Citrus L. plant named ‘ASUKI’

Abstract

A new and distinct variety of Citrus L. plant named ASUKI, 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.

Claims

1. A new and distinct variety of Citrus L. plant named ASUKI, as described and illustrated herein.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The accompanying colored photographs (FIGS. 1-9) show typical tree, flower and fruit characteristics for the new Citrus L. plant, ASUKI. Colors shown are as accurate as can be reasonably reproduced by photographic means. In some cases, the color might differ slightly from the colors of ASUKI recited in the description.

(2) FIG. 1 shows a tree of Citrus L. plant ASUKI (photographed date: Mar. 13, 2015; photographed location: Okitsu-town, Shimizu-ward, Shizuoka-city, Shizuoka-prefecture, Japan; and the age of photographed ASUKI: 15 years).

(3) FIG. 2 shows whole flowers of Citrus L. plant ASUKI (photographed date: May 12, 2015; photographed location: same as FIG. 1; and the age of photographed ASUKI: 15 years).

(4) FIG. 3 shows broken-down parts of the flower of Citrus L. plant ASUKI (photographed date: May 12, 2015; photographed location: same as FIG. 1; and the age of photographed ASUKI: 15 years).

(5) FIG. 4 shows whole fruits of Citrus L. plant ASUKI (photographed date: Mar. 5, 2015; photographed location: same as FIG. 1; and the age of photographed ASUKI: 15 years).

(6) FIG. 5 shows a longitudinal and a horizontal section of whole fruits of Citrus L. plant ASUKI (photographed date: Mar. 5, 2015; photographed location: same as FIG. 1; and the age of photographed ASUKI: 15 years).

(7) FIG. 6 shows a comparison of flowers of ASUKI with those of ASUMI and SETOKA (both of which are varieties morphologically similar to ASUKI in terms of fruit). Upper: ASUKI, medium: ASUMI, lower: SETOKA (photographed date: May 12, 2015; photographed location: same as FIG. 1; and the age of photographed ASUKI: 15 years).

(8) FIG. 7 shows a comparison of fruits of ASUKI with those of ASUMI and SETOKA. Left: ASUKI, medium: ASUMI, right: SETOKA (photographed date: Mar. 5, 2015; photographed location: same as FIG. 1; and the age of photographed ASUKI: 15 years).

(9) FIG. 8 shows a comparison of thicknesses of fruit rind of ASUKI with those of ASUMI and SETOKA. Left: ASUKI, medium: ASUMI, right: SETOKA. Thickness of fruit rind of ASUKI: thin, ASUMI and SETOKA: extremely thin (photographed date: Mar. 5, 2015; photographed location: same as FIG. 1; and the age of photographed ASUKI: 15 years).

(10) FIG. 9 shows fruits on a tree of ASUKI (photographed date: Mar. 13, 2015; photographed location: same as FIG. 1; and the age of photographed ASUKI: 15 years).

DETAILED DESCRIPTION OF THE VARIETY

(11) 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.

(12) 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 asexually reproduced ASUKI by grafting it onto trifoliate orange rootstocks in Okitsu-town, Shimizu-ward, Shizuoka-city, Shizuoka-prefecture, Japan, 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. The plant age of all the plants of ASUKI was 15 years. In addition, the growing conditions of these plants were the following: (a) the annual rainfall in the observed area (Skizuoka-city, Shizuoka-prefecture, Japan) was 1800 mm to 2700 mm (more than 200 mm per month in March to October, and less than 100 mm per month in November to February, which corresponds to maturation season of the fruits of ASUKI); (b) the annual sunshine in hours in the observed area was about 2000 hours per year; (c) the average annual temperature in the observed area was 16 to 17 C. (the highest temperature: 37 C. and the lowest temperature: 3.8 C.); and (d) the soil property in the observed field was fertile brown forest soil, including compost.

(13) (1) Tree Characteristics

(14) The tree vigor of ASUKI was slightly stronger than those of SETOKA, AOSHIMAUNSHIU and SHIRANUI. The color of tree bark of ASUKI was Strong Yellowish Brown N199D (The R.H.S. Colour Chart). The tree shape of ASUKI was spheroid to ellipsoid, and the growth habit was upright to spreading. The average trunk circumference of ASUKI was 77 cm (n=5), the average trunk diameter of ASUKI was 12.5 cm (n=5), and the trunk surface texture of ASUKI was slightly smooth without pitting. The shoot length of ASUKI was long (for example, average length of shoot: about 13.5 cm, n=30), and the diameter (for example, about 2.9 mm) and density of shoots were medium. The internode length of ASUKI was medium (for example, average length of internode: about 1.9 cm, n=30). The percentage of occurrence of thorns on shoots was low (8%, n=30), 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).

(15) TABLE-US-00001 TABLE 1 Numbers and length of 'ASUKI' thorns Year 2013 2014 Variety Number Length Number Length ASUKI medium short none ASUMI many short SETOKA medium short many short AOSHIMAUNSHIU none none SHIRANUI none none Year Evaluation 2015 through three years Variety Number Length Number Length ASUKI few short none to few short ASUMI many medium many short to medium SETOKA many short medium to short many AOSHIMAUNSHIU none none SHIRANUI none none : not investigated Numbers of thorns were observed including summer and fall shoots. none: without thorn. few: intermediate (there were thornless parts on shoots). many: thorns occurred on most shoots. Length of thorns were observed on average spring shoots. short: less than 1 cm. medium: 1 to 2 cm. long: no less than 2 cm.

(16) The shape of leaf blade of ASUKI was lanceolate, just like those of ASUMI and SETOKA, and the length (for example, average length of leaf: about 9.2 cm, n=30) and the size (for example, about 25.3 cm.sup.2) of leaf blade was medium, and the width of leaf blade was narrow (for example, average width of leaf: about 3.8 cm, n=30). The thickness of leaf of ASUKI (for example, about 0.37 mm) was at the same level as those of ASUMI and SETOKA. The color of upper surface of leaf of ASUKI was Moderate Olive Green 137A (The R.H.S. Colour Chart), and the color of lower surface of leaf of ASUKI was Moderate Yellow Green 146B (The R.H.S. Colour Chart). The petiole wings of ASUKI was wedge shaped, and its length (for example, average length of petiole wings: about 14.7 mm, n=30) was medium and its width (for example, average width of petiole wings: about 3.7 mm, n=30) was narrow. The length of petiole of ASUKI was medium (for example, average length of petiole: about 18.7 mm, n=30), and its diameter was wide (for example, average diameter of petiole: about 2.0 mm, n=30). 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 color of opened flower of ASUKI was White NN155D (The R.H.S. Colour Chart). 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.

(17) 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).

(18) TABLE-US-00002 TABLE 2 Degree of occurrence of ASUKI plant diseases Year 2013 2014 citrus citrus citrus citrus Variety conker scab canker scab ASUKI none none none none ASUMI none none slight none SETOKA none none slight none AOSHIMAUNSHIU none none none none SHIRANUI none none none none Year Evaluation through 2015 three years citrus citrus citrus citrus Variety canker scab canker scab ASUKI none none none none ASUMI slight none none to slight none SETOKA slight none none to slight none AOSHIMAUNSHIU none none none none SHIRANUI none none none none citrus canker disease, citrus scab: degree of damages on fruits and trees under conventional control. none: no symptom was observed. slight: some pathological spots were observed, but no problem fix cultivation. moderate: intermediate. severe: a lot of pathological spots appeared, and there is a problem on cultivation.
(2) Fruit Characteristics

(19) 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).

(20) TABLE-US-00003 TABLE 3 Maturing time of ASUKI fruits Evaluation Year through Variety 2013 2014 2015 three years ASUKI early March early March late February late February to March ASUMI early late January late January late January to February early February SETOKA late late February late February late February February AOSHI- early late late November MAUNSHIU December November to early December SHIRANUI late February late February late February : not investigated Maturing time of fruits: determined by progress degree of coloration and fruit quality.

(21) The fruit shape of ASUKI was oblate in form, the color of fruit rind (skin of fruit) of ASUKI was Vivid orange 28B (The R.H.S. Colour Chart), and the surface of fruit was smooth. The average thickness of fruit rind of ASUKI was about 2.7 mm (n=15) 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 fruit flesh of ASUKI was Strong Orange 169B (The R.H.S. Colour Chart), 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 external color of seed of ASUKI was Pale Yellow 160D (The R.H.S. Colour Chart), and the color of inner seed coat of ASUKI was Moderate Yellow 161A (The R.H.S. Colour Chart). The average fruit weight of ASUKI was about 180 g, (n=15), and it was at the same level as those of ASUMI and SETOKA.

(22) 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).

(23) TABLE-US-00004 TABLE 4 Fruit characteristics of ASUKI Year investi- 2013 gation Acid 2014 date Weight content Weight Month. of fruit Brix g/100 Bitter- of fruit Variety Day g % ml ness g ASUKI 2.20 172 16.1 1.57 none 171 3.20 165 16.8 1.33 none 176 ASUMI 2.20 161 14.3 1.10 none 173 SETOKA 2.20 194 14.4 1.42 none 176 AOSHIMA- 11.20 166 9.5 0.70 none 168 UNSHIU SHIRANUI 2.20 220 15.9 1.33 none 277 Year 2014 2015 Acid Acid content Weight content Brix g/100 Bitter- of fruit Brix g/100 Variety % ml ness g % ml ASUKI 15.7 1.48 none 200 15.1 1.05 15.7 1.18 none 187 15.7 1.03 ASUMI 14.0 0.93 none 185 15.0 0.68 SETOKA 13.6 1.53 none 195 13.8 1.19 AOSHIMA- 9.7 0.81 none 154 9.9 0.78 UNSHIU SHIRANUI 14.2 1.04 none 281 14.7 0.90 Year Evaluation through three years Acid 2015 Weight content Bitter- of fruit Brix g/100 Bitter- Variety ness g % ml ness ASUKI none 181 15.6 1.37 none none 176 16.1 1.18 none ASUMI none 173 14.4 0.97 none SETOKA none 188 13.9 1.38 none AOSHIMA- none 163 9.7 0.76 none UNSHIU SHIRANUI none 259 14.9 1.09 none

(24) 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).

(25) TABLE-US-00005 TABLE 5 Occurrence of physiological disorder on 'ASUKI' fruits Year 2013 Rind Granu- Variety puffing Cracking lation Others ASUKI none none none slight: ASUMI none slight none sunacald SETOKA none none none AOSHIMAUNSHIU medium none none SHIRANUI little none none Year 2014 Rind Granu- Variety puffing Cracking lation Others ASUKI none none none slight: ASUMI none slight none sunacald SETOKA none slight none AOSHIMAUNSHIU little none none SHIRANUI little none none Year 2015 Rind Granu- Variety puffing Cracking lation Others ASUKI none none none slight: ASUMI none slight none sunacald SETOKA none slight none AOSHIMAUNSHIU much none none SHIRANUI little none none Rind puffing was numeralized as follows: none: no occurrence of rind puffing (score 0), little: rind was puffed around pedicel (score 1), medium: rind puffing was reached to equatorial portion of fruit (score 2), and much: rind was puffed throughout whole fruit (score 3), and evaluated by their average valule. Cracking of fruits were based on observation. none: without craking fruit. slight: less than 10% of fruits were craking fruits. many: no less than 10% of fruits were craking fruits. Granulation of fruits were based on observation. none: no granulation was observed. slight: slight granulations were observed. moderate: granulations were apparently observed, but not greater than of fruit pulps. severe: no less than of fruit pulps were granulated. When another physiological disorder was present, the type and degree of the physiological disorder was described. slight: some physiological disorder were found, but no problem for production of fruits. severe: there is a problem on production of fruits.

(26) 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.

(27) TABLE-US-00006 TABLE 6 Degree of fruit juice dripping of ASUKI The amount of The amount fruit juice of fruit juice dripping Investi- dripping immediately gation after after cutting of month Variety Name storage* (g) fruit** (mg) 2 Orange (Citrus sinensis) 0.527 6.87 3 ASUKI (Citrus L.) 0.562 4.25 2 ASUKI (Citrus L.) 0.655 3.85 4 KAWANONATSUDAIDAI 1.189 9.69 (Citrus natsudaidai Hayata f. Kawanonatsudaidai) 2 Grapefruit (Citrus paradisi) 1.384 12.25 12 AOSHIMAUNSHIU 1.444 5.57 (Citrus unshiu) 3 KIYOMI (Cirrus unshiu x Citrus 1.847 4.83 sinensis) *The amount of fruit juice dripping per 100 g of fruit pulp, after sealed storage at 4 C. for 24 hour. **The amount of fruit juice dripping per cross section (1 cm.sup.2).