (pollen parent). Crossed in 2002.

Tochigi No.19 TOC0000190

Pedigree

Skip the diagram and read the list
Norin No.22 → Koshihikari Norin No.1 → Koshihikari Norin No.8 → Norin No.22 Norin No.6 → Norin No.22 Moritawase → Norin No.1 Rikuu No.132 → Norin No.1 Ginbozu → Norin No.8 Asahi → Norin No.8 Joshu → Norin No.6 Sen'ichi → Norin No.6 Rikuu No.20 → Rikuu No.132 Kamenoo No.4 → Rikuu No.132 Aikoku → Rikuu No.20 Koshihikari → Nasuhikari Nasuhikari → Tochiginohoshi Tochigi No.11 → Tochiginohoshi Aichi No.87 → Nasuhikari Tochiginohoshi Tochigi No.19 ・ 1% Nasuhikari Tochigi No.7 Tochigi No.11 Koshihikari Etsunan No.17 ・ 32.6% Aichi No.87 Norin No.22 Kinki No.34 Norin No.1 Hokuriku No.4 Moritawase Rikuu No.132 Rikuu No.20 Kamenoo No.4 Aikoku Norin No.8 Kinki No.15 Norin No.6 Kinki No.9 Joshu Sen'ichi Ginbozu Asahi
The diagram shows this variety's own parents and the line that connects it to Koshihikari. Among the descendants only the main varieties are drawn; the other parent of each cross, and every descendant not drawn here, are listed in full below. Faint boxes are unnamed breeding lines.

Parents

Cross combination: 栃木11号/栃木7号

Descendants

Relations are counted along the shortest line of descent. The rows in the diagram follow the order of crosses, so a variety with more than one path down can sit lower in the diagram than its relation here suggests.

A variety for planting after wheat

The breeding report for Tochiginohoshi contains one sentence on the cross.

In August 2002 a hand cross was made with Tochigi No.11 as the seed parent and Tochigi No.7 (later Nasuhikari) as the pollen parent

The pollen parent Tochigi No.7 is the later Nasuhikari. Nasuhikari is a child of Koshihikari.

Tochigi Prefecture's breeding objective states where this variety is placed: in the double-cropping belt, with a maturity that does not compete with the wheat work. Not only the taste, but the ordering of the field work is written into the objective.

Enduring high temperature, resisting rice stripe disease

The assessment in the breeding report:

High-temperature ripening is "strong" Rice stripe disease is "resistant"

Rice stripe disease is a viral disease carried by the small brown planthopper, and chemicals alone cannot hold it down. Resistance has to come from the variety's side. The same design thinking as Kinumusume.

On eating quality, Tochigi Prefecture's document writes in comparison with existing varieties.

Eating quality is slightly superior to "Asahinoyume" The brown rice is large-grained

Plant variety registration on 26 March 2015, registration number 24269.

Share of paddy rice area in the 2024 crop: 1.0%.

Follow the diagram above and it returns to Koshihikari by way of Nasuhikari. Tochiginohoshi is a grandchild of Koshihikari.

Sources disagree

Which parent of Koshihikari was the seed parent

The NARO historical document states in words that Norin No.22 was the seed parent and Norin No.1 the pollen parent. Niigata Prefecture, which bred the variety, states the reverse. The diagram follows the historical document; Niigata's account is recorded here. We call neither wrong.

The year of the cross

The NARO documents appear to reproduce the prefectures' original applications for recommended-variety status and give 1945 — and the documents for Honenwase, Hatsunishiki and Yamasenishiki, all from the same cross, give 1945 as well, four in agreement. Niigata's own account says the cross was made in 1944 and that the 1945 planting was skipped for lack of hands. We use 1944 and note the discrepancy.

How the seed parent of Norin No.1 is written

The two spellings appear in the same NARO database, in the pedigree field and in the historical document respectively. We use the pedigree field's spelling and list the other.

How Kamenoo No.4 is written

We follow the NARO database. The commonly seen spelling uses a katakana no; we prefer the spelling we can cite.

On naming

Variety names are proper nouns. We use a name in this language only where a published source for it can be cited; otherwise the Japanese name stands.

What we have not yet confirmed

We have not looked below the top twenty

The site covers the twenty most widely planted varieties of the 2024 crop and the varieties that connect them back to Koshihikari. Many descendants exist below that line; we have not yet verified them against primary sources.

The year Masshigura was crossed

Neither Aomori Prefecture's table of recommended-variety characteristics nor the NARO database gives the year Masshigura (Aokei No.138) was crossed. The cross itself, Ou No.341 / Yamagata No.40, and its adoption as a recommended variety in fiscal 2004 are confirmed from primary sources; the year of the cross is not. For the same reason we do not say which parent was the seed parent. On 8 October 2026 we went back to the breeder's own side. The Masshigura page in the variety database of the Aomori Prefectural Industrial Technology Research Center's Agriculture and Forestry Research Institute carries a heading reading “The origin of Masshigura” — with nothing under it. Of the institute's bulletins, only No.42 (2015) onward are online, and the issue that would hold the breeding report for Masshigura is not among them. So the year of the cross is absent from the breeder's own published material as well.

Sources

The source document is in Japanese.

  1. イネ品種データベース検索システム「越南17号（コシヒカリ）」品種来歴文書 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  2. イネ品種データベース検索システム 交配系譜図「越南17号」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  3. イネ品種データベース検索システム「北陸4号（水稲農林1号）」品種来歴文書 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  4. イネ品種データベース検索システム 交配系譜図「北陸4号」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  5. イネ品種データベース検索システム「北陸4号を親とする品種一覧」（全263行） — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-10-01
  6. イネ品種データベース検索システム「越南17号を親とする品種一覧」（全607行） — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-10-01
  7. イネ品種データベース検索システム 交配系譜図「近畿34号（水稲農林22号）」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-10-01
  8. イネ品種データベース検索システム 交配系譜図「近畿15号（水稲農林8号）」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  9. イネ品種データベース検索システム 交配系譜図「近畿9号（水稲農林6号）」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  10. イネ品種データベース検索システム 交配系譜図「陸羽132号」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  11. イネ品種データベース検索システム 交配系譜図「陸羽20号」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  12. コシヒカリのエピソード1 〜交配から系統の育成まで〜 — Niigata Prefectural Government ・ primary source ・ accessed 2026-09-10
  13. 新潟コシヒカリの軌跡 〜誕生から定着に至るまで〜 — Niigata Prefectural Government ・ primary source ・ accessed 2026-09-10
  14. 戦後日本のイノベーション100選「コシヒカリ」経緯 — Japan Institute of Invention and Innovation ・ accessed 2026-09-10
  15. 令和6年産 水稲の品種別作付割合 — Rice Stable Supply Support Organization ・ primary source ・ accessed 2026-09-10
  16. イネ品種データベース検索システム 交配系譜図「栃木7号（なすひかり）」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  17. イネ品種データベース検索システム 交配系譜図「栃木19号（とちぎの星）」 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-10
  18. あきさかりの良さを引き出す栽培法 — Fukui Prefectural Government ・ primary source ・ accessed 2026-09-10
  19. ぎふクリーン農業／県産品種 ハツシモ — Gifu Prefectural Government ・ primary source ・ accessed 2026-09-11
  20. 水稲「あさひの夢」の奨励品種採用（研究成果情報） — National Agricultural Research Center, NARO ・ primary source ・ accessed 2026-09-11
  21. コシヒカリのエピソード2 〜奨励品種への採用から〜 — Niigata Prefectural Government ・ primary source ・ accessed 2026-09-10
  22. コシヒカリBLの導入のねらい — Niigata Prefectural Government ・ primary source ・ accessed 2026-09-10
  23. 水稲新品種「とちぎの星」の育成（栃木県農業試験場研究報告） — Tochigi Prefectural Agricultural Experiment Station ・ primary source ・ accessed 2026-09-11
  24. イネ品種データベース検索システム「近畿15号（水稲農林8号）」品種来歴文書 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-16
  25. イネ品種データベース検索システム「近畿9号（水稲農林6号）」品種来歴文書 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-09-16
  26. 品種登録データベース「なすひかり」登録番号第14775号 — Ministry of Agriculture, Forestry and Fisheries ・ primary source ・ accessed 2026-10-01
  27. イネ品種データベース検索システム「越南12号（ヤマコガネ）」品種来歴文書 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-10-01
  28. イネ品種データベース検索システム「山陰47号（ヤエホ）」品種来歴文書 — Institute of Crop Science, NARO ・ primary source ・ accessed 2026-10-01