Patent Application
20180368300
The Latin name of the genus and species of the novel variety disclosed herein is: Citrus L.
The novel variety of the Citrus L. disclosed herein has been given the variety denomination: ‘ASUKI’.
This application claims the benefit of Japanese Plant Breeder's Rights Application No. 32235 filed Jun. 19, 2017, which is incorporated by reference herein as if set forth in its entirety.
The present invention relates to a new and distinct hybrid variety of Citrus L., which was obtained in May 1992, from the cross between the ‘KANKITSU OKITSU 46’ (mother plant, undisclosed breeding material) and the ‘HARUMI’ (father plant, Japanese Variety Registration No. 7506, registered on Nov. 25, 1999), which was carried out in the Okitsu branch of the Division of Citrus Research, Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization, Shizuoka, Japan. The hybrid seeds were collected in November 1992, and immediately sown in a glasshouse to grow hybrid seedlings. The seedlings were grafted on satsuma mandarin inter-stocks in April 1994, and first fruits were observed in 1997.
After the first fruiting, tests for fruits quality were carried out on the above-mentioned individuals grafted on satsuma mandarin inter-stocks, and among these, No. P-92 was first selected as the best individual in 2005, based on its high brix and excellent fruits quality. The No. P-92 was phylogenetically named as ‘KANKITSU OKITSU 60’ (which was varietally denominated as ‘ASUKI’ at a later date), and subjected to the national trial in 29 test sites in Japan, from April 2006. As a result of the above-mentioned national trial, on August 2016, it was evaluated that ‘ASUKI’ matured around medium to late March, and had high brix and extremely excellent taste stably every year, in almost all the test sites.
The present invention relates to a new and distinct variety of Citrus L. plant named ‘ASUKI’, as described and illustrated herein. Specifically, ‘ASUKI’ is a new and distinct variety of Citrus L., characterized by being late-maturing, having high brix and excellent taste, being easy to eat because of its soft segment membrane, having no occurrence of fruit rind puffing, and having less dripping of fruit juice.
The accompanying colored photographs (
The following is a detailed description of the new Citrus L. variety known as ‘ASUKI’, based upon the traits evaluated in each test sites in Japan.
As described above, ‘ASUKI’ was obtained from the cross between ‘KANKITSU OKITSU 46’ as a mother plant and ‘HARUMI’ as a father plant. The applicants had maintained ‘ASUKI’ by grafting on trifoliate orange rootstocks, and from 2013 to 2015, the traits evaluation of ‘ASUKI’ was carried out by being compared with other Citrus L. varieties ‘ASUMI’ (Japanese variety registration No. 23723, registered on Sep. 30, 2014) and ‘SETOKA’ (Japanese variety registration No. 9398, registered on Oct. 18, 2001)(both of which are varieties morphologically similar to ‘ASUKI’ in terms of fruit) as well as ‘AOSHIMAUNSHIU’ and ‘SHIRANUI’ (both of which are leading citrus varieties in Japan). The results of the traits evaluation were as follows.
(1) Tree characteristics
The tree vigor of ‘ASUKI’ was slightly stronger than those of ‘SETOKA’, ‘AOSHIMAUNSHIU’ and ‘SHIRANUI’. The tree shape of ‘ASUKI’ was spheroid to ellipsoid, and the growth habit was upright to spreading. The shoot length of ‘ASUKI’ was long (for example, about 13.5 cm), and the diameter (for example, about 2.9 mm) and density of shoots were medium. The internode length of ‘ASUKI’ was medium (for example, about 1.9 cm). The percentage of occurrence of thorns on shoots was low (8%), so that the density of thorns on shoots was sparse, and in some years, there was almost no occurrence of thorn. The length of thorns on shoots of ‘ASUKI’ were short (Table 1).
The shape of leaf blade of ‘ASUKI’ was lanceolate, just like those of ‘ASUMI’ and ‘SETOKA’, and the length (for example, about 9.2 cm) and the size (for example, about 25.3 cm2) of leaf blade was medium, and the width of leaf blade was narrow (for example, about 3.8 cm). The thickness of leaf of ‘ASUKI’ (for example, about 0.37 mm) was at the same level as those of ‘ASUMI’ and ‘SETOKA’. The petiole wings of ‘ASUKI’ was wedge shaped, and its length (for example, about 14.7 mm) was medium and its width (for example, about 3.7 mm) was narrow. The length of petiole of ‘ASUKI’ was medium (for example, about 18.7 mm), and its diameter was wide (for example, about 2.0 mm). The weight of a flower (for example, about 0.44 g) and the size of a petal (for example, length: about 14.5 mm; width: about 7.2 mm) of ‘ASUKI’ were smaller than those of ‘ASUMI’, and larger than those of ‘SETOKA’. The flower of ‘ASUKI’ did not have inflorescence and was solitary. The color of flower petals of ‘ASUKI’ was white, and one flower had 5 petals. The number of flower filaments of ‘ASUKI’ was few (for example, about 18.8) and the filaments were separated from each other. The amount of pollen of ‘ASUKI’ was at the same level as that of ‘ASUMI’, and larger than that of ‘SETOKA’. The flower's style of ‘ASUKI’ was arched, and the curvature degree of the style was lower than that of ‘ASUMI’.
The number of flower setting of ‘ASUKI’ was medium, and there was little preharvest drops. The alternate bearing of ‘ASUKI’ was lighter than those of ‘ASUMI’ and ‘SETOKA’, and the yielding ability of ‘ASUKI’ was medium. The degree of occurrence of citrus canker disease was lower than those of ‘ASUMI’ and ‘SETOKA’. There was no occurrence of citrus scab on ‘ASUKI’ under conventional control (Table 2).
(1) Fruit characteristics
The time of sprouting of ‘ASUKI’ (early April) was almost the same as those of ‘ASUMI’ and ‘SETOKA’, and the full bloom stage of ‘ASUKI’ (early May) was at the same time as those of ‘ASUMI’ and ‘SETOKA’. While the beginning time of fruit coloration of ‘ASUKI’ (middle October) was at the same time as that of ‘ASUMI’, it was 10 to 15 days later than those of ‘SETOKA’ and ‘AOSHIMAUNSHIU’. The time of complete coloring of fruits of ‘ASUKI’ was late (latter half of December), and it was at the same level as ‘ASUMI’. The time of maturing of fruits of ‘ASUKI’ was late February to March, and it was more than 1 month later than that of ‘ASUMI’ (Table 3).
The fruit shape of ‘ASUKI’ was oblate in form, the color of fruit rind was orange, and the surface of fruit was smooth. The thickness of fruit rind of ‘ASUKI’ was about 2.7 mm and it was thicker than those of ‘ASUMI’ and ‘SETOKA’, and ‘ASUKI’ was easier to be peeled than ‘ASUMI’. The fruit rind of ‘ASUKI’ had orange-like flavor. The color of flesh of ‘ASUKI’ was dark-orange, and the pulp rate was relatively high (for example, about 82.6%). The segment membrane of ‘ASUKI’ was relatively thin and soft, and the fruit flesh texture was medium to slight firm. The average fruit weight of ‘ASUKI’ was about 180 g, and it was at the same level as those of ‘ASUMI’ and ‘SETOKA’.
The brix of fruit juice of ‘ASUKI’ was more than 15% around February 20, and it was increased up to about 16% around March 20, and was higher than those of ‘ASUMI’ and ‘SETOKA’. The acid content of fruit juice of ‘ASUKI’ was about 1.18 g/100 ml around March 20, and the fruit of ‘ASUKI’ had extremely rich taste (Table 4).
The fruit of ‘ASUKI’ was tight and there was no occurrence of fruit rind puffing. And also, there was neither occurrence of fruit cracking nor physiological granulation (Table 5).
When being cut by knife, the degree of dripping of fruit juice of ‘ASUKI’ was lower than those of Grapefruit (Citrus paradisi), Kawano-natsudaidai orange (Citrus natsudaidai f. kawanonatsudaidai) etc. (see Table 6 below), and was almost the same level as that of Sweet Orange (Citrus sinensis), so that ‘ASUKI’ is suitable for being used as cut fruits.
