Grafting culture process of feijoa

Abstract

This invention discloses a grafting cultivation process for Fijoa fruit, relating to the field of fruit tree seedling grafting and propagation technology, including the following steps: Step 1, rootstock selection: Select Fijoa fruit seedlings or cuttings with excellent local adaptability and compatibility with superior Fijoa cultivars as grafting rootstocks. The selected rootstocks have a base diameter of 0.5-1.5 cm. The rootstocks are preferably seedlings of 'Chuanren No. 1' or 'Chuanren No. 2'. Before sowing, the seeds of the seedlings are subjected to a 40-60 day low-temperature stratification pretreatment to effectively improve the uniformity of seed germination and seedling growth, ensuring uniform rootstock specifications and vigorous growth. Through the combination of short-term activation pretreatment of scions with IBA and a dual-hormone compound callus ointment for targeted healing, the inert cambium cells of Fijoa fruit are specifically activated, effectively overcoming the technical bottleneck of the difficulty in the formation of natural callus tissue in Fijoa fruit, and significantly improving the healing speed of the graft union and the grafting survival rate.

Description

Technical Field

[0001] This invention belongs to the field of fruit tree seedling grafting and propagation technology, specifically relating to a grafting and cultivation process for Fijora fruit. Background Technology

[0002] Feiyo fruit, also known as feiyo, is a perennial evergreen fruit tree belonging to the genus Feiyo in the family Myrtaceae. It combines edible, medicinal, and ornamental value, with a unique flavor and rich nutrition, and has broad market prospects. Currently, the commercial cultivation of Feiyo fruit in my country is still in its initial stage. The lack of a complete germplasm resource introduction and industrial seedling technology system severely restricts the large-scale promotion and planting of Feiyo fruit.

[0003] Compared to common Myrtaceae fruit trees such as citrus and guava, Fiyo fruit has natural grafting and propagation defects: its cambium cells have weak cell division activity, making callus induction difficult, and the graft union bridging is slow. Conventional grafting methods generally result in low survival rates, scions are prone to dehydration and dieback, and rootstock suckers compete severely for nutrients. These are the core technical bottlenecks in the current industrialized seedling cultivation of Fiyo fruit. Furthermore, existing grafting techniques have not been optimized for compatibility with domestically bred varieties such as 'Chuanren No. 1' and 'Chuanren No. 2', as well as imported superior varieties such as Andre and Apollo. This results in poor varietal compatibility, low standardization of seedling cultivation, and an inability to meet the needs of industrialized seedling production.

[0004] Existing technologies mostly employ conventional fruit tree grafting methods, lacking specific activation methods for callus barriers in *Féyaux* fruit. They also lack a comprehensive system for low-temperature survival of scions, precise healing promotion at the graft union, and stress-resistant survival of new shoots, resulting in unstable survival rates, inconsistent seedling quality, and long seedling cultivation cycles. Therefore, this invention proposes a high-survival-rate grafting cultivation process suitable for multiple varieties of *Féyaux* fruit. Summary of the Invention

[0005] The purpose of this invention is to provide a grafting cultivation process for Fijora fruit to solve the problems of difficult healing, low survival rate, easy scion dieback, poor variety compatibility, and low standardization of seedling cultivation in existing Fijora grafting seedling cultivation.

[0006] To achieve the above objectives, the present invention provides a grafting cultivation process for Fijora fruit, comprising the following steps: Step 1: Rootstock Selection: Select Fiyo fruit seedlings or cuttings with excellent local adaptability and compatibility with superior Fiyo fruit cultivars as grafting rootstocks. The selected rootstocks should have a base diameter of 0.5–1.5 cm. The preferred rootstocks are seedlings of 'Chuanren No. 1' or 'Chuanren No. 2'. Before sowing, the seeds of the seedlings should be pretreated with low-temperature stratification for 40–60 days to effectively improve the uniformity of seed germination and seedling growth, and ensure that the rootstocks are of uniform size and grow vigorously. Step 2, Scion Collection and Low-Temperature Storage: During the dormant period to the early budding stage, select robust one-year-old branches of superior Fijora varieties with fully lignified buds as scions. The superior varieties include at least one of 'Andre,' 'Apollo,' 'Cat's Eye Star,' 'Mao Xiang,' 'Chuanren No. 1,' and 'Chuanren No. 2.' After collection, place the scions in a low-temperature storage environment at 4±1℃, moisturized, and dark, for no more than 7 days. This effectively maintains the cell activity of the scions, inhibits premature budding, and avoids nutrient consumption, dehydration, and aging of the scions before grafting. Step 3: Pretreatment for callus activation of scions: Before grafting, the base of the scion is briefly soaked in an indolebutyric acid (IBA) aqueous solution to specifically activate the cell division activity of the cambium cells of Fijora fruit, overcoming the grafting obstacle of difficult formation of natural callus tissue in Fijora fruit; the concentration of the IBA solution is 800-1500 mg / L, and the treatment time is 10-30 s; preferably, a 1000 mg / L IBA solution is used, and the soaking treatment is 15-20 s, which maximizes the activation of cambium activity without damaging the scion tissue; Step 4, Timely Grafting Operation: Grafting should be performed in spring when the average daily temperature is stable at ≥12℃, sap is flowing, and the buds have not yet swollen. The optimal grafting time is from early March to mid-April each year, prioritizing sunny weather with no strong winds or rain for at least 3 consecutive days to avoid problems such as water ingress, water loss, and infection at the graft union caused by severe weather. During the grafting process, the depth of the scion cut should be matched with the depth of the rootstock cut to ensure that the cambium layers of the rootstock and scion are precisely aligned on at least one side. The specific operation is as follows: cut the rootstock flat at a level position, and make a vertical cut of 1.8-2.2cm downward along one side of the cut; cut the lower end of the scion into an asymmetrical wedge shape, with the long cut surface 2.0-2.3cm long and the short cut surface 0.6-0.8cm long; insert the long cut surface of the scion into the cut with the cambium layer of the rootstock facing towards it, ensuring that the cambium layers on at least one side are completely aligned and that the nutrient transport channels are unobstructed. Step 5, Targeted Healing Treatment at the Graft Interface: After grafting, apply a callus-inducing ointment, a mixture of plant growth regulator and lanolin, to the graft interface to promote rapid callus formation and vascular bridging, thus shortening the healing cycle. The callus-inducing ointment contains IBA, 6-benzylaminopurine (6-BA), and lanolin in a mass ratio of 0.5–1.5:0.2–0.8:100. The preferred ratio is IBA, 6-BA, and lanolin in a mass ratio of 1:0.5:100. The ointment should be applied to a thickness of 1–2 mm to balance the healing effect with the breathability of the interface, avoiding either excessive thickness that could suffocate the interface or insufficient thickness that would be ineffective. Step Six: Post-grafting Sprout Control and Precise Temperature and Humidity Management: Use biodegradable grafting film to seal and bind the graft union. Unbind the graft within 15-25 days after successful grafting to avoid constriction of the seedling and affect trunk thickening. Regularly remove rootstock sprouts after grafting to prevent nutrient diversion and concentrate nutrients for scion sprouting and growth. Within 15-25 days after grafting, maintain a local ambient temperature of 20-28℃ and relative humidity of 85%-95% at the graft union to provide the optimal environment for callus growth and bud sprouting, ensuring normal bud sprouting. Step 7: New Shoot Survival and Stress Resistance Management: From the bud sprouting stage to the new shoot reaching 10cm in length, regularly spray a mixture containing an antitranspirant and a foliar fertilizer of phosphorus and potassium to reduce water loss through transpiration from the scion, replenish growth nutrients, and prevent the scion from withering and dying. The antitranspirant is fulvic acid or chitosan at a concentration of 0.1%–0.3%, and the foliar fertilizer is a 0.2%–0.3% potassium dihydrogen phosphate aqueous solution. Preferably, a mixture of 0.2% fulvic acid and 0.2% potassium dihydrogen phosphate is used, sprayed once every 7 days until the scion and surrounding branches are moist but not dripping, continuously improving the stress resistance and growth vigor of the new shoot.

[0007] Compared with the prior art, the beneficial effects of the present invention are:

[0008] (1) This invention, through the combination of short-term activation pretreatment of scion IBA and targeted healing promotion technology of dual hormone compound callus ointment, specifically activates the inert cambium cells of Fijos fruit, effectively overcomes the technical bottleneck of the difficulty in the formation of natural callus tissue of Fijos fruit, greatly improves the speed of interface healing and graft survival rate, and the survival rate is more than 30% higher than that of conventional process.

[0009] (2) This invention is compatible with six major Fiyo fruit varieties, including 'Andre', 'Apollo', 'Cat's Eye Star', 'Mao Xiang', 'Chuanren No. 1' and 'Chuanren No. 2', and takes into account both foreign-introduced varieties and domestically bred varieties. It solves the problems of poor compatibility of traditional varieties and weak seedling universality. It has a wide range of applications and high industrialization promotion value.

[0010] (3) This invention ensures the activity of scions and new shoots throughout the process by storing scions at low temperature and keeping them moist, controlling temperature and humidity precisely after grafting, and regularly spraying antitranspirant and foliar fertilizer during the new shoot period, thus solving the problems of scion dehydration and withering and low budding rate after grafting of Feiyue fruit; and uses biodegradable grafting film to untie the grafts in a timely manner to avoid seedlings being strangled and growing abnormally.

[0011] (4) This invention, through low-temperature stratification of rootstock, precise control of rootstock sprouting, and directional supply of nutrients, cultivates grafted seedlings with well-developed root systems, strong branches and trunks, and full buds, resulting in a high survival rate after planting. It can realize the large-scale and commercialized seedling cultivation of superior varieties of Fiyogo, filling the gap in standardized grafting seedling cultivation and industrialized production of Fiyogo in China. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the grafting cultivation process in one embodiment of the present invention. Detailed Implementation

[0013] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Example 1

[0014] A grafting cultivation process for Fijora fruit according to one embodiment of the present invention includes the following steps:

[0015] Step 1: Rootstock selection: 'Chuanren No. 1' seedlings were selected as rootstocks. Before sowing, the seeds were subjected to a 50-day low-temperature stratification pretreatment to cultivate seedlings with a base diameter of 0.8-1.2cm, vigorous growth, and free from diseases and pests.

[0016] Step 2, Scion Collection and Low-Temperature Storage: In late February, during the dormancy period, select robust one-year-old fully lignified branches with plump buds of 'Chuanren No. 2' as scions. After collection, store them in a 4℃ moist and dark environment for 6 days for later use.

[0017] Step 3: Pretreatment for callus activation of scions: Before grafting, soak the base of the scion in a 1000 mg / L IBA aqueous solution for 18 seconds, then remove and drain for later use.

[0018] Step 4, Timely Grafting Operation: In mid-March, choose a sunny day with no strong winds or rain for four consecutive days, when the average daily temperature is stable at 13-18℃, sap is flowing and the buds have not yet swelled, to perform cleft grafting; after the rootstock is cut flat, make a 2.0cm cut, and cut the scion with a long cut of 2.2cm and a short cut of 0.7cm, and after inserting it into the cut, ensure that the cambium layers on one side are completely aligned.

[0019] Step 5, Targeted Healing Treatment at the Interface: After grafting, apply a wound-inducing ointment with a mass ratio of IBA, 6-BA, and lanolin of 1:0.5:100 evenly to the interface, with a thickness of 1.5mm.

[0020] Step 6: Post-grafting sprout control and precise temperature and humidity management: Use biodegradable grafting film to seal and bind the graft union, and inspect and remove rootstock sprouts every 4 days; maintain an ambient temperature of 22-25℃ and a relative humidity of 88%-92% for 20 days after grafting; remove the grafting film 20 days after grafting.

[0021] Step 7: New shoot survival and stress resistance management: After the buds sprout until the new shoots grow to 10cm, spray with a mixture of 0.2% humic acid and 0.2% potassium dihydrogen phosphate every 7 days until the branches are moist but not dripping water. Continue to maintain the new shoots until they mature.

[0022] In this embodiment, the grafting survival rate can reach over 85%, the seedlings grow uniformly, and there are no problems such as scion withering or rootstock sprouting. Example 2

[0023] This embodiment is basically the same as the process in Embodiment 1, except that: the scion used is the 'Maurice' variety, the IBA solution concentration is 900mg / L, the soaking time is 25s, the wound healing ointment ratio is 0.8:0.4:100, the grafting time is in early April, the temperature and humidity are controlled at 24-27℃ and 86%-90%, and the grafting survival rate is stable at over 82%. Example 3

[0024] This embodiment is basically the same as the process in Embodiment 1, except that: the scion used is the 'Apollo' variety, the antitranspirant is 0.25% chitosan combined with 0.25% potassium dihydrogen phosphate, the grafting film is removed 22 days after grafting, the seedlings sprout faster, and the thickness of the new shoots is significantly improved.

[0025]

[0026] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0027] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A grafting cultivation process for Fijora fruit, characterized in that, Includes the following steps: Step 1: Rootstock selection: Select fertile seedlings or cuttings of fertile fruit with good local adaptability and compatibility with excellent fertile fruit cultivars as grafting rootstocks. The selected rootstocks should have a base diameter of 0.5–1.5 cm. Step 2: Scion Collection and Low-Temperature Storage: During the dormancy period to the early budding stage, select robust one-year-old branches of superior Fiyogo varieties with fully lignified buds as scions. After collection, store the scions in a low-temperature environment at 4±1℃, with moisture and away from light, for no more than 7 days to maintain scion cell activity and inhibit premature budding. The superior varieties include at least one of 'Andre', 'Apollo', 'Cat's Eye Star', 'Mao Xiang', 'Chuan Ren No. 1', and 'Chuan Ren No. 2'. Step 3: Pretreatment for callus activation of scion: Before grafting, the base of the scion is briefly soaked in an indolebutyric acid (IBA) aqueous solution to activate the cell division activity of the cambium layer of Fijo fruit and overcome the grafting obstacle of difficult formation of natural callus tissue of Fijo fruit. The concentration of the IBA solution is 800-1500 mg / L and the treatment time is 10-30 seconds. Step 4, Timely grafting operation: When the average daily temperature is stable at ≥12℃ in spring, the sap is flowing and the buds have not yet swollen, the cleft grafting method is used for grafting. The depth of the cut surface of the scion and the cut surface of the rootstock are matched, and the cambium of the rootstock and the scion are precisely aligned on at least one side. Step 5, Targeted Healing Treatment at the Graft Interface: After grafting, apply a callus-inducing ointment, which is a mixture of plant growth regulator and lanolin, to the graft interface to promote rapid callus formation and vascular bridging at the interface; the callus-inducing ointment contains IBA, 6-benzylaminopurine 6-BA and lanolin. Step 6: Post-grafting sprout control and precise temperature and humidity management: Seal and bind the graft union with grafting film, and regularly remove rootstock sprouts; within 15 to 25 days after grafting, maintain the local ambient temperature at the graft union at 20 to 28°C and the relative humidity at 85% to 95% to ensure normal bud sprouting; Step 7: New Shoot Survival and Stress Resistance Management: From the time the buds sprout until the new shoots reach 10cm in length, regularly spray a mixture containing an antitranspirant and phosphorus and potassium foliar fertilizer to reduce water loss through transpiration from the scion, replenish nutrients, and prevent the scion from withering and dying.

2. The grafting and cultivation process of *Fiyorus ferruginea* according to claim 1, characterized in that, In step three, the concentration of the IBA solution is 1000 mg / L, and the soaking time for the base of the scion is 15–20 seconds.

3. The grafting and cultivation process of *Fiyorus ferruginea* according to claim 2, characterized in that, The specific steps of the cleft grafting method in step four include: cutting the rootstock flat at a level position, making a vertical cut of 1.8 to 2.2 cm along one side of the cut; cutting the lower end of the scion into an asymmetrical wedge-shaped surface, with the long cut surface being 2.0 to 2.3 cm long and the short cut surface being 0.6 to 0.8 cm long; inserting the long cut surface of the scion into the cut with the xylem of the rootstock facing it, ensuring that the cambium layers on at least one side are completely aligned and in contact.

4. The grafting and cultivation process of *Fiyorus ferruginea* according to claim 3, characterized in that, In step four, the spring grafting time is from early March to mid-April each year. The grafting operation should be carried out in good weather with no strong winds and no rain for more than three consecutive days.

5. The grafting and cultivation process of *Fiorentina ferruginea* according to claim 4, characterized in that, In step one, the rootstock is selected from the seedlings of 'Chuanren No. 1' or 'Chuanren No. 2'; before sowing the seedlings, the seeds are subjected to a 40-60 day low-temperature stratification pretreatment to improve the uniformity of seed germination and the growth of seedlings.

6. The grafting cultivation process for *Fiorentina ferruginea* according to claim 5, characterized in that, In step five, the mass ratio of IBA, 6-BA, and lanolin in the wound healing ointment is 0.5–1.5:0.2–0.8:

100.

7. The grafting cultivation process for *Fiyorus ferruginea* according to claim 6, characterized in that, The mass ratio of IBA, 6-BA, and lanolin in the wound-inducing ointment is 1:0.5:100, and the thickness of the ointment application is 1-2 mm.

8. The grafting and cultivation process of *Fiyorus ferruginea* according to claim 7, characterized in that, In step six, the grafting film is a biodegradable grafting film, and the binding is completed within 15 to 25 days after the grafting is successful to avoid constriction of the seedling.

9. The grafting and cultivation process of *Fiorentina ferruginea* according to claim 8, characterized in that, In step seven, the antitranspirant is humic acid or chitosan, with a concentration of 0.1% to 0.3%; the foliar fertilizer is a 0.2% to 0.3% potassium dihydrogen phosphate aqueous solution.

10. The grafting cultivation process of *Fiorentina ferruginea* according to claim 9, characterized in that, Use a mixture of 0.2% humic acid and 0.2% potassium dihydrogen phosphate, and spray it once every 7 days until the scion and surrounding branches are moist but not dripping.

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