JP2013183702A - Method for diagnosing growing state of plant and device used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a convenient method for diagnosing the growing state of a plant, capable of performing objective determination, and a device used for the same.SOLUTION: As a method for diagnosing the growing state of a plant, the growing state is diagnosed by a delayed light emission-measuring step of measuring the delayed light emission of leaves of the plant under a prescribed temperature condition to obtain delayed light emission data, a chlorophyll-measuring step of measuring the amount of chlorophyll of the leaves of the plant to obtain chlorophyll data, a delayed light emission amount-correcting step of obtaining first and second delayed light emission amounts based on the delayed light emission data and chlorophyll data, and correcting each of them with the chlorophyll amount per the prescribed area of leaves of the plant to calculate the corrected first and second delayed light emission amounts and a determining step of determining the activity of the plant at the neighborhood part of leaves of the plant based on the comparison of the corrected first and second light emission amounts calculated by the delayed light emission amount-correcting step with the corrected first and second light emission amounts becoming the standard of the plant.

Description

  The present invention relates to a method for diagnosing the growth state of a plant and an apparatus used therefor.

  It is important for environmental conservation, agriculture, agricultural processing industry, etc. to diagnose the growth state of agricultural products such as trees, horticultural plants, vegetables, etc., and to distinguish mutations such as lesions, aging, or death early. It is becoming.

JP 2005-308733 A

  However, conventionally, a subjective method based on visual observation is generally used to discriminate the growth state of these plants, and the actual situation is that discrimination with an objective index is hardly realized.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for diagnosing the growth state of a plant that can be easily and objectively determined, and an apparatus used therefor.

The present invention is a method for diagnosing the growth state of a plant,
(A) a delayed luminescence measurement step of measuring delayed luminescence of a plant leaf under a predetermined temperature condition and acquiring delayed luminescence data;
(B) a chlorophyll measurement step of measuring the amount of chlorophyll in the leaves of the plant and obtaining chlorophyll data;
(C) Based on the delayed emission data and the chlorophyll data,
When the xylem pressure potential is lowered, a first delayed emission amount that is a delayed emission amount corresponding to a time region in which the delayed emission amount increases,
A second delayed emission amount that is a delayed emission amount corresponding to a time region in which the delayed emission amount decreases when the xylem pressure potential is lowered;
A delayed light emission amount correction step for calculating a first corrected delayed light emission amount and a second corrected delayed light emission amount by correcting each with a chlorophyll amount per predetermined area of the leaf of the plant,
(D) The first corrected delayed emission amount and the second corrected delayed emission amount calculated in the delayed emission amount correction step, and the first corrected delayed emission amount and the second corrected delayed emission amount that serve as a reference for the plant. A determination step of determining the vitality of the plant in the vicinity of the plant leaf based on the comparison with
Providing a method.

  The present invention corrects the first delayed luminescence amount per predetermined area of the plant leaf and the second delayed luminescence amount per predetermined area of the plant leaf by the chlorophyll amount per predetermined area of the leaf, respectively. By determining the first corrected delayed emission amount and the second corrected delayed emission amount and using the first corrected delayed emission amount and the second corrected delayed emission amount as an index, simple and objective determination is possible. It becomes possible to provide a method for diagnosing the growth state of plants.

  The vitality preferably reflects the influence of drought stress.

  Difference between the first corrected delayed emission amount and the second corrected delayed emission amount calculated in the delayed emission amount correction step, and the first corrected delayed emission amount and the second corrected delayed emission amount, which are the standard of the plant. It is preferable to determine that the greater the is, the lower the vitality of the plant in the vicinity of the leaves of the plant.

The present invention also includes a light source unit for irradiating the leaves of the plant with light,
A first detection unit for detecting delayed luminescence of the leaves of the plant caused by light emitted by the light source unit;
A temperature control unit for detecting the delayed light emission under a predetermined temperature condition;
A second detection unit for detecting light reflecting the amount of chlorophyll in the plant leaves caused by light emitted by the light source unit;
A recording unit for recording delayed emission data corresponding to the delayed emission detected by the first detection unit and chlorophyll data corresponding to light reflecting the chlorophyll amount detected by the second detection unit;
An apparatus for diagnosing the growth state of a plant is provided.

  According to the present invention, by adopting such a configuration, it is possible to provide a device for diagnosing the growth state of a plant that can be easily and objectively determined.

  According to the present invention, it is possible to provide a method for diagnosing the growth state of a plant that can be easily and objectively determined, and an apparatus used therefor.

It is a flowchart explaining the method to diagnose the growth state of the plant which concerns on this embodiment. It is a graph showing the change of the delayed light emission pattern of a plant when changing a xylem pressure potential. It is a graph which shows correlation with the amount of delayed light emission, and drought stress. It is a graph which shows correlation with the amount of delayed light emission, and drought stress. It is a graph which shows the correlation with the growth state of the plant which grows wild outdoors, and the amount of delayed luminescence. It is a mimetic diagram showing one embodiment of a device for diagnosing the growth state of a plant. It is a schematic diagram which shows other embodiment of the apparatus for diagnosing the growth state of a plant.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  FIG. 1 is a flowchart illustrating a method for diagnosing the growth state of a plant according to the present embodiment. The present embodiment includes (a) a delayed luminescence measurement step, (b) a chlorophyll measurement step, (c) a delayed luminescence amount correction step, and (d) a determination step.

  (A) In the delayed luminescence measurement step, delayed luminescence of a plant leaf is measured under a predetermined temperature condition to obtain delayed luminescence data. The leaves collected from plants may be used, or the leaves growing on the plants may be used directly.

  The predetermined temperature condition in the measurement of delayed luminescence is not particularly limited as long as it is constant during the measurement, but is preferably 5 to 35 ° C, more preferably 20 to 30 ° C.

The measurement of delayed luminescence is performed by a known apparatus and method, for example, WO 2005/062027.
Can be carried out by the apparatus and method described in No. 1. More specifically, for example, there is a method of measuring the weak luminescence emitted from the leaves of the plant under dark conditions after darkening the leaves of the plant and irradiating with excitation light.

  The time for darkening the leaves of the plant is preferably 5 to 1200 seconds, and more preferably 150 to 600 seconds.

  The wavelength of the excitation light applied to the leaves of the plant is preferably 280 to 900 nm, and more preferably 400 to 750 nm.

  The time for which the leaves of the plant are irradiated with excitation light is preferably 0.1 to 60 seconds, and more preferably 0.5 to 20 seconds.

The time for measuring the weak luminescence emitted from the leaves of the plant is preferably 0.01 to 1200 seconds, more preferably 5 to 600 seconds.

In the measurement of delayed luminescence, the exposed area of the leaves with respect to the delayed luminescence detector is preferably a predetermined area. By doing so, the later-described (c) delayed light emission amount correction step can be performed more simply. The predetermined area is not particularly limited preferably 0.15~80cm ^2, 0.5~10cm ² is more preferable.

  (B) In the chlorophyll measurement step, the amount of chlorophyll in the leaves of the plant is measured to obtain chlorophyll data.

  The method for measuring the amount of chlorophyll is not particularly limited as long as it is a known method. However, as described in JP 2011-38879 A, a method using reflected light obtained by irradiating light on the plant leaves, A method using transmitted light obtained by irradiating light on the leaves of the plant such as SPAD-502 chlorophyll meter (manufactured by Konica Minolta) is preferably used.

When the amount of chlorophyll is measured using reflected light or transmitted light, the exposed area of the leaves with respect to the detector of reflected light or transmitted light is preferably a predetermined area. By doing so, the later-described (c) delayed light emission amount correction step can be performed more simply. The predetermined area is not particularly limited preferably 0.06~80cm ^2, 0.5~10cm ² is more preferable.

  (C) In the delayed emission amount correction step, a first delayed emission amount and a second delayed emission amount are obtained based on the delayed emission data and the chlorophyll data, The first corrected delayed emission amount and the second corrected delayed emission amount are calculated by correcting with the chlorophyll amount.

  The first delayed light emission amount is a delayed light emission amount per predetermined area of the plant leaf corresponding to a time region in which the delayed light emission amount increases when the xylem pressure potential is lowered. The second delayed light emission amount is a delayed light emission amount per predetermined area of the plant leaf corresponding to a time region in which the delayed light emission amount decreases when the xylem pressure potential is lowered.

  For example, when the xylem pressure potential is changed as shown in FIG. 2 and the delayed light emission pattern of the cherry tree leaves is observed, the time region in which the delayed light emission amount increases when the xylem pressure potential is lowered is (A) When the xylem pressure potential is lowered, the time region where the delayed light emission decreases is the region (B). These time regions differ depending on the plant type. By changing the xylem pressure potential according to the type of plant, it is possible to determine the time domain unique to that plant. In addition, a more optimal time region can be set with reference to a sample group that has been clearly stressed and a sample group that can be determined to have appropriate growth.

  The first delayed luminescence amount and the second delayed luminescence amount determined as described above are corrected, for example, by dividing by the chlorophyll amount per predetermined area of the plant leaf. The first corrected delayed emission amount and the second corrected delayed emission amount (S) may be calculated from the following equations.

T: first delayed emission amount and second delayed emission amount U: chlorophyll amount e, g per predetermined area, f: weighting of delayed emission amount and chlorophyll amount, f, h: measured value of delayed emission, and It is a baseline of the measured value of the amount of chlorophyll.

  Hereinafter, the respective delayed emission amounts after correction are referred to as a first corrected delayed emission amount and a second corrected delayed emission amount. By determining the first corrected delayed emission amount and the second corrected delayed emission amount by correction, the vitality of the plant can be clearly determined in the determination step (d) described later.

  (D) In the determination step, the first corrected delayed emission amount and the second corrected delayed emission amount calculated in the delayed emission amount correction step, the first corrected delayed emission amount and the second correction emission amount serving as the plant reference Based on the comparison with the corrected delayed light emission amount, the vitality of the plant in the vicinity of the plant leaf is determined.

  The first corrected delayed luminescence amount and the second corrected delayed luminescence amount serving as a reference for the plant can be set as appropriate. For example, the first corrected delayed luminescence amount was obtained from the leaves of the plant showing a standard growth state. Examples include the average value of the first corrected delayed emission amount and the second corrected delayed emission amount.

  Comparison between the first corrected delayed emission amount and the second corrected delayed emission amount calculated in the delayed emission amount correction step, and the first corrected delayed emission amount and the second corrected delayed emission amount that serve as a reference for the plant May directly compare the first corrected delayed emission amount and the second corrected delayed emission amount, or calculate other parameters based on the first corrected delayed emission amount and the second corrected delayed emission amount. Then, the obtained other parameters may be compared with each other. Examples of other parameters include distance parameters and angle parameters shown below.

Calculation of the distance parameter from the reference position coordinate of the reference sample The reference position coordinate is determined by the average value x of the first corrected delayed luminescence amount of the leaf of the reference plant and the average value y of the second corrected delayed luminescence amount. Determine. The distance parameter d of the target plant leaf is obtained from the reference position coordinate (x, y) and the delayed light emission amount coordinate (a, b) of the target plant leaf according to the following equation. Here, a indicates the first corrected delayed emission amount, and b indicates the second corrected delayed emission amount.

Calculation of angle parameter from reference position coordinate of reference sample The angle of the line connecting the reference position coordinate (x, y) and the delayed light emission amount coordinate (a, b) of the leaf of the target plant is obtained. For example, the angle can be calculated from the radian θ of a line connecting (x, y) and (a, b) using an arctangent function as shown in the following equation.

  Examples of the vicinity of the leaves of the plant include branches and stems on which the leaves of the plant are attached. However, since plants absorb soil water and nutrients and send them to branches, stems and leaves, the vicinity of the leaves of the plant reflects the state of the whole plant such as roots, trunks, branches and stems. In order to more appropriately diagnose the growth state of a plant, it is preferable to measure a site where the leaves of the plant are susceptible to stress, for example, a leaf located on the top of a plant body and exposed to light.

  The vitality of plants decreases under the influence of stress, and examples of the stress include drought, high temperature, freezing, poor nutrition, trace element deficiency, salt damage, and pest damage. In the method according to the present embodiment, the vitality preferably reflects the influence of drought stress.

  The determination of the vitality of the plant in the vicinity of the plant leaf based on the comparison is, for example, the first corrected delayed emission amount and the second corrected delayed emission amount calculated in the delayed emission amount correction step, and the plant standard. It can be determined that the greater the difference between the first corrected delayed emission amount and the second corrected delayed emission amount, the lower the vitality of the plant in the vicinity of the plant leaf.

  Moreover, when the above-mentioned distance parameter and angle parameter are used, drought stress can be specifically detected by evaluating the angle parameter. When a wild cherry is used as a plant, it can be determined that the one showing a negative angle parameter with respect to the reference position is subjected to drought stress.

  Next, the apparatus for diagnosing the growth state of the plant which concerns on this embodiment is demonstrated. The apparatus according to the present embodiment includes a light source unit for irradiating light on a plant leaf, a first detection unit for detecting delayed luminescence of a plant leaf caused by light irradiated by the light source unit, and a predetermined temperature condition Detected by a temperature control unit for detecting delayed luminescence below, a second detection unit for detecting light reflecting the amount of chlorophyll in plant leaves caused by light emitted by the light source unit, and a first detection unit A recording unit that records the delayed emission data corresponding to the delayed emission and the chlorophyll data corresponding to the light reflecting the amount of chlorophyll detected by the second detection unit. Details will be described below.

  FIG. 6 is a schematic diagram showing an embodiment of an apparatus for diagnosing the growth state of a plant. The apparatus 100 for diagnosing the growth state of the plant includes a light source unit 6 for irradiating the sample 3 such as a plant leaf with light, and a sample 3 such as a plant leaf generated by the light irradiated by the light source unit 6. A chlorophyll of a sample 3 such as a plant leaf generated by light emitted from the first detection unit 1 for detecting delayed luminescence, a temperature adjusting unit 19 for detecting delayed luminescence under a predetermined temperature condition, and the light source unit 6 A second detector 8 for detecting light reflecting the amount, delayed light emission data corresponding to the delayed light emission detected by the first detector 1, and light reflecting the amount of chlorophyll detected by the second detector 8. And a recording unit 15 for recording corresponding chlorophyll data.

  The light source 6 is composed of a single light source or a plurality of light sources capable of emitting a plurality of wavelengths. That is, a multi-wavelength light source such as a halogen lamp, a combination of a wavelength selection filter and a set of LEDs having different peak wavelengths, and the like.

  The light source unit 6 irradiates the sample 3 with light having a predetermined wavelength, and the wavelength is 400 nm to 1000 nm. Here, the light source unit 6 may be a monochromatic light source or a light source in which a plurality of light sources are combined. The light emission of the light source unit 6 may be continued for a predetermined time or may be pulsed in an arbitrary pattern. In addition, a plurality of light sources having the same or different wavelength characteristics may be sequentially emitted, or a plurality of light sources may be simultaneously emitted. In order to cut off the afterglow of the light source, the shutter 2 may be combined to open and close in synchronization with turning on and off of the light source unit 6.

  The first detection unit 1 detects the amount of delayed light emission generated from the sample 3 by being irradiated with the excitation light, and is used to limit the light incident on the light sensor and the light sensor that detects the delayed light emission. A delay light emission amount calculation unit that calculates a delay light emission amount based on a signal detected and output by the filter and the optical sensor is provided.

  For example, a photon counter using a photomultiplier tube or a faint light measuring device using an avalanche photodiode can be used as the first detection unit 1.

  The second detection unit 8 has a small spectroscope, a wavelength selection filter, and a plurality of light receiving units in order to obtain spectral information of the reflected light reflected from the portion of the sample 3 exposed by the opening 7 of the sample 3. The structure is a combination of vessels.

  For the second detector 8, a photomultiplier tube, an avalanche photodiode, a silicon photodiode, or the like can be used.

  The recording unit 15 may be provided in the analysis device 11 as described later.

  Further, the apparatus 100 includes a shutter 2 that controls light incident on the first detection unit 1, a first light collecting unit 4 that guides delayed light emission emitted from the sample 3 to the first detection unit 1, and a sample 3. Of the sample 3 placed in the sample placement unit 5, the opening 7 exposing only a predetermined shape and area of the sample 3 stored in the sample placement unit 5, and the reflected light reflected from the sample 3 is guided to the second detection unit 8. The communication part 10 which electrically transmits the data obtained by the 2nd condensing part 9, and the 1st detection part 1 and the 2nd detection part 8 to the analyzer 11 mentioned later is provided.

  The first detection unit 1 and the second detection unit 8, the shutter 2, the sample 3, the first light collection unit 4, the second light collection unit 9, the sample installation unit 5, and the light source unit 6 are light from the outside. Is stored in the light shielding portion 13 that can be blocked. The light shielding unit 13 is, for example, a dark box.

  The sample setting unit 5 can set a container containing the sample 3 or insert the sample 3 into the sample setting unit 5 fixed in advance. The sample placement unit 5 is separated from the outside by a hatch 14, and the sample 3 can be exchanged by opening and closing the hatch 14 as necessary.

  The first detection unit 1 and the second detector 8, the shutter 2, the light source unit 6, the communication unit 10, and the temperature adjustment unit 19 are electrically connected to the analysis device 11 and are in the analysis device 11. The function is controlled by the unit 12.

  The analysis device 11 includes a recording unit 15 for recording measurement data transmitted from the communication unit 10 and information necessary for analysis, a calculation unit 16 for performing calculation analysis of measurement results, and a display unit for displaying analysis results. 17. An input unit 18 is provided for inputting information necessary for control.

  The control unit 12 is a control device that can control the operating status of the device 100 according to a predetermined procedure, and a combination of a computer, a timer, a relay, and the like can be used.

  The analysis device 11 and the control unit 12 may use a single computer having both functions, or have functions corresponding to the control unit 12, the recording unit 15, the calculation unit 16, the display unit 17, and the input unit 18. A computer may be used.

  FIG. 7 is a schematic view showing another embodiment of an apparatus for diagnosing the growth state of a plant. The basic components of the device are the same as those of the device 100 shown in FIG. 6, but the light emitted from the light source unit 6 is emitted from the light source unit 6 by the second detection unit 8 and the second light collection unit 9. It differs in that it is arranged so as to detect the transmitted light that has passed through the sample 3 at the portion exposed at the opening 7. The second detection unit 8 and the second light collection unit 9 are installed on the opposite side of the light source unit 6 with the opening 7 a of the sample installation unit 5 interposed therebetween. For example, the second detection unit 8 and the second light collection unit 9 can be installed in the hatch 14. In such a configuration, the light emitted from the light source unit 6 can be transmitted through the opening 7a of the sample setting unit 5 toward the second detector 8 so that the sample 3 is sandwiched from the opening 7a on the opposite side. An opening 7b connected to the second condensing part 9 is provided.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Test 1: Mountain cherry leaf dehydration test (drought stress experiment)
Yamazakura (Cerasus jamasakura var. Jamasakura) leaves showing a healthy growth state were collected, immediately transported to the laboratory, and measured according to the following protocol. First, the leaves were placed in a pressure chamber (trade name: DIK-7000, manufactured by Daikai Chemical Co., Ltd.), and the xylem pressure potential in a natural state was measured with high-pressure nitrogen gas. Next, the leaves are put into a weak light emission measuring device (Hamamatsu Photonics, TYPE-6100A, a leaf adapter with a mask), subjected to dark treatment for 300 seconds, and excited light (680 nm, 10 μmol / m ² / s) for 10 seconds. After irradiation, weak luminescence was measured for 400 seconds under dark conditions. At this time, two circular portions having a diameter of 7 mm, which are exposed to the detector, were exposed symmetrically across the central vein (main vein) of the leaf. Thereafter, the chlorophyll meter value (SPAD) and the spectral reflectance were measured sequentially. Similarly, it dehydrated in the range of -1.0MPa--3.0MPa in the pressure chamber, and the measurement was repeated according to said protocol.

Correlation between xylem pressure potential and delayed luminescence pattern A control group that did not give drought stress to the leaves of Yamazakura, and stress that gave drought stress to the leaves of Yamazakura until the xylem pressure potential was -3.0 MPa. Delayed luminescence pattern of leaves of wild cherry with group is shown in FIG. When the xylem pressure potential decreases due to dehydration, the delayed emission pattern changes, and a point (cross point) where the delayed emission pattern in the natural state (control group) and the delayed emission pattern of the xylem pressure potential of −3.0 MPa intersect is formed. At the xylem pressure potential of −3.0 MPa, the delayed emission amount increased in the time region (A region) before the cross point compared to the natural state (that is, the first delayed emission amount). In addition, in the time region (region B) after the cross point, the delayed light emission amount decreased compared to the natural state (that is, the second delayed light emission amount). That is, the cross point time can be used as a reference for distinguishing between the first delayed emission amount and the second delayed emission amount. For example, the delayed light emission amount of 1 to 5 seconds (A region) after the measurement may be the first delayed light emission amount, and the delayed light emission amount of 20 to 300 seconds (B region) after the measurement may be the second delayed light emission amount. it can. In FIG. 2, there is one cross point for comparison of the delayed light emission patterns of two samples. Even when the delayed light emission patterns of a plurality of samples are compared, it can be set to one point if the cross points coincide with each other in the plurality of samples. In addition, if the cross points do not match in a plurality of samples, it cannot be set to one point, but the first delayed emission amount and the second delayed emission amount are distinguished in a time region including all or some of the cross points. It can be a standard.

Correlation between delayed luminescence amount and drought stress Regarding the measurement result of delayed luminescence of the sample of test 1, the first delayed luminescence amount (1-5 seconds after measurement) selected by the above method is plotted on the horizontal axis. By plotting the second delayed luminescence amount (time region of 20 to 300 seconds after measurement) on the vertical axis, the control group not giving drought stress to the leaves of Yamazakura and the xylem pressure potential becomes −3.0 MPa. A comparison was made with a stress group in which drought stress was applied to the leaves of Yamazakura (FIG. 3 (a)). Also, the first corrected delayed emission amount obtained by dividing the first delayed emission amount by the chlorophyll amount is plotted on the horizontal axis, and the second corrected delayed emission amount obtained by dividing the second delayed emission amount by the chlorophyll amount is plotted on the vertical axis. Also in the plot, the control group and the stress group were compared (FIG. 3B). In FIG. 3 (b), both the control group and the stress group are plotted with the first corrected delayed emission amount on the horizontal axis and the second corrected delayed emission amount on the vertical axis. It was suppressed and the distribution gathered in different positions.

  In order to clarify the evaluation when the plots of FIGS. 3A and 3B are drawn, the control group and the stress group were again compared and examined by the following method.

1. Calculation of the distance parameter from the reference position coordinates of the reference sample The reference position coordinates were determined by the average value x of the first delayed emission amount of the reference sample and the average value y of the second delayed emission amount. The reference sample in this case was the 80 to 100th percentile group of the xylem pressure potential. Here, the 80th percentile is a leaf sample at a position corresponding to 80% of the whole sample, counting from the sample with the lowest xylem pressure potential when all the samples are arranged in ascending order of xylem pressure potential. . Therefore, the 80 to 100th percentile group is estimated to be a sample with particularly low stress among the control group. The distance parameter d of each sample was obtained from the reference position coordinates (x, y) and the delayed emission amount coordinates (a, b) of each sample according to the following formula. Here, a represents the first delayed emission amount, and b represents the second delayed emission amount.

2. Calculation of the angle parameter from the reference position coordinates of the reference sample The angle of the line connecting the reference position coordinates (x, y) and the delayed emission amount coordinates (a, b) of each sample is obtained. For example, the angle can be calculated from the radian θ of a line connecting (x, y) and (a, b) using an arctangent function as shown in the following equation.

  Using the data of each sample used when the plots of FIGS. 3A and 3B were drawn, the distance parameter and the angle parameter were obtained and plotted according to the method described above. The result is shown in FIG. Although the delayed light emission amount coordinates of the leaf sample subjected to drought stress were distributed at positions apart from the reference position and had a certain range of angle parameters (-30 ° to -60 °), the stress group There was a sample of the control group distributed within, and there was also a sample of the stress group distributed within the control group. For this reason, it was found that the area A and the area B can roughly distinguish the control group and the stress group, but some are indistinguishable. Therefore, the first corrected delayed emission amount is used instead of the first delayed emission amount, and the second corrected delayed emission amount is used instead of the second delayed emission amount. The result is shown in FIG. 3 (d). As can be seen from FIG. 3 (d), the variation in distribution was suppressed compared to FIG. 3 (c).

  In order to further improve the analysis accuracy, the range of the region A and the region B was narrowed to 0.5 to 1.5 seconds after measurement and 20 to 100 seconds after measurement, and the analysis was performed again. The result is shown in FIG. FIG. 4 (a) shows a control group in which drought stress is not applied to the leaves of Yamazakura by plotting the results without correction, that is, the first delayed luminescence amount on the horizontal axis and the second delayed luminescence amount on the vertical axis. And the stress group in which drought stress was applied to the leaves of the cherry tree until the xylem pressure potential became −3.0 MPa. FIG. 4B shows the result of correction by the chlorophyll amount, that is, the first corrected delayed emission amount obtained by dividing the first delayed emission amount by the chlorophyll amount on the horizontal axis, and the second delayed emission amount by the chlorophyll amount. This is a result of comparing the control group and the stress group by plotting the second corrected delayed luminescence amount divided by the vertical axis. In FIG. 4B, in both the control group and the stress group, the variation of each group is obtained by plotting the first corrected delayed emission amount on the horizontal axis and the second corrected delayed emission amount on the vertical axis. It can be seen that the distribution is concentrated at different positions. Using the data of each sample used when the plots of FIGS. 4A and 4B were drawn, the distance parameter and the angle parameter were obtained and plotted according to the method described above. The result is shown in FIG. In any plot, the delayed luminescence coordinates of the drought-stressed leaf sample are distributed at positions away from the reference position, and a certain range of angle parameters (−30 ° to −60 °) is obtained. A sample of the control group distributed in the stress group seen in FIG. 3 (c) and FIG. 3 (d) and a stress distributed in the control group. The group sample was significantly reduced. Thus, by setting the optimal time region for the A region and the B region, the control group and the stress group can be easily distinguished. FIG. 4 shows a plot obtained when the first corrected delayed emission amount is used instead of the first delayed emission amount and the second corrected delayed emission amount is used instead of the second delayed emission amount. The distribution in (d) was the same as in FIG. 4 (c).

Test 2: Field measurement (Yamazakura)
A tree branch of a cherry tree (Cerasus jamasakura var. Jamasakura) growing in the field (outdoor) was collected, transported to a measurement site with care not to damage it, and measured according to the following protocol. The amount of top branch growth of the transported tree branch was measured, and two leaves that were representative in appearance were selected from the leaves of the tree branch, and the weak light emission was immediately measured for the two leaves. Although the measurement time is 300 seconds, it is different from Test 1, but the other conditions are the same as those of Test 1. Thereafter, the chlorophyll meter value (SPAD) and the spectral reflectance were measured sequentially. In addition, two persons skilled in the diagnosis of trees in eight items of tree vigor, tree shape, amount of branch elongation, withering of treetops, branch leaf density, leaf shape / size, leaf color, and bark were visually judged by two trees. The vitality evaluation was performed.

  The obtained sample of each leaf was divided into two groups of 0 to 20th percentile group and 80 to 100th percentile group according to the extension amount of the branch where the leaf grew. For example, when the samples of each leaf are arranged in the order of the extension amount of the branch where the leaf grew, the leaf sample located at a position corresponding to 20% of the whole sample, counting from the sample with the smallest extension amount of the branch Is called the sample located at the 20th percentile. Here, the 0-20th percentile group was defined as a “growth failure group”, and the 80-100th percentile group was defined as a “reference sample group”. For these two groups, a distance parameter and an angle parameter are obtained based on the first delayed emission amount (0.5 to 1.5 seconds after measurement) and the second delayed emission amount (20 to 100 seconds after measurement). A plot was made. At this time, the reference position was obtained using a sample of the reference sample group as a reference sample. The result is shown in FIG. FIG. 5B shows a plot obtained using the first corrected delayed emission amount instead of the first delayed emission amount and the second corrected delayed emission amount instead of the second delayed emission amount. ).

  In FIG. 5A, the distance parameter of the poor growth group tended to be separated from the reference position, but the angle parameter was dispersed in the direction of ± 90 ° from the reference position. On the other hand, the distance parameter of the growth failure group tends to be separated from the reference position by using the data (first corrected delayed emission amount and second corrected delayed emission amount) obtained by correcting the delayed emission amount with the chlorophyll amount. In addition to the observation, as in the case of the drought stress experiment (ideal condition) of Test 1, the angle parameter of the poorly grown group was directed to −30 ° to −60 ° (FIG. 5B). This result shows that the correction of the delayed luminescence amount by the chlorophyll concentration is effective for diagnosis of the growth state of the plant.

  Therefore, when trying to diagnose tree stress (especially drought stress) using the first corrected delayed emission amount and the second corrected delayed emission amount, the field is based on the reference position of the preset control group. The angle parameter and the distance parameter of each plant measured in step (1) are calculated, and it can be estimated that the sample whose distance parameter is far from the reference position is a stressed sample. Moreover, from the experiment of Test 1 (ideal condition), it is known that the Yamazakura subjected to drought stress is separated at a specific angle (−30 ° to −60 °) with respect to the reference position. By evaluating the angle parameter, drought stress can be specifically detected.

DESCRIPTION OF SYMBOLS 1 ... 1st detection part, 3 ... Sample (plant leaf), 6 ... Light source part, 8 ... 2nd detection part, 15 ... Recording part, 19 ... Temperature control part, 100 ... Diagnosing the growth state of a plant Equipment for.

Claims (4)

A method for diagnosing the growth state of a plant,
(A) a delayed luminescence measurement step of measuring delayed luminescence of a plant leaf under a predetermined temperature condition and acquiring delayed luminescence data;
(B) measuring the amount of chlorophyll in the leaves of the plant, and obtaining chlorophyll data;
(C) Based on the delayed emission data and the chlorophyll data,
When the xylem pressure potential is lowered, a first delayed emission amount that is a delayed emission amount corresponding to a time region in which the delayed emission amount increases,
A second delayed emission amount that is a delayed emission amount corresponding to a time region in which the delayed emission amount decreases when the xylem pressure potential is lowered;
Determining the amount of chlorophyll per predetermined area of the leaves of the plant and calculating a first corrected delayed emission amount and a second corrected delayed emission amount, respectively, a delayed emission amount correction step,
(D) The first corrected delayed emission amount and the second corrected delayed emission amount calculated in the delayed emission amount correction step, and the first corrected delayed emission amount and the second corrected delayed emission amount that serve as a reference for the plant. A determination step of determining the vitality of the plant in the vicinity of the plant leaf based on the comparison with
Including a method.   The method of claim 1, wherein the vitality reflects the effects of drought stress.   Difference between the first corrected delayed emission amount and the second corrected delayed emission amount calculated in the delayed emission amount correction step, and the first corrected delayed emission amount and the second corrected delayed emission amount, which are the standard of the plant. The method according to claim 1, wherein the larger the is, the lower the vitality of the plant in the vicinity of the leaf of the plant is. A light source for irradiating the leaves of the plant with light;
A first detection unit for detecting delayed light emission of the leaves of the plant caused by light emitted by the light source unit;
A temperature control unit for detecting the delayed light emission under a predetermined temperature condition;
A second detection unit that detects light reflecting the amount of chlorophyll in the leaves of the plant produced by light emitted by the light source unit;
A recording unit for recording delayed emission data corresponding to the delayed emission detected by the first detection unit and chlorophyll data corresponding to light reflecting the amount of chlorophyll detected by the second detection unit;
A device for diagnosing the growth state of a plant.

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