Propagation of Platycodon grandiflorum can be done through seeds or by using the root head (rhizome or reed head). Currently, seed propagation is the most commonly used method. In practical production, two approaches are typically used: direct seeding and transplanting seedlings. Direct sowing is preferred because it results in higher yields, fewer root bifurcations, easier processing, better quality, and is widely adopted in farming. 1. Seed Propagation (a) Seed Characteristics 1. The seeds of Platycodon grandiflorum are obovate or long-ovate in shape, with a wing on one side. They measure 2.0–2.6 mm in length, 1.2–1.6 mm in width, and 0.6–0.8 mm in thickness. The surface is brown or dark brown, shiny, and under a microscope, vertical dark lines can be observed. The umbilicus is located at the base, appearing as a small pit. The wings are thin, measuring 0.2–0.4 mm wide, and often lighter in color. The endosperm is white and translucent with oil content, while the embryo is small, straight, and consists of two cotyledons. The thousand-seed weight ranges from 0.93 to 1.4 grams. 2. Storage and Viability: Fresh seeds should be used within the same year for optimal germination. New seeds have high germination rates, produce uniform and robust seedlings, and are easier to manage. However, seeds stored for more than a year show significantly reduced germination. According to experiments, after 17 months of storage at room temperature, the germination rate dropped to 68.35%, and after 30 months, it was only 33.6%. Some reports suggest that seeds stored for over two years lose viability quickly. 3. Germination Conditions: Platycodon grandiflorum seeds can germinate between 15°C and 30°C, with the best germination occurring between 15°C and 25°C. Gibberellin treatments (50–200 ppm) can enhance germination. Ultrasound treatment (250W, 20,000Hz for 13 minutes) has also been shown to increase germination rates by up to 2.1 times compared to untreated seeds. 4. Seed Selection Tips: - Distinguish between fresh and old seeds: Fresh seeds have a high germination rate (around 70%), while older seeds have very low viability. Check the surface; fresh seeds are oily and shiny, while old seeds are dry and dull. - Avoid "doll species" (seeds from annual plants), which are thin, light-colored, and produce weak seedlings. Opt for seeds from two-year-old plants, which are larger, plumper, and have a higher germination rate and yield. - Sow in autumn for better growth. Autumn sowing allows for a longer growing season, leading to higher yield and quality. In China, autumn sowing is usually done in mid-October, winter sowing in early November, and spring sowing in late March to mid-April. Seeds can be sown directly in shallow furrows spaced 20–25 cm apart, with a depth of 2–3 cm. Mixing seeds with fine sand (1:10 ratio) helps distribute them evenly. After sowing, cover the soil lightly and press it down. In some regions, fire ash is used to protect the soil. Watering is necessary in dry areas to keep the soil moist. To speed up germination, soak seeds in warm water (50°C) for 8 hours, then wrap them in a damp cloth and keep them at 25–30°C. Water them daily until they sprout, which usually takes 4–5 days. Alternatively, soak seeds in a 0.3–0.5% potassium permanganate solution for 24 hours before sowing. 2. Transplanting Seedlings Seedlings are typically transplanted in March. Choose a sunny, wind-shielded area and prepare well-fertilized soil. Create raised beds about 120 cm wide and 15–20 cm high. Open shallow furrows 2–3 cm deep, spaced 15 cm apart, and sow the treated seeds. Mix the seeds with compost and ash, cover with 0.5–1 cm of soil, and protect with mulch to retain moisture and prevent erosion. After 10–15 days, remove weak or thin seedlings when they reach 1.5 cm in height. Thin them further when they grow to 3 cm, spacing them 3–4 cm apart. Regular weeding, watering during dry periods, and proper fertilization help ensure healthy growth. By autumn or early spring, the plants are ready for transplanting. 3. Rhizome Propagation Root head propagation is another common method, especially in autumn. Harvest mature, disease-free plants, cut the reed heads 1 cm below the top, mix with fine fire ash, and plant them. This helps prevent rot and promotes callus formation, making rooting easier. Choose well-drained sandy loam soil with plenty of sunlight. Prepare the field by digging 30–40 cm deep, level the soil, and create mounds 1.5 meters wide and 20–25 cm high. Open horizontal furrows 10 cm deep, spacing them 10 cm apart. Apply 2–3 kg of human manure water per ditch, cover with soil, and add decomposed organic fertilizer (about 3,000 kg per mu). This improves moisture retention and provides nutrients for early growth. In the second year, each plant will typically produce 2–3 shoots. candy， vegan candy Montreal Shantou Food Co., Ltd , https://www.montrealsnack.com
Campanulaceae breeding method