A method for creating strawberry germplasm for controlling weeds and application thereof

Abstract

The application provides a method for creating a strawberry germplasm for controlling weeds and application thereof, and belongs to the technical field of biological breeding. Forest strawberry 'Ruegen' is used as a female parent, and yellow hair strawberry is used as a male parent, F1 generation is obtained by hybridization, F2 generation is obtained by screening selfing of the F1 generation, and the F2 generation is screened to obtain a strain with less flowering, no fruiting, easy to sprout stolon and easy to tiller, which is the strawberry for controlling weeds. The forest strawberry 'Ruegen' with strong resistance and not sprouting stolon is crossbred with the yellow hair strawberry with easy sprouting stolon, the offspring is selected to have easy sprouting stolon, easy tillering and only flowering, and the strain is transplanted and applied to orchards and woodland, so that the growth of weeds can be inhibited.

Description

Technical Field

[0001] This invention belongs to the field of biological breeding technology, and in particular relates to a method for creating and applying strawberry germplasm for weed control. Background Technology

[0002] Weed management is a crucial aspect of agricultural production, impacting the agricultural ecological environment and ecological security, particularly in orchards. Chemical weed control poses significant safety risks, while physical weeding is labor-intensive and severely hinders the green development of the fruit industry. Previous research has shown that "planting grass to suppress weeds" can effectively improve understory management in orchards, promote fruit tree growth, and reduce management costs. Clover, alfalfa, and ryegrass are commonly used as understory grasses for weed suppression, soil protection, and fertilization to reduce costs and improve management. However, because their growth coincides with that of fruit trees, they inevitably compete for water and fertilizer. Furthermore, their rapid growth and tall stature necessitate manual mowing to alleviate competition, which is time-consuming and labor-intensive. Therefore, selecting suitable grass species is an effective strategy to properly address this issue.

[0003] Strawberry (Fragariae Strawberries) are small, perennial evergreen herbaceous plants, typically 5–40 cm tall, with short stems bearing whorled, clustered leaves. Slender runners, the reproductive organs of the strawberry, emerge from the leaf axils, forming new plants at the nodes. Therefore, creating a strawberry variety that reproduces quickly, readily produces runners and tillers, flowers but does not bear fruit, and does not interfere with the nutrient absorption and normal growth of the fruit tree, and transplanting it to orchards and woodlands to suppress weed growth, would effectively promote the green development of orchards and woodlands. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for creating strawberry germplasm for weed control, and the created strawberry can be applied to orchards and woodlands to suppress weed growth.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A method for creating strawberry germplasm for weed control involves using forest strawberry 'Ruegen' as the female parent and yellow-haired strawberry as the male parent to cross and obtain the F1 generation. The F1 generation is then screened for self-pollination to obtain the F2 generation. The F2 generation is selected for lines that have few flowers, do not produce fruit, easily produce runners, and easily tiller, which are the strawberry strains for weed control.

[0007] Preferably, the F1 generation selection criteria are lines with fewer flowers, fewer fruits, the ability to produce stolons, and easy tillering.

[0008] Preferably, pollen from the male parent is collected, pollinated on the stigma of the female parent, isolated by bagging, and the fruit is collected to obtain seeds, which are then sown to obtain the F1 generation.

[0009] Preferably, the F1 generation selected dominant plants are bagged with inflorescences, fruits are collected to obtain seeds, and sown to obtain the F2 generation.

[0010] Preferably, the seeds are stored at 4–8°C for 7–14 days before sowing.

[0011] Preferably, the seed substrate is used for sowing and seedling raising until the seedlings have three leaves and one bud, and then transplanted to a greenhouse for permanent planting.

[0012] Preferably, the planting method includes: thoroughly watering the transplanting bed surface, covering it with film, punching holes, and then planting the seedlings.

[0013] Another object of the present invention is to provide the application of strawberry germplasm obtained by the method in weed control.

[0014] Preferably, the obtained strawberry germplasm is planted in orchards and / or open spaces under trees.

[0015] Preferably, the planting spacing is 15-20cm × 15-20cm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention provides a method for creating strawberry germplasm for weed control. It utilizes interspecific hybridization between the resistant, non-runner-producing forest strawberry 'Ruegen' and the runner-producing yellow-haired strawberry. The offspring are selected from the dominant plants that readily produce runners and tillers, flowering but not fruiting. These are then transplanted into orchards and woodlands. The strawberry strain created by this invention reproduces rapidly, has a moderate plant height, grows quickly, requires no pruning, has shallow root systems, produces few flowers, does not bear fruit, consumes little nutrition, and does not affect the nutrient absorption and normal growth of fruit trees and woodland plants, effectively suppressing weed growth. This invention applies strawberry to suppress weed growth in orchards and woodlands, effectively promoting the green development of these areas. Attached Figure Description

[0018] Figure 1 Hybrid parents: Left: Maternal parent 'Ruegen' (Red Forest Strawberry), Right: Male parent 'Yellow Hairy Strawberry' plant;

[0019] Figure 2 SL-RxHM plants and leaves;

[0020] Figure 3 : The situation of 'strawberry grass' planted between the rows of grapevines one year ago;

[0021] Figure 4 Comparison of leaf traits: Left: Example 1 'Strawberry', Middle: Forest strawberry 'Ruegen', Right: Comparative Example 1 hybrid strawberry;

[0022] Figure 5Comparison of plant traits: Left: Mother plant 'Ruegen' (Forest Strawberry), Right: Example 1 'Strawberry'. Detailed Implementation

[0023] This invention provides a method for creating strawberry germplasm for weed control. Using forest strawberry 'Ruegen' as the female parent and yellow-haired strawberry as the male parent, hybridization is carried out to obtain F1 generation. The F1 generation is screened for self-pollination to obtain F2 generation. The F2 generation is selected for lines that have few flowers, do not produce fruit, easily produce runners, and easily tiller, which are the strawberry strains for weed control.

[0024] Forest strawberry is a wild diploid, with relatively short plants, 10-15cm tall, and somewhat weak growth. Its leaves are green and thin, with little pubescence. It exhibits strong drought resistance, salt tolerance, and shade tolerance. Forest strawberry varieties include those that produce runners and those that do not. This invention uses the non-runner forest strawberry 'Ruegen' as the female parent, whose fruit is red, also known as the red-fruited forest strawberry 'Ruegen'. The male parent is the yellow-haired strawberry, a wild diploid, with plants 12-18cm tall, vigorous growth, and readily producing runners. Its petioles and runners are robust, with dark green, thick, pinnately trifoliate leaves. The leaves, petioles, runners, and flower stalks are densely covered with erect, brownish-yellow pubescence, and it is resistant to leaf spot disease.

[0025] This invention utilizes interspecific hybridization between the resistant, non-runner forest strawberry 'Ruegen' and the runner-producing yellow-haired strawberry. In the F1 generation, lines with fewer flowers and fruits, but capable of producing runners and easily tillering, are selected for self-pollination to obtain the F2 generation. In the F2 generation, lines that easily produce runners and tillering, but only flower and do not bear fruit, are selected. After phenotypic observation, propagation, and transplanting, these lines are applied to orchards and woodlands to suppress weed growth. These lines not only reproduce quickly, but also have moderate plant height and vigor, requiring no pruning, have shallow root systems, produce few flowers and no fruit, consume little nutrition, and do not affect the nutrient absorption and normal growth of fruit trees.

[0026] In this invention, the standard for low number of flowers is ≤2 inflorescences per plant; the standard for low number of fruits is ≤2 normally developing fruits per plant; the standard for easy production of stolons is ≥6 stolons per mother plant; and the standard for easy tillering is ≥4 new stem branches per mother plant.

[0027] This invention discloses a method for creating strawberry germplasm, comprising interspecific hybridization: Pollen from the male parent is collected in April to May and pollinated onto the stigma of the female parent. The pollinated plants are then isolated by labeling and bagging. After the hybrid fruits mature, the fruits are collected to obtain seeds. Preliminary selection: After sowing the seeds, F1 generation plants are obtained. The traits of all F1 generation plants are observed, and lines with fewer flowers and fruits, capable of producing runners, and readily tillering are selected, denoted as SL-RxHM. Secondary selection: The inflorescences of the selected dominant F1 generation plants are isolated by bagging. Self-pollinated fruits of the F1 generation are collected to obtain seeds. After sowing these seeds, F2 generation plants are obtained. The traits of all F2 generation plants are observed, and further line selection is performed. Final selection: Among all F2 generation plants, the superior plants with strong growth, few flowers, no fruit, and readily tillering and producing runners are selected. These superior plants are propagated, transplanted into greenhouses, and their stability and uniformity are observed. The F2 generation strain obtained by screening in this invention easily produces stolons, easily tillers, and can reproduce rapidly; it is denoted as 'Strawberry'.

[0028] In this invention, the fruit pulp is washed away with running water. After rinsing, the seeds are left in a bag to air dry naturally indoors, and then sealed for storage. As an feasible method, the fruit is placed in a nylon bag and manually rubbed to wash away the pulp quickly and effectively. This rubbing process also breaks the seed coat, improving the germination rate. Allowing the seeds to air dry naturally in the bag reduces the need for drying space and prevents mixing of seeds from different hybrid combinations. The seeds are stored at 4–8℃ for 7–14 days before sowing, preferably 10–12 days. Low-temperature treatment of the seeds effectively improves the germination rate.

[0029] This invention employs substrate sowing and seedling cultivation from late May to early June. The substrate is a mixture of peat and vermiculite in a volume ratio of 2-4:1. The substrate used in this invention has good water retention, which is beneficial for promoting seed germination. Seedlings with three leaves and one bud are selected for transplanting to greenhouses from late August to mid-September. Before transplanting, the planting beds are thoroughly watered with a sprinkler system, then covered with black plastic film, and holes are punched for planting the seedlings. Covering the transplanting beds with film and punching holes before planting strawberry seedlings with three leaves and one bud reduces damage to the plants during mulching, and the increased soil temperature after mulching promotes rapid plant growth. From November to May of the following year, all obtained plants are observed for their characteristics, and dominant plants are selected.

[0030] The present invention also provides the application of strawberry germplasm obtained by the method in weed control.

[0031] The F2 generation strains screened by the above method of the present invention are the strawberry germplasm for weed control—Strawberry Grass. The Strawberry Grass is transplanted in orchards and / or open spaces under forests in March, with a plant spacing of 15-20cm × 15-20cm. At the time of planting, the roots are straight and "shallow enough not to expose the roots, and deep enough not to bury the crown". The canopy closes in September of the same year, and the understory remains evergreen all year round, so as to achieve the effect of controlling weeds.

[0032] The present invention relates to water and fertilizer management after transplanting the strawberry grass. After planting, the strawberry grass should be thoroughly watered immediately to help it establish roots. Subsequently, it should be watered once every 7 days, morning and evening, and allowed to dry slightly between waterings once it has established itself. A 0.2%-0.3% compound fertilizer solution should be sprayed once in late November to early December, and a 0.2%-0.4% urea solution should be sprayed once in early February. At other times, a 0.3%-0.4% compound fertilizer solution should be sprayed monthly. The compound fertilizer described in this invention has an N:P2O5:K2O ratio of 15:15:15 or 17:17:17.

[0033] In a specific embodiment of this invention, pest and disease management includes: during the high temperature and humidity period from May to July, drench the roots 2-3 times with a mixture of 1000x azoxystrobin + 1000x metalaxyl / cymoxanil / oxadixyl + 0.3% urea + 0.3% potassium dihydrogen phosphate + 200g / mu of Bacillus subtilis preparation to prevent root rot and anthracnose and promote root growth. For underground pests such as grubs, mole crickets, and cutworms, 5% phoxim granules can be used at a rate of 2.5-3 kg per mu, mixed with 25-30 kg of fine soil and applied as a trap. In this invention, when preventing root rot and anthracnose, any one of the metalaxyl, cymoxanil, and oxadixyl can be used.

[0034] In March of the second year after planting, the strawberries of this invention can be transplanted to a new site if they are too densely planted, which will result in stronger growth and reduced disease.

[0035] The strawberry plant created by this invention only flowers and produces few flowers, without bearing fruit, which effectively reduces the plant's nutrient consumption and avoids pests and diseases caused by fruit rot; the strawberry plant is of medium height (16.9-20.6cm), has strong disease resistance, does not require pruning, and effectively reduces management costs.

[0036] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0037] Example 1

[0038] A method for creating strawberry germplasm for weed control

[0039] In April 2019, the Red Forest Strawberry 'Ruegen' (which does not produce runners) was used as the female parent, and the Yellow Hairy Strawberry from Guizhou (which produces runners) was used as the male parent (male and female parents are as follows). Figure 1 (As shown), interspecific hybridization was carried out. Pollen from the male parent was collected and used to pollinate the stigma of the female parent. The pollinators were then isolated by labeling and bagging. The hybrid fruits were collected in mid-May after they matured. The fruits were hand-washed in nylon stockings to remove the pulp, leaving only the seeds. The seeds were kept in the nylon stockings and air-dried indoors. After air-drying, they were placed in a 4°C refrigerator for 10 days. In early June, seedlings were sown using a substrate with a peat moss and vermiculite volume ratio of 3:1. By late August, the three-leaf-one-heart seedlings were transplanted to a greenhouse to obtain F1 generation plants.

[0040] The traits of all F1 generation plants were observed for two consecutive years, and the dominant plant SL-RxHM (plant and leaves as shown) was obtained. Figure 2 As shown in the image, the plant produces stolons and is also prone to tillering, flowering, and producing a small amount of fruit.

[0041] In April 2021, the inflorescences of the SL-RxHM strain were bagged to obtain self-pollinated fruits. The fruits were hand-washed to remove the pulp, leaving only the seeds. The seeds were kept in nylon stockings and dried indoors in the shade before being placed in a 4℃ refrigerator for 10 days. In early June, seedlings were sown using a peat:vermiculite (volume ratio) of 3:1. In September, three-leaf-one-heart seedlings were transplanted to a greenhouse. The traits of all F2 generation plants were observed for two consecutive years. A strain with uniform growth, no trait segregation, few flowers, no fruit, and easy tillering and stolon formation was selected and named 'Strawberry Grass'.

[0042] Example 2

[0043] Application of 'Berry Grass' in Weed Control

[0044] In April 2023, 'Strawberry' was transplanted between grape rows and under trees, with a spacing of 15cm x 20cm. After planting, it was thoroughly watered immediately to help the roots establish. Watering was then repeated twice daily (morning and evening) for the next 7 days, allowing the soil to dry slightly between waterings after it had established itself. 'Strawberry' began to close the canopy in September, remaining evergreen year-round. A small number of white flowers appeared in March of the following year, but no fruit set. A 0.2% compound fertilizer solution (N:P2O5:K2O = 15:15:15) was sprayed once at the end of November, and a 0.3% urea solution was sprayed once in early February. Other monthly sprays with a 0.3% compound fertilizer solution were applied, while paying close attention to pest and disease control.

[0045] 'Strawberry' is planted between grape rows and completely closed off after one year (e.g.) Figure 3 As shown in the image, the plant grows in dense clumps with branching branches. The average plant height is 15.68 cm, with 6-8 compound leaves. The average petiole length of the third leaf is 12.78 cm, and the average leaf area is 18.38 cm². 2 The average rhizome diameter is 5.67 mm, with an average of 13.4 roots larger than 0.2 mm, and the longest root has an average length of 9.72 cm.

[0046] Comparative Example 1

[0047] The difference between this comparative example and Example 1 is that the maternal parent is *Strawberry 'Ruegen'*, and the paternal parent is *Strawberry ginkgo biloba*. The paternal parent was introduced from the strawberry germplasm resource nursery of Shenyang Agricultural University.

[0048] Experimental Example 1

[0049] This experiment compared the traits of Example 1, Comparative Example 1, and the parental forest strawberry 'Ruegen' plant.

[0050] Table 1 Comparison of plant traits

[0051]

[0052] From Table 1 and Figure 4 As can be seen, the 'Strawberry' plant in Example 1 is semi-erect, with yellowish-green, spoon-shaped leaves, auricles, 3-5 leaflets, rhomboid leaflets, serrated edges of the central leaflet, and light red stipules. It is significantly different from its parent, the Forest Strawberry 'Ruegen', and easily distinguishable. This indicates that 'Strawberry' is a new strain.

[0053] Table 2 Comparison of plant height and leaf size

[0054] Material Plant height / cm Number of compound leaves / sheet Petiole length / cm Leaf length / cm Leaf width / cm Leaf area / cm2 Example 1 18.30±1.42c 75.0±9.82a 11.50±1.78c 4.10±0.58c 2.80±0.31c 23.43±5.98c Forest Strawberry 'Ruegen' 25.70±2.32a 56.0±7.78b 18.43±0.68a 6.40±0.07a 4.13±0.18a 52.94±2.86a Comparative Example 1 22.47±1.68b 48.67±0.82b 14.93±1.35b 4.73±0.25b 3.50±0.37b 33.37±5.34b

[0055] Table 2 shows that 'Strawberry' has an average plant height of 18.30 cm, significantly shorter than its parent, Forest Strawberry. It has more compound leaves, shorter petioles, and smaller leaf area. This indicates that the plant is short and robust, with small and numerous leaves, making it very suitable as a green ground cover plant. It is highly competitive and can effectively suppress weed growth.

[0056] Table 3 Comparison of root, stem, and flower characteristics

[0057]

[0058] From Table 3 and Figure 5 The results showed that 'Mei Cao' had an average of 34 roots longer than 0.2 mm, with the longest root averaging 16.07 cm, significantly shorter than the forest strawberry 'Ruegen' and the hybrid strawberry of Comparative Example 1. It also had 15.67 new stem branches, significantly more than both the forest strawberry and the hybrid strawberry of Comparative Example 1. The number of runners was 21, more than the parent plant, and no inflorescences were observed at the time of the analysis. This indicates that 'Mei Cao' has strong tillering ability and produces many runners, enabling rapid propagation, superior to both the parent plant, forest strawberry, and the hybrid strawberry of Comparative Example 1. Furthermore, 'Mei Cao' rarely produced inflorescences after one year of planting; the plants were without inflorescences at the time of the analysis, while the forest strawberry 'Ruegen' and the hybrid strawberry of Comparative Example 1 had an average of 8.5 and 7.5 inflorescences respectively. The fact that 'Mei Cao' produces fewer inflorescences and no fruit suggests reduced nutrient consumption.

[0059] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for creating strawberry germplasm for weed control, characterized in that, Using the forest strawberry 'Ruegen' as the female parent and the yellow-haired strawberry as the male parent, the F1 generation was obtained by hybridization. The F1 generation was screened for self-pollination to obtain the F2 generation. The F2 generation was selected for lines that had fewer flowers, did not produce fruit, easily produced runners, and easily tillered. These were the strawberry lines for weed control. The selection criteria for the F1 generation are lines with fewer flowers, fewer fruits, the ability to produce stolons, and easy tillering.

2. The method for creating strawberry germplasm according to claim 1, characterized in that, Pollen from the male parent was collected and used to pollinate the stigma of the female parent. The pollen was then isolated by bagging, and the fruits were collected to obtain seeds. The seeds were then sown to obtain the F1 generation.

3. The method for creating strawberry germplasm according to claim 2, characterized in that, The inflorescences of the dominant plants selected in the F1 generation were bagged, the fruits were collected to obtain seeds, and the seeds were sown to obtain the F2 generation.

4. The method for creating strawberry germplasm according to claim 2 or 3, characterized in that, The seeds were stored at 4-8℃ for 7-14 days before sowing.

5. The method for creating strawberry germplasm according to claim 4, characterized in that, The seeds are sown in a substrate and raised until they have three leaves and one heart, then transplanted to a greenhouse for permanent planting.

6. The method for creating strawberry germplasm according to claim 5, characterized in that, The planting method includes: thoroughly watering the transplanting bed, covering it with film, punching holes, and then planting the seedlings.

7. The application of strawberry germplasm obtained by the method according to any one of claims 1 to 6 in weed control.

8. The application according to claim 7, characterized in that, The obtained strawberry germplasm was planted in orchards and / or open spaces under trees.

9. The application according to claim 8, characterized in that, The planting spacing is 15-20cm × 15-20cm.

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