Method for rapid seed germination and seedling raising of goodenia citrina

Abstract

The application provides a method for rapid seed germination and seedling raising of Survillea austrosinensis, and comprises the following steps: taking the Survillea austrosinensis seeds, removing the exocarp, then removing the lignified mesocarp, peeling the air-dried seeds, and taking out the seed embryo, and directly sowing the seeds; the seeds directly sowed start to germinate in 6 days, and the germination rate reaches 94.3%; the direct seed embryo germination is the fastest seed germination method of Survillea austrosinensis, and the subsequent transplanting survival rate is high, and the survival rate can reach 98.1% after 30 days of transplanting. The Survillea austrosinensis seeds with the removed exocarp and mesocarp and the directly taken seed embryo for germination greatly shorten the seed germination time, and the germination rate and the transplanting survival rate are high, which lays a foundation for the growth of Survillea austrosinensis on the sandy coast belt of the beach, large coral stones and the like.

Description

Technical Field

[0001] This invention relates to the field of plant propagation, and in particular to a method for the rapid germination and seedling development of Pittosporum tobira seeds. Background Technology

[0002] Scaevola taccada is a perennial evergreen shrub or small tree belonging to the genus Scaevola L. of the family Goodenianceae. It is a semi-mangrove plant with erect or spreading shrubs. Plants of the genus Scaevola in the family Goodenianceae are mainly distributed along the tropical or subtropical coasts of the Pacific and Indian Oceans. More than 130 species of Scaevola are known, with over 90 species found in Australia. In the southern coastal areas of my country, only two species are found: Scaevola taccada and Scaevola hainanensis Hance.

[0003] *Scabiosa spp.* (also known as Indian pittosporum) commonly grows in clumps along the tidal flats of sandy coastlines and can also survive on large coral reefs formed by wind and waves. It exhibits typical characteristics of coastal plants, preferring sunlight and disliking shade, and is tolerant of high temperatures, drought, salinity, and poor soil. It possesses strong resilience, photosynthetic capacity, and water utilization, thus demonstrating excellent adaptability and distribution on tropical islands, making it a major dominant species (Wang et al., 2020). *Scabiosa spp.* serves as a key member of the first-line shrubbery on tropical coasts, playing a vital role in windbreak and sand fixation, vegetation restoration, and ecological construction on islands. Simultaneously, *Scabiosa spp.* has significant medicinal value; its leaves are rich in palmitic acid, linolenic acid, and other chemical components, and are used to treat cuts, animal bites, improve eye redness and pain, as well as for contraception and enhancing sexual function. With its vibrant green leaves, unique flower shape, beautiful branch form, rapid growth, and long flowering period, *Scabiosa spp.* has been developed and utilized as an ornamental garden plant in many coastal areas of southern my country.

[0004] Due to insufficient awareness of environmental protection and the wanton destruction of coastal habitats, the germplasm resources of this species are extremely limited. Reproduction of Pittosporum species includes sexual and asexual reproduction. Sexual reproduction, using seeds, is conventional, but its reproductive capacity is poor. Because of its hard endocarp, the seeds hatch slowly, resulting in a low germination rate. Furthermore, the rich nutrients in the exocarp can cause the seeds to mold and rot, further reducing survival rates. Therefore, propagation by cuttings is commonly used, but this method is also inefficient. The germination method for Pittosporum seeds disclosed in Chinese Patent CN107889576B still requires a relatively long time for germination. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a method for the rapid germination and seedling development of Pittosporum tobira seeds. By directly peeling open the Pittosporum tobira seeds, taking out the embryos and planting them directly, the Pittosporum tobira seeds can germinate earlier and have a high germination rate.

[0006] The technical solution of this invention is implemented as follows:

[0007] A method for rapid germination and seedling development of Pittosporum tobira seeds includes the following steps: taking Pittosporum tobira seeds, removing the outer pericarp, then removing the lignified mesocarp, peeling open the air-dried seeds, taking out the embryo, and sowing directly.

[0008] A further method is to remove the outer pericarp of the fruit of Pittosporum tobira by manual peeling (direct method) or by soaking the fruit in water for 24-48 hours to loosen the pericarp and then rubbing it off by hand (indirect method).

[0009] A further proposed solution is that the seeds of Pittosporum tobira are mature seeds collected during the seed maturity period of Pittosporum tobira from August to October.

[0010] A further approach is to include natural air drying before removing the lignified mesocarp.

[0011] A further method is to sow the embryos onto the culture medium at intervals of 1-2 cm, and then cover them with another 1-2 cm of culture medium.

[0012] A further option is that the culture medium comprises coarse sand and loam in a mass ratio of 1-2:1-2.

[0013] A further embodiment includes removing the embryo and subjecting the embryo to magnetic field treatment, wherein the magnetic field treatment conditions are: magnetic field strength of 20-50 mT and magnetic field treatment time of 1-2 h.

[0014] A further approach is to sow and cultivate the seedlings until they are obtained, then transplant them into a planting substrate to cultivate the target Pittosporum to obtain the target Pittosporum. The planting substrate includes nutrient soil, peat moss, and vermiculite.

[0015] A further embodiment is that the mass ratio of the nutrient soil, peat soil and vermiculite is 2-3:2-3:1.

[0016] A method for rapid germination and seedling development from Pittosporum tobira seeds includes the following steps: Take Pittosporum tobira seeds, remove the outer pericarp, air-dry, then remove the lignified mesocarp, grind and air-dry the lower end of the seed to a depth of 0.3–0.5 mm, and then sow to obtain the target Pittosporum tobira. Through grinding, it was found that the upper end of the Pittosporum tobira seed is close to the embryo, and the lower end is close to the radicle. Seeds with a lower end ground down to 0.3–0.5 mm have a higher germination rate.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The method for directly extracting the embryo and sowing provided by this invention can shorten the germination time of Pittosporum to 6 days, achieve a germination rate of 94.3%, and achieve a survival rate of 98.1% 30 days after transplanting, resulting in good growth quality.

[0019] The method proposed in this invention, which involves removing the exocarp and mesocarp from Pittosporum to directly extract the embryo for germination, significantly shortens the germination time of Pittosporum seeds and achieves high germination and transplant survival rates. This lays the foundation for the growth of Pittosporum in sandy coastal mudflats and large coral rocks. The method is simple, highly efficient, and effective. Attached Figure Description

[0020] Figure 1 An artist's rendering of fresh Pittosporum tobira fruit;

[0021] Figure 2 The effect of air-drying the fruit of Pittosporum tobira for 2 weeks;

[0022] Figure 3 The image shows the effect of removing the woody mesocarp from Pittosporum tobira.

[0023] Figure 4 Image showing the effect of directly extracting embryos from Pittosporum tobira seeds;

[0024] Figure 5 Image showing the top and bottom of a Pittosporum tobira seed;

[0025] Figure 6 Image showing the effect of removing the outer pericarp after soaking Pittosporum tobira for 24-48 hours;

[0026] Figure 7 This is a picture showing the effect of Pittosporum tobira seeds 60 days after germination.

[0027] Figure 8 This is a picture showing the effect of transplanting Pittosporum tobira seedlings 40 days after transplanting. Detailed Implementation

[0028] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0029] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0030] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0031] Example 1

[0032] A method for rapid germination and seedling development from Pittosporum tobira seeds is as follows:

[0033] (1) Seed collection and preservation: The seeds were collected in Xixiu Beach, Haikou City, Hainan Province during the period of large-scale seed maturity from August to October. The collected seeds were soaked in clean water in the laboratory for 24 to 48 hours to loosen the outer pericarp, and the outer pericarp was removed until the outer pericarp was completely removed and the water was completely clear. The water was then poured out, and the seeds were spread out to air dry for later use.

[0034] (2) Selecting and removing impurities: Select robust and plump seeds of Pittosporum tobira that are free from pests and damage;

[0035] (3) Dry storage: Place the naturally air-dried Pittosporum seeds into a sterile sealed bag and add an appropriate amount of desiccant (silica gel - containing color change indicator). It can be stored at room temperature for 1 to 3 years for future use.

[0036] (4) Carefully extract the embryos: Select uniform-sized seeds of Pittosporum tobira, peel the seeds open manually with a hammer, select intact embryos, and sow them for later use.

[0037] (5) Prepare culture containers and culture medium: use seedling trays or seedbeds as culture containers and sand as culture medium. Put 5-8cm thick sand into the culture containers; the culture medium is coarse sand: loam = 1:1, where the coarse sand is taken from Xixiu Beach, Haikou City, Hainan Province, and the loam is purchased from the company.

[0038] (6) Sowing and Management: Add an appropriate amount of tap water to the culture container to fully moisten the sand. Place the prepared *Symplocos cuspidata* seed embryos flat on the sand at 1-2 cm intervals, and then cover them with 2 cm of moist sand. Spray an appropriate amount of water daily to ensure the sand bed humidity is between 60% and 90%, and observe and record the seed germination. Seedling emergence on the sand surface is considered to be when the embryo emerges. The observation and recording period is 60 days.

[0039] Experimental Example 1

[0040] To determine the effect of the pericarp in the lignification of Pittosporum tobira on seed germination, Pittosporum tobira fruits were collected in August 2023 for seed germination experiments. The specific steps are as follows:

[0041] (1) Fruit collection: Mature fruits of Pittosporum tobira were collected in August 2023. The collection site was Xixiu Beach, Haikou City, Hainan Province. After soaking in clean water for 24 to 48 hours, the outer pericarp was removed and the fruits were naturally air-dried in the laboratory.

[0042] (2) Fruit selection: Take the fruit of Pittosporum tobira after removing the outer pericarp and air drying;

[0043] (3) Fruit treatment: The fruits of Pittosporum tobira were randomly divided into experimental group 1 and experimental group 2. Experimental group 1 consisted of fruits without removing the mesocarp, while experimental group 2 consisted of seeds with the lignified mesocarp removed.

[0044] Seed germination: The two groups of treated seeds were sown separately on a moist sand bed for germination incubation. The germination temperature was 25℃~28℃, and an appropriate amount of water was sprayed daily to ensure that the humidity of the sand bed was between 60% and 90%. Seed germination was observed and recorded for 60 days.

[0045] The seed germination experiment conducted using the above method yielded the results shown in Table 1:

[0046] Table 1. Germination status of Pittosporum tobira seeds 60 days after sowing.

[0047]

[0048] Table 1 shows that the fruits in experimental group 1 with the mesocarp retained began germinating 30 days after sowing, while the seeds in experimental group 2 with the mesocarp removed began germinating 23 days after sowing, with germination rates of 35.6% and 62.5%, respectively. This indicates that the seeds in experimental group 2 with the mesocarp removed germinated 7 days earlier than those in experimental group 1, and their germination rate was higher. During seed germination, some of the Pittosporum tobira fruits in experimental group 1 with the mesocarp retained showed signs of mold and rot. This is because, in addition to the rich nutrients in the exocarp, the mesocarp also contains some nutrients and easily stores moisture, making it prone to mold growth and seed rot. Therefore, the mesocarp, to a certain extent, affects the germination of Pittosporum tobira seeds. Removing the mesocarp can alleviate this inhibitory effect, thereby advancing the germination time and increasing the germination rate. After removing the lignified mesocarp, no mold or rot was observed in the seeds of experimental group 2, indicating that mold and rot are one of the reasons for the low germination rate of Pittosporum tobira seeds.

[0049] Experiment 1 shows that one of the reasons for the low germination rate of Pittosporum tobira seeds is that removing the lignified mesocarp from the seeds helps to improve the germination rate. However, the germination process of the seeds under this treatment is time-consuming and the germination rate is low, which does not meet the requirements for rapid germination and seedling development. Therefore, further research is needed.

[0050] Experimental Example 2

[0051] To determine whether polishing different parts of a seed affects seed germination, a seed germination experiment was conducted in September 2023 using seeds with the lignified mesocarp removed. The specific steps are as follows:

[0052] (1) Fruit selection: Take 200 seeds of Pittosporum tobira after removing the lignified mesocarp;

[0053] (2) Seed treatment: The selected seeds were divided into four equal groups of 50 seeds each, labeled as experimental groups 2 to 5. Three groups were treated by polishing different parts of the seeds with a polisher. Experimental group 2 consisted of unpolished seeds, experimental group 3 consisted of seeds with the ends polished (0.3-0.5 mm at the top and bottom) with a polisher, experimental group 4 consisted of seeds with the top end polished (0.3-0.5 mm) with a polisher, and experimental group 5 consisted of seeds with the bottom end polished (0.3-0.5 mm) with a polisher.

[0054] (3) Seed germination: The four groups of treated seeds were sown on a moist sand bed for seed germination incubation. The germination temperature was 25℃~28℃, and an appropriate amount of water was sprayed every day to ensure that the humidity of the sand bed was between 60% and 90%. Seed germination was observed and recorded for 60 days.

[0055] The seed germination experiment was conducted using the above method, and the results are shown in Table 2.

[0056] Table 2. Effects of different treatments involving polishing different parts of the seeds on the germination of Pittosporum tobira seeds.

[0057]

[0058] Table 2 shows that seeds sown directly on a moist sand bed without polishing took longer to germinate and had a lower germination rate than polished seeds. Seeds with both ends polished (Group 3) and seeds with the lower end polished (Group 5) germinated in the same time (20 days), but the germination rate of Group 5 was higher than that of Group 3 (89.3% and 80.4%, respectively). Seeds with the upper end polished (Group 4) germinated in 22 days with a germination rate of 73.7%, but both the germination time and rate were lower than those of Groups 3 and 4. Polishing revealed that the upper end of the Pittosporum tobira seed is closer to the plumule, and the lower end is closer to the radicle. The low germination rate of seeds in experimental group 4 is because during the germination process, the radicle first forms roots to obtain nutrients from the soil, which are then provided to the plumule to grow stems and leaves. The germination rate of seeds in experimental group 3 is lower than that in experimental group 5 because the radicle cannot form roots in time to provide sufficient nutrients for the growth of stems and leaves.

[0059] Although the seed germination rate is already high, the time required for the seeds to begin germinating is still relatively long. Further research is needed to shorten the time required for seed germination.

[0060] Experimental Example 3

[0061] To determine the effect of direct embryo germination on seed germination, a seed germination experiment was conducted on October 15, 2023, using seeds of Pittosporum tobira with the lignified mesocarp removed. The specific steps are as follows:

[0062] (1) Seed selection: Take 100 seeds of Pittosporum tobira after removing the lignified mesocarp;

[0063] (2) Seed treatment: The seeds of Pittosporum tobira, after the lignified mesocarp was removed, were divided into two equal groups of 50 seeds each, labeled as experimental group 5 and experimental group 6. In one group, the seeds were directly peeled open with a hammer to extract the embryos for later use. Experimental group 5 consisted of seeds that had been polished at the bottom, while experimental group 6 consisted of embryos extracted directly with a hammer.

[0064] (3) Seed germination: The two groups of treated seeds were sown on a moist sand bed for seed germination incubation. The germination temperature was 25℃~28℃, and an appropriate amount of water was sprayed every day to ensure that the humidity of the sand bed was between 60% and 90%. Seed germination was observed and recorded for 60 days.

[0065] The seed germination experiment was conducted using the above method, and the results are shown in Table 3.

[0066] Table 3. Effects of direct embryo extraction treatment on the germination of Pittosporum tobira seeds.

[0067]

[0068] Table 3 shows that seeds from directly extracted embryos (experimental group 6) began germinating in just 6 days, with a germination rate of 94.3%. During embryo extraction, the integrity of the embryos was close to 90%. Compared to seeds treated by grinding the lower end, the germination time of seeds in experimental group 6 was significantly shortened. Therefore, direct embryo extraction is the fastest method for germinating Pittosporum tobira seeds.

[0069] Test Example 4

[0070] To determine the effect of electromagnetic field treatment on the direct germination of seed embryos, in November 2023, the seeds of Pittosporum tobira were directly peeled open with a hammer to collect the embryos for later use. The specific steps are as follows:

[0071] (1) Seed selection: Take 100 embryos of Pittosporum tobira;

[0072] (2) Seed treatment: The embryos of *Pterocarya stenoptera* were divided into two equal parts, each containing 50 seeds, and labeled as experimental group 6 and experimental group 7 respectively. Experimental group 6 consisted of embryos extracted directly with a hammer, while experimental group 7 consisted of embryos that were placed in an electromagnetic field processor for 50 mT electromagnetic field treatment for 1 h.

[0073] (3) Seed germination: The two groups of treated seeds were sown on a moist sand bed for seed germination incubation. The germination temperature was 25℃~28℃, and an appropriate amount of water was sprayed every day to ensure that the humidity of the sand bed was between 60% and 90%. Seed germination was observed and recorded for 60 days.

[0074] The seed germination experiment was conducted using the above method, and the results are shown in Table 4.

[0075] Table 4. Effects of magnetic field treatment on embryo germination of Pittosporum tobira seeds.

[0076]

[0077] As shown in Table 4, the embryos of *Symplocos cuspidata* (experimental group 7) began to germinate in just 5 days after electromagnetic field treatment, and the germination rate reached 95.7%. Electromagnetic field treatment can further shorten the germination time.

[0078] Experimental Example 5

[0079] The specific method used for the transplanting experiment of Pittosporum tobira seedlings is as follows:

[0080] The seedlings with good growth obtained from the experimental group 6 of Example 3 were carefully transplanted into black seedling trays (54cm×28cm, 50 cells) containing a substrate (the substrate consisted of nutrient soil: peat moss: vermiculite = 2:2:1). After one month, they were transferred to black seedling bags to make bag seedlings. When transplanting, care should be taken not to damage the roots of the seedlings, and sufficient water should be given to help them settle in.

[0081] The transplanting of *Scabiosa henryi* seedlings using the above method yielded the following results:

[0082] The survival rate of the seedlings of *Symplocos cuspidata* was 98.3% 20 days after transplanting and 98.1% 30 days after transplanting. The survival rate did not change much, and the seedlings did not show any signs of rotting.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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.

Claims

1. A method for rapid germination and seedling development from seeds of Pittosporum tobira, characterized in that, The process includes the following steps: Take Pittosporum tobira seeds, soak them in water for 24-48 hours, remove the outer pericarp, air dry them naturally, then remove the lignified mesocarp, peel open the air-dried seeds, take out the embryo, and sow them directly.

2. The method for rapid germination and seedling development of Pittosporum tobira seeds according to claim 1, characterized in that, The seeds mentioned are mature seeds collected during the seed maturity period of Pittosporum tobira from August to October.

3. The method for rapid germination and seedling development of Pittosporum tobira seeds according to claim 1, characterized in that, The embryos are sown onto the culture medium at intervals of 1-2 cm, and then covered with another 1-2 cm of culture medium.

4. The method for rapid germination and seedling development of Pittosporum tobira seeds according to claim 3, characterized in that, The culture medium consists of coarse sand and loam in a mass ratio of 1~2:1~2.

5. The method for rapid germination and seedling development of Pittosporum tobira seeds according to claim 1, characterized in that, It also includes treating the embryo with a magnetic field, wherein the conditions for magnetic field treatment are: magnetic field strength of 20~50 mT and magnetic field treatment time of 1~2 h.

6. The method for rapid germination and seedling development of Pittosporum tobira seeds according to claim 1, characterized in that, When seedlings of Pittosporum tobira are obtained, they are transplanted into a planting substrate for cultivation to obtain the target Pittosporum tobira. The planting substrate includes nutrient soil, peat moss and vermiculite.

7. The method for rapid germination and seedling development of Pittosporum tobira seeds according to claim 6, characterized in that, The mass ratio of the nutrient soil, peat soil and vermiculite is 2~3:2~3:1.

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