Application of new wheat-eriocheir sinensis ecological planting and breeding mode to improvement of adult crab quality

Abstract

The invention relates to the technical field of eriocheir sinensis breeding, in particular to application of a new wheat-eriocheir sinensis ecological planting and breeding mode in improving the quality of adult crabs, which comprises the following steps: planting wheat in a field, digging ditches around to protect eriocheir sinensis, and performing field operation in the growth period of wheat; after wheat is harvested, straw is removed, then land is ploughed, and water is injected for grass planting; after 15 days, Chinese mitten crabs are bred in the wheat field; through a new wheat-eriocheir sinensis ecological planting and breeding mode, the maturity and quality of adult eriocheir sinensis are improved.

Description

Technical Field

[0001] The invention relates to the technical field of Chinese mitten crab breeding, and in particular to application of a new ecological breeding model of wheat-Chinese mitten crab in improving the quality of adult crabs. Background Art

[0002] Chinese mitten crab (Eriocheir sinensis) is an important freshwater crustacean that is widely cultured in most provinces of China and has high nutritional and economic value. In recent years, with the development of large-scale crab farming, crab farming faces challenges from various diseases affected by the farming environment. Therefore, it is crucial to establish a more sustainable Chinese mitten crab farming model.

[0003] The wheat-Chinese mitten crab ecological breeding model (hereinafter referred to as: wheat-crab ecological breeding model) makes use of the gap period of wheat planting to create a good living environment for Chinese mitten crabs, thereby forming a wheat-crab system that promotes each other. Wheat is a drought-loving crop, and Chinese mitten crabs can be bred in staggered crops based on the growth habits of wheat. The present invention overcomes this technical difficulty and achieves successful breeding. For wheat, this model enriches the soil during the crab breeding process, so the wheat planting process achieves fertilizer control and drug reduction, and the planting of wheat also reduces the organic matter and inorganic salt components of the bottom mud, providing crabs with a poor water quality habitat suitable for crab life, greatly reducing the disease risk of crabs. In summary, this model has the advantages of saving water and soil and efficient circulation, and can significantly improve economic benefits.

[0004] The food sources of Chinese mitten crab are not only commercial granular feed, but also natural foods such as benthic animals, plankton, aquatic plants, etc. Compared with the single pond crab farming model, not only the water quality habitat is different, but also the food composition has changed. Therefore, there may be differences in the growth traits, nutritional composition of edible parts and intestinal flora of Chinese mitten crab.

[0005] In view of the above-mentioned defects, the inventors of the present invention finally obtained the present invention after a long period of research and practice. Summary of the invention

[0006] The purpose of the invention is to solve the problem of how to improve the quality of Chinese mitten crabs through a breeding model, and to provide an application of a new ecological breeding model of wheat-Chinese mitten crabs in improving the quality of adult crabs.

[0007] In order to achieve the above-mentioned object, the present invention discloses an application of a new ecological breeding model of wheat-Chinese mitten crab in improving the quality of adult crabs, and the new ecological breeding model of wheat-Chinese mitten crab comprises the following steps:

[0008] S1, after selecting the field, carry out field engineering, set up escape prevention and oxygenation facilities, and plant grass in the ditch;

[0009] S2, in February, water level management and daily management were carried out after Chinese mitten crab seedlings were released into the ring ditch;

[0010] S3, in mid-November, after the adult Chinese mitten crabs were harvested, wheat was sown in the field and then wheat management was carried out;

[0011] S4, in mid-to-late May, mechanized low-stubble wheat harvesting was adopted. After wheat harvesting, the straw was transported out as much as possible. After three days of sun exposure, the water was added to the enclosure after rotary tillage, and the verticillium was planted at 300 kg / mu. At the same time, water quality management was carried out;

[0012] S5, 20 days after planting Hydrilla verticillata, Chinese mitten crab seeds were added from the temporary pond, with the same specifications as those in the ring ditch;

[0013] S6, water level management, feeding management and disease control in the field;

[0014] S7, from late September to early November, Chinese mitten crabs were captured manually.

[0015] In step S1, the field area is 31×667m 2 The field works are as follows: dig a ring ditch with a width of 2m to 2.5m, a depth of 0.8-1.2m, and a slope ratio of 1:3. The excavated soil is mainly used to heighten and reinforce the ridge. The ring ditch area does not exceed 10% of the total wheat field area.

[0016] In step S1, the escape prevention and oxygenation facilities are specifically set as follows: the escape prevention wall is made of materials such as calcium plastic board and aluminum platinum board, buried 10cm to 20cm in the soil, 50cm above the ground, fixed with wooden stakes or bamboo supports, the four corners are arc-shaped, the inner and outer edges are paved and compacted with crushed soil to prevent water accumulation and holes, and equipped with two waterwheel oxygenation equipment.

[0017] In step S1, the ring ditch grass planting is specifically as follows: before the New Year, 7 to 10 days after cleaning and disinfection, Elodea is planted with a row spacing of 2.0m to 3.0m.

[0018] In step S2, the stocking of Chinese mitten crab seedlings is specifically as follows: In February, the water temperature is above 10°C and the weather is fine. The stocking specification is 100 to 120 crabs / kg, and the crab seedlings are placed every 667m 2 500 are released;

[0019] The specific water level management is as follows: the difference between the water level in the ring ditch and the wheat field is ≥10cm, which is the minimum difference to ensure the normal growth of wheat;

[0020] The specific daily management is as follows: After the crab seeds are put into the pond in February, the feeding rate is adjusted according to the weather and feeding conditions. The crude protein content of the feed is required to be ≥40%. The feed can be fermented by lactic acid bacteria and EM bacteria for 3 to 5 days before feeding.

[0021] In step S3, wheat sowing is specifically as follows: in mid-November, wheat seeds with a short growth period are selected, and the seeds are mixed with an available fungicide before sowing. Except for the ring ditch, wheat seeds are sown. 2 The wheat sowing amount is 15-20kg.

[0022] In step S3, wheat management is specifically as follows: decide whether to water the wheat during the winter based on soil entropy conditions, and if watering the wheat during the winter, do so before the wheat freezes; apply fertilizer appropriately during the greening and jointing stages; and do a good job in pest and weed control and prevent late frost damage.

[0023] In step S4, water quality management is as follows: after wheat harvest, within 20 days after water supply, pay close attention to water quality changes, change water frequently during this period, and kill insects in time if sandworms are found to multiply in large numbers; after 20 days, when aquatic plants grow vigorously, the water quality can be stabilized. After the water quality is stable, every 10 to 15 days, the water quality should be adjusted according to the water quality per 667m 2 Dissolve 5 kg of quicklime in water and sprinkle once.

[0024] In step S6, the water level management is specifically as follows: from July to August, the water level in the shallow water area is maintained at a depth of 60 cm to 80 cm; from September to October, the water level in the shallow water area is maintained at a depth of 40 cm to 50 cm.

[0025] The specific feeding management is as follows: the crude protein content of the feed should not be less than 40%, and it should be fed once a day in the evening. From August to October, corn, pumpkin, and wheat can be added, and the daily feeding rate is 5% to 8%;

[0026] The specific methods of disease prevention and control are as follows: regular application of quicklime and the use of various probiotics to assist in regulating water quality.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1. The present invention illustrates the effects of the wheat-crab ecological breeding model and the pond single breeding model on the growth performance, physiological and biochemical characteristics and intestinal microbiota of adult Chinese mitten crabs. There was no significant difference in the weight gain of adult crabs under the wheat-crab ecological breeding model, but the maturity of adult Chinese mitten crabs under the wheat-crab culture model was significantly higher than that under the single pond culture model. The results of the present invention show that the new wheat-crab culture model has the prospect of commercial-scale breeding;

[0029] 2. The new wheat-crab ecological breeding model of the present invention has a per-acre yield of river crabs that is basically equivalent to the yield of river crabs raised alone in ponds, that is, it is mainly based on raising river crabs, and a per-acre yield of 200-400 jin of river crabs is achievable. In this model, wheat needs to be planted directly on the pond bottom after the pond is dried, and crabs are raised after grass is planted after wheat is harvested. Advantages of this model: Wheat planted at the bottom of the pond saves fertilizers and absorbs nutrients from the bottom of the pond. After the crabs are released, the eutrophication of the pond bottom has been reduced by wheat, and this oligotrophic water quality is exactly the favorite living environment of river crabs, so the incidence of river crab diseases will be greatly reduced, the breeding risk is reduced, and the recapture rate of river crabs is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the wheat-crab ecological breeding model diagram;

[0031] Figure 2 The effects of the wheat-crab ecological breeding model and the pond monoculture model on the hepatopancreatic immune indexes of Chinese mitten crabs. Note: C♀: female Chinese mitten crabs in the pond monoculture model; C♂: male Chinese mitten crabs in the pond monoculture model; W♀: female crabs in the wheat-crab ecological breeding model; W♂: female crabs in the wheat-crab ecological breeding model. MDA: malondialdehyde content, SOD: total superoxide dismutase, GSH-Px: glutathione peroxidase, CAT: catalase; data are expressed as mean ± standard deviation (n = 6), the same letters indicate no significant difference (p>0.05), different letters indicate significant difference (p<0.05), and this note is used in other figures;

[0032] Figure 3 The effects of two models on the serum biochemistry of Chinese mitten crab. Note: ALT: alanine aminotransferase; ALP: alkaline phosphatase; TG: triglyceride; TP: total protein; CHO: total cholesterol; AMY: amylase;

[0033] Figure 4 The two models show the expression levels of hepatopancreas genes in Chinese mitten crab. Note: ALF2: anti-lipopolysaccharide factor 2; Myd88: myeloid differentiation primary gene 88; ProPO: prophenoloxidase; IL: interleukin; Keap1: kelch-like ech-related protein 1; CncC: captain collar isoform C;

[0034] Figure 5 OPLS-DA score plots (A: C♀vs-W♀, B: C♂vs-W♂) and permutation tests (C: C♀vs-W♀, D: C♂vs-W♂) in negative ion mode for quality evaluation of C♀-vs-W and C♂-vs-W metabolomics data;

[0035] Figure 6The top 20 KEGG pathways of C♀-vs-W♀ differential metabolites. Note: The larger the bubble, the greater the impact factor; the darker the bubble color, the more significant the enrichment. This annotation applies to other graphics;

[0036] Figure 7 The top 20 KEGG pathways of C♂-vs-W♂ differential metabolites;

[0037] Figure 8 The effects of the two models on the α diversity index (C, D, E, F) and β diversity index (A, B) of the intestinal flora of Chinese mitten crab;

[0038] Fig. 9 The effects of the two models on the intestinal flora composition of Chinese mitten crab. Note: A: Impact on microbial abundance at the flora level; B: Impact on microbial abundance at the genus level; C: VENN at the genus level; D: Significant differences in microorganisms at the phylum level; E: Significant differences in microorganisms at the genus level. DETAILED DESCRIPTION

[0039] The above and other technical features and advantages of the present invention are described in more detail below in conjunction with the accompanying drawings.

[0040] The experiment was conducted at the wheat-crab ecological breeding new model demonstration site (Guangfeng Aquaculture Family Farm) in Dangtu County, Anhui Province (longitude: 118.58°, latitude: 31.46°).

[0041] Example

[0042] Wheat-crab ecological breeding model:

[0043] 1. Management of crab breeding in wheat fields (February-May)

[0044] (1) Field selection

[0045] Select a water source with sufficient and unpolluted water, a flat field with no leakage, good water retention, and independent water inlet and drainage facilities with an area of ​​31×667m 2 .

[0046] (2) Field Engineering

[0047] Dig a ring ditch with a width of 2m to 2.5m, a depth of 0.8-1.2m, and a slope ratio of 1:3. The excavated soil is mainly used to heighten and reinforce the ridge. The area of ​​the ring ditch shall not exceed 10% of the total area of ​​the wheat field.

[0048] (3) Escape prevention and oxygenation facilities

[0049] The anti-escape wall is made of materials such as calcium plastic board and aluminum platinum board, buried 10cm to 20cm into the soil, 50cm above the ground, fixed with wooden stakes or bamboo supports, and the four corners are in an arc shape. The inner and outer edges are paved and compacted with crushed soil to prevent water accumulation from penetrating holes.

[0050] Equipped with two water truck oxygenation equipment.

[0051] (4) Planting grass around the ditch

[0052] Years ago, 7 to 10 days after cleaning and disinfection, Elodea was planted with a row spacing of 2.0m to 3.0m.

[0053] (5) Crab seedlings stocking

[0054] In February, choose sunny weather with water temperature above 10℃. The specification is 100 to 120 pieces / kg. Every 667m 2 500 are released into the wild.

[0055] (6) Water level management

[0056] The difference between the water level in the ditch and the wheat field should be ≥10cm to ensure the normal growth of wheat. Change the water regularly according to the water quality to ensure the growth of crab seedlings in the ditch.

[0057] (7) Daily management

[0058] After the crabs are put into the pond in February, the feeding rate should be adjusted according to the weather and feeding conditions. It is advisable to have a small amount left on the feeding table on the second day. The crude protein content of the feed is required to be ≥40%. The feed can be fermented by lactic acid bacteria and EM bacteria for 3 to 5 days before feeding.

[0059] 2. Wheat planting and management

[0060] (1) Wheat sowing

[0061] Try to choose wheat seeds with a short growth period, and mix the seeds with fungicides before sowing.

[0062] Wheat-crab ecological breeding new model In the ponds except the ring ditch, wheat seeds are sown. When sowing, a little water is left on the flat field, and after sowing, the water level is lowered, so that the wheat seeds do not need to be covered with soil.

[0063] After the crabs are harvested, usually in mid-November, 667m 2 The wheat sowing amount is 15-20kg, and the maximum sowing amount cannot exceed 20kg.

[0064] (2) Wheat management

[0065] Decide whether to water the plants during the winter based on the soil entropy. If you do, water them before the plant freezes. Apply fertilizer appropriately during the greening and jointing stages. Do a good job in pest and weed control and prevent late frost damage.

[0066] (3) Wheat harvest

[0067] In mid-to-late May, mechanized low-stubble harvesting is used, and the wheat straw is best baled before transportation to prevent it from rotting.

[0068] 3. River crab farming after wheat stubble (May-November)

[0069] (1) Planting grass

[0070] After the wheat was harvested on May 17, the straw was transported out as much as possible. After three days of exposure to the sun, the land was tilled and water was added to the enclosure to start planting Hydrilla verticillata, with 300kg / mu of Hydrilla verticillata.

[0071] (2) Water quality management

[0072] After wheat harvest, pay close attention to water quality changes within 20 days after water supply. Due to the decay of straw, the water color quickly turns reddish brown. During this period, change the water frequently. Once a large number of sandworms are found, kill the insects in time to prevent the sandworms from being too dense and causing hypoxia.

[0073] Generally, after 20 days, when the aquatic plants grow vigorously, the water quality will be stable. After the water quality is stable, every 10 to 15 days, the water quality should be adjusted according to the water quality of every 667 m 2 Dissolve 5 kg of quicklime in water and sprinkle once.

[0074] (3) Supplementing crab species

[0075] Generally, 20 days after planting grass, crab seeds are added from the temporary pond, with the same specifications as the crab seeds in the ring ditch, and the number is 500 per mu. In the early stage, the number of crab seeds in the ring ditch is 500 per mu, totaling 1,000 per mu.

[0076] (4) Water level management

[0077] As the temperature rises, the water level gradually deepens. From July to August, the water level in the shallow water area remains at 60cm to 80cm; from September to October, the water level in the shallow water area remains at 40cm to 50cm.

[0078] (5) Feeding management

[0079] The crude protein content of the feed should not be less than 40%, and it should be fed once a day in the evening. From August to October, it can be combined with corn, pumpkin, wheat, etc., with a daily feeding rate of 5% to 8%.

[0080] (6) Disease prevention and control

[0081] Prevention is the main approach, with quicklime sprinkled regularly and a small amount of various probiotics used to help regulate water quality, so there is basically no disease.

[0082] (7) Fishing

[0083] From late September to early November, various methods such as light trapping and ground trapping were used for manual capture.

[0084] Comparative Example

[0085] Pond culture model: area 30×667m 2 , plant grass in December, release crabs in March, density 1500 / 667m 2 (10g±2g). A 35cm high fence was set up around the two research sites to prevent crabs from escaping. In addition, water intakes and outlets were installed. Each experimental field was equipped with 2 water turbine aerators (2.20kw / h). During the experiment, commercial pellet feed (Tongwei Co., Ltd., crude protein 40%, crude fat 4%) was fed twice a day at 4% of body weight. The feeding times were 6:30 am and 3:00 pm, respectively, and the feeding amount was adjusted according to changes in body weight and daily feed residues. The water supply, feeding and daily management of the two breeding experimental areas were the same.

[0086] 1. Sample collection

[0087] On October 15, after the Chinese mitten crab matured, random sampling was performed in the wheat-crab ecological breeding model (10 female crabs: W♀; 10 male crabs: W♂); sampling of Chinese mitten crabs cultured in ponds (10 female crabs: C♀; 10 male crabs: C♂;), cryoanaesthesia for 15 minutes, and hemolymph was extracted from the bottom of the third leg with a sterile syringe. The supernatant of the hemolymph sample was centrifuged at 10,000×g for 12 minutes at 4℃, and stored at -80℃ for analysis. The hepatopancreas, muscle, and gonads were dissected and weighed. The hepatopancreas and muscle were taken and stored at -80℃ for analysis. The intestinal chyme specimens were stored at -80℃ on a sterile operating table.

[0088] After 24 hours of starvation, the crab's satiety score (FNS), muscle yield (MYI), hepatopancreatic index (HSI) and gonadotropin index (GSI) were calculated. The calculation formula is as follows:

[0089] FNS, (g / cm) = total body weight / carapace length 3

[0090] HIS, 100% = 100 × hepatopancreas weight (g) / total body weight (g)

[0091] GSI, 100% = 100 × gonadal weight (g) / total body weight (g)

[0092] MYI, 100% = 100 × muscle weight (g) / total body weight (g)

[0093] The growth performance of Chinese mitten crab under the two culture systems is shown in Table 1. The final weight of crabs in C♀ and W♀ groups was significantly lower than that in C♂ and W♂ groups (P<0.05). The GSI of W♀ group was significantly higher than that of other groups (P<0.05), and the HIS was significantly lower than that of other groups (P<0.05). The MYI of C♂ and W♂ groups was significantly higher than that of C♀ and W♀ groups (P<0.05). There was no significant difference in the degree of fullness (FNS) (P>0.05).

[0094] Table 1 Growth performance and tissue indexes of Chinese mitten crab under the pond monoculture model and wheat-crab ecological culture model

[0095] Terms Weight (g) HIS(%) GSI (%) MYI (%) FNS(%) C♀ 166.92±24.11 8.43±1.02 <![CDATA[4.45±1.09 b ]]> 26.53±2.31 <![CDATA[0.43±0.01 a ]]> C♂ 220.75±43.97 8.67±1.35 <![CDATA[2.86±0.41 a ]]> <![CDATA[29.41±1.68 b ]]> <![CDATA[0.46±0.04 a ]]> W♀ 167.30±25.06 7.68±0.81 <![CDATA[5.59±2.07 b ]]> <![CDATA[26.63±1.45 a ]]> <![CDATA[0.43±0.02 a ]]> W♂ 221.43±38.49 8.01±1.07 <![CDATA[3.37±0.53 a ]]> <![CDATA[29.08±2.04 b ]]> <![CDATA[0.47±0.03 a ]]>

[0096] Note: C♀: female crabs cultured in ponds under monoculture mode; C♂: male crabs cultured in ponds under monoculture mode; W♀: female crabs cultured in wheat-crab ecological breeding mode; W♂: female crabs cultured in wheat-crab ecological breeding mode. a P>0.05 (not statistically significant); b P<0.05.

[0097] 2. Biochemical analysis

[0098] Weigh the hepatopancreas sample and homogenize it with 10 volumes (v / w) of 0.85% iced saline. Centrifuge the homogenate at 4°C, 1500rpm for 30min, collect the supernatant, and store at -80°C for the determination of antioxidant parameters. Determine the content of malondialdehyde (MDA), total superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), alanine aminotransferase (ALT), alkaline phosphatase (ALP), triglyceride (TG), total protein (TP), total cholesterol (CHO), and amylase (AMY) in the hepatopancreas, muscle, and hemolymph. All indicators were detected using a kit (Nanjing Jiancheng). Follow the manufacturer's instructions.

[0099] Hepatopancreas ( Figure 2 ), the SOD activity of C♀ and W♀ groups was significantly higher than that of C♂ group (P<0.05). The CAT activity of W♀ group was significantly higher than that of other groups (P<0.05). The GSH-Px activity of W♂ group was significantly higher than that of C♀ group (P<0.05), while there was no significant difference between W♀ group and C♀ group (P>0.05). There was no significant difference in DMA activity among the groups (P>0.05).

[0100] In serum ( Figure 3 ), the TP and CHO contents of C♀ and W♀ groups were higher than those of C♂ and W♂ groups (p<0.05), while there were no significant differences in ALT, TG and ALP activities among the groups (p>0.05). The AMY content of W♂ group was significantly higher than that of W♀ group (p<0.05), and there were no significant differences among the other groups (p>0.05).

[0101] 3. Gene expression

[0102] Total RNA was extracted from the samples using Trizol reagent. Primers were designed using Oligo 6.0 (Table 2). The conditions for real-time quantitative PCR were consistent with those described in our previous report, and the β-actin gene was used as an internal control. At the same time, each sample was run 3 times during the detection process.

[0103] Table 2 Real-time PCR primer sequences

[0104]

[0105]

[0106] Figure 4 The expression of ALF2, Myd88, and CncC genes in the hepatopancreas of male crabs was significantly higher than that of female crabs (P<0.05). The expression of IL and Keap1 genes in W♂ was significantly higher than that in other groups (P<0.05). The expression of ProPO gene in the ecological breeding mode of wheat crab (W♂ and W♀) was significantly higher than that in the pond monoculture mode (C♂ and C♀) (P<0.05).

[0107] 5. Non-targeted metabolomics analysis

[0108] Non-targeted metabolomics of muscle tissue (50 mg) was performed by Origingene (Shanghai, China). Metabolites were obtained and annotated using the Human Metabolome Database (HMDB) and Metlin databases. Differential metabolites between different groups were screened with metabolic enrichment analysis and using KEGG key metabolic pathways with a significant threshold of VIP >1, P <0.05.

[0109] OPLS-DA was used to analyze the effects of different culture modes on muscle metabolism of Chinese mitten crab. Figure 5 As shown, the OPLS-DA score diagram ( Figure 5 A and B, A: C♀-vs-W♀, B: C♂-vs-W♂) showed significant differences between different groups, indicating that there were significant differences in metabolites related to different rolling times. The permutation test showed that the R2 and Q2 intercepts of ESI(-) between the C♀ and -W♀ groups were R2=(0.0,0.9) and Q2=(0.0,-0.17), respectively, and the R2 between the C♂ and -W♂ groups were R2=(0.0,0.99) and Q2=(0.0,0.1), indicating that the OPLS-DA model is reliable ( Figure 5 C and D).

[0110] KEGG pathway enrichment analysis was performed on the differential metabolites. Figure 6 The top 20 metabolic pathways were enriched, including important metabolic pathways such as glutathione metabolism, caffeine metabolism, thiamine metabolism, vitamin B6 metabolism, arginine biosynthesis, vitamin digestion and absorption, and lysine degradation. In the C♂-vs-W group, the top 20 enriched metabolic pathways included important metabolic pathways such as polyketide unit biosynthesis, phosphonate and phosphonate metabolism, microbial metabolism in different environments, purine metabolism, glycerolipid metabolism, and glycerophospholipid metabolism ( Figure 7 ).

[0111] 6. Intestinal flora

[0112] DNA purity and concentration were monitored on a 1% agarose gel and diluted to 1 μg / μL. Primers 341F (5′-CCT AYGGGR BGC ASC G-3′) and 806R (5′-GGACTA CNN GGG TAT CTAAT-3′) were used to amplify the V3-V4 hypervariable region of the bacterial 16S rRNA gene with barcodes. Guangzhou Gidio Technology Service Co., Ltd. used the Illumina Nova Seq platform and 300 bp paired-end reads to target the V3-V4 hypervariable region of the bacterial 16S rRNA gene.

[0113] β-diversity analysis showed that there were significant differences among the four groups (W♂, W♀, C♂, and C♀) according to the Adonis (permanova) test (genus: R2 = 0.2364, P = 0.001); Out: r2 = 0.2103, p = 0.001; Figure 8 A, B). Meanwhile, according to Krug-Wall, there were also differences in the alpha diversity index (Chao 1: P = 0.0016; Sobs: P = 0.0016; Simpson: P = 0.0087; Shannon: P = 0.0001; Figure 8 C, D, E and F).

[0114] A Venn diagram was drawn based on the number of genera in each group. There were 115 (C♂), 92 (W♂), 143 (C♀), and 118 (C♂) genera in the intestinal flora. Among them, 40 genera appeared in all groups, accounting for 34.19% ( Fig. 9 C). In the ecological breeding mode of crab and the single breeding mode in ponds, the door ( Fig. 9 D) and genus ( Fig. 9 The structure and composition of the crab gut flora at the E level changed. The four most abundant phyla were Firmicutes, Proteobacteria, Bacteroidetes, and Fusobacteria ( Fig. 9A). The nine most abundant genera were Candidatus_Hepatoplasma, Candidatus_Bacilloplasma, Bacteroides, Vibrio, Acinetobacter, Paracoccus, Aeromonas, Roseimarinus, and Fusobacterium ( Figure 8 B).

[0115] This invention illustrates for the first time the effects of the new wheat-crab ecological breeding model and the single pond breeding model on the growth performance, physiological and biochemical characteristics, and intestinal microbiota of Chinese mitten crab. There is no significant difference in the weight gain of Chinese mitten crab under the new wheat-crab ecological breeding model, but the maturity of Chinese mitten crab under the new wheat-crab ecological breeding model is significantly higher than that under the single pond culture model. Therefore, under the new wheat-crab ecological breeding model, the maturity of Chinese mitten crab can be advanced to be put on the market before the Mid-Autumn Festival, with significant economic benefits. The results of this study show that the comprehensive wheat-crab breeding model has the prospect of commercial-scale breeding.

[0116] The above description is only a preferred embodiment of the present invention, which is only illustrative and not restrictive of the present invention. Those skilled in the art understand that many changes, modifications, and even equivalences may be made to the present invention within the spirit and scope defined by the claims of the present invention, but all of them will fall within the scope of protection of the present invention.

Claims

1. Application of a new ecological breeding model of wheat-Chinese mitten crab in improving the quality of adult crabs, characterized in that: The new ecological breeding model of wheat and Chinese mitten crab The following steps are involved: S1, after selecting the field, carry out field engineering, set up escape prevention and oxygenation facilities, and plant grass in the ditch; S2, in February, water level management and daily management were carried out after Chinese mitten crab seedlings were released into the ring ditch; S3, in mid-November, after the adult Chinese mitten crabs were harvested, wheat was sown in the field and then wheat management was carried out; S4, in mid-to-late May, mechanized low-stubble wheat harvesting was adopted. After wheat harvesting, the straw was transported out as much as possible. After three days of sun exposure, the water was added to the enclosure after rotary tillage, and the verticillium was planted at 300 kg / mu. At the same time, water quality management was carried out; S5, 20 days after planting Hydrilla verticillata, Chinese mitten crab seeds were added from the temporary pond, with the same specifications as those in the ring ditch; S6, water level management, feeding management and disease control in the field; S7, from late September to early November, Chinese mitten crabs were captured manually.

2. The application of a new ecological breeding model of wheat-Chinese mitten crab as claimed in claim 1 in improving the quality of adult crabs, characterized in that: In step S1, the field area is 31×667m 2 The specific field works are as follows: dig a ring ditch with a width of 2m to 2.5m, a depth of 0.8 to 1.2m, a slope ratio of 1:3, and the area of ​​the ring ditch shall not exceed 10% of the total area of ​​the wheat field.

3. The application of a new ecological breeding model of wheat-Chinese mitten crab as claimed in claim 1 in improving the quality of adult crabs, characterized in that: In step S1, the escape prevention and oxygenation facilities are specifically set as follows: the escape prevention wall is made of materials such as calcium plastic board and aluminum platinum board, buried 10cm to 20cm in the soil, 50cm above the ground, fixed with wooden stakes or bamboo supports, the four corners are arc-shaped, the inner and outer edges are paved and compacted with crushed soil to prevent water accumulation and holes, and equipped with two waterwheel oxygenation equipment.

4. The application of a new ecological breeding model of wheat-Chinese mitten crab as claimed in claim 1 in improving the quality of adult crabs, characterized in that: In step S1, the ring ditch grass planting is specifically as follows: before the New Year, 7 to 10 days after cleaning and disinfection, Elodea is planted with a row spacing of 2.0m to 3.0m.

5. The application of a new ecological breeding model of wheat-Chinese mitten crab as claimed in claim 1 in improving the quality of adult crabs, characterized in that: In step S2, the stocking of Chinese mitten crab seedlings is specifically as follows: in February, select sunny weather with a water temperature above 10°C, and the stocking specification is 100 to 120 crabs / kg, every 667m 2 500 are released; The specific water level management is as follows: the difference between the water level in the ring ditch and the wheat field is ≥10cm; The daily management is as follows: After the crabs are put into the pond in February, the feeding rate is adjusted according to the weather and feeding conditions. The crude protein content of the feed is required to be ≥40%. The feed is fermented by lactic acid bacteria and EM bacteria for 3 to 5 days before feeding.

6. The application of a new ecological breeding model of wheat and Chinese mitten crab as claimed in claim 1 in improving the quality of adult crabs, characterized in that: In step S3, wheat sowing is specifically as follows: in mid-November, wheat seeds with a short growth period are selected, and the seeds are mixed with an available fungicide before sowing. Except for the ring ditch, wheat seeds are sown. 2 The wheat sowing amount is 15 to 20 kg.

7. The application of a new ecological breeding model of wheat and Chinese mitten crab as claimed in claim 1 in improving the quality of adult crabs, characterized in that: In step S3, wheat management is specifically as follows: decide whether to water the wheat during the winter based on soil entropy conditions, and if watering the wheat during the winter, do so before the wheat freezes; apply fertilizer appropriately during the greening and jointing stages; and do a good job in pest and weed control and prevent late frost damage.

8. The application of a new ecological breeding model of wheat and Chinese mitten crab as claimed in claim 1 in improving the quality of adult crabs, characterized in that: In step S4, water quality management is as follows: after wheat harvest, within 20 days after water supply, pay close attention to water quality changes, change water frequently during this period, and kill insects in time if sandworms are found to multiply in large numbers; after 20 days, when aquatic plants grow vigorously, the water quality can be stabilized. After the water quality is stable, every 10 to 15 days, the water quality should be adjusted according to the water quality per 667m 2 Dissolve 5 kg of quicklime in water and sprinkle once.

9. The application of a new ecological breeding model of wheat and Chinese mitten crab as claimed in claim 1 in improving the quality of adult crabs, characterized in that: In step S6, the water level management is specifically as follows: from July to August, the water level in the shallow water area is maintained at a depth of 60 cm to 80 cm; from September to October, the water level in the shallow water area is maintained at a depth of 40 cm to 50 cm. The specific feeding management is as follows: the crude protein content of the feed should not be less than 40%, and it should be fed once a day in the evening. From August to October, corn, pumpkin, and wheat can be added, and the daily feeding rate is 5% to 8%; The specific methods of disease prevention and control are as follows: regular application of quicklime and the use of various probiotics to assist in regulating water quality.

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