Root box device and method for micro-domain root system simulation experiment

Abstract

The invention discloses a root box device and method for a micro-domain root system simulation experiment, the root box device comprises a root box with a through top, the root box is provided with a detachable side plate, the interior of the root box is uniformly divided into three analysis chambers by two partition plates along the horizontal direction, and after the side plate is detached, the three analysis chambers are separated by the partition plates. One side, close to the side plate, of each analysis chamber is through; avoiding openings are formed in the two partition plates, separation nets are assembled on the avoiding openings, each separation net is provided with a plurality of separation holes, the separation holes in one separation net prevent root systems from passing through and allow hyphae to pass through, and the separation holes in the other separation net prevent the root systems and the hyphae from passing through at the same time. According to the root box device disclosed by the invention, the interior of the root box is divided into a plurality of relatively independent analysis chambers through the arrangement of the partition plates, the plurality of analysis chambers are connected with one another through the partition nets with different pore diameters, root systems or hyphae can be selectively allowed to enter, and then related indexes of the plant root systems and AMF hyphae can be independently researched.

Description

Technical Field

[0001] The invention relates to the technical field of plant root system and rhizosphere micro-domain research, and in particular to a root box device and method for micro-domain root system simulation experiments. Background Art

[0002] The study of plant roots and rhizosphere micro-domains has been going on for many years and has become a research focus in the fields of geochemistry, botany, and environmental science. Arbuscular mycorrhizal fungi (AMF) are functional microorganisms that are widely present in the soil and can form symbiotic mycorrhizae with more than 80% of plant roots (Smith and Read, 2010). AMF colonization growth and hyphae expansion can enhance the nutrient absorption capacity and stress resistance of plants, and the rapid turnover of hyphae and mycorrhizal secretions promote the input of fresh carbon sources in the rhizosphere. The important impact of arbuscular mycorrhizal symbiosis on plant growth status and rhizosphere micro-domain environment is the focus and frontier of rhizosphere-related research. However, due to the interaction between soil components and the difficulty of studying AMF hyphae independently, the quantitative contribution of AMF to soil structure, element cycle, and microbial activity is difficult to characterize in situ. At present, the action process of AMF in the plant-soil continuum is still regarded as a biochemical "black box". Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a root box device for micro-domain root simulation experiments, which can not only carry out mycorrhizal infection and plant drought resistance research, but also study the activation mechanism of soil phosphorus by arbuscular mycorrhizal symbiosis.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A root box device for micro-domain root system simulation experiments, comprising a root box with a through top, a detachable side panel, and an interior evenly divided into three analysis chambers by two partitions in the horizontal direction, and when the side panel is removed, the side of each analysis chamber close to the side panel is through; avoidance openings are opened on the two partitions, and an isolation net is installed on the avoidance opening, and the isolation net has a plurality of isolation holes, and the isolation holes on one isolation net block the passage of the root system and allow the passage of hyphae, and the isolation holes on the other isolation net block the passage of both the root system and hyphae. When implemented, the three analysis chambers are filled with Soil, and the analysis room in the middle is used as the central plant room for planting plants and accessing fungi. During the growth of plants and fungi, the plant roots selectively enter one of the analysis rooms on the side through the isolation net on the partition, and the analysis room is used as the root room; the hyphae generated by the fungi can selectively enter another analysis room on the side through the isolation net on the partition, and the analysis room is used as the mycelium room. By observing the growth morphology of the roots in the root room and analyzing the soil samples in the mycelium room, the relevant indicators of plant roots and AMF mycelium can be independently studied.

[0006] Preferably, a partition groove is opened inside the root box on the side away from the side panel, and one side of the partition can be removably inserted into the partition groove, and the other side rests on the side panel, so that the partition can be removably replaced inside the root box.

[0007] Preferably, the root box is made of acrylic sheet material, and the transparent property of acrylic sheet material is utilized to facilitate in-situ observation and characterization of plant root growth.

[0008] Preferably, the aperture of the isolation hole for blocking the passage of roots and hyphae at the same time is 0.45 μm, and the aperture of the isolation hole for blocking the passage of roots and allowing hyphae to pass through is 38 μm.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] 1. The root box device disclosed in the present invention divides the inside of the root box into a plurality of relatively independent analysis chambers by setting a partition. The plurality of analysis chambers are interconnected by isolation nets with different apertures, and roots or hyphae can be selectively allowed to enter, thereby independently studying the relevant indicators of plant roots and AMF hyphae.

[0011] 2. The present invention utilizes the detachable side panels on the root box so that multiple analysis chambers can be opened from the side, thereby facilitating the collection of plant roots, AMF hyphae, and rhizosphere soil when independently studying the relevant indicators of plant roots and AMF hyphae. At the same time, the damage to the root system and the disturbance to the soil can be reduced during the collection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0013] Figure 2 is a schematic diagram of the root box of the present invention after the side panels are removed;

[0014] Figure 3 It is a schematic structural diagram of the partition of the present invention;

[0015] Figure 4 It is a schematic diagram of the avoidance hole distribution of the present invention.

[0016] Figure symbols: 1. Root box, 11. Side panel, 12. Analysis chamber, 13. Partition groove, 2. Partition, 21. Avoidance hole, 3. Isolation net. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0018] Example 1

[0019] This embodiment discloses a root box device for micro-domain root system simulation experiments, which can not only carry out mycorrhizal infection and plant drought resistance research, but also study the activation mechanism of soil phosphorus by arbuscular mycorrhizal symbiosis.

[0020] The structure of the root box device is as follows: Figure 1-4 As shown, the root box 1 includes a top-through root box 1, the root box 1 has a detachable side panel 11, the interior of the root box 1 is evenly divided into three analysis chambers 12 by two partitions 2 in the horizontal direction, the three analysis chambers 12 are relatively independent, the two partitions 2 are provided with avoidance openings 21, and the avoidance openings 21 are equipped with isolation nets 3. During implementation, the three analysis chambers 12 are filled with soil, and the analysis chamber 12 located in the middle is used as a central plant chamber for planting plants and accessing bacterial agents. During the growth of plants and bacterial agents, the plant roots are blocked by the isolation nets 3 on the partitions 2. The central plant The plant chamber forms a mycorrhizal chamber (with both roots and hyphae); at the same time, the AMF hyphae selectively pass through the isolation net 3 on the partition 2 and enter one of the analysis chambers 12 on the side, which serves as a hyphae chamber (without roots but with hyphae); the plant roots and hyphae are blocked by the isolation net 3 on the other side partition 2, and the analysis chamber 12 on this side serves as a sterile root chamber (i.e., without roots and hyphae). By observing the growth morphology of the roots in the mycorrhizal chamber and analyzing the soil samples in the hyphae chamber, the relevant indicators of the plant roots and AMF hyphae can be independently studied.

[0021] The two isolation nets 3 mentioned above both have multiple isolation holes, and the isolation holes on one of the isolation nets 3 block the passage of roots and allow the passage of hyphae, and the isolation holes on the other isolation net 3 block the passage of both roots and hyphae. Preferably, the pore size of the isolation holes that block the passage of both roots and hyphae is 0.20-0.50 μm; the pore size of the isolation holes that block the passage of roots and allow the passage of hyphae is 35-45 μm.

[0022] After the above-mentioned side panel 11 is disassembled, the side of each analysis chamber 12 close to the side panel 11 is connected, which is convenient for the in-situ collection and analysis of samples such as plant roots and rhizosphere soil. At the same time, the damage to the plant roots and the disturbance to the soil samples during the sampling process are relatively small. Preferably, the side panel 11 is connected to the main body of the root box 1 by bolts.

[0023] As a preferred solution of the above embodiment, a partition groove 13 is opened inside the root box 1 on the side away from the side panel 11, and one side of the partition 2 can be removably inserted into the partition groove 13, and the other side is against the side panel 11, so as to achieve the purpose of removable and replaceable partitions inside the root box. By replacing partitions with isolation nets of different apertures, the root box device can meet the needs of different experiments.

[0024] As a preferred solution of the above embodiment, the root box 1 is made of acrylic sheet material, and the transparent property of the acrylic sheet material is utilized to facilitate in-situ observation and characterization of the growth of plant roots.

[0025] Application Examples

[0026] The root box device disclosed in the above embodiment is used to carry out research on mycorrhizal infection and plant drought resistance, as well as research on the activation mechanism of soil phosphorus by arbuscular mycorrhizal symbiosis, wherein the analysis chamber 12 inside the root box device is 20 cm high×5 cm wide×4 cm thick.

[0027] 1. Research on mycorrhizal infection and plant drought resistance:

[0028] The specific steps of using the root box device of the present invention to carry out mycorrhizal infection and plant drought resistance research are as follows:

[0029] S1.1, prepare multiple root box devices, and fill each root box device with 1200g of sterilized soil according to the soil bulk density, and plant alfalfa as a model plant in the central plant room;

[0030] S1.2. Multiple root box devices are grouped in pairs, and the model plants are cultured using a two-factor experiment, as follows:

[0031] S1.2-1. Treat the soil in the root box with different moisture content:

[0032] The first group of root box devices: Well-watered, WW, soil moisture is 60% to 70% of the maximum field water holding capacity;

[0033] The second root box device: light drought, Light-drought, LD, soil moisture is 45% to 55% of the maximum field water holding capacity;

[0034] The third group of root box devices: Middle-drought, MD, soil moisture is 30% to 40% of the maximum field water holding capacity;

[0035] The fourth group of root box devices: Severe-drought, SD, soil moisture is 15% to 25% of the maximum field water holding capacity.

[0036] S1.2-2. The alfalfa in each group of root box devices is inoculated with AMF. Specifically, the alfalfa in each group of root box devices is inoculated with AMF Pseudomonas mosseae and inoculated with inactivated AMF.

[0037] S1.3. Move the root box device to a plant incubator for growth. The temperature in the plant incubator is 25±1℃ and the sunshine time is 16h. During the growth period, control and replenish water by weighing method every day to keep the moisture content of the soil at the moisture content corresponding to S1.2-1. After the alfalfa has grown for 8 weeks, collect the aboveground part, underground part and soil part of the plant for determination of other indicators.

[0038] After 8 weeks of cultivation experiment through the above steps, the mycorrhizal infection rate of alfalfa root system treated with AMF decreased from 56%±6% to 36%±5% with the increase of drought degree; no AMF hyphae or vesicles were observed in the root system of alfalfa treated with inactivated AMF. With the increase of drought stress (normal moisture→mild drought→moderate drought→severe drought), the plant height of alfalfa treated with AMF decreased from 26±4cm to 8.4±2cm; the plant height of alfalfa treated with inactivated AMF decreased from 24±2cm to 4±1cm. In addition, the indexes such as root length, aboveground and underground biomass, root-crown ratio, tiller number, osmotic regulation and antioxidant capacity showed the same pattern. The analysis of soil samples in the mycelium chamber confirmed that AMF hyphae passed through the 38μm pore size isolation net, expanding the range of water absorption of plants.

[0039] The above results all confirm that the symbiosis between AMF and alfalfa root system enhances the drought resistance of alfalfa.

[0040] The specific steps of using the root box device of the present invention to study the activation mechanism of soil phosphorus by arbuscular mycorrhizal symbiosis are as follows:

[0041] S2.1. Prepare multiple root box devices, each group of root box devices is filled with 1200g of sterilized soil according to the soil bulk density, and the multiple root box devices filled with sterilized soil are grouped in groups of three;

[0042] S2.2. In each group of root box devices, one of the root box devices was used as a control and a 10g bacterial agent was added to the substrate, and then alfalfa was planted in the central plant room as a model plant. The other two root box devices were inoculated with 10g bacterial agent using the "two-layer inoculation method" and then alfalfa was planted in the central plant room as a model plant. The bacterial agent inoculated in one of the root box devices was AMF, and the bacterial agent inoculated in the other root box device was inoculated with inactivated AMF. The specific steps of inoculating the bacterial agent are as follows:

[0043] S2.2-1. Fill the root box device with sterilized soil to 1 / 3 of its height, and then evenly sprinkle a layer of expanded bacterial agent on it. The amount used is about 3 / 5 of the amount of soil inserted into a single root box device.

[0044] S2.2-2, fill the root box with sterilized soil to 3 / 4 of the height, and evenly apply the remaining bacterial agent to the root box and then cover it with a layer of sterilized soil;

[0045] S2.2-3. Sow the germinated alfalfa seeds and then cover them with a layer of sterilized soil.

[0046] S2.3. The root box device was moved to a plant incubator for growth. The temperature in the plant incubator was 25±1℃ and the sunshine time was 16h. During the growth period, the water content of the soil was controlled and supplemented by weighing method every day to keep the moisture content of the soil at 16%. Various indicators were measured after the alfalfa had grown for 8 weeks.

[0047] After 8 weeks of cultivation experiment through the above steps, the available phosphorus content of rhizosphere soil and non-rhizosphere soil treated with AMF inoculation was 18.24g / kg and 26.58g / kg, respectively, which was 3.24g / kg and 1.06g / kg higher than that of the control treatment treated with inactivated AMF inoculation; under the treatment of AMF inoculation, the pH of rhizosphere soil decreased by 0.2-0.4, and the pH of non-rhizosphere soil remained unchanged; the organic matter content of rhizosphere soil treated with AMF inoculation and control treatment was 21.48g / kg and 20.15g / kg, respectively. In addition, the increase of available phosphorus content and organic matter content was observed in the mycelium chamber, which represents the contribution of AMF mycelium.

[0048] In summary, the root box device of the present invention has good application prospects in studying the effects of arbuscular mycorrhiza on soil properties.

[0049] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A root box device for micro-domain root system simulation experiment, characterized in that: The root box (1) comprises a top-through root box (1), the root box (1) having a detachable side plate (11), the interior of which is evenly divided into three analysis chambers (12) in the horizontal direction by two partition plates (2), and when the side plate (11) is detached, the side of each analysis chamber (12) close to the side plate (11) is through-connected; Both of the partitions (2) are provided with an escape opening (21), and an isolation net (3) is mounted on the escape opening (21). The isolation net (3) has a plurality of isolation holes, and the isolation holes on one of the isolation nets (3) block the passage of roots but allow the passage of hyphae, while the isolation holes on the other isolation net (3) block the passage of both roots and hyphae.

2. The root box device for micro-domain root system simulation experiment according to claim 1, characterized in that: A partition groove (13) is provided inside the root box (1) on a side away from the side plate (11), and one side of the partition (2) is detachably inserted into the partition groove (13), while the other side abuts against the side plate (11).

3. The root box device for micro-domain root system simulation experiment according to claim 1, characterized in that: The root box (1) is made of acrylic sheet.

4. The root box device for micro-domain root system simulation experiment according to any one of claims 1 to 3, characterized in that: The aperture of the isolation hole that blocks the passage of roots and hyphae at the same time is 0.45 μm, and the aperture of the isolation hole that blocks the passage of roots and allows the passage of hyphae is 38 μm.

Images