Cucurbit vegetable grafted seedling healing promoting agent

Abstract

The invention discloses a healing promoting agent for melon vegetable grafted seedlings. The healing promoting agent contains abscisic acid and ribulose phosphate. The effect of promoting communication of phloem and xylem of grafted seedlings can be achieved by spraying the healing promoting agent before grafting, the healing time of the melon vegetable grafted seedlings is shortened, the operation of film uncovering and film covering in the healing period is reduced, the healing period management is simplified, and the healing cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of vegetable seedling technology, specifically relating to a healing agent for grafted seedlings of cucurbit vegetables. Background Technology

[0002] Cucurbit vegetables are a major category of greenhouse vegetables in my country. Rich in vitamins, they play a role in regulating blood pressure and blood sugar, providing essential vitamins for human health and possessing high economic and nutritional value. However, years of cultivation often lead to problems such as continuous cropping obstacles and soil-borne diseases. Grafting can significantly improve the plant's resistance to low temperatures, salinity, soil-borne diseases, and continuous cropping obstacles, promote water and mineral nutrient absorption, and increase yield and quality. It has become a core element of intensive seedling cultivation.

[0003] However, graft healing management is a crucial step in grafted seedling production. Whether grafted seedlings heal promptly and fully directly determines later survival rate, seedling establishment speed, and early yield. Traditional healing management mainly relies on physical methods such as airtight humidity control, temperature and light control, which are cumbersome, energy-intensive, and often extend the healing period to over 10 days in low-temperature, low-light seasons. This results in low vascular bundle connectivity between the rootstock and scion, making them highly susceptible to later physiological disorders such as "cavities" and "discontinuities." This necessitates stricter management, increases labor costs, and the prolonged healing period increases the risk of leaf rot, leading to reduced survival rate and quality, thus becoming a bottleneck restricting the large-scale production of high-quality seedlings. Therefore, developing a simple, efficient, and low-cost exogenous healing-promoting technology has become a critical issue that the industry urgently needs to address. Summary of the Invention

[0004] To improve the grafting survival rate of grafted seedlings of cucurbit vegetables, this invention proposes a grafting agent for cucurbit grafted seedlings, which can achieve a grafting survival rate of over 95% and simultaneously enable rapid healing of grafted seedlings, shortening the healing time and reducing the cost of the healing period.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A healing promoter for grafted seedlings of cucurbit vegetables, wherein the healing promoter contains abscisic acid and ribulose phosphate. Preferably, the concentration of abscisic acid used is 33-67 mg·L⁻¹. -1 The concentration of ribulose phosphate used is 0.17~0.33 mM; more preferably, the concentration of abscisic acid used is 50 mg·L⁻¹. -1 The concentration of ribulose phosphate used was 0.25 mM.

[0006] The above-mentioned healing agent is used to promote the connection between the phloem and xylem of grafted cucurbit seedlings: grafting is carried out about 10 days after the rootstock emerges from the soil. The healing agent is sprayed on the leaves of the rootstock one day before grafting. This can promote the connection between the phloem and xylem of the grafted cucurbit seedlings, and at the same time, it can achieve rapid healing of the grafted cucurbit seedlings, shorten the healing time, and reduce the cost of the healing period. Attached Figure Description

[0007] Figure 1 The effect of different concentrations of exogenous abscisic acid on the reconnection of phloem / xylem in grafted watermelon seedlings. A. Phloem connectivity, B. Xylem connectivity.

[0008] Figure 2 The effect of different application times of exogenous abscisic acid on the reconnection of phloem / xylem in grafted watermelon seedlings. A. Phloem connectivity rate, B. Xylem connectivity rate.

[0009] Figure 3 The effect of different concentrations of exogenous ribulose phosphate on phloem / xylem reconnection in grafted watermelon seedlings. A. Phloem connectivity, B. Xylem connectivity.

[0010] Figure 4 The effect of different ratios of exogenous abscisic acid and ribulose phosphate on phloem / xylem reconnection in grafted seedlings. A. Phloem connectivity, B. Xylem connectivity.

[0011] Figure 5 The effects of exogenous abscisic acid and ribulose phosphate on the growth status of grafted seedlings. Detailed Implementation

[0012] The watermelon scion variety used in the test was Zaojia '84-24', and the pumpkin-type rootstock variety used was 'Deli No. 2'. Seeds were coated with Liangdun mulch and sown directly in seed trays filled with a mixture of peat moss and perlite (3:1, v / v) at a substrate moisture content of 20% and a sowing depth of 1.5 cm. After sowing, the seeds were covered with a thin film and placed in a germination chamber at 30℃ for 48-72 h to germinate. Once the seeds emerged from the soil, they were transferred to an artificial climate chamber. The artificial climate chamber conditions were: temperature 28℃ / 18℃ (day / night), photoperiod 12 h, light intensity 7000 Lx. Scions and rootstocks were sown on the same day, and grafting was performed 10 days after sowing. Grafting was performed using the adhesive grafting method. The day before grafting, the rootstock leaves were sprayed with different treatments to ensure each leaf had a mist of water droplets. Each treatment was replicated three times, with 20 seedlings per replicate. The control (CK) was treated with water. After grafting, cover with a thin film to allow for healing. During the healing period, maintain the following conditions: temperature 28℃ / 18℃ (day / night), photoperiod 12 h, light intensity 5000 Lx, and relative humidity 60%~80%. Begin removing the film on the 3rd day after grafting, adjusting the removal time according to whether the grafted seedlings are wilting.

[0013] The specific method for detecting phloem / xylem connectivity is as follows: Phloem testing: Select cotyledons of watermelon scions and sand the epidermis with sandpaper (be careful not to damage the true leaves). Drop 150 μL of 5 mg / ml Esculin working solution onto oil paper, place the wound in the solution, cover with a thin film, and place in an artificial climate chamber with environmental conditions of 28℃ and 50 μmol·m² light. -2 ·s -1 Two hours later, a stem segment (rootstock) 0.5 cm below the grafting point was cut off, and connectivity was observed and counted using a stereofluorescence microscope M205FA (Leica, Germany) with GFP. Phloem connectivity (%) = number of rootstock stem segments with detected fluorescence / total number of rootstocks used for phloem testing × 100. Twenty rootstocks were selected each time, and observations were repeated for 4-6 days post-grafting, with three replicates.

[0014] Xylem testing: Clean the roots of the grafted seedlings with water, retaining only 1 cm of root system from the base of the stem, ensuring the same root volume for each grafting combination; place the grafted seedling roots into centrifuge tubes containing 1.5 ml of 0.5% Acid fuchsin working solution, cover with a thin film, and incubate at 28℃ under 50 μmol·m² light. -2 ·s -1 Two hours later, a stem segment (scion) 0.5 cm above the graft union was cut off and observed using a stereofluorescence microscope M205FA (Leica, Germany) with GFP. The xylem connectivity rate (%) was calculated as: (Number of scion stem segments with detected fluorescence / Total number of scions used for xylem detection) × 100. Twenty scions were selected each time, and observations were conducted continuously for 4-6 days post-grafting, with the experiment repeated three times.

[0015] 1. Effects of different concentrations of exogenous abscisic acid on graft healing in watermelon Treatment included: spraying the rootstock leaves with 25 mg·L⁻¹ fertilizer the day before grafting. -1 ABA (ABA-25), 50 mg·L -1 ABA (ABA-50), 100 mg·L -1 ABA (ABA-100), 200 mg·L -1 ABA (ABA-200). After spraying, ensure that each leaf has a mist of water droplets.

[0016] like Figure 1 As shown, spray 50 mg·L -1 ABA and 100 mg·L -1 ABA promotes xylem connection in watermelon grafts. Spraying with 50 g·L⁻¹ ABA 4 days after grafting... -1 ABA and 100 mg·L -1Compared to the control treatment, ABA increased xylem connectivity by 50.00% and 62.44%, respectively. (Spraying 25 mg·L...) -1 ABA did not show a significant difference from the control treatment in terms of phloem and xylem connectivity. Spraying 200 mg·L... -1 ABA inhibits the connection between the phloem and xylem of watermelon. The connection rates of the phloem and xylem decreased by 130.85% and 128.20% respectively 5 and 6 days after grafting compared with the control.

[0017] 2. Effects of different application times of exogenous abscisic acid on graft healing in watermelon Treatment included: spraying the rootstock with 100 mg·L⁻¹ for three consecutive days prior to grafting. -1 ABA (ABA-1); spray the rootstock with 100 mg·L for three consecutive days before grafting. -1 ABA + scion spray 0.5 mg·L -1 Auxin and 0.5% glucose (ABA-2); spray the rootstock with 100 mg·L⁻¹ for three consecutive days before grafting. -1 Add 0.33 g·L⁻¹ to the ABA+ spray solution on the second-to-last day before grafting. -1 Paclobutrazol (ABA-3); spray both rootstock and scion with 100 mg·L for three consecutive days before grafting. -1 ABA (ABA-4).

[0018] ABA-1 and ABA-3 treatments promoted the connection between the phloem and xylem of grafted seedlings. Figure 2 On the 5th day after grafting, regarding the phloem, the rootstock was sprayed with 100 mg·L⁻¹ for three consecutive days prior to grafting. -1 ABA (ABA-1) and 100 mg·L⁻¹ foliar spray on rootstock for three consecutive days before grafting. -1 Add 0.33 g·L⁻¹ to the ABA+ spray solution on the second-to-last day before grafting. -1 Compared with the control treatment, the phloem connectivity of (ABA-3) increased by 38.98% and 42.43%, respectively; in terms of xylem, the ABA-1 and ABA-3 treatments also increased by 33.75% and 28.59%, respectively, compared with the control. The rootstock was sprayed with 100 mg·L⁻¹ fertilizer for three consecutive days before grafting. -1 ABA + scion spray 0.5 mg·L -1 Auxin and 0.5% glucose (ABA-2) showed no significant difference in phloem and xylem connectivity compared to the control. Conversely, spraying both rootstock and scion with 100 mg·L⁻¹ for three consecutive days prior to grafting... -1 ABA (ABA-4) showed a significant inhibitory effect on the connection between phloem and xylem, reducing the connection by 198.92% and 276.19% respectively on the 5th day after grafting compared with the control.

[0019] 3. Effects of different concentrations of exogenous ribulose phosphate on graft healing in watermelon The treatment includes spraying the rootstock leaves with 0.1 mM ribulose phosphate (RuBP-0.1), 0.5 mM ribulose phosphate (RuBP-0.5), or 1 mM ribulose phosphate (RuBP-1) one day before grafting. After spraying, ensure that each leaf has a mist of water droplets on it.

[0020] Different concentrations of exogenous ribulose phosphate had varying effects on graft healing in watermelons. Spraying with three concentrations of ribulose phosphate promoted graft healing in watermelons. Five days after grafting, spraying with 0.1 mM, 0.5 mM, and 1 mM ribulose phosphate increased the phloem connectivity by 14.07%, 53.12%, and 41.59%, respectively, compared to the control treatment. Figure 3 A); Regarding xylem connectivity, spraying with 0.5 mM ribulose phosphate and 1 mM ribulose phosphate promoted xylem connectivity in watermelon grafts. Five days after grafting, the xylem connectivity rates of the 0.5 mM and 1 mM ribulose phosphate treatments increased by 61.18% and 48.17% respectively compared to the control treatment, while the 0.1 mM ribulose phosphate treatment showed no significant difference compared to the control treatment. Figure 3 B).

[0021] 4. Effects of different ratios of exogenous abscisic acid and ribulose phosphate on graft healing in watermelon Treatment included: administering 100 mg·L⁻¹ -1 ABA (ABA-100) and 0.5 mM ribulose phosphate (RuBP-0.5) were mixed at volume ratios of 1:1, 1:2 and 2:1, respectively. The rootstock leaves were sprayed one day before grafting, and each leaf was ensured to have a mist of water droplets on it after spraying.

[0022] Spraying ABA-100 and RuBP-0.5 at volume ratios of 1:1, 1:2, and 2:1 increased the phloem connectivity of grafted watermelon seedlings by 33.91%, 21.81%, and 28.11% respectively on day 5 after grafting compared to the control treatment. Figure 4 A) significantly promoted xylem connectivity. On the 5th day after grafting, the xylem connectivity rates of ABA-100 and RuBP-0.5 at volume ratios of 1:1, 1:2, and 2:1 increased by 75.57%, 53.40%, and 58.32%, respectively, compared to the control treatment. Figure 4 B).

[0023] 5. Effects of exogenous abscisic acid and ribulose phosphate on the growth of grafted watermelon seedlings Treatment included: spraying the rootstock leaves with 100 mg·L⁻¹ fertilizer the day before grafting.-1 ABA (ABA-100) and 0.5 mM ribulose phosphate (RuBP-0.5). After spraying, ensure that each leaf has a mist of water droplets.

[0024] Figure 5 The T treatment in the figure was a 1:1 mixture of ABA-100 and RuBP-0.5. As can be seen from the graph, 100 mg·L⁻¹ - 1 The grafted seedlings treated with a 1:1 mixture of ABA and 0.5 mM ribulose phosphate grew significantly faster than the control group.

Claims

1. A healing agent for grafted seedlings of cucurbit vegetables, characterized in that, The healing agent contains abscisic acid and ribulose phosphate.

2. The healing agent for grafted seedlings of cucurbit vegetables according to claim 1, characterized in that, The concentration of abscisic acid used is 33~67 mg·L. -1 The concentration of ribulose phosphate used is 0.17~0.33 mM.

3. The grafted seedling healing agent according to claim 2, characterized in that, The concentration of abscisic acid used is 50 mg·L⁻¹. -1 The concentration of ribulose phosphate used was 0.25 mM.

4. The application of the healing agent according to any one of claims 1 to 3 in promoting the connection between the phloem and xylem of grafted seedlings of cucurbit vegetables.

5. The application according to claim 4, characterized in that, Spray a healing agent on the rootstock leaves the day before grafting.

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