Breeding method for adjusting color of broccoli flower ball and application thereof

Abstract

The present application belongs to the field of agricultural quality improvement technology, and particularly relates to a breeding method for adjusting the color of broccoli florets and application thereof. The cold plasma treatment technology is applied to adjusting the color of broccoli florets for the first time. It is found through research that the cold plasma technology with different treatment powers can improve the cold resistance of broccoli seedlings, and further adjust the content of anthocyanins in the florets. The technology can be applied to the breeding of broccoli to select new varieties of broccoli with green color and unchanged color at low temperature. The present application provides a new method for adjusting the color of broccoli florets and breeding broccoli. Compared with the traditional methods for adjusting the color of broccoli and breeding broccoli, the method of the present application realizes the rapid improvement of the color of broccoli florets, and therefore has important scientific research and economic values.

Description

Technical Field

[0001] This invention belongs to the field of agricultural quality improvement technology, specifically relating to a breeding method for adjusting the color of broccoli florets and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Broccoli (scientific name: *Brassica oleracea* var. *italica*, English: broccoli), also known as green cauliflower, is rich in vitamin C and dietary fiber, and contains various nutrients with potent anti-cancer properties. It is also rich in minerals such as calcium, phosphorus, iron, potassium, zinc, and manganese. The artificial grading indicators for broccoli mainly include fresh weight, color, and appearance quality. Color is one of the most important quality indicators.

[0004] Anthocyanins are water-soluble pigments and one of the main pigments that contribute to the color of petals and fruits. Broccoli florets turn purple due to low temperatures. While the florets themselves may appear normal, the purple color of the buds negatively impacts their marketability. This is a physiological disorder caused by low temperatures. When broccoli florets are exposed to temperatures below 0°C during their formation, glycosides within the floret tissue are converted into anthocyanins, resulting in purple florets. The purple color disappears once the temperature returns to normal, but purple florets caused by secondary freezing damage are generally difficult to reverse. Currently, both the export and domestic markets for broccoli have increasingly higher requirements for the appearance and quality of florets. Selecting florets with good color, attractive shape, and a round shape is a primary goal in the breeding of new broccoli varieties. Specifically, broccoli varieties should have small, dark green buds that do not change color at low temperatures. If the tips of the florets turn pale purple or slightly red at harvest, it will affect their marketability. Therefore, the color of the broccoli florets is a very important indicator in agricultural production.

[0005] Plasma, the fourth state of matter, is a higher-energy aggregate state containing a large number of excited molecules, atoms, free radicals, electrons, and other active particles. Plasma is mainly used in chemical smelting, spraying, and welding; in recent years, it has been applied to seed treatment in agriculture. The numerous active particles in plasma can act on plants, causing changes in certain traits. Applying this technology to agricultural breeding is still a relatively new research area both domestically and internationally, primarily for improving target traits such as disease resistance, germination rates, yield, and marketability in crops like wheat, corn, peanuts, and soybeans. Currently, there are no reports or studies on the application of cold plasma treatment in breeding methods for regulating the color of broccoli florets. Summary of the Invention

[0006] To overcome the aforementioned technical problems, this invention provides a breeding method for adjusting the color of broccoli florets and its application. Specifically, this invention is the first to apply cold plasma treatment technology to adjust the color of broccoli florets. Research has shown that treating broccoli seedlings with cold plasma technology at different power levels can improve the cold resistance of broccoli, thereby regulating the anthocyanin content in the florets. Applying this technology to broccoli breeding allows for the selection of new broccoli varieties that are green and do not change color at low temperatures. This provides a new method for adjusting the color of broccoli florets and for broccoli breeding. Compared to traditional methods for adjusting broccoli color and breeding, this invention achieves rapid improvement of broccoli floret color, thus possessing significant scientific research and economic value. Based on the above research results, this invention was completed.

[0007] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0008] A first aspect of the invention provides the application of cold plasma in adjusting the color of broccoli florets.

[0009] Specifically, the application includes: using cold plasma to treat broccoli seedlings, which effectively improves the cold resistance of broccoli, thereby reducing the anthocyanin content in the florets, resulting in green florets at maturity that do not turn red at low temperatures, improving their marketability and edibility, and increasing the added value of agricultural products.

[0010] A second aspect of the present invention provides a breeding method for adjusting the color of broccoli florets, the breeding method comprising: treating broccoli seedlings with cold plasma to breed new broccoli varieties that are green in color and do not change color at low temperatures.

[0011] The breeding method specifically includes: treating broccoli seeds with broccoli seedlings, subjecting the broccoli seedlings to cold plasma treatment, and planting the treated broccoli seedlings in the field to obtain cold-resistant broccoli; furthermore, assisting conventional breeding to obtain new broccoli varieties with improved cold resistance and no reddening at low temperatures.

[0012] A third aspect of the invention provides the use of the above-described applications and / or the above-described breeding methods in any one or more of the following (b1)-(b6):

[0013] (b1) Promotes an increase in the longest root length and stem diameter of broccoli;

[0014] (b2) Promotes the increase of SOD activity in broccoli;

[0015] (b3) Improve the low-temperature resistance of broccoli;

[0016] (b4) Reduce the anthocyanin content in broccoli florets;

[0017] (b5) Adjusting the color of the broccoli florets;

[0018] (b6) Breed new varieties of broccoli.

[0019] The beneficial technical effects of one or more of the above technical solutions are as follows:

[0020] 1. The above technical solution uses cold plasma to treat broccoli at the three-leaf-one-heart stage, which can increase the SOD content under low temperature stress, increase the length of the longest root and the stem diameter, and obtain cold-resistant broccoli seedlings that can be directly used for field planting.

[0021] 2. The above technical solution uses cold plasma treatment to resist the low temperature climate during the ripening period, reduce the anthocyanin content of the cauliflower head, and obtain broccoli florets with a bright green color.

[0022] 3. The above technical solution combines field planting and conventional breeding, and the application of cold plasma treatment in the targeted breeding of broccoli has important scientific research value and practical application value. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 This is a flowchart illustrating the breeding and application of cold-resistant broccoli varieties obtained through cold plasma treatment as described in this invention. Detailed Implementation

[0025] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0026] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. It should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for the purpose of describing specific embodiments and not for limiting the scope of protection of the present invention.

[0027] As mentioned earlier, color is one of the important quality indicators in the artificial grading of broccoli. However, broccoli florets turn purple due to low temperatures, so selecting florets with good color, beautiful shape, and roundness is the primary goal in the breeding of new broccoli varieties.

[0028] In view of this, in a typical embodiment of the present invention, the application of cold plasma in adjusting the color of broccoli florets is provided.

[0029] In another specific embodiment of the present invention, the application includes: treating broccoli seedlings with cold plasma to effectively improve the cold resistance of broccoli, thereby reducing the anthocyanin content in the florets, resulting in green florets at maturity that do not turn red at low temperatures, thus improving their marketability and edibility, and increasing the added value of agricultural products.

[0030] In another specific embodiment of the present invention, the improvement of the cold resistance of broccoli is specifically manifested in at least one of the following (a1)-(a2):

[0031] (a1) Promotes an increase in the longest root length and stem diameter of broccoli;

[0032] (a2) Promotes the increase of SOD activity in broccoli.

[0033] In another specific embodiment of the present invention, a breeding method for adjusting the color of broccoli florets is provided. The breeding method includes: treating broccoli seedlings with cold plasma to select new broccoli varieties that are green in color and do not change color at low temperatures.

[0034] In another specific embodiment of the present invention, the breeding method specifically includes: treating broccoli seeds with broccoli seedlings, treating the broccoli seedlings with cold plasma, and planting the treated broccoli seedlings in the field to obtain cold-resistant broccoli; furthermore, by assisting conventional breeding, a new broccoli variety with improved cold resistance and no reddening at low temperatures is obtained.

[0035] Specifically, the broccoli seedlings are broccoli seedlings at the three-leaf-one-heart stage.

[0036] The specific conditions for the cold plasma treatment are as follows:

[0037] The cold plasma treatment power is 10-1000W, and the treatment time is 0-10s.

[0038] In another specific embodiment of the present invention, the cold plasma treatment power is 500-800W and the treatment time is 3-6s.

[0039] In another specific embodiment of the present invention, the cold plasma treatment power is 600W and the treatment time is 5s.

[0040] In another specific embodiment of the present invention, the above-described applications and / or the above-described breeding methods are provided for use in any one or more of the following (b1)-(b6):

[0041] (b1) Promotes an increase in the longest root length and stem diameter of broccoli;

[0042] (b2) Promotes the increase of SOD activity in broccoli;

[0043] (b3) Improve the low-temperature resistance of broccoli;

[0044] (b4) Reduce the anthocyanin content in broccoli florets;

[0045] (b5) Adjusting the color of the broccoli florets;

[0046] (b6) Breed new varieties of broccoli.

[0047] Specifically, in step (b5), adjusting the color of the broccoli florets means obtaining broccoli florets that are green and do not turn red at low temperatures.

[0048] In (b6), the selection and breeding of new broccoli varieties specifically refers to the selection and breeding of new broccoli varieties with improved cold resistance, green flower heads, and no reddening at low temperatures.

[0049] The technical solution of the present invention will be described below through specific embodiments. The raw materials used in the following embodiments are all commercially available, and the equipment used is all existing equipment.

[0050] Example 1

[0051] 1. Select healthy broccoli seedlings with consistent growth as experimental materials.

[0052] 2. Place the three-leaf broccoli seedlings into a cold plasma treatment device with a treatment power of 10-1000W and a treatment time of 0-10s.

[0053] 3. Treated broccoli seedlings and untreated broccoli seedlings from the same batch were planted in the field.

[0054] 4. When the broccoli seedlings grow to the stage of four leaves and one bud, the treated broccoli seedlings and the untreated broccoli seedlings from the same batch are placed in a light-cured culture room for 4℃ low-temperature stress treatment. After 15 days of low-temperature treatment, they are moved to room temperature for 15 days of recovery treatment. The longest root length and stem diameter of each variety are measured before treatment, after treatment, and after recovery. The growth of the longest root length and stem diameter after recovery compared to before treatment is calculated. Fresh leaves are weighed after the low-temperature treatment recovery to measure the SOD activity of each treatment.

[0055] (1) Low temperature stress treatment, cold plasma treatment on the growth of the longest root length and stem diameter of broccoli after recovery, and comparison of the effect of cold plasma treatment on the cold resistance of broccoli seedlings.

[0056] Table 1. Effects of different cold plasma treatments on the growth of broccoli under low-temperature stress.

[0057]

[0058] Table 1 shows the percentage increase in longest root length, indicating the percentage increase in longest root length among broccoli seedlings treated with cold plasma after recovery from low-temperature stress, compared to the same batch of untreated broccoli seedlings selected in step 1. For example, at a treatment power of 600W and a treatment time of 5s, the highest increase in longest root length was observed in variety LZ28 (38.42%), while the lowest was observed in variety LZ4 (22.56%). The remaining experimental varieties showed increases in longest root length ranging from 22.56% to 38.42%.

[0059] The percentage increase in stem diameter represents the percentage increase in stem diameter of broccoli seedlings treated with cold plasma after recovery from low-temperature stress, compared to the same batch of untreated broccoli seedlings selected in step 1. For example, at a treatment power of 600W and a treatment time of 5s, the highest increase in stem diameter was observed in variety LZ7 at 7.14%, while the lowest was observed in variety LZ16 at 4.62%. The remaining experimental varieties showed increases in stem diameter ranging from 4.62% to 7.14%.

[0060] Under low temperature stress, the seedlings treated with cold plasma showed increased growth in the longest root length and stem diameter compared to the untreated seedlings of the same batch. The treated seedlings grew faster under low temperature conditions, indicating that cold plasma treatment promoted the low temperature resistance of broccoli seedlings and improved their cold tolerance during the seedling stage.

[0061] (2) Comparison of the effects of low temperature stress treatment and cold plasma treatment on SOD in broccoli seedlings.

[0062] Superoxide dismutase (SOD) is an important protective enzyme that plays a crucial role in plant responses to abiotic stresses such as low temperature. Increased SOD activity can effectively scavenge excess oxygen. 2- This method helps maintain normal physiological functions in plants and enhances their resistance to adverse conditions. The NBT (nitroblue tetrazolium) photoreduction method was used to determine SOD activity, with a dark control as a blank. The absorbance of the reaction solution was measured at 560 nm, and the results are calculated as follows:

[0063]

[0064] In the formula, A0: absorbance of the control tube under light; As : Absorbance of sample measurement tube; V t Total volume of sample extract (mL); V s : Volume of crude enzyme solution taken during the assay (mL); t: Irradiation time for the colorimetric reaction (min); FW: Fresh weight of the sample (g)

[0065] The effects of low-temperature stress treatment on the SOD activity ratio of broccoli seedlings treated with cold plasma compared to the same batch of broccoli seedlings selected in step 1 without any treatment are as follows:

[0066] Table 2. Effects of different cold plasma treatments on SOD activity in broccoli under low-temperature stress.

[0067]

[0068]

[0069] Table 2 shows the percentage increase in SOD activity, indicating the increase in SOD activity in broccoli seedlings treated with cold plasma after recovery from low-temperature stress compared to the same batch of untreated broccoli seedlings selected in step 1. For example, at a treatment power of 600W and a treatment time of 5s, the highest increase in SOD activity was observed in variety LZ28 (9.61%), while the lowest was observed in variety LZ7 (6.52%). The increase in SOD activity for the remaining experimental varieties ranged from 6.52% to 9.61%. This indicates that under low-temperature stress conditions, cold plasma treatment increased SOD activity in broccoli seedlings, enhancing their response to low-temperature stress and increasing their cold resistance.

[0070] Example 2

[0071] 1. Place broccoli seeds into a cold plasma treatment device with a treatment power of 10-1000W and a treatment time of 0-10s; cultivate seedlings under the same conditions as untreated broccoli seeds, as treatment 1.

[0072] 2. Select healthy, uniformly growing broccoli seedlings with three leaves and one heart, and place them into a cold plasma treatment device with a treatment power of 10-1000W and a treatment time of 0-10s. This is called treatment 2.

[0073] 3. The same batch of untreated broccoli seedlings served as a control.

[0074] 4. Treated broccoli seedlings and untreated broccoli seedlings from the same batch were planted in the field.

[0075] 5. After 5 days of low-temperature treatment at 0℃ during the ripening period and 5 days of recovery growth, the anthocyanin content of the florets was determined, and the effect of cold plasma treatment on the anthocyanin content of broccoli florets was compared. The anthocyanin components in the sample solution were analyzed and detected by high-performance liquid chromatography (HPLC) to obtain the anthocyanin content.

[0076] Table 3. Effects of different cold plasma treatments on anthocyanin content in mature broccoli florets.

[0077]

[0078]

[0079] Table 3 shows the anthocyanin reduction rate, indicating the percentage decrease in anthocyanin content in broccoli heads after recovery from low-temperature stress at maturity, compared to the same batch of untreated broccoli heads selected in step 1. For example, with a treatment power of 600W and a treatment time of 5s, the largest reduction in anthocyanin content in the heads after low-temperature treatment at maturity was observed in the cold-plasma-treated *Hanmei* seedlings (12.17%), while the smallest reduction was observed in LZ12 (7.52%). The reduction in anthocyanin content in the heads of the other tested varieties ranged from 7.52% to 12.17%, indicating that cold plasma treatment of seeds had little effect on anthocyanin content in broccoli heads under the same conditions. This suggests that under the same conditions, cold plasma treatment of seeds had little effect on the anthocyanin content of mature broccoli heads, failing to achieve the expected results. Cold plasma treatment of broccoli seedlings enhanced cold resistance, and when exposed to low temperatures at maturity, the anthocyanin content in the heads was lower than in untreated seedlings, meaning the heads did not change color at low temperatures, thus improving marketability.

[0080] Example 3

[0081] 1. Select healthy broccoli seedlings with consistent growth as experimental materials.

[0082] 2. Place the three-leaf, one-heart broccoli seedlings into a cold plasma treatment device with a treatment power of 600W and a treatment time of 5s.

[0083] 3. The treated broccoli seedlings and the untreated broccoli seedlings from the same batch were planted in the field. Under the conditions of cold plasma treatment power of 600W and treatment time of 5s, the conventional breeding of broccoli was assisted, and the effect of low temperature stress on the maturity period of the bred new varieties on anthocyanins was compared.

[0084]

[0085]

[0086] The percentage reduction in anthocyanins in the new broccoli varieties indicates that, after recovering from low-temperature stress as described in step 5 of Example 2, the new broccoli varieties bred from seedlings treated with cold plasma showed a 5.71-10.68% reduction in anthocyanins compared to the untreated varieties. This demonstrates that the florets of the bred new broccoli varieties did not turn red under low-temperature conditions, meeting the expected target.

[0087] The new broccoli varieties underwent quality identification tests, plot comparison tests, demonstration projects, and production promotion, resulting in new broccoli varieties with good cold resistance and no discoloration at low temperatures.

[0088] A new broccoli variety, Hanmei, was developed. Variety rights application number: 20241003627.

[0089] New broccoli combinations LZ4, LZ7, LZ12, LZ16, and LZ28 have passed quality assessment tests.

[0090] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of them. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Although the specific embodiments of the present invention have been described above, they are not intended to limit the protection scope of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. The application of cold plasma in adjusting the color of broccoli florets, the application including: Cold plasma treatment of broccoli seedlings effectively improves the cold resistance of broccoli, thereby reducing the anthocyanin content in the florets, resulting in green florets at maturity that do not turn red at low temperatures; The specific conditions for the cold plasma treatment are as follows: the cold plasma treatment power is 400-800W, and the treatment time is 3-6s.

2. The application as described in claim 1, characterized in that, The improvement of broccoli's cold resistance is specifically manifested in at least one of the following (a1)-(a2): (a1) Promotes an increase in the longest root length and stem diameter of broccoli; (a2) Promotes the increase of SOD activity in broccoli.

3. A breeding method for adjusting the color of broccoli florets, characterized in that, The breeding method includes: treating broccoli seedlings with cold plasma to breed new broccoli varieties that are green in color and do not change color at low temperatures; The specific conditions for the cold plasma treatment are as follows: the cold plasma treatment power is 400-800W, and the treatment time is 3-6s.

4. The breeding method as described in claim 3, characterized in that, The breeding method specifically includes: treating broccoli seeds to obtain broccoli seedlings, subjecting the broccoli seedlings to cold plasma treatment, and planting the treated broccoli seedlings in the field to obtain cold-resistant broccoli; furthermore, assisting conventional breeding to obtain new broccoli varieties with improved cold resistance and no reddening at low temperatures.

5. The breeding method as described in claim 4, characterized in that, The broccoli seedlings mentioned are specifically broccoli seedlings at the three-leaf-one-heart stage.

6. The breeding method as described in claim 3, characterized in that, The cold plasma treatment power is 600W, and the treatment time is 5s.

7. Use of the breeding method according to any one of claims 3-6 in any one or more of the following (b1)-(b6): (b1) Promotes an increase in the longest root length and stem diameter of broccoli; (b2) Promotes the increase of SOD activity in broccoli; (b3) Improve the low-temperature resistance of broccoli; (b4) Reduce the anthocyanin content in broccoli florets; (b5) Adjust the color of the broccoli florets; (b6) Breed new varieties of broccoli.

8. The use as described in claim 7, characterized in that, In (b5), adjusting the color of the broccoli florets specifically means obtaining broccoli florets that are green and do not turn red at low temperatures.

9. The use as described in claim 7, characterized in that, In (b6), the selection and breeding of new broccoli varieties specifically refers to the selection and breeding of new broccoli varieties with improved cold resistance, green flower heads, and no reddening at low temperatures.

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