-
Detailed Explanation of Key Points on Off-Season Breeding Technology for Ayu Sweetfish
I. Facilities and Methods (I) Facilities 1. Nursery room. Converted from a plastic shed, 500 cubic meters of water body, black shading net to regulate light intensity, controlling light intensity below 5000 lux. 2. Broodstock rearing pond. Cement pond, rectangular (3 m x 2.65 m), pond depth 1 m, also serves as bait pond and nursery pond. 3. Water supply facilities. Groundwater is used, supplied by pumps through main and branch pipelines. 4. Aeration equipment. 2 ordinary air pumps, one air diffuser stone placed every 1-2 sq m in the nursery pond.
-
Effective prevention and treatment methods for reproductive stress in breeding sows
1. Symptoms: (1) Abnormal bone metabolism, weak limbs and hooves, abnormal limb morphology and gait. Soft feet, hoof cracks, hemorrhage under the hoof shell, and in severe cases postpartum paralysis. (2) Sows show reproductive disorders, especially first-litter sows, with delayed estrus, anestrus or failure to come into estrus. More piglets born in the first litter, fewer in the second; or more in one litter and fewer in the next. Sows have weak disease resistance, reduced immune function, incomplete uterine involution, increased incidence of endometritis and mastitis, and are prone to various infections, with a higher culling rate. (3) Sow fertility and pig
-
Procedures for Individual Selection in Fox Breeding
1. Primary selection: After weaning, selection is mainly based on the production performance of their ancestors. Those whose parents have excellent production performance, were born early, and developed normally are retained for breeding. For primary selection, young silver-black foxes should be born before April 5 for males and before April 10 for females; young Arctic foxes selected in the primary selection should be born before May 20. During primary selection, 40% more should be retained than the breeding plan requires. Selection of adult male foxes is carried out after mating, and selection of adult female foxes is carried out after the cubs are separated. Those with poor mating ability and poor semen quality
-
Detailed Explanation of Tea Plant Clonal Breeding Techniques and Methods
A breeding method that combines single-plant selection with vegetative propagation to develop new varieties. Tea varieties developed through clonal breeding are called tea clonal varieties or tea vegetative propagation line varieties. They can reflect the heredity of the mother tree, maintain the excellent traits of improved tea varieties, have fast propagation speed and a short propagation cycle, and can be propagated through cutting seedling raising at the seedling stage, with a relatively high propagation coefficient. Since the promotion and success of short-stem tea cuttings, tea clonal breeding has been the selection method of "single-plant selection -- cutting propagation." The breeding method
-
Tea plant sexual-line breeding methods and key technical points
A breeding method in which sexual progeny of tea plants are produced through the union of male and female gametes and, after selection, new cultivars are developed. The cultivars developed are called sexual-line cultivars. The methods are: 1. Selection of superior individual plants or types: according to the breeding objectives, carry out individual plant selection or group selection from the original material nursery or production tea gardens; 2. Seed collection and seedling raising: for the initially selected individual plants or groups, separately reserve and collect seeds, and raise seedlings separately by line, carrying out identification of seedling-stage traits and cultivar purity; 3. Family or group comparative trials: arrange comparative trials of the selected families or groups together with control
-
Identification Methods and Technical Key Points for Tea Plant Breeding Materials
Observe the traits of breeding materials, analyze the characteristics and features of various variant materials, select the superior and eliminate the inferior according to breeding objectives, and finally develop new varieties through comparative trials. The identification content is divided into 3 aspects: yield traits, quality traits and resistance. The yield traits of tea plants are mainly reflected in sprouting density and bud-leaf weight, growth speed, length of growth period, regeneration capacity after picking, and recovery capacity after suffering disasters or wounds; quality traits are mainly reflected in the chemical composition, color, pubescence,
-
Tea plant breeding yield identification methods and technical key points
A method for measuring the breeding yield of tea plants (individuals, lines or strains). The direct measurement of yield is calculated based on the harvested amount of buds and leaves per unit land area of the tea plant. ① Annual picking calculation method: according to a certain picking standard, pick in stages and batches by plant or plot, then separately count the total yield of each season within a year. In black tea and green tea regions, picking is generally done at the standard of one bud and two or three leaves; in dark tea regions and oolong tea regions, picking is done at the standard of 4-5 leaves at the resting shoot. In the later stages of breeding, yield performance must be measured to identify production potential.
-
Key Points and Practical Methods of Tea Plant Breeding Techniques Explained
In conventional tea plant breeding, single-plant selection and crossbreeding are mainly used. More than 90% of new tea plant varieties at home and abroad have been developed using these two methods. Single-plant selection uses naturally mutated material, that is, selecting superior individual plants from existing tea plant populations, then expanding their numbers through propagation while maintaining their superior traits. Crossbreeding uses gene recombination and interaction, making it possible for hybrid offspring to show combined superior traits of the parents or types superior to the parents. ① Correctly select parents; ② Master crossbreeding techniques; ③ Strengthen management after pollination.
-
Methods and Technical Key Points for Quality Evaluation in Tea Plant Breeding
Methods for evaluating the quality traits of individuals, types, or strains in tea plant selection and breeding. The quality of tea generally refers to the four factors of "color, aroma, taste, and shape," collectively known as appearance and internal quality. Direct quality evaluation involves producing finished tea according to the picking standards and processing techniques of different tea types, and then assessing the quality. Using a small amount of fresh leaves and small-scale machinery to make tea is called the "small-amount tea-making method," which is the early quality evaluation of young tea plants or individual plants. Indirect quality evaluation is based on the correlation between bud and leaf morphology and the quality of finished tea, using field observations and instrumental analysis for evaluation.
-
Detailed Explanation of Tea Plant Hybrid Breeding Techniques and Methods
A breeding method in which tea plant parents with different genetic characteristics are crossed sexually to produce variation in the hybrid population, which is then subjected to selection to develop new tea plant varieties. The selection and matching of hybrid parents determines the success or failure of hybrid breeding and the level of breeding achieved. The general principles are: 1) The parental traits should complement each other's strengths and weaknesses, and the superior traits should be outstanding; 2) The parents' adaptability to local environmental conditions, especially the material selected as the female parent, should have strong adaptive capacity; 3) The flowering periods of both parents should be relatively consistent, and the female parent's seed-setting
条件筛选