Method for interplanting bauhinia trees and tea trees based on ecological niche complementation and application

Abstract

The invention relates to the field of tea planting, in particular to a method for interplanting bauhinia trees and tea trees based on ecological niche complementation and application. According to the method for interplanting the bauhinia trees and the tea trees based on ecological niche complementation, the bauhinia trees and the tea trees are interplanted in soil, the row spacing of tea tree planting is 0.5 m * 1 m, and the row spacing of white-flower bauhinia trees is 1 m * 2 m. The method has the following effects: 1, the soil fertility is effectively improved; 2, the diversity of soil microorganisms Alpha and Beta is improved through intercropping; 3, diseases such as tea anthracnose and tea ring spot are effectively reduced;

Description

Technical Field

[0001] The present invention relates to the field of tea planting, and in particular to a method and application of interplanting tea trees with Bauhinia trees based on niche complementarity. Background Art

[0002] Tea is a major cash crop in my country, and the quality and taste of its tea are key determinants of its market value. However, this quality is significantly influenced by the ecological environment of tea gardens. Currently, the drawbacks of large-scale, contiguous monoculture in tea gardens are becoming increasingly apparent, severely restricting the sustainable development of the tea industry. Intercropping, as a green and sustainable cultivation model, holds significant significance for addressing current ecological challenges in tea gardens. However, previous research on intercropping in tea gardens has primarily focused on green manure, and there is currently a lack of systematic theoretical support for the selection of optimal intercropping species.

[0003] Previous studies have shown that tea garden intercropping patterns significantly affect the chemical characteristics of tea quality through ecological interactions between species. Gu Junrong et al. studied the intercropping of tea trees with chestnut, bayberry, citrus and other fruit trees, and found that there were significant differences between monoculture tea gardens and tea-bayberry and tea-citrus intercropping gardens. Different fruit-tea intercropping patterns effectively increased the gallic acid content in the fresh leaves of Dongting Biluochun, which had a positive effect on improving tea quality. Liu Xin et al. observed in the forest-tea intercropping system that the water extract and amino acid content of tea in the composite tea garden were significantly higher than those in the pure tea garden. This is closely related to the scattered light environment formed by the upper forest canopy that promotes nitrogen metabolism in tea trees. Wu Manxia's research revealed that the tea-Cornus officinalis and tea-chestnut intercropping patterns increased the total amount of tea amino acids and reduced the total amount of catechins and phenol-ammonia ratio through the regulation of root secretions, thereby improving the quality of tea to a certain extent. The green manure intercropping pattern improves tea quality through soil improvement effects. Zhu Shijun's research shows that tea gardens intercropped with leguminous green manures such as white clover and Chinese milk vetch show significant decreases in tea caffeine, tea polyphenols, and the phenol-to-ammonia ratio, while also increasing soil organic matter. Notably, intercropping aromatic plants exhibits unique quality-regulating effects. Tea-basil and tea-perilla intercropping systems, while repelling pests through volatiles, reduce tea polyphenols and caffeine content in tea leaves, increase soluble sugars and catechins, and enhance tea quality. This provides new directions for exploring and innovating intercropping models in tea gardens.

[0004] Current research on intercropping in tea gardens primarily focuses on the impact of legumes, which can reduce the phenol-ammonia ratio, thereby improving the freshness of the tea. Qin Xiaomin et al., through multi-season sampling and analysis, found that legume intercropping tea gardens had increased soluble sugar and amino acid levels in spring, summer, and autumn compared to monoculture tea gardens, and reduced tea bitterness. Furthermore, Li Jinting et al. further revealed that tea-soybean intercropping not only increased soluble sugar and caffeine levels but also maintained stable quality components even under reduced nitrogen fertilizer application conditions. This suggests that legume intercropping achieves the dual goals of "reducing nitrogen consumption and increasing efficiency" through biological nitrogen fixation, providing a scientific basis for green tea garden management. Summary of the Invention

[0005] The present invention aims to provide a method and application of interplanting tea trees with Bauhinia trees based on niche complementarity. The specific scheme is as follows:

[0006] A method for interplanting tea trees with Bauhinia trees based on niche complementarity, wherein the Bauhinia trees and tea trees are interplanted in soil, with a row spacing of 0.5 m×1 m between tea trees and a row spacing of 1 m×2 m between white Bauhinia trees.

[0007] Soil pH range is 4.5-5.5.

[0008] During the intercropping production process, weeding is carried out twice a year.

[0009] The tea tree variety is the Mengku large-leaf variety.

[0010] A method of interplanting tea trees with Bauhinia oleracea based on niche complementarity is used to reduce the incidence of tea anthracnose and tea ring spot diseases in tea trees.

[0011] A method of interplanting tea trees with Bauhinia oleracea based on niche complementarity is used to increase the contents of soil organic matter, alkaline-hydrolyzable nitrogen, available potassium, and effective phosphorus.

[0012] A method of interplanting Bauhinia trees with tea trees based on niche complementarity was applied to improve soil microbial diversity.

[0013] The present invention has found that the following effects are achieved by intercropping Bauhinia chinensis and tea trees:

[0014] (1) The contents of soil organic matter, alkaline-hydrolyzable nitrogen, available potassium, and available phosphorus increased to varying degrees. Among them, the alkaline-hydrolyzable nitrogen content was 356.15 mg kg -1 , the fast-acting potassium content is 224.88 mg·kg -1 It is significantly higher than that in single-crop tea gardens. It can be seen that intercropping Bauhinia alba in tea gardens has a positive effect on the physical and chemical properties of tea garden soil and significantly improves soil fertility.

[0015] (2) Analysis of the Alpha and Beta diversity of soil microorganisms showed that the Chao and Shannon indices of bacteria and fungi in the intercropped rhizosphere soil were significantly increased. In addition, the contents of water extract, soluble sugars, amino acids, and total catechins increased significantly under the intercropping pattern, while the contents of caffeine, tea polyphenols, and phenol-to-ammonia ratio decreased significantly.

[0016] (3) The incidence of tea anthracnose in intercropping tea gardens was only 0.53% and 0.93%, while the disease index of tea anthracnose in monocropping tea gardens was 22.5 and 10.44 times that of intercropping, respectively; the incidence of tea ring spot in intercropping tea gardens was 0.0% and 0.67%, while the disease index of tea ring spot in CK1 (non-intercropping control group) in monocropping tea gardens was 19 times that of DH1 (intercropping example). It can be seen that intercropping Bauhinia alba in tea gardens can significantly reduce the incidence and disease index of tea anthracnose and tea ring spot. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The effects of intercropping of Bauhinia alba and tea trees on tea quality components (including water extract content (Part A); soluble sugar content (Part B); caffeine content (Part C); tea polyphenols content (Part D); amino acid content (Part E); phenol-ammonia ratio (Part F));

[0018] Figure 2 The effects of Bauhinia alba-tea tree intercropping on soil pH and nutrients (including pH value (A); electrical conductivity content (B); organic matter content (C); alkaline nitrogen content (D); available potassium content (E); and available phosphorus content (F)).

[0019] Figure 3 Effects of Bauhinia alba-tea tree intercropping on soil microbial Beta diversity (bacteria (A); fungi (B));

[0020] Figure 4 The incidence rate (A) and disease index (B) of tea anthracnose in tea gardens under monoculture and intercropping patterns;

[0021] Figure 5 The incidence rate (A) and disease index (B) of tea ring spot disease in tea gardens under monocropping and intercropping patterns. DETAILED DESCRIPTION

[0022] 1. Test location and materials

[0023] The experimental site is located in Nadameng Tea Garden, Banpen Village, Menghai County, Xishuangbanna Prefecture, Yunnan Province (100°30′26″E, 21°46′9″N), and the tea variety planted is Mengku large-leaf variety. The average annual temperature in the area is 18.7℃, the annual precipitation is about 1374mm, and the altitude is about 1619.10-1649.52m. The soil type is acidic red soil rich in organic matter. The row spacing between tea trees in this tea garden is 0.5m×1m, and in the intercropped tea garden, the row spacing between white flowered Bauhinia trees is 1m×2m. The tea garden management mode is the traditional clear tillage mode, and manual weeding is carried out twice a year according to the growth of weeds. No fertilizer has been applied to the tea garden for many years. This study set up tea tree monoculture (CK) and intercropping of Bauhinia trees and tea trees (DH), with an area of 667m per plot. 2 ,In this study, 6 plots were selected for each observation, and the ,experimental plots were consistent with the tea garden management.

[0024] This study monitored the effects of intercropping on tea plant growth and the tea garden environment for two consecutive years (2023 and 2024). Tea leaves and rhizosphere soil samples were collected from April 1–6, 2023, and 2024, respectively. 500 g of uniformly healthy young shoots (one bud and two leaves) were collected from six plots under monoculture and intercropping systems. 400 g of fresh leaves were immediately microwave-solidified, bagged, and labeled for subsequent tea quality component testing and analysis; 100 g of fresh leaves were stored in liquid nitrogen for volatile metabolite analysis. Rhizosphere soil samples were collected using a five-point sampling method. Surface weeds were removed, and soil was collected from the tea plant roots at a depth of 30 cm. After screening to remove debris and roots, the soil was bagged, labeled, and transported back to the laboratory for storage at −80°C for microbial community analysis and at 4°C for soil physical and chemical property testing.

[0025] Antibacterial activity assay against Bauhinia acuminata: Test strains were selected: Colletotrichum camelliae 1-4DH and Pestalotiopsis kenyana 23-FN, previously isolated and identified from diseased leaves of tea plants in the Nadameng tea garden in Banpen Village, Menghai County, Xishuangbanna Prefecture, Yunnan Province. Flowers and leaves of Bauhinia acuminata L. were collected from the Nadameng tea garden in Banpen Village, Menghai County, Xishuangbanna Prefecture, Yunnan Province. Potato dextrose agar (PDA) was used as the test medium for the cultivation of Colletotrichum camelliae 1-4DH and Pestalotiopsis kenyana 23-FN. Sodium hypochlorite (Beijing Fengxi Qiaobo Biotechnology Co., Ltd.) was used as the test reagent.

[0026] 2. Experimental Methods

[0027] 2.1 Determination of fresh tea leaf quality components and soil physical and chemical indicators

[0028] The determination of tea water extract refers to the "Determination of Tea Water Extract: GB / T8305-2013"; the determination of soluble sugar is carried out by the anthrone-sulfuric acid colorimetric method; the amino acid is determined by the ninhydrin colorimetric method; the tea polyphenols are determined by the folin phenol method, with reference to the "Determination of Tea Polyphenols and Catechins in Tea: GB / T8313-2013", using a multi-function microplate reader; the caffeine and catechin contents are analyzed by high performance liquid chromatography (HPLC).

[0029] Soil pH was determined using the potentiometric method; organic matter content was titrated using potassium dichromate volumetric method; soil samples were reduced with a reducing agent and then spread in a diffusion dish, and then diluted with 1.8 mol·L -1 Soil samples were hydrolyzed with NaOH solution, and the ammonium nitrogen produced by hydrolysis was absorbed by boric acid solution and titrated with standard acid to calculate the content of soil alkaline nitrogen. Available phosphorus and available potassium were determined by molybdenum antimony colorimetry and flame spectrophotometry, respectively.

[0030] 2.2 Metabolomics analysis of fresh tea leaves

[0031] Samples were removed from a -80°C freezer and ground with liquid nitrogen. Vortex-mixed, approximately 500 mg (1 mL) of each sample was weighed into a headspace vial. A saturated NaCl solution and 20 μL (10 μg / mL) of internal standard solution were added. Samples were extracted using fully automated headspace solid-phase microextraction (HS-SPME) for GC-MS analysis. HS-SPME extraction conditions included constant temperature at 60°C, oscillation for 5 minutes, insertion of a 120 μm DVB / CWR / PDMS extraction tip into the sample headspace vial, headspace extraction for 15 minutes, and desorption at 250°C for 5 minutes. Separation and identification were then performed by GC-MS. The extraction head was conditioned at 250°C for 5 min before sampling. Chromatographic conditions: a DB-5MS capillary column (30 m × 0.25 mm × 0.255 μm, Agilent J&W Scientific, Folsom, CA, USA), high-purity helium (≥99.999%) carrier gas, constant flow rate of 1.2 mL / min, splitless injection at an inlet temperature of 250°C, and a solvent delay of 3.5 min. The temperature program was: 40°C for 3.5 min, then increased at 10°C / min to 100°C, then at 7°C / min to 180°C, and finally at 25°C / min to 280°C, where it was held for 5 min. Mass spectrometry conditions: electron impact ionization (EI) source temperature of 230°C, quadrupole temperature of 150°C, mass spectrometer interface temperature of 280°C, electron energy of 70 eV, and selected ion detection (SIM) mode for precise qualitative and quantitative ion scanning. Data analysis was performed based on secondary spectra using the Metware database (MWDB) developed by Maiwei (Wuhan) Biotechnology Co., Ltd. and the public metabolite information database. Mass spectrometry data were processed using MassHunter 8.0 software. Hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) were performed using SIMCA 14.1 software.

[0032] 2.3 Analysis of tea garden soil microbial community diversity by bacterial 16S rRNA sequencing and fungal ITS sequence sequencing

[0033] Soil samples were collected using sampling tubes and immediately frozen in liquid nitrogen before being transported back to the laboratory. Soil sample sequencing and data analysis were performed by Chongqing Meiji Tongyan Biopharmaceutical Technology Co., Ltd. PCR amplification of bacterial 16S rDNA was performed using primers 338F (5′-ACTCCTACGGGAGGCAGCA-3′) and 806R (5′-GGACTACHVGGGTWTCTAAT-3′). The fungal ITS_V1 region was amplified using primers ITS5F (5′-GGAAGTAAAAGTCGTAACAAGG-3′) and ITS2R (5′-GCTGCGTTCTTCATCGATGC-3′). PCR products were purified and sequenced using the Illumina HiSeq 2500 platform. The raw data obtained from sequencing were split and spliced to generate raw tag data. Valid tags were clustered to form OTUs (operational taxonomic units). Representative OTU sequences were selected for alignment against the Silver database, and sequences with unannotated or sequencing errors were removed. Based on OUT annotation information and absolute abundance, the annotation percentage of each sample at each taxonomic level was calculated. Data quality control was performed using Qiime software, and bacterial and fungal diversity within each sample and between groups were compared. Soil microbial community composition, species diversity analysis, and marker species screening were all performed on the MajorBio Cloud Platform (https: / / www.majorbio.com).

[0034] 2.4 Survey and statistics of tea garden field diseases

[0035] Tea tree disease surveys and statistics were conducted in six plots under tea monoculture and intercropping systems. A five-point sampling method was used in each plot to collect diseased leaves and collect disease data. Twenty-five tea leaves were randomly picked from ten tea trees in each plot, totaling 125 leaves per sampling point, for a total of 725 leaves across the six plots. The collection time and location were recorded in detail. The samples were brought back to the base on the same day, where they were promptly morphologically identified. The number of diseased leaves at each disease stage was recorded according to the disease severity grading standard.

[0036] Disease grading standard: 0-4 grade grading standard is used. Grade 0, no lesions on leaves; Grade 1, 1-2 lesions on leaves; Grade 2, 3-4 lesions on leaves or occupying less than 1 / 3 of the leaf area; Grade 3, 5-7 lesions on leaves or occupying 1 / 2 of the leaf area; Grade 4, more than 8 lesions on leaves or occupying more than 2 / 3 of the leaf area, and lesions on petioles or young shoots. Calculate the incidence and disease index of tea anthracnose and tea ring spot in monoculture and intercropping tea gardens, and compare and analyze the differences in disease occurrence. Calculation formula for incidence and disease index:

[0037] (1) Incidence rate = number of diseased leaves / total number of leaves surveyed × 100%.

[0038] (2) Disease index = (Σ(value of each level × number of leaves at the corresponding level)) / (total number of leaves surveyed × value of the highest level) × 100%.

[0039] 3. Results and Analysis

[0040] 3.1 Effect of intercropping Bauhinia chinensis on tea quality

[0041] The test results of tea quality components show that ( Figure 1 ), the content of tea water extract ranged from 42.67%±1.46% to 50.87%±1.21%. Compared with CK, the content of DH water extract increased significantly and DH2 increased significantly by 19.21% ( Figure 1 A); the soluble sugar content of tea samples ranged from 5.97% ± 0.04% to 8.82% ± 0.04%. Compared with CK, the soluble sugar content of DH increased significantly, and DH2 increased significantly by 47.9% ( Figure 1 B); the caffeine content of tea samples ranged from 3.90% ± 0.01% to 4.98% ± 0.09%. Compared with CK, the caffeine content of DH was significantly reduced and DH2 was significantly reduced by 21.56% ( Figure 1 C); tea polyphenol content in tea samples Compared with CK, the tea polyphenol content of DH was significantly lower, and the decreasing trend was consistent between the years ( Figure 1 D). The amino acid content of tea samples ranged from 2.39% ± 0.05% to 2.77% ± 0.03%. Compared with CK, the DH amino acid content increased significantly, and DH2 was significantly higher than DH1 ( Figure 1 E). The phenol-ammonia ratio of tea samples ranged from 1.92±0.05 to 2.66±0.06. Compared with CK, the phenol-ammonia ratio of DH was significantly lower, and the decreasing trend was consistent between years ( Figure 1 F).

[0042] 3.2 Effects of intercropping Bauhinia trees on soil physical and chemical properties and soil fertility in tea gardens

[0043] The test results of the physical and chemical composition of tea garden soil showed that ( Figure 2 ), the soil pH ranged from 4.64±0.03 to 5.12±0.03. Compared with CK, the soil pH of DH decreased significantly, and DH1 was significantly lower than DH2 ( Figure 2 A); soil electrical conductivity range is 40.52μm·cm -1 ±2.52 μm·cm -1 ~61.67μm·cm -1 ±2.66 μm·cm -1Compared with CK, the conductivity of DH increased significantly, with DH1 increasing by 52.2% compared with CK1. There was no significant difference between the two years ( Figure 2 B); soil organic matter content is 39.88 g·kg -1 ±3.77g·kg-1~53.25g·kg -1 ±0.8g·kg -1 Compared with CK, the organic matter content of DH increased significantly, and there was no significant difference between the years ( Figure 2 C); soil alkaline nitrogen content is 236.83 mg kg -1 ±6.49 mg kg -1 ~361.48 mg·kg -1 ±44.96 mg kg -1 Compared with CK, the alkaline nitrogen content of DH increased significantly, and there was no significant difference between the two years ( Figure 2 D); soil available potassium content is 95.98 mg kg -1 ±2.58mg·kg -1 ~243.89 mg·kg -1 ±7.87 mg kg -1 Compared with CK, the available potassium content of DH increased significantly, and the available potassium content of DH2 increased by 118.02% and was significantly higher than that of DH1 ( Figure 2 E); the available phosphorus content in the soil is 46.98 mg·kg -1 ±3.5mg·kg -1 ~89.35 mg·kg -1 ±4.73 mg kg -1 Compared with CK, the available phosphorus content of DH increased significantly, and the available phosphorus content of DH2 increased by 90.2%. The difference between the two years was significant ( Figure 2 F).

[0044] 3.3 Effects of intercropping Bauhinia chinensis on the microecology of the rhizosphere soil of tea trees

[0045] Effects of intercropping on soil microbial Alpha and Beta diversity

[0046] Community coverage (Coverage) showed that the current sequencing depth covered all bacteria and fungi in the soil, comprehensively reflecting the soil bacterial and fungal communities (Table 1). After intercropping Bauhinia alba in tea gardens, the Chao (richness) and Shannon index (diversity) of bacteria in DH significantly increased compared to CK, with DH2 significantly higher than DH1. The Heip index (evenness) did not vary significantly within the same year but increased significantly between years. Compared to CK, the Chao and Shannon indices of fungal communities in DH significantly increased, while the Heip index varied significantly within the same year but not between years.

[0047] Table 1

[0048]

[0049] This study compared the differences in bacterial and fungal community structure between tea monoculture (CK) and tea-Bauhinia intercropping (DH) using species-level PCoA analysis (Binary-Jaccard). The first and second axes represent the contribution of the first and second principal components to the treatment differences. In the bacterial community, the first and second principal components accounted for 31.96% and 19.61%, respectively. Figure 3 A). In the fungal community, the first principal component and the second principal component accounted for 41.49% and 27.11% respectively ( Figure 3 B). Bacterial and fungal communities were clearly separated between the two planting patterns.

[0050] 3.4 Survey and statistics of tea garden field diseases

[0051] 3.4.1 Occurrence of tea anthracnose

[0052] The survey results of tea anthracnose disease showed that ( Figure 4 ), the incidence of tea anthracnose in CK1 and CK2 (according to the above because there are two sets of data for 2023 and 2024) were 9.33% and 9.6% respectively, while the incidence of tea anthracnose in DH1 and DH2 was only 0.53% and 0.93%, respectively. The incidence of CK1 and CK2 was 17.5 times and 10.29 times that of the former, respectively. The difference was extremely significant, but the difference between different years was not significant ( Figure 4 A). The anthracnose disease index of tea in CK1 and CK2 were 3.0 and 3.13 respectively, while the anthracnose disease index of tea in DH1 and DH2 were 0.13 and 0.3 respectively. The disease index of CK1 and CK2 were 22.5 and 10.44 times higher than that of CK1 and CK2 respectively, which were extremely significant. However, the difference between different years was not significant ( Figure 4 B). Intercropping Bauhinia alba with tea can significantly reduce the incidence and disease index of tea anthracnose.

[0053] 3.4.2 Occurrence of tea ring spot disease

[0054] The survey results of tea ring spot disease showed that ( Figure 5 ), the incidence of tea ring spot in CK1 and CK2 was 2.4% and 2.67% respectively, while the incidence of tea ring spot in DH1 and DH2 was only 0.00% and 0.67%, respectively. The difference was very significant, but the difference between different years was not significant ( Figure 5 A). The disease indexes of CK1 and CK2 were 0.63 and 0.77, respectively, while the disease indexes of DH1 and DH2 were 0.03 and 0.17, respectively. The disease index of CK1 was 19 times that of DH1, which was a very significant difference. However, the differences between different years were not significant ( Figure 5 B) Intercropping tea trees with Bauhinia alba can significantly reduce the incidence and disease index of tea ring spot disease.

[0055] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for interplanting tea trees with Bauhinia trees based on niche complementarity, characterized by: Bauhinia trees and tea trees were interplanted in the soil, with the row spacing between tea trees being 0.5m×1m and the row spacing between white Bauhinia trees being 1m×2m.

2. The method for interplanting tea trees with Bauhinia chinensis trees based on niche complementarity as claimed in claim 1, characterized in that: Soil pH range is 4.5-5.

5.

3. The method for interplanting tea trees with Bauhinia trees based on niche complementarity as claimed in claim 1, characterized in that: During the intercropping production process, weeding is carried out twice a year.

4. The method for interplanting tea trees with Bauhinia trees based on niche complementarity according to claim 1, wherein: The tea tree variety is the Mengku large-leaf variety.

5. A method of interplanting tea trees with Bauhinia trees based on niche complementarity is used to reduce the incidence of tea anthracnose and tea ring spot diseases in tea trees.

6. A method of interplanting tea trees with Bauhinia trees based on niche complementarity is used to increase the content of soil organic matter, alkaline nitrogen, available potassium and effective phosphorus.

7. A method of interplanting tea trees with Bauhinia trees based on niche complementarity is applied to improve soil microbial diversity.

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