Breeding method for cultivating cold-resistant and high-temperature-resistant ananas comosus germplasm

A breeding method for cultivating a cold-resistant and high-temperature-resistant Ananas comosus germplasm, the breeding method comprising:

• creating a controllable greenhouse environment simulating a natural environment, wherein an application condition that illumination is increased in rainy weather is satisfied;
• setting a height of a ridge on the ground to be 40 cm, applying a 50 kg/mu compound fertilizer and a 300 kg/mu organic farmyard manure at a N:P:K ratio of 17:17:17 on the ridge as a base fertilizer, performing spray irrigation, and testing and adjusting a relative humidity of soil to be 40%;
• and selecting 20-30 cm Ananas comosus offset germplasm seedlings for field planting, and planting the seedlings after covering a plastic film on a ridge surface (S1);
• adjusting a temperature to be 28-30° C. until a first fertilization after the field planting, and implementing a first root irrigation and fertilization upon 30 days after the field planting, wherein the fertilization comprises:
• using a water-soluble compound fertilizer at the N:P:K ratio of 17:17:17 for the root irrigation and fertilization, preparing a 100-fold aqueous solution for root irrigation once every 30 days by 300 ml/plant, and performing the root irrigation and fertilization 3 times in total in a seedling stage;
• upon 7 days after the first root irrigation and fertilization, performing first application of a foliar fertilizer, the foliar fertilizer comprising a trace-element water-soluble fertilizer containing Mg:B:Zn:Gu:Fe:Mo:Mn at a ratio of 13‰:5‰:5‰:3‰:2‰:0.05‰:5‰, preparing a 800-fold solution, and applying the foliar fertilizer every 30 days by spraying on a leaf surface;
• upon 15 days after the first foliar fertilization, performing a cold-resistant domestication culture, wherein the cold-resistant domestication culture comprises:
• adjusting and reducing a room temperature by 6-8° C. every day, keeping the room temperature for 5 days after being reduced to 4-6° C., and then increasing the room temperature by 5-7° C. every day, and keeping the room temperature at 36-38° C. in daytime after being recovered and heated to 36° C., keeping a minimum temperature at 25-28° C. in nighttime, and continuing the cold-resistant domestication culture for 90 days;
• and observing a soil moisture content to implement spray irrigation during the period (S2);
• preparing a 2000-fold aqueous solution of chlormequat chloride in response to observing that 25 leaves come out, and spraying the solution on front and back leaf surfaces to promote growth and culture;
• after 30 days, adjusting a temperature to be 22-25° C. to prepare for flower forcing, and performing the flower forcing during the period, and after 10 days, adjusting the temperature to be 30-33° C.;
• and on a 30th day after the flower forcing, observing a plant crown for emergence of a red inflorescence, and applying a foliar fertilizer prepared by compounding the foliar fertilizer in (S2) with a 2000-fold aqueous solution of brassinolide on a leaf surface once (S3);
• preparing an aqueous solution by compounding 2‰ potassium dihydrogen phosphate with the foliar fertilizer in (S2) on a 60th day after the flower forcing, and spraying the solution on the leaf surface once;
• and adjusting a temperature to be 36-38° C. in daytime, and controlling a minimum temperature to be 25-28° C. in nighttime (S4);
• and
• picking fruits on a 120th day after the flower forcing, and after 7 days spraying a 1500-fold solution of 3% gibberellic acid on the leaf surface once, and then performing fertilization according to the operations of fertilization in (S2);
• 20 days after a first fertilization in (S5), when observing that 2-3 cm buds appear under a leaf axil, performing cold-resistant domestication culture according to the operations of cold-resistant domestication culture in (S2), after a plurality of offsets are bred from each mother plant, obtaining cold-resistant and high-temperature-resistant germplasm seedlings, and when the seedlings grow to 20-30 cm, harvesting and transplanting the seedlings;
• and after a first round of seedling harvesting, repeating (S2) for a plurality of rounds, and harvesting the seedlings for a plurality of rounds, so as to multiply a production of the seedlings (S5).