New variety of white clover "green bear," and breeding method therefor

Abstract

The present invention relates to a new variety of white clover "green bear" and a breeding method therefor, and more specifically, to a new variety of white clover "green bear" plant and a breeding method therefor, the new variety being obtained by irradiating flowers of a white clover parent plant Ladino, and the new variety having a white V mark width 1.4-2.5 times greater at upper and lower lamina borders than that of the parent plant Ladino, being 70% or more leaves with four or more leaflets, and having the accession number of KCTC16025BP.

Description

New white clover variety 'Green Bear' and its breeding method

[0001] The present invention relates to a new white clover variety, 'Green Bear', and a breeding method thereof.

[0002]

[0003] This invention was researched with the support of the University Key Research Institute Support Project and the Creative Challenge Research Base Support Project of the National Research Foundation of Korea (Project No. 2019R1A6A1A11052070 and 2020R1I1A1A01063379).

[0004] White clover (Trifolium repensL.) is native to Europe and Central Asia and is one of the most important pasture perennial legumes in temperate regions worldwide. Due to its high protein content, white clover is widely used as livestock feed. Its rapid growth and efficient nitrogen fixation make it a popular cover crop and nitrogen-fixing crop. White clover leaves are generally circular or inverted heart-shaped, with white V-shaped markings and three leaflets. Its diverse morphology makes it an excellent ornamental plant, leading to the cultivation of numerous cultivars worldwide.

[0005] The technologies developed for white clover can be broadly divided into three types. The first type is a technology for fancy products using white clover leaves, especially the four leaves that symbolize good luck. The second type is a technology that utilizes the physiological activity of white clover. The third type is a technology for breeding four-leaf clovers.

[0006] The four-leaf clover, which is believed to bring good luck, is a kind of mutation. Most clovers have three leaves, and the four-leaf clover is rare, with only one for every three-leaf clover. Recently, the value of edible four-leaf clovers has increased as famous companies use them as toppings.

[0007] Meanwhile, Korean Patent Publication No. 2010-0122474 discloses a 'method for producing white clover in which a mutation in the number of leaves is induced', and Korean Patent Publication No. 2002-0031125 discloses a 'new four-leaf clover variety 'Lucky Together' and a method for mass-producing the same', but there is no description of the 'new white clover variety 'Green Bear' and a breeding method thereof' of the present invention.

[0008] The present invention was derived from the above-mentioned needs, and in order to develop a new white clover variety, the inventors irradiated the flowers of the white clover mother plant Ladino with radiation to cultivate a new white clover variety 'Green Bear' plant having external characteristics of Ladino, a wider white V mark at the upper and lower leaf blade borders, and having 70% or more leaves with 4 or more leaves, thereby completing the present invention.

[0009] In order to solve the above problem, the present invention provides a new white clover variety 'Green Bear' plant, which is obtained by irradiating the flower of the white clover mother plant Ladino with radiation, has a white V mark at the upper and lower leaf blade border that is 1.4 to 2.5 times wider than that of the mother plant Ladino, and has 70% or more leaves with 4 or more leaves, and has a deposit number of KCTC16025BP.

[0010] In addition, the present invention provides a part of the new white clover variety 'Green Bear' plant or a progeny plant derived therefrom.

[0011] In addition, the present invention comprises the steps of (a) irradiating flowers of white clover Ladino and then cultivating them to collect M1 seeds; (b) cultivating the M1 seeds of step (a) to select individuals exhibiting the traits of a white V mark on the upper and lower leaf blade borders and having four or more leaflets, and then propagating them vegetatively; (c) irradiating flowers of the vegetatively propagated individuals of step (b) to then cultivate them to collect M2 seeds; And (d) a step of cultivating the M2 seeds of the step (c) above, selecting individuals exhibiting the trait of having a white V mark at the upper and lower leaf blade border and having 4 or more leaflets, and propagating them through vegetative propagation; the present invention provides a method for breeding a new white clover variety 'Green Bear' plant having a width of a white V mark at the upper and lower leaf blade border that is 1.4 to 2.5 times larger than that of the parent plant Ladino, having 70% or more leaves with 4 or more leaflets, and having the deposit number KCTC16025BP.

[0012] The new white clover variety 'Green Bear' of the present invention has new leaf characteristics that are not found in existing white clover, and is expected to greatly contribute to increasing farm income through the cultivation of new high value-added clover varieties and to becoming a new variety with high economic value.

[0013] Figure 1 shows the white clover trait survey items.

[0014] Figure 2 is a photograph of the white clover mother variety Ladino and the applied variety 'Green Bear'.

[0015] In order to achieve the object of the present invention, the present invention provides a new white clover variety 'Green Bear' plant, which is obtained by irradiating a flower of a white clover mother plant Ladino with radiation, has a white V mark at the border of the upper and lower leaf blades that is 1.4 to 2.5 times wider than that of the mother plant Ladino, has 70% or more leaves with 4 or more leaves, and has a deposit number of KCTC16025BP.

[0016] The new white clover variety 'Green Bear' of the present invention has the morphological characteristics as described in Table 1, and is characterized by a white V mark at the upper and lower leaf blade border that is 1.4 to 2.5 times wider than that of the parental Ladino. In addition, the new white clover variety 'Green Bear' was confirmed to have leaves with 4 or more leaves in 70% or more, more preferably 80 to 90%, and specifically, based on 100 randomly selected leaflets, 15% had 3 leaves, 24% had 4 leaves, and 61% had 5 leaves. In contrast, the parental Ladino had 100% of 3 leaves out of 100 randomly selected leaflets, and no leaves with 4 or more leaves were confirmed.

[0017] According to one embodiment of the present invention, a new white clover variety, 'Green Bear', was bred by irradiating the white clover Ladino variety, which was being bred at the Jeju National University Subtropical Horticultural Industry Research Institute, and selecting individuals with many leaves having four or more leaves in addition to the external characteristics of the Ladino variety (white V marks on the borders of the upper and lower leaf blades).

[0018] The inventor of the present invention pedigree-fixed a white clover individual having the above-mentioned characteristics, named it White Clover (Trifolium repens) 'Green Bear', and deposited its callus to the Korean Collection for Type Cultures (KCTC) on October 10, 2023 (Accession number: KCTC19121P), and was assigned an international accession number on August 28, 2024 (Accession number: KCTC16025BP).

[0019] The present invention also provides a part of a new white clover variety 'Green Bear' plant having the above-described deposit number KCTC16025BP or a descendant plant derived therefrom.

[0020] The 'partial body' of the plant according to the present invention is not limited thereto, but may include roots, stems, leaves, flowers, pollen, etc. of the new white clover variety 'Green Bear'. In addition, the offspring plant may be a offspring plant derived through asexual reproduction (vegetative propagation) of the new white clover variety 'Green Bear', or a offspring plant derived through crossbreeding with another variety using the new white clover variety 'Green Bear' as a mother plant, but is not limited thereto.

[0021] The present invention also provides:

[0022] (a) A step of collecting M1 seeds by cultivating white clover Ladino flowers after irradiating them;

[0023] (b) A step of cultivating the M1 seeds of step (a) above, selecting individuals exhibiting the trait of a white V mark on the upper and lower leaf margins and having 4 or more leaflets, and propagating them through vegetative propagation;

[0024] (c) a step of collecting M2 seeds by cultivating the flowers of the vegetatively propagated individuals of step (b) by irradiating them; and

[0025] (d) a step of cultivating the M2 seeds of the above step (c) and selecting individuals exhibiting the trait of having a white V mark at the upper and lower leaf margins and having four or more leaflets, and propagating them through vegetative propagation; a method for breeding a new white clover variety 'Green Bear' plant having a width of a white V mark at the upper and lower leaf margins that is 1.4 to 2.5 times larger than that of the parent plant Ladino, having more than 70% of leaves with four or more leaflets, and having the deposit number KCTC16025BP is provided.

[0026] Additionally, in this specification, the "flower" of white clover refers to a flower in which each organ of the flower, namely the pistil, stamen, petal, and sepal, is in a differentiated state. Generally, flowering occurs after the flower bud is formed, and the flower's organs, namely the pistil, stamen, petal, and sepal, differentiate from this flower bud, and the differentiated flower's organs mature. Therefore, the "flower" of white clover can be understood to mean a flower in a state from the time when each organ of the flower is differentiated after the flower bud is formed until it is withered.

[0027] In the breeding method according to one embodiment of the present invention, the radiation irradiation in steps (a) and (c) may preferably be irradiating gamma rays at a dose of 40 to 60 Gy, more preferably irradiating gamma rays at a dose of 50 Gy, but is not limited thereto. In addition, the gamma rays are preferably 60 Co may be, but is not limited to.

[0028] In addition, the term "vegetative propagation" in this specification is a form of asexual reproduction, and is also expressed as vegetative reproduction, vegetative multiplication, or replication. Vegetative propagation is a complex process in which vegetative parts, excluding the reproductive organs, develop into a complete plant through stages such as redifferentiation. In terrestrial vascular plants, almost all vegetative parts, such as leaves, stems, and roots, are capable of vegetative propagation. A new organism with the same genetic information as the parent organism is created through vegetative propagation only through mitosis without exchanging genetic material with other organisms.

[0029] In one embodiment of the present invention, the vegetative propagation may preferably be carried out by cutting the 4th to 5th internode starting from where new leaves emerge and transplanting it into a new pot, but is not limited thereto.

[0030]

[0031] Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are merely illustrative of the present invention, and the content of the present invention is not limited to the following examples.

[0032]

[0033] Example 1. Development of a new white clover variety

[0034] In the present invention, the white clover Ladino variety, which is being bred at the Subtropical Horticultural Research Institute of Jeju National University, was used as a mother plant. The Ladino variety was received from Professor Jun Inoue of Kyushu University, Japan in March 1984, and was maintained by vegetative propagation after germination at Suncheon National University. After receiving it from Suncheon National University in 2003, it was maintained by vegetative propagation and used for cultivar development. The vegetative propagation was performed by cutting the 4th or 5th internode starting from where new leaves emerge and transplanting it to a new pot.

[0035] The white clover mother variety Ladino was grown under natural light conditions in a pot in a greenhouse at Jeju National University in 2020. During the flowering season (June to July), flowers of Ladino with flower stalks that had grown to about 20 cm were selected and irradiated with gamma rays. Gamma irradiation 60Using Co, gamma-irradiation was performed for 2 hours at a dose of 50 Gy using the radiation facility of Jeju National University's Radiation Research Institute. After gamma-irradiation, the flowers were covered with paper bags to prevent cross-pollination until the seeds matured, and M1 seeds were collected 1-2 months later. The collected M1 seeds were sown in different pots in the greenhouse and cultivated. Individuals that showed a white V mark at the upper and lower leaf blade margins and more than 70% of the leaflets had four or more leaves out of 100 randomly selected leaflets were selected and propagated vegetatively. Each selected individual was re-irradiated with gamma rays during the second vegetative propagation process. The gamma-irradiation conditions were the same as described above. After gamma-irradiation, the flowers were covered with paper bags to prevent cross-pollination, and the plants were cultivated in the greenhouse, and M2 seeds were collected 1-2 months later. The collected M2 seeds were sown in different pots in the greenhouse and grown. Individuals showing the characteristics of white V marks on the upper and lower leaf margins and more than 70% of the leaflets having 4 or more leaves were selected and propagated by vegetative propagation at least 3 times. It was confirmed that the characteristics of white V marks on the upper and lower leaf margins and more than 70% of the leaflets having 4 or more leaves were maintained during the propagation process.

[0036]

[0037] Example 2. Characteristics of the new white clover variety 'Green Bear'

[0038] The characteristics of the parent Ladino variety and the selected individuals (hereinafter referred to as “Green Bear”) that had more than 70% of leaves with four or more leaves and the external characteristics of the Ladino variety (white V marks on the upper and lower leaf blade borders) after two rounds of radiation exposure and three or more rounds of vegetative propagation were compared and analyzed.

[0039] The analysis of morphological characteristics was performed with reference to the "Crop Characteristics Survey Guidelines for New Cultivation Evaluation of the National Agricultural Products Resources of the Ministry of Agriculture, Food and Rural Affairs (https: / / www.seed.go.kr / seed / 192 / subview.do)" (https: / / www.seed.go.kr / seed / 192 / subview.do), and the plant form, leaf shape, leaf edge shape, number of leaves, upper lamina color, lower lamina color, upper and lower leaf margins (white V marks), midrib color, internode length, stolon thickness, petiole length, petiole thickness, central leaflet length, central leaflet width, leaf margin color, and flower color were investigated (Fig. 1). Five individuals were used for each plant, and the leaflets were examined using the central leaflets of the three-node expanded leaves from the top of the stem, and the color-related items were measured using the RHS color chart.

[0040] As a result of the analysis, as shown in Table 1 below, it can be seen that the new white clover cultivar Green Bear generally exhibits the external characteristics of its parental model, Ladino. While the width of the white V mark at the upper and lower leaf blade border of the parental model, Ladino, was 5.04±0.66 mm, the new cultivar Green Bear was confirmed to be 9.49±1.28 mm, which was 1.4 to 2.5 times larger than that of the parental model, Ladino (Fig. 2). In addition, it was found that the number of leaflets was mixed with 3, 4, and 5 leaves.

[0041]

[0042] In order to compare the number of leaves with 4 or more leaves in more detail, 100 leaflets were randomly selected from each plant and classified. As a result, in the case of the applied variety, Green Bear, it was confirmed that 15% of the 100 randomly selected leaflets had 3 leaves, 24% had 4 leaves, and 61% had 5 leaves. In the case of the parent variety, Ladino, all the leaves of the 100 randomly selected leaflets were confirmed to have 3 leaves, and no leaves with 4 or more leaves were observed.

[0043] Through this, it was found that the new white clover variety 'Green Bear' of the present invention has the morphological characteristics of the parent plant (white V marks on the borders of the upper and lower leaf blades) and has a significantly increased number of leaves of four or more compared to the parent plant, so that it can be utilized as a new white clover variety.

[0044] The inventor of the present invention induced callus of a new white clover variety, Green Bear, having the above characteristics, and deposited a patent therefor with the Korea Center for Biological Resources (KCTC) on October 10, 2023 (Accession Number: KCTC19121P), and was assigned an international deposit number on August 28, 2024 (Accession Number: KCTC16025BP). The callus of Green Bear was induced using the following method: Petioles of white clover Green Bear were collected, immersed in 70% ethanol for 30 seconds, and then washed twice with sterile water. Then, they were immersed in a 2% sodium hypochlorite (NaClO) solution for 20 minutes, and then washed three times with sterile water. Washed petioles were cut into 1-1.5 cm lengths and then plated on MS solid medium (pH 5.8) supplemented with 2.0 mg / L 2,4-D (2,4-dichlorophenoxyacetic acid) and 0.4 mg / L benzyladenopurine (BA). The petioles were cultured in the dark at 25°C and subcultured at 3-4 week intervals to induce callus. Once callus was induced on the petioles, only the callus was transferred to a new MS solid medium (containing 2,4-D and BA) and propagated.

[0045] [Accession number]

[0046] Name of depositor: Korea Research Institute of Bioscience and Biotechnology, Biological Resource Center (KCTC)

[0047] Accession number: KCTC16025BP

[0048] Date of acceptance: 20240828

[0049]

Claims

1. A new white clover variety, 'Green Bear', plant, deposit number KCTC16025BP, obtained by irradiating the flowers of the white clover mother plant, Ladino, with a white V mark 1.4 to 2.5 times wider at the upper and lower leaf blade borders than the mother plant, and with more than 70% of leaves having four or more leaves.

2. Part of the plant of the new white clover variety ‘Green Bear’ of Article 1.

3. In the second paragraph, a partial body of a new white clover variety 'Green Bear' plant, characterized in that the partial body is a root, stem, leaf, flower or pollen of the plant.

4. Offspring plants derived from the new white clover variety ‘Green Bear’ plant of paragraph 1. 5.(a) Step of collecting M1 seeds by irradiating the flowers of white clover Ladino and then cultivating them; (b) A step of cultivating the M1 seeds of step (a) above, selecting individuals exhibiting the trait of a white V mark on the upper and lower leaf margins and having 4 or more leaflets, and propagating them through vegetative propagation; (c) a step of collecting M2 seeds by cultivating the flowers of the vegetatively propagated individuals of step (b) by irradiating them; and (d) A method for breeding a new white clover variety 'Green Bear' plant, deposited number KCTC16025BP, which has a width of a white V mark at the upper and lower leaf blade boundaries that is 1.4 to 2.5 times larger than that of the parent plant Ladino and has 70% or more leaves with 4 or more leaves, including a step of cultivating the M2 seeds of step (c) above and selecting and propagating the plants through vegetative propagation.

6. A breeding method for a new white clover variety 'Green Bear' plant, whose deposit number is KCTC16025BP, characterized in that the radiation irradiation in steps (a) and (c) in paragraph 5 is irradiated with gamma rays at a dose of 40 to 60 Gy.

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