Wheat scab resistance identification method

Abstract

The invention belongs to the field of plant resistance identification, and relates to a wheat scab resistance identification method, which comprises the following steps: sowing wheat in a foam seedling raising tray, adding a proper amount of potassium permanganate into seedling raising matrix soil to sterilize, putting into an artificial climate box to culture, and when wheat seedlings grow to a one-leaf one-core stage to a two-leaf one-core stage, taking out the seedlings; the method comprises the following steps: cutting the top end of a first leaf by 0.3-0.5 cm, inoculating fusarium graminearum spore suspension at a wound to inoculate the leaves, wrapping and sealing the leaves by using a plastic film, observing the morbidity of the leaves 10-15 days after inoculation, and judging the resistance of wheat to gibberellic disease according to the extension length of germs on the leaves. The method disclosed by the invention can be used for identifying the gibberellic disease resistance in the wheat seedling stage, and has the advantages of short identification period, simplicity in operation, good repeatability, no time limitation and the like.

Description

Technical Field

[0001] The invention relates to the technical field of wheat, and in particular to a method for identifying wheat scab resistance. Background Art

[0002] Wheat is a herbaceous plant of the Gramineae family and the Triticeae genus. After long-term development, it has become one of the most widely distributed and largest grain crops in the world. Wheat caryopsis is one of the staple foods of humans. After being ground into flour, it can be made into bread, steamed buns, biscuits, noodles and other foods. After fermentation, it can be made into beer, alcohol, and liquor. In addition to being eaten by humans, flour is also used in small quantities to produce starch, ethanol, gluten, etc. Wheat starch also has the effects of anti-inflammatory, analgesic, and dehumidification, and can also be used as a base agent for medicines.

[0003] Wheat fusarium head blight, also known as ear rot, is a disease of wheat caused by infection with a variety of Fusarium fungi. It can occur from the seedling stage to the ear stage, causing seedling rot, stem base rot, stalk rot and ear rot, with ear rot being the most harmful. When the humidity is high, a pink mold layer can be seen on the diseased part. After wheat is infected, the thousand-grain weight decreases, the germination rate decreases, the germination potential weakens, the flour yield is low, the flour quality is poor, the color is gray, and the commercial value is reduced. Diseased wheat contains toxins such as vomiting toxins and estrogen-like toxins, which can cause acute poisoning after being eaten by humans and animals.

[0004] The prevention and control methods of wheat fusarium head blight are mainly based on the selection of antibacterial varieties, and the use of pesticides to mix seeds is an important measure. A large number of studies on wheat fusarium head blight have been carried out in the existing technology, and the genetic resources of wheat fusarium head blight resistance have been discovered and identified. Among them, the method for identifying wheat fusarium head blight resistance is generally the single flower drip method, which is to use a concentration of 1×10 5 —5×10 5 / mL of spore suspension, inject 20μL into a small flower in the middle of the wheat ear, and 15 ears need to be inoculated for each material. Within a period of time after inoculation (usually several days to weeks), regularly observe the disease of the inoculated florets and surrounding tissues. Record relevant data such as the time of onset and the severity of symptoms. The advantage of the single flower drip method is that it can accurately inoculate and observe a single floret, so as to more accurately evaluate the resistance of wheat varieties to ergot in a single flower position, with high accuracy and strong pertinence. However, its operation process is relatively cumbersome, time-consuming and labor-intensive, difficult to apply on a large scale, and easily affected and disturbed by environmental factors such as temperature and humidity. Moreover, it is also limited by the special identification period, and the identification cycle is long. Summary of the invention

[0005] The invention aims to provide a method for identifying resistance to fusarium scaber in wheat, which can be used for identifying resistance to fusarium scaber in wheat seedlings and has the effects of short identification cycle, simple operation, good repeatability and no time limit.

[0006] The above technical purpose of the present invention is achieved through the following technical scheme: a method for identifying wheat fusarium head blight resistance, comprising the following steps: sowing and culturing wheat, and when the wheat seedlings grow to the one-leaf-one-heart stage to the two-leaf-one-heart stage, cutting off the top of the first leaf, inoculating the wound with a suspension of Fusarium graminearum spores to inoculate the leaves with the fungus, and wrapping and sealing the leaves with plastic film, and observing the disease condition of the leaves after a period of inoculation, and judging the resistance of wheat to fusarium head blight according to the extension length of the pathogen on the leaves.

[0007] The present invention is further configured as follows: if the extension length of the pathogen is ≤0.5cm, the resistance is evaluated as highly resistant; if the extension length of the pathogen is 0.5cm<the extension length of the pathogen is ≤1.5cm, the resistance is evaluated as moderately resistant; if the extension length of the pathogen is 1.5cm<the extension length of the pathogen is ≤4cm, the resistance is evaluated as moderately susceptible; if the extension length of the pathogen is >4cm, the resistance is evaluated as highly susceptible.

[0008] By adopting the above technical scheme, there is a precedent in the prior art for using wheat detached leaves for fusarium head blight identification, but it has the disadvantages of interference with the metabolic activity of detached leaves and inability to reflect the ear specificity. It is suitable for the initial screening of the breeding link, and can only simply screen disease-resistant varieties and disease-susceptible varieties, and it needs to be verified later, and its application value is not great. The resistance identification of the present invention selects the position of the top of the first leaf of the wheat seedling, because some fusarium head blight resistance genes are expressed in both the first leaf of the seedling and the ear of the mature plant, and there is spatiotemporal coordination of gene expression. Its resistance identification results can maintain good consistency with the ear inoculation identification results, and can be used as an effective means for wheat fusarium head blight resistance identification in practice, with high accuracy.

[0009] Compared with simply identifying wheat varieties as susceptible varieties and resistant varieties, the present invention can make detailed distinctions in resistance levels and has the following effects: First, it can guide breeding more accurately. High-resistant varieties may be accompanied by adverse agronomic traits such as low yield, and medium-resistant varieties may achieve a balance between yield and resistance, making them more suitable as intermediate materials for breeding. Second, it is helpful for regional layout and precise regulation of pesticides. High-resistant varieties are preferentially arranged in areas with high incidence of ergot disease, and frequent application of pesticides may not be required. Medium-resistant varieties are preferentially arranged in areas with lower risks, and are supplemented with application of pesticides in years with high incidence of diseases. Third, it is helpful for the study of resistance mechanisms. Different resistance levels may correspond to different resistance mechanisms. Through the association analysis of resistance levels and molecular markers, specific markers can be developed to accelerate the process of disease-resistant breeding. Fourth, many regions require wheat varieties to reach a specific resistance level (such as medium resistance and above) before they can be promoted. The identification of different resistance levels is conducive to the rapid approval, market pricing and promotion of varieties. Therefore, the detailed differentiation of wheat fusarium resistance levels is of great significance for research, breeding, variety approval and market promotion.

[0010] The present invention is further configured as follows: wheat is sown in a seedling tray, and the seedling substrate soil in the seedling tray is sterilized with potassium permanganate in advance.

[0011] The present invention is further configured as follows: the sown wheat is placed in an artificial climate box for cultivation.

[0012] The present invention is further configured as follows: the top of the first blade is reduced by 0.3-0.5 cm.

[0013] The present invention is further configured as follows: the concentration of the Fusarium spore suspension is 10 5 / mL.

[0014] The present invention is further configured as follows: observing the disease condition of the leaves 10-15 days after inoculation.

[0015] The beneficial effects of the present invention are:

[0016] 1. The present invention can identify resistance to fusarium wilt in wheat seedlings, and has the advantages of short identification cycle, simple operation, good repeatability, and no time limit.

[0017] 2. Compared with the prior art which uses isolated wheat seedling tissue to identify resistance to ergot, the present invention innovatively adopts the method of inoculating a spore suspension of Fusarium graminearum on the leaf wounds of living wheat seedlings. After inoculation, as the wheat seedlings grow and develop, the resistance of wheat to ergot is judged according to the extension length of the pathogen on the leaves. Different resistances have different extension lengths of the pathogen, and there is a relatively obvious gap between them. The judgment is clear and accurate, which reduces the interference of human factors and improves the accuracy of the identification results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a picture of the identification result of the present invention used for wheat variety Annong 8455.

[0020] Figure 2 This is a picture of the identification result of the present invention for wheat variety Yangmai 158.

[0021] Figure 3 This is a picture of the identification result of the present invention used for the wheat variety Sumai No. 3.

[0022] Figure 4 This is the identification result picture of the present invention used for the wheat variety Huaimai 20 DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] A method for identifying wheat scab resistance comprises sowing wheat in a foam seedling tray, adding an appropriate amount of potassium permanganate to the seedling substrate soil in the seedling tray for sterilization, and placing the wheat seedling in an artificial climate box for cultivation. When the wheat seedlings grow to the one-leaf-one-heart stage or the two-leaf-one-heart stage, the top of the first leaf is cut off by 0.3-0.5 cm, and a spore suspension of Fusarium graminearum is inoculated at the wound to inoculate the leaf. The concentration of the spore suspension of Fusarium graminearum is 10 5 / mL, and wrap and seal the leaves with plastic film, and observe the disease condition of the leaves 10-15 days after inoculation. The resistance of wheat to ergot is judged according to the extension length of the pathogen on the leaves.

[0025] Experimental part:

[0026] Four wheat varieties were selected, namely Annong 8455, Yangmai 158, Sumai No. 3, and Huaimai 20. The above-mentioned wheat fusarium head blight resistance identification method was used to identify the resistance to fusarium head blight. The resistance identification standard was: if the pathogen extension length was ≤0.5cm, the resistance was evaluated as high resistance; if the pathogen extension length was 0.5cm<1.5cm, the resistance was evaluated as medium resistance; if the pathogen extension length was 1.5cm<4cm, the resistance was evaluated as medium sensitivity; if the pathogen extension length was >4cm, the resistance was evaluated as high sensitivity. Figure 1-4 As shown, Annong 8455 is highly susceptible to ergot, Yangmai 158 is moderately susceptible to ergot, Huaimai 20 is moderately resistant to ergot, and Sumai 3 is highly resistant to ergot.

[0027] Control experiment (single flower drip method)

[0028] Four wheat varieties, namely Annong 8455, Yangmai 158, Sumai 3, and Huaimai 20, were selected and the conidia of four highly pathogenic wheat fusarium rust strains (F0301, F0609, F0980, and F1312) were cultured by single flower dripping at the heading stage. The conidia were mixed and diluted to 10 5conidia / ml. The conidia solution was dripped into a floret in the middle of the wheat ear at the early stage of flowering, with 20 ears for each variety. The inoculation date was the early stage of flowering for each variety. The wheat was investigated before yellow ripening (25 days after inoculation), and the severity of each variety was calculated based on the disease level of each inoculated ear. Grading standard: Level 1, the inoculated spikelet was diseased, and the cob was not diseased; Level 2, the cob was diseased, but the number of diseased spikelets was less than 1 / 4 of the whole ear; Level 3, the number of diseased spikelets accounted for 1 / 4 to 1 / 2 of the whole ear; Level 4, the number of diseased spikelets accounted for more than 1 / 2 of the whole ear. Resistance evaluation standard: Resistant (R), average severity ≤1.37; Moderately resistant (MR), 1.37<average severity ≤2.42; Moderately susceptible (MS), 2.42<average severity ≤3.29, susceptible (S), average severity>3.29.

[0029] After identification, the results of disease resistance are as follows: Annong 8455 is highly susceptible to ergot, Yangmai 158 is moderately susceptible to ergot, Huaimai 20 is moderately resistant to ergot, and Sumai No. 3 is highly resistant to ergot.

[0030] As can be seen from the above, the experimental results of the present invention are consistent with the results of the control experiment (single flower drip method).

Claims

1. A method for identifying wheat fusarium head blight resistance, characterized in that: The method comprises the following steps: sowing and culturing wheat, and when the wheat seedlings grow to the one-leaf-one-heart stage to the two-leaf-one-heart stage, cutting off the top of the first leaf, inoculating the wound with a spore suspension of Fusarium graminearum to inoculate the leaves with the fungus, and wrapping and sealing the leaves with a plastic film, observing the disease condition of the leaves after a period of inoculation, and judging the resistance of the wheat to ergot according to the extension length of the pathogen on the leaves.

2. A method for identifying wheat scab resistance according to claim 1, characterized in that: The extension length of the pathogen is ≤0.5cm, and the resistance is evaluated as high resistance; 0.5cm<bacterial extension length≤1.5cm, the resistance evaluation is medium resistance; If the pathogen extension is 1.5cm<≤4cm, the resistance is evaluated as moderately susceptible; if the pathogen extension length is greater than 4cm, the resistance is evaluated as highly susceptible.

3. A method for identifying wheat scab resistance according to claim 1, characterized in that: Wheat was sown in seedling trays, and the seedling medium soil in the seedling trays was sterilized with potassium permanganate in advance.

4. A method for identifying wheat scab resistance according to claim 1, characterized in that: After sowing, the wheat is placed in an artificial climate chamber for cultivation.

5. A method for identifying wheat scab resistance according to claim 1, characterized in that: Subtract 0.3-0.5cm from the top of the first leaf.

6. A method for identifying wheat scab resistance according to claim 1, characterized in that: The concentration of the Fusarium spore suspension was 10 5 / mL.

7. A method for identifying wheat scab resistance according to claim 1, characterized in that: Observe the disease condition of leaves 10-15 days after inoculation.

Images