Large-scale Seedling raising of sexual Propagation of Dioscorea zingiberensis in greenhouse

Dioscorea zingiberensis (Dioscoreace.C.H.Wright), the scientific name of Dioscorea zingiberensis, contains diosgenin ligands, commonly known as diosgenin or diosgenin (hereinafter referred to as diosgenin). It is an ideal plant for extracting diosgenin and is known as "medicinal gold". Planting turmeric has a high economic return, and it has developed rapidly throughout the country. Many counties and townships have established turmeric production bases, taking the cultivation of turmeric as a pillar industry to promote local economic development, and the scale of development is on the rise. Conventional asexual propagation with rhizome requires a large number of species and high cost, and the rapid development of turmeric leads to serious shortage of provenances, hybrid varieties, yield decline and other problems. Sexual reproduction is one of the better ways to solve the above problems.

1 materials and methods

1.1 cultivation of sexual seeds

Establish a seed cultivation base of 1 hectare to introduce and collect high-quality resources from Shimen and Anhua in Hunan, Neixiang County in Shaanxi Province, Lijiang and Honghe in Yunnan, Fang County, Yunxi, Yichang, Changyang and Yuan'an in Hubei Province, and mixed planting in the seed cultivation base to make it pollinate naturally. In management, emphasis is placed on promoting the formation of flowers, fruits and seeds to ensure the quality and quantity of seeds. therefore, organic fertilizer and nitrogen, phosphorus and potassium compound fertilizer are applied when sowing in the orchard. The rack should be more than 1.8m, and the mixed solution of 0.2% potassium dihydrogen phosphate and 0.1% potassium dihydrogen phosphate and 0.1% borax should be sprayed at the early flowering stage; spray once every 7 to 10 days, a total of 3 times. When the leaf color is light, spray 0.3% 0.4% urea and 800 times seaweed fertilizer. Remove the weak flowers and fruits on the female plant in time to ensure the seed quality.

1.2 seed harvesting and treatment

The sign of the seed maturity of Dioscorea zingiberensis is that the fruit grows full, the capsule changes from green to blue, and finally it is black-blue and hard. When the winged kernel is brown and yellow, the capsule will be harvested. Because the turmeric in the seed orchard is a heterozygous group and the mature period is inconsistent, it should be harvested in batches. Pick up the leaves of the capsule and spread it in a cool and ventilated place to dry for a week. In order to prevent the capsule from getting hot, mildew and spoilage, the spreading thickness should not exceed 20cm. Wait for the capsule to turn blue and black completely before it is exposed to the sun. After cracking, it can be gently turned and tapped to let the seeds fall off naturally.

The sun-dried seeds were harvested in mid-December. The seeds were disinfected with 1000 times 25% carbendazim wettable powder aqueous solution for 12 hours, then washed with 30 ℃ warm water, then soaked in 30 ℃ warm water for 10 hours, stirred continuously during soaking, removed blighted seeds and insect seeds, fished out and dried; then soaked with 10mg/L GA for 24 hours, picked up and drained the seeds. Finally, the sand storage method was used to treat for 20-30 days, the temperature was controlled below 2-5 ℃, and the humidity was kept at about 50%.

1.3 seed germination

The size of the germination chamber is determined according to the germination scale, generally the seed capacity of each batch is 80kg, and the area of the germination chamber is 20 square meters, which is required to avoid light, ventilation and heat preservation. And matching germination plate, and then build a supporting germination rack, put the seedling plate on the germination rack, strictly control the temperature, and leave ventilation holes in the budding room.

The budding began at the beginning of January, and the budding room and supporting equipment were disinfected with 25% carbendazim 800 times solution before budding. Then spread the sterilized sawdust evenly on the plate, and then evenly spread the treated seeds on the plate with an area of 3500cm2, each plate with about 80, 000 seeds of 1kg. Put it in the sprouting room and control the temperature at 25: 30 ℃ in the first two days, then keep it at about 25 ℃, keep the relative humidity above 80%, keep away from light and ventilate evenly. It begins to sprout in 7 days, sprouts in 10-12 days, 50% in 13-15 days, and sprouts above 80% in 15 days.

1.4 Seedling raising in greenhouse

One month before sowing, prepare nutritious soil at the rate of 90 cubic meters per hectare, use 70% fine sand, 10% plant ash, 20% mature organic fertilizer, and 5kg/ cubic meter of high-efficiency compound fertilizer, fully stir and compact, then cover with plastic film.

Half a month before sowing, the greenhouse seedling bed 30cm was turned into a bed with a width of 1.2m and a height of 0.2m. The bed surface was leveled and crushed, and the screened nutrient soil was evenly sprinkled on the bed surface with a thickness of about 2cm, and then sprayed with 25% carbendazim 800x solution and watered one week before sowing. Sowing in the middle of January, the sowing method is to horizontally open a shallow trench on the bed surface, the ditch depth 2~3cm, row spacing 15cm, sow the budding seeds evenly in the ditch, and cover the sifted nutrient soil of 2cm. In addition, the seeds with buds longer than 2cm were planted in the ditch according to the distance of 2cm.

After sowing, the bed should be kept moist, the temperature in the greenhouse should be kept at 20: 28 ℃, and the temperature should be maintained by uncovering and covering the film. When the temperature is low, build another shed in the greenhouse. The relative humidity was kept above 80%, and seedlings began to emerge about 15 days after sowing. One or two complete leaves can be grown in about 30 days. At this time, ventilation should be often given to the greenhouse. Seedling emergence for 50 to 60 days, that is, plastic film training at the beginning of April, is about 3 months after emergence (at the end of April). Most turmeric seedlings grow to 3-5 complete leaves and can come out of the nursery. When training seedlings, if Rain Water is more, spray with 50% Xinling 800x liquid to control the disease of turmeric, and kill the ground tiger with insects. Keep the seedbed free of weeds.

1.5 transplanting seedlings

At the end of April and the beginning of May, when the seedlings grow to about 3 leaves, they can be planted in the nursery. The roots of the seedlings should be kept intact, carry as much soil as possible, and be transported in seedling trays or cartons. Select sunny day planting, seedling depth according to the size of the seedling, generally 2~3cm, after planting, pour enough fixed root water.