Method for identifying cold resistance of oats and application thereof

Abstract

The invention belongs to the technical field of crop cold resistance identification, and particularly relates to an oat cold resistance identification method and application thereof. The method comprises the following steps: performing low-temperature stress treatment on seedlings of a to-be-identified oat variety; the oat seedlings subjected to low-temperature stress treatment are subjected to growth recovery under the condition of 22-25 DEG C; and after the growth is recovered, counting the green leaf area ratio, the relative survival rate and the standardized conductivity of the oat seedlings, calculating the comprehensive score of the oat according to a formula IV, and determining the cold resistance of the to-be-identified oat variety. According to the method, the seedlings of the to-be-identified oat variety are subjected to low-temperature stress, the identification mode is not limited by seasons, and the oat germplasm can be identified all the year round; identification can be completed in the early growth stage of the oats, and later-stage cost input is reduced. Besides, three indexes are selected for investigation, so that the one-sidedness of only investigating a single index is avoided, the cold resistance of the oat can be accurately and efficiently identified, and a technical support is provided for cultivating cold-resistant oat germplasm.

Description

Technical Field

[0001] The invention belongs to the technical field of cold resistance identification of crops, and particularly relates to a method for identifying the cold resistance of oats and an application thereof. Background Art

[0002] Oats are an annual dual-purpose crop used for both grain and feed. Because they don't compete with major grain crops for arable land, they have become an important specialty crop in the restructuring of agricultural planting structures. High-quality oat grass plays an increasingly important role in the development of my country's animal husbandry, so identifying the cold tolerance of oats and cultivating cold-resistant germplasm is of great significance.

[0003] Currently, oat cold tolerance testing primarily involves field testing and laboratory testing. Field testing, however, suffers from environmental uncontrollability, significant climate fluctuations, and lengthy testing cycles, leading to unstable and difficult-to-reproduce results. Furthermore, due to geographical and seasonal constraints, it cannot be conducted year-round, impacting testing efficiency. While laboratory testing can simulate low-temperature environments, its selection of indicators struggles to accurately reflect the cold tolerance mechanisms of oats. Therefore, a method is urgently needed that can efficiently and accurately assess oat cold tolerance using appropriate indicators. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for identifying the cold resistance of oats and an application thereof. The method of the present invention can accurately and efficiently identify the cold resistance of oats.

[0005] The present invention provides a method for identifying the cold resistance of oats, comprising the following steps: subjecting seedlings of an oat variety to be identified to low temperature stress; allowing the oat seedlings treated with low temperature stress to recover their growth at 22-25°C; after the recovery, calculating the green leaf area percentage, relative survival rate, and standardized conductivity of the oat seedlings, and calculating a comprehensive score of the oats according to Formula IV to determine the cold resistance of the oat variety to be identified;

[0006] Comprehensive score = percentage of green leaf area × 0.4 + relative survival rate × 0.3 + standardized conductivity × 0.3 (Formula IV);

[0007] When 0.00<comprehensive score≤0.40, the cold resistance of the oats is extremely cold-resistant;

[0008] When 0.40 < comprehensive score ≤ 0.55, the cold tolerance of the oats is highly cold-resistant;

[0009] When 0.55 < comprehensive score ≤ 0.70, the cold resistance of the oats is moderate cold resistance;

[0010] When 0.70 < comprehensive score ≤ 0.85, the cold resistance of the oats is highly cold-resistant;

[0011] When 0.85 < comprehensive score ≤ 1.00, the cold resistance of the oat is extremely cold-resistant;

[0012] The temperature of the low temperature stress treatment is -5°C to 2°C; the time of the low temperature stress treatment is 10 to 48 hours;

[0013] The recovery growth time is 7 to 14 days;

[0014] The relative survival rate is calculated according to Formula I: relative survival rate = survival rate of oats under low temperature stress ÷ survival rate of oats under normal growth conditions × 100% Formula I;

[0015] The standardized conductivity determination method comprises: chopping oat seedling leaves to obtain chopped oat leaves; mixing the chopped oat leaves with deionized water, soaking the mixture for 20 to 30 minutes to obtain a mixed solution, and measuring the initial conductivity of the mixed solution, which is recorded as R1; boiling the mixed solution for 10 to 15 minutes, cooling the mixture, and measuring the conductivity of the mixed solution after boiling, which is recorded as R2, and calculating the relative conductivity of the leaves according to formula II;

[0016] Relative conductivity = (R1 / R2) × 100% Formula II;

[0017] The relative conductivity is normalized according to formula III to obtain a normalized conductivity;

[0018] Normalized conductivity = 1 ÷ (1 + relative conductivity) Formula III.

[0019] As a preferred embodiment, the seedlings include oat seedlings in the two-leaf, one-heart stage.

[0020] As a preferred solution, the recovery growth conditions are 16h light / 8h dark, relative humidity of 60%, and light intensity of 650μmol·m -2 ·s -1 .

[0021] As a preferred embodiment, the mass volume ratio of the crushed oat leaves to deionized water is 1g:20mL.

[0022] As a preferred solution, the temperature of the low temperature stress treatment is -5°C to 0°C.

[0023] As a preferred solution, the temperature of the low temperature stress treatment is -3°C to -1°C.

[0024] As a preferred solution, the low temperature stress treatment time is 10 to 24 hours.

[0025] As a preferred solution, the recovery growth time is 7 days.

[0026] As a preferred embodiment, the oat seedlings are pre-cultured before the low temperature stress treatment; the pre-culture conditions are 22-25° C., 16 h light / 8 h dark; and the pre-culture time is 1-2 days.

[0027] The present invention also provides the application of the method described in the above scheme in cultivating cold-resistant oat germplasm.

[0028] Beneficial effects: The present invention provides a method for identifying the cold resistance of oats, comprising the following steps: subjecting the seedlings of the oat variety to be identified to low temperature stress; allowing the oat seedlings after low temperature stress treatment to resume growth under conditions of 22-25°C; after the recovery of growth, statistically analyzing the green leaf area ratio, relative survival rate and standardized conductivity of the oats, calculating the comprehensive score of the oats according to Formula IV, and determining the cold resistance of the oat variety to be identified. The present invention subjects the seedlings of the oat variety to low temperature stress, and the identification method is not restricted by season, and the oat germplasm can be identified throughout the year; and the identification can be completed in the early growth stage of the oats, reducing the cost investment in the later stage. In addition, the present invention examines three indicators of oat green leaf area, relative survival rate, and standardized conductivity, avoiding the one-sidedness of examining only a single indicator, and can accurately and efficiently identify the cold resistance of oats, providing technical support for the cultivation of cold-resistant oat germplasm. DETAILED DESCRIPTION

[0029] The present invention provides a method for identifying the cold resistance of oats, comprising the following steps: subjecting seedlings of an oat variety to be identified to low temperature stress; allowing the oat seedlings treated with low temperature stress to recover their growth at 22-25°C; after the recovery, calculating the green leaf area percentage, relative survival rate, and standardized conductivity of the oat seedlings, and calculating a comprehensive score of the oats according to Formula IV to determine the cold resistance of the oat variety to be identified;

[0030] Comprehensive score = percentage of green leaf area × 0.4 + relative survival rate × 0.3 + standardized conductivity × 0.3 (Formula IV);

[0031] When 0.00<comprehensive score≤0.40, the cold resistance of the oats is extremely cold-resistant;

[0032] When 0.40 < comprehensive score ≤ 0.55, the cold tolerance of the oats is highly cold-resistant;

[0033] When 0.55 < comprehensive score ≤ 0.70, the cold resistance of the oats is moderate cold resistance;

[0034] When 0.70 < comprehensive score ≤ 0.85, the cold resistance of the oats is highly cold-resistant;

[0035] When 0.85 < comprehensive score ≤ 1.00, the cold resistance of the oat is extremely cold-resistant;

[0036] The temperature of the low temperature stress treatment is -5°C to 2°C; the time of the low temperature stress treatment is 10 to 48 hours;

[0037] The recovery growth time is 7 to 14 days;

[0038] The relative survival rate is calculated according to Formula I: relative survival rate = survival rate of oats under low temperature stress ÷ survival rate of oats under normal growth conditions × 100% Formula I;

[0039] The standardized conductivity determination method comprises: chopping oat seedling leaves to obtain chopped oat leaves; mixing the chopped oat leaves with deionized water, soaking the mixture for 20 to 30 minutes to obtain a mixed solution, and measuring the initial conductivity of the mixed solution, which is recorded as R1; boiling the mixed solution for 10 to 15 minutes, cooling the mixture, and measuring the conductivity of the mixed solution after boiling, which is recorded as R2, and calculating the relative conductivity of the leaves according to formula II;

[0040] Relative conductivity = (R1 / R2) × 100% Formula II;

[0041] The relative conductivity is normalized according to formula III to obtain a normalized conductivity;

[0042] Normalized conductivity = 1 ÷ (1 + relative conductivity) Formula III.

[0043] In the present invention, the seedlings of the oat variety to be identified are subjected to low temperature stress treatment. In the present invention, the seedlings can be seedlings obtained by culturing seeds of the oat variety to be identified, or they can be grown seedlings of the oat variety to be identified. As an embodiment, the seedlings include oat seedlings in the two-leaf, one-heart stage. The oat seedlings in the two-leaf, one-heart stage have just entered the rapid growth period and are more sensitive to changes in the external environment. By observing the reactions of the oat seedlings during this period, the cold resistance of different oat varieties can be effectively evaluated. As an embodiment, the number of seedlings of the oat variety to be identified is 30 to 60 plants; the number of oat seedling samples suitable for the present invention can accurately reflect the overall characteristics, reduce sample errors, and avoid the influence of individual differences on the identification results. In a specific embodiment of the present invention, the number of seedlings of the oat variety to be identified is 45 plants, and 3 replicate groups are set, with 15 plants in each group.

[0044] In one embodiment, the cold stress treatment further includes pre-culturing the oat seedlings before the cold stress treatment; the pre-culturing conditions are 22-25°C, 16 hours of light / 8 hours of darkness, and the pre-culturing time is 1-2 days. The cold stress treatment is performed directly after the pre-culturing, which can reduce experimental errors.

[0045] The temperature of the low temperature stress treatment of the present invention is -5℃~2℃. As an embodiment, the temperature of the low temperature stress treatment is -5℃~0℃; as another embodiment, the temperature of the low temperature stress treatment is -3℃~-1℃. The time of the low temperature stress treatment of the present invention is 10~48h. As an embodiment, the time of the low temperature stress treatment is 10~24h. In a specific embodiment of the present invention, the time of the low temperature stress treatment can be any value in the range of 10~48h, such as 10h, 14h, 16h, 18h, 20h, 21h, 24h, 30h, 36h or 48h. In a specific embodiment of the present invention, the low temperature stress is carried out in a low temperature incubator, and the oat seedlings are evenly distributed to avoid uneven temperature and light due to position differences, thereby ensuring the accuracy of the identification results.

[0046] The present invention restores the growth of oat seedlings after low temperature stress treatment at 22-25°C. As an embodiment, the conditions for the restoration of growth are 16 hours of light / 8 hours of darkness, a relative humidity of 60%, and a light intensity of 650 μmol·m -2 ·s -1 . The time for recovery growth described in the present invention is 7 to 14 days. As an embodiment, the time for recovery growth is 7 days. In a specific embodiment of the present invention, the time for recovery growth can be any value between 7 and 14 days, such as 7 days, 8 days, 10 days, 11 days, 12 days or 14 days. The present invention sets a suitable time for recovery growth, which allows the oat seedlings to recover so as to accurately assess the survival of the oats. The recovery growth time described in this application allows oats to show the characteristics of whether they can recover from frost damage, including the growth of new leaves or the restart of other growth activities.

[0047] The present invention counts the green leaf area percentage, relative survival rate and normalized conductivity of the oat seedlings after the oat seedlings have recovered their growth. As an embodiment, the green leaf area percentage of the oat seedlings is the ratio of the area of the first true leaf and the second true leaf of the oat seedling that has not been frozen to the total area of the first true leaf and the second true leaf. As an embodiment, the green leaf percentage of each oat seedling of the variety to be identified is counted, and then the average value is calculated as the green leaf area percentage of the variety to be identified. As an embodiment, the frost damage criteria include leaf color change and / or tissue state change; the color change includes green to brown, black or grayish white; the tissue state change includes one or more of the tissue becoming transparent, spotted and withered. In the present invention, the appearance of one of the above-mentioned frost damage criteria means that the oat seedlings have been frost damaged. As an embodiment, the method for obtaining the green leaf area ratio of the oat seedlings includes: setting the total area of the first true leaf and the second true leaf of the oat seedling as 1, counting the areas of the first true leaf and the second true leaf of the oat seedling that have suffered frost damage, and determining the green leaf area ratio of the oat seedlings based on the obtained frost damage area ratio. The present invention calculates the green leaf area ratio of the oat seedlings by dividing the frost damage area of the first true leaf and the second true leaf by the total area of the first true leaf and the second true leaf × 100% = the frost damage area ratio, and then calculating 1-the frost damage area ratio = the green leaf area ratio of the oat seedlings. In a specific embodiment of the present invention, when the oat leaves are not frozen, the proportion of the green leaf area of the oat seedlings is recorded as 1; when the proportion of the area of the oat leaves damaged by frost is 10%, the proportion of the green leaf area of the oat seedlings is recorded as 0.9; when the proportion of the area of the oat leaves damaged by frost is 20%, the proportion of the green leaf area of the oat seedlings is recorded as 0.8; when the proportion of the area of the oat leaves damaged by frost is 30%, the proportion of the green leaf area of the oat seedlings is recorded as 0.7; when the proportion of the area of the oat leaves damaged by frost is 40%, the proportion of the green leaf area of the oat seedlings is recorded as 0.6; when the proportion of the area of the oat leaves damaged by frost is 50%, the proportion of the green leaf area of the oat seedlings is recorded as 0. When the percentage of oat seedling green leaf area is 60%, the percentage of oat seedling green leaf area is 0.4; when the percentage of oat leaf area is 70%, the percentage of oat seedling green leaf area is 0.3; when the percentage of oat leaf area is 80%, the percentage of oat seedling green leaf area is 0.2; when the percentage of oat leaf area is 90%, the percentage of oat seedling green leaf area is 0.1; when the percentage of oat leaf area is 100%, the percentage of oat seedling green leaf area is 0.0. The present invention limits the oat seedlings in the two-leaf and one-heart stage to low temperature stress, and then recovers to grow for 7 to 14 days. The green leaf percentage of the first true leaf and the second true leaf is counted, which can accurately reflect the cold resistance of the oat seedlings. The present invention does not limit the method for measuring the freezing area, and conventional measurement methods in the field can be used.

[0048] The relative survival rate described in the present invention is calculated according to Formula I: Relative survival rate = survival rate of oats treated with low temperature stress / survival rate of oats under normal growth conditions × 100% Formula I. In one embodiment, the survival rate of oats under low temperature stress = the number of surviving seedlings treated with low temperature stress / the total number of seedlings treated with low temperature stress × 100%; the survival rate of oats under normal growth conditions = the number of surviving oats under normal growth conditions / the total number of seedlings under normal growth conditions × 100%. The survival rate of oats under normal growth conditions described in the present invention is the survival rate of oats not subjected to low temperature stress, and all other treatment parameters are the same as those for oat seedlings treated with low temperature stress. In a specific embodiment of the present invention, the determination of the survival rate of oats under normal growth conditions includes: selecting healthy oat seedlings with two leaves and one heart in the same growth state, pre-culturing them for 1 to 2 days, growing them under normal growth conditions, and calculating the survival rate of oats under normal growth conditions; the pre-culturing of oat seedlings treated with low temperature stress is carried out under the conditions of 22 to 25°C and 16 hours of light / 8 hours of darkness; the growth time under normal growth conditions is the sum of the low temperature stress treatment time and the recovery growth time. As an embodiment, the normal growth conditions include 16 hours of light / 8 hours of darkness, a relative humidity of 60%, and a light intensity of 650 μmol·m -2 ·s -1 As an embodiment, the oats under normal growth conditions are divided into groups and the number of plants in each group is the same as that in the stress treatment group.

[0049] The method for measuring standardized electrical conductivity described herein comprises: chopping oat seedling leaves to obtain chopped oat leaves; mixing the chopped oat leaves with deionized water, soaking the mixture for 20-30 minutes, and measuring the initial electrical conductivity of the mixture, denoted as R1; boiling the mixture for 10-15 minutes, cooling it, and measuring the electrical conductivity of the boiled mixture, denoted as R2. The relative electrical conductivity of the leaves is calculated according to Formula II. In one embodiment, the standardized electrical conductivity is the mean of three replicate groups. In one embodiment, the standardized electrical conductivity is measured using the first and second true leaves of the seedlings. In a specific embodiment of the present invention, three oat seedlings are randomly selected from each group, and the first and second true leaves of each oat seedling are chopped and mixed to obtain the chopped oat leaves. In another embodiment, the mass-to-volume ratio of the chopped oat leaves to deionized water is 1g:20mL.

[0050] Relative conductivity = (R1 / R2) × 100% Formula II;

[0051] The relative conductivity is normalized according to formula III to obtain a normalized conductivity;

[0052] Normalized conductivity = 1 ÷ (1 + relative conductivity) Formula III.

[0053] In the present invention, the relative conductivity needs to be processed inversely. A higher conductivity means a lower cold resistance. Therefore, the relative conductivity needs to be standardized.

[0054] The present invention assigns different weights according to the importance of the three indicators of green leaf area ratio, relative survival rate and normalized conductivity, calculates the oat comprehensive score according to Formula IV, and determines the cold resistance of the oat variety to be identified;

[0055] Comprehensive score = percentage of green leaf area × 0.4 + relative survival rate × 0.3 + standardized conductivity × 0.3 (Formula IV).

[0056] When 0.00<comprehensive score≤0.40, the cold resistance of the oats is extremely cold-resistant;

[0057] When 0.40 < comprehensive score ≤ 0.55, the cold tolerance of the oats is highly cold-resistant;

[0058] When 0.55 < comprehensive score ≤ 0.70, the cold resistance of the oats is moderate cold resistance;

[0059] When 0.70 < comprehensive score ≤ 0.85, the cold resistance of the oats is highly cold-resistant;

[0060] When 0.85<comprehensive score≤1.00, the cold resistance of the oats is extremely cold-resistant.

[0061] In the present invention, taking the oat seedling stage as the object, the extreme cold intolerance means that the plant cannot tolerate any low temperature, that is, a slight low temperature of 0°C ≤ temperature < 2°C can cause significant damage or death to the plant, or a slight low temperature exposure for a short period of time (3h < time < 5h) can cause serious damage or death to the plant; the high cold intolerance means that the plant can only tolerate a slight low temperature of 0°C ≤ temperature < 2°C, that is, it can survive a slight low temperature for a short period of time (10h < time < 24h), but will be damaged by long-term exposure (≥ 24h); the moderate cold intolerance means that the plant can only tolerate a slight low temperature of 0°C ≤ temperature < 2°C, that is, it can survive a slight low temperature for a short period of time (10h < time < 24h), but will be damaged by long-term exposure (≥ 24h); The term "cold-resistant" means being able to tolerate mild low temperatures of 0°C ≤ <2°C, i.e., it can survive in mild low temperatures for a short period of time (<24 hours), but will be damaged if exposed for a long period of time (≥24 hours); the term "highly cold-resistant" means being able to tolerate relatively cold low temperatures of -5°C < ≤-3°C, i.e., it can survive in relatively cold low temperatures for a short period of time (<48 hours), but will be damaged if exposed for a long period of time (≥48 hours); the term "extremely cold-resistant" means being able to tolerate extreme low temperatures of ≤-5°C, i.e., it can maintain a good condition for a long period of time (≥48 hours) at extreme low temperatures of ≤-5°C.

[0062] The present invention also provides the application of the method described in the above-mentioned solution to the cultivation of cold-tolerant oat germplasm. The method described in the present invention is not restricted by season and can be used to identify oat germplasm year-round. Furthermore, identification can be completed early in the oat growth period, reducing later costs. Furthermore, the present invention selects three indicators for assessment, avoiding the one-sidedness of examining only a single indicator. This allows for accurate and efficient assessment of the cold tolerance of oats, providing technical support for the cultivation of cold-tolerant oat germplasm.

[0063] To further illustrate the present invention, a method for identifying cold resistance of oats and its application provided by the present invention are described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present invention.

[0064] Example 1

[0065] (1) Seed selection: Randomly select seeds of the oat variety Aberglen to be identified that are uniform in size, color, and plumpness, free of mold, damage, and with intact seed coats; culture the seeds in seedling trays and germinate into seedlings.

[0066] (2) Pre-culture: After the oat seedlings in step (1) grow to the two-leaf and one-heart stage, pre-culture is performed to make the growth state of the oat seedlings similar and reduce experimental errors; wherein the pre-culture conditions are 16 h light, 25 ° C, and the light intensity is 650 μmol·m -2 ·s -1 ; 8h darkness, 22℃; pre-culture time is 1 day.

[0067] (3) Low temperature stress treatment:

[0068] The healthy oat seedlings with the same growth status after pre-culture were randomly divided into a low temperature stress treatment group and a control treatment group, with 3 replicates in each group and 15 seedlings in each replicate.

[0069] Low temperature treatment group: After pre-culture treatment, oat seedlings were placed in a low-temperature incubator at -1.5°C for 16 hours. After the low temperature treatment, the samples were quickly removed from the light incubator and transferred to normal growth conditions for 7 days of recovery growth. The normal growth conditions were set as 16 hours of light, 25°C, and a light intensity of 650 μmol·m -2 ·s -1 ; 8h darkness, 22℃; relative humidity 60%.

[0070] Control treatment group: The oat seedlings in the control treatment group were placed in a plant growth culture room; the plant growth culture room conditions were set to 16 h light, 25 ° C, and a light intensity of 650 μmol·m -2 ·s -1 8 hours of darkness, 22°C, and 60% relative humidity. The culture time of the control treatment group = low temperature treatment time + recovery growth time, which is 7 days and 16 hours (a total of 184 hours).

[0071] (4) Statistical analysis of oat green leaf area, relative survival rate, and leaf conductivity

[0072] After the low temperature treatment group in step (3) has recovered its growth, the green leaf area (G b ) percentage, relative survival rate (G I ) and leaf electrical conductivity, and the values obtained were the means of three replicate groups.

[0073] A. Calculate the proportion of green leaf area of oat seedlings

[0074] The proportion of green leaf area of oat seedlings is the ratio of the area of the first true leaf and the second true leaf of the oat seedlings that is not frozen to the total area of the first true leaf and the second true leaf.

[0075] 1. Count the percentage of green leaves on each oat seedling. Frost damage to true leaves includes leaf discoloration to brown, black, or off-white; leaf translucency; wilting; or spotting. Any of these characteristics indicates frost damage. The total area of the first and second true leaves of an oat seedling is set as 1. Count the frost-damaged areas of the first and second true leaves. Calculate the frost-damaged area of the oat seedlings using the formula: "Area of frost-damaged first and second true leaves divided by total area of first and second true leaves × 100% = frost-damaged area ratio."

[0076] The green leaf area ratio of oat seedlings is calculated using the formula "1 - frost-damaged area ratio = green leaf ratio of oat seedlings." For example, if the oat leaves are not frost-damaged, the green leaf area ratio is 1; if the frost-damaged area ratio is 10%, the green leaf area ratio is 0.9.

[0077] ② Count the percentage of oat green leaf area in each replicate group: According to the percentage of green leaf area of each oat seedling counted in step ①, calculate the average value as the percentage of oat green leaf area in the replicate group. The results are shown in Table 1.

[0078] Table 1. Proportion of green leaf area of oat seedlings

[0079]

[0080] ③ Calculate the green leaf area percentage: Average the green leaf area percentages of each replicate group in step ② to obtain the green leaf area of the oats in the low-temperature treatment group. The green leaf area percentage of the oats in the low-temperature treatment group was 0.75.

[0081] B. Statistical analysis of oat survival rate

[0082] According to the formula "survival rate = number of surviving oat plants / total number of oat plants", the oat survival rate of each replicate group was calculated. The results are shown in Table 2. The mean of the three replicate groups was used to calculate the survival rate of oats in the low-temperature treatment group and the control treatment group. Among them, the survival rate of oats in the low-temperature treatment group was 75%, and the survival rate of oats in the control group was 98%.

[0083] Table 2 Survival rate of oats

[0084] Survival rate Repeat 1 Repeat 2 Repeat 3 average value Low temperature treatment group 80 75 70 75％ Control treatment group 99 98 97 98％

[0085] The relative survival rate of oats was calculated according to Formula I: relative survival rate = survival rate of oats under low temperature stress ÷ survival rate of oats under normal growth conditions × 100% Formula I; the survival rate of oats under normal growth conditions was the survival rate of oats in the control group.

[0086] It was calculated that the relative survival rate of oats in the low temperature treatment group was 77%.

[0087] C. Statistical leaf conductivity

[0088] ① Relative conductivity measurement: Three oat seedlings were randomly selected for each low temperature stress treatment replicate group, and the first and second true leaves were removed. The removed oat leaves were cut into small pieces (about 0.5 cm 2 ) and mixed evenly to obtain crushed oat leaves; 0.5 g of crushed oat leaves were randomly selected and placed in 10 mL of deionized water for 30 min; after the soaking, the initial conductivity (R1) of the solution was measured using a conductivity meter; the solution was then boiled for 15 min, cooled to room temperature, and the conductivity (R2) of the boiled solution was measured again using a conductivity meter. The relative conductivity of the leaves was calculated according to Formula II, and the obtained results were R1 = 32 and R2 = 449.4.

[0089] Relative conductivity = (R1 / R2) × 100% Formula II

[0090] The relative conductivity of the other two replicate groups was calculated according to the above steps, and the average value was obtained to obtain the relative conductivity of the oat leaves. The results are shown in Table 3. The relative conductivity of the oat leaves was calculated to be 5.64%.

[0091] Table 3 Oat conductivity values

[0092] Group Repeat 1 Repeat 2 Repeat 3 R1 32 41.8 36.4 R2 449.4 870.8 728 Relative conductivity 7.12％ 4.80％ 5.00％

[0093] ② Normalized conductivity: Relative conductivity is negatively correlated with the cold tolerance of plants. Higher conductivity means lower cold tolerance. Therefore, relative conductivity needs to be reversed. The relative conductivity in step ① is normalized according to formula III:

[0094] Normalized conductivity = 1 ÷ (1 + relative conductivity) Formula III.

[0095] Calculation shows that the standardized electrical conductivity of oat leaves is 0.947.

[0096] (5) Identification of cold resistance of oats

[0097] Cold tolerance was evaluated based on the percentage of green leaf area, oat survival rate and standardized electrical conductivity.

[0098] A. Weighted scoring: Assign different weights to different indicators according to their importance, and calculate the comprehensive score of the oat plant according to Formula IV.

[0099] Comprehensive score = proportion of green leaf area × 0.4 + relative survival rate × 0.3 + standardized conductivity × 0.3 (Formula IV).

[0100] Calculation showed that the comprehensive score of oats in the low-temperature treatment group was 0.815.

[0101] B. Cold resistance identification

[0102] The comprehensive score of oats in step A was used to judge the cold resistance of oats according to Table 4.

[0103] Table 4 Oat frost injury relative survival rate classification and cold tolerance evaluation standards

[0104] level Comprehensive score range Cold resistance evaluation 1 0.85<comprehensive score≤1.00 Extremely cold-resistant 3 0.70<comprehensive score≤0.85 Highly cold-resistant 5 0.55<comprehensive score≤0.70 Moderately cold-resistant 7 0.40<comprehensive score≤0.55 Highly cold-resistant 9 0.00<Comprehensive score≤0.40 Extremely cold-intolerant

[0105] According to Table 4, Aberglen is highly cold-resistant.

[0106] Example 2

[0107] The well-known oat variety 'yellow oat' was used as the variety to be identified to verify the accuracy of the method of the present invention.

[0108] (1) Seed selection: The procedure was carried out in accordance with step (1) of Example 1, except that the oat variety to be identified was 'yellow oat'.

[0109] (2) Pre-culture: proceed according to step (2) of Example 1.

[0110] (3) Low temperature stress treatment: proceed according to step (3) of Example 1.

[0111] (4) Statistical analysis of oat green leaf area, relative survival rate, and leaf conductivity

[0112] According to step (4) of Example 1, the green leaf area ratio of 'yellow oat' was determined to be 0.75; the relative survival rate was 65%; and the standardized conductivity was 0.713. The comprehensive score of oat 'yellow oat' calculated according to formula IV was 0.709. According to Table 4, the cold resistance of oat 'yellow oat' is highly cold-resistant, which is consistent with the prior art disclosure (see [Yang Xiuling, Wei Zhenwu. Study on the Cold Resistance of Oat Seedlings [J]. Sichuan Grassland, 2005, (06): 23-24.]). This shows that the cold resistance of oats can be accurately identified using the method described in the present invention.

[0113] Example 3

[0114] At the same time, 50 varieties of oats were selected for cold resistance identification.

[0115] (1) Seed selection: 90 seeds were randomly selected from each oat variety to be identified, and 6 replicates were set up, with 15 seeds in each replicate, including 3 replicates in the low temperature treatment group and 3 replicates in the control treatment group.

[0116] (2) Pretreatment: proceed according to step (2) of Example 1.

[0117] (3) Low temperature stress treatment: proceed according to step (3) of Example 1.

[0118] (4) Statistics of oat green leaf area, survival rate and conductivity

[0119] After low temperature treatment, normal growth conditions were restored and the green leaf area (G b ), relative survival rate (G I ) and leaf electrical conductivity.

[0120] A. Counting green leaf area

[0121] Proceed according to operation A in step (4) of Example 1.

[0122] B. Statistical analysis of oat survival rate

[0123] Proceed according to the operation B in step (4) of Example 1.

[0124] C. Statistical leaf conductivity

[0125] Proceed according to operation C in step (4) of Example 1.

[0126] (5) Identification of cold resistance of oats

[0127] Cold tolerance was evaluated based on green leaf area percentage, oat survival rate, and normalized electrical conductivity. The comprehensive scores and cold tolerance traits of some of the oat varieties to be identified are shown in Table 5.

[0128] Table 5 Test results of oat varieties to be identified

[0129]

[0130] In summary, the method described in the present invention can be used to accurately and efficiently identify the cold resistance of oats, providing technical support for cultivating cold-resistant oat germplasm.

[0131] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for identifying the cold resistance of oats, characterized in that: The following steps are involved: The oat seedlings of the oat variety to be identified were subjected to low temperature stress treatment; the oat seedlings after low temperature stress treatment were allowed to recover at 22-25°C; after recovery, the percentage of green leaf area, relative survival rate, and standardized electrical conductivity of the oat seedlings were calculated, and the comprehensive score of the oats was calculated according to Formula IV to determine the cold tolerance of the oat variety to be identified; Comprehensive score = percentage of green leaf area × 0.4 + relative survival rate × 0.3 + standardized conductivity × 0.3 (Formula IV); When 0.00<comprehensive score≤0.40, the cold resistance of the oats is extremely cold-resistant; When 0.40 < comprehensive score ≤ 0.55, the cold tolerance of the oats is highly cold-resistant; When 0.55 < comprehensive score ≤ 0.70, the cold resistance of the oats is moderate cold resistance; When 0.70 < comprehensive score ≤ 0.85, the cold resistance of the oats is highly cold-resistant; When 0.85 < comprehensive score ≤ 1.00, the cold resistance of the oat is extremely cold-resistant; The temperature of the low temperature stress treatment is -5°C to 2°C; the time of the low temperature stress treatment is 10 to 48 hours; The recovery growth time is 7 to 14 days; The relative survival rate is calculated according to Formula I: relative survival rate = survival rate of oats under low temperature stress ÷ survival rate of oats under normal growth conditions × 100% Formula I; The method for measuring the standardized electrical conductivity comprises: chopping oat seedling leaves to obtain chopped oat leaves; The crushed oat leaves are mixed with deionized water and soaked for 20 to 30 minutes to obtain a mixed solution, and the initial conductivity of the mixed solution is measured, which is recorded as R1; the mixed solution is boiled for 10 to 15 minutes, cooled, and the conductivity of the mixed solution after boiling is measured, which is recorded as R2. The relative conductivity of the leaves is calculated according to Formula II; Relative conductivity = (R1 / R2) × 100% Formula II; The relative conductivity is normalized according to formula III to obtain a normalized conductivity; Normalized conductivity = 1 ÷ (1 + relative conductivity) Formula III.

2. The method according to claim 1, characterized in that The seedlings include oat seedlings in the two-leaf and one-heart stage.

3. The method according to claim 1, characterized in that The recovery growth conditions were 16 h light / 8 h dark, relative humidity of 60%, and light intensity of 650 μmol·m -2 ·s -1 .

4. The method according to claim 1, wherein The mass volume ratio of the crushed oat leaves to deionized water is 1 g:20 mL.

5. The method according to claim 1, characterized in that The temperature of the low temperature stress treatment is -5°C to 0°C.

6. The method according to claim 1 or 5, characterized in that The temperature of the low temperature stress treatment is -3°C to -1°C.

7. The method according to claim 1, characterized in that The low temperature stress treatment time is 10 to 24 hours.

8. The method according to claim 1, characterized in that The recovery growth time is 7 days.

9. The method according to claim 1, characterized in that The method further comprises pre-culturing the oat seedlings before the low temperature stress treatment; the pre-culturing conditions are 22-25° C., 16 h light / 8 h dark; and the pre-culturing time is 1-2 days.

10. Use of the method according to any one of claims 1 to 9 in cultivating cold-resistant oat germplasm.

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