Hokuto

A triploid Aomori apple registered in 1983 as Fuji × Mutsu; DNA studies have since ruled Mutsu out as its father

Origin: Kuroishi, Aomori Prefecture, Japan, registered 1983
Raised by: Aomori Prefecture (its experiment station at Kuroishi)
Parentage: Fuji × Rero 11 Registered in 1983 as a cross of Fuji and Mutsu. S-RNase and SSR analyses (Kitahara and others, 2005) excluded Mutsu, Indo and Shin Indo as the pollen parent and identified Rero 11; Fuji as the seed parent is as recorded. Aomori's industry council gives the pollen parent as unknown.
Uses: Dessert
Picked: October and November, in Aomori Prefecture
Keeps: Longer than Starking Delicious, by its registration
Skin: Yellow-green ground with clear crimson or purplish-red stripes, fewer than on Fuji; smooth
Flesh: Yellowish white or cream, fairly firm, dense and extremely juicy; readily watercored
Flavour: Sweet, with strong to moderate acidity
Ploidy: Triploid

History

Hokuto (北斗) was bred by Aomori Prefecture at its experiment station at Kuroishi^1,6. The prefecture applied to register it in December 1981, and it was registered on 24 February 1983 as a seedling of a cross between Fuji and Mutsu^1,2. In 1987 Norton, Stebbins and Yoshida, drawing on Japanese nursery catalogues, described it as an apple of excellent quality that stored well².

Its recorded pollen parent has not survived DNA testing. In 2005 Kitahara and colleagues, using S-RNase analysis and SSR markers, excluded Mutsu, together with Indo and Shin Indo, which had also been named as its father³. A second study by the same team that year identified Rero 11 as the pollen parent⁴. Aomori’s industry council now lists the father as unknown⁶.

Hokuto is triploid, and Aomori’s Industrial Technology Research Center counts its pollen, like that of Mutsu and Jonagold, as unsuitable for pollinating other varieties⁵. In 2018 it covered 562.1 hectares, 1.6 per cent of Japan’s apple orchards, seventh among varieties⁷, but the Aomori council reports its production falling, partly because it is hard to grow⁶.

The fruit

The registration describes a large, round fruit of 300–350 grams that resembles Fuji, with clear crimson stripes, though fewer of them, on a yellow-green ground, and a smooth skin of moderate gloss¹. The flesh is yellowish white, fairly firm, fine-textured and extremely juicy, at about 14 °Brix with strong acidity¹. The 1987 account gives 320–350 grams, a purplish-red stripe and cream, dense flesh, sweet with moderate acidity². Aomori’s council gives about 400 grams and describes fruit that readily develops watercore, with fine-textured, juicy flesh and a balanced flavour⁶.

It ripens in late October at Kuroishi, about two weeks before Fuji^1,2, and is picked in Aomori from late October into early November⁶. It keeps longer than Starking Delicious¹.

Growing

The registration describes a vigorous tree, intermediate in habit and size between its recorded parents, with shoots stouter than theirs, large lenticels, and many spurs and axillary flower buds; the leaves are round and large¹. Fuji is not a suitable pollinator for it: the Aomori centre lists Hokuto × Fuji among the incompatible combinations⁵.

Where the sources disagree

Pollen parent. The 1983 registration and the 1987 account give Mutsu^1,2. DNA analyses exclude Mutsu, Indo and Shin Indo and point to Rero 11^3,4; the Aomori council gives the father as unknown⁶.
Date of registration. The registration record gives 24 February 1983¹, and Norton and colleagues give 1983²; the Aomori council gives 1979⁶.
Size and acidity. Weights range from 300–350 grams in the registration¹ to about 400 grams in the council’s account⁶. The registration calls the acidity strong¹; the 1987 account calls it moderate², and the council calls the flavour balanced⁶.

Family tree

Parents, grandparents and great-grandparents, as the entries in the atlas record them.

Hokuto Japan, registered 1983
- Seed parent Fuji Japan, 1939
  - Seed parent Ralls Janet United States, about 1800
  - Pollen parent Delicious United States, 1872
    - Parent Winesap United States, by 1817
- Pollen parent Rero 11

Where Hokuto came from.

Sources

Registered variety database: Hokuto, registration no. 368 (in Japanese), Ministry of Agriculture, Forestry and Fisheries (MAFF), plant variety registration database, 1983-02-24. Supports: 北斗 (Hokuto), applied for on 8 December 1981 and registered on 24 February 1983, registrant Aomori Prefecture; a seedling of a cross of Fuji and Mutsu; maturing in late October at the breeding site (Kuroishi, Aomori Prefecture), about two weeks before Fuji; fruit like Fuji in appearance, good to eat, keeping well; tree intermediate between the parents in habit and size, vigorous, with shoots thicker than the parents', large lenticels, many spurs and axillary flower buds, round large leaves; fruit round, 300–350 g, yellow-green ground with clear crimson stripes, like Fuji but less striped, moderate gloss, smooth surface; flesh yellowish white, fairly firm, fine-textured, extremely juicy; about 14 °Brix, strong acidity; keeping longer than Starking Delicious.
Current status of several Japanese apple cultivars, R. A. Norton, R. L. Stebbins and Y. Yoshida, Fruit Varieties Journal 41(1):22–28, American Pomological Society, 1987. Supports: Table 1 (descriptions from Japanese nursery catalogues; date is the year of registration): Hokuto, Aomori (1983), registration P368, Fuji × Mutsu; season with Mutsu, 14 days before Fuji; 320–350 g, round, purplish-red stripe over a yellow ground, cream, dense flesh, sweet with moderate acidity, excellent quality, long storage.
Parent identification of eight apple cultivars by S-RNase analysis and simple sequence repeat markers, Kentaro Kitahara, Shogo Matsumoto and others, HortScience 40(2):314–317 (abstract), 2005. Supports: "Previously mentioned 'Mutsu', 'Indo', and 'Shin Indo' were excluded as paternal parents of 'Hokuto'".
Molecular characterization of apple cultivars in Japan by S-RNase analysis and SSR markers, Kentaro Kitahara, Shogo Matsumoto and others, Journal of the American Society for Horticultural Science 130(6):885–892 (abstract), 2005. Supports: Rero 11 identified as the paternal parent of Hokuto, described as having an unknown paternal parent.
Cross-compatibility of apple varieties (in Japanese), Aomori Prefectural Industrial Technology Research Center, selection of 100 recent research results, p. 44. Supports: the pollen of triploid varieties, Jonagold, Mutsu and Hokuto among them, normally unsuitable for pollination; Hokuto × Fuji among the main incompatible combinations (table 1, with Hokuto as the pistil parent and Fuji as the pollen).
Apple varieties (in Japanese), Aomori Prefecture Apple Council (Aomori-ken Ringo Taisaku Kyōgikai). Supports: Hokuto (北斗): (mother) Fuji × (father) unknown; bred by the prefecture's experiment station and registered in 1979 (Shōwa 54); picked from late October to early November; about 400 g, red with stripes; readily watercored, fine-textured, juicy flesh with balanced sweetness and acidity; production falling, partly because it is hard to grow.
Apple area by variety, 2018 (in Japanese), National Agriculture and Food Research Organization (NARO), Institute of Fruit Tree and Tea Science, from the Ministry of Agriculture, Forestry and Fisheries' survey of the 2018 crop. Supports: Hokuto on 562.1 ha, 1.6 per cent of Japan's apple area, seventh among varieties (2018).