阅读说明：本技术 一种小麦收获期遭遇降雨的灾害性评价方法 (Method for evaluating disastrous rainfall encountered during wheat harvesting period ) 是由 谢淑芹 肖磊 蔺桂芬 李平 裴艳婷 于 2020-04-28 设计创作，主要内容包括：本发明公开了一种小麦收获期遭遇降雨的灾害性评价方法,属于农业灾害评价技术领域,包括如下步骤：随机选取完整麦穗,并分别将上部和中部籽粒进行脱粒；以上部籽粒为对照组,中部籽粒为评价组,分别放入100℃沸水中保持10min；将对照组和评价组籽粒研磨至糊状并过滤定容至50ml容量瓶；在不同试管中分别加入0.5ml对照籽粒滤液和待评价籽粒滤液,再向试管中各加入5ml班氏试剂,然后沸水浴中保持3-5min,并观察试管中沉淀变化；依据沉淀颜色、沉淀量多少和始现时间对小麦遭遇降雨的灾害性进行评价。本发明以相同穗上部籽粒为对照,利用中部籽粒遭遇降雨产生还原性糖与班氏试剂显色反应,通过不同还原性糖形成的显色差异对小麦收获期遭遇降雨的灾害性程度进行评价。(The invention discloses a method for evaluating the calamity of rainfall encountered in the harvest period of wheat, which belongs to the technical field of agricultural disaster evaluation and comprises the following steps: randomly selecting complete wheat ears, and threshing the upper and middle grains respectively; respectively placing the upper seed grains as control group and the middle seed grains as evaluation group in 100 deg.C boiling water for 10 min; grinding the control group and the evaluation group to be pasty, filtering and fixing the volume to a 50ml volumetric flask; respectively adding 0.5ml of control grain filtrate and grain filtrate to be evaluated into different test tubes, respectively adding 5ml of Banner reagent into the test tubes, keeping in boiling water bath for 3-5min, and observing the change of precipitation in the test tubes; and evaluating the calamity of the wheat encountering rainfall according to the color of the sediment, the amount of the sediment and the initial time. The method takes the upper part of the same ear as a control, utilizes the color development reaction of reducing sugar generated by the rainfall of the middle part of the kernel and the Babylonian reagent, and evaluates the degree of the calamity of the rainfall during the harvest period of the wheat through the color development difference formed by different reducing sugars.)

1. A method for evaluating the disastrous rainfall encountered in the harvest period of wheat is characterized by comprising the following steps:

s1 selecting more than 50 complete ears randomly for 3 times in the year of raining or humid climate before wheat is mature and is harvested;

s2, taking the seeds on the upper part of the spike in S1 as a control group, taking the seeds in the middle part as a disaster evaluation material, and threshing the seeds in the upper part and the middle part respectively to be marked as a control group and an evaluation group respectively;

s3, weighing 5g of seeds of the control group and the evaluation group respectively, then putting the seeds of the control group and the evaluation group into different test tubes filled with boiling water, and keeping the seeds in the boiling water at 100 ℃ for 10 min;

s4, respectively putting the seeds of the control group and the evaluation group which are boiled in the S3 in a mortar, adding a small amount of quartz sand into the mortar, then adding 2ml of leaching liquor, and respectively grinding the seeds of the control group and the evaluation group into paste;

s5, filtering the pasty substances of the control group and the pasty substances of the evaluation group in the S4 into 50ml volumetric flasks respectively, and adding distilled water to fix the volume to scale marks to obtain control kernel filtrate and kernel filtrate to be evaluated;

s6, respectively adding 0.5ml of contrast grain filtrate and grain filtrate to be evaluated into different test tubes, and then respectively adding 5ml of Banner reagent into the test tubes to respectively obtain a contrast reaction system and a reaction system to be evaluated;

s7, placing the test tube containing the control reaction system and the reaction system to be evaluated in the S6 into a boiling water bath for heat preservation;

s8 observing and recording the color change of the reaction system, the initial time of the precipitate and the amount of the precipitate in S7, and recording the color change time, the color difference, the depth and the amount of the precipitate in detail;

s9, evaluating the disaster of rainfall in the harvest period of the wheat according to the result recorded in S8, when the recorded results of the comparison reaction system and the reaction system to be evaluated are completely the same, evaluating the disaster of rainfall in the harvest period of the wheat according to the following table:

note: according to the grading standard of the disaster degree, the disaster of the rainfall encountered in the harvest period of the wheat is evaluated, wherein the disaster degree of the wheat is gradually increased from the I level to the VI level, namely: grade I, no disaster; grade II, the disaster degree is the lightest; grade III, the disaster degree is light; grade IV, moderate disaster degree; grade V, the disaster degree is heavy; grade VI, the most severe disaster.

2. The method for evaluating the disastrous rainfall at the harvest time of wheat according to claim 1, wherein when the number of spikelets of the wheat head is even, 2 grains are respectively taken from the top row and the bottom row; and when the number of wheat ears is odd, selecting 4 grains in the middle.

3. The method as claimed in claim 1, wherein the selection of 4 kernels from the top kernel of the spike is performed in the control group.

4. The method as claimed in claim 1, wherein the leaching solution added during the kernel grinding is sodium citrate-sodium carbonate.

5. The method for evaluating the disaster of the rainfall encountered during the harvest period of the wheat according to claim 1, wherein the ratio of the Banner reagent to the control kernel filtrate to the kernel filtrate to be evaluated is 10: 1.

6. The method as claimed in claim 1, wherein the pH of the control reaction system and the pH of the reaction system to be evaluated are maintained at 7.5 or higher.

7. The method for evaluating the disastrous occurrence of rainfall during the harvest time of wheat according to claim 1, wherein the temperature of the control reaction system and the reaction system to be evaluated in a boiling water bath is kept for 3-5 min.

8. The method according to claim 1, wherein the reaction system to be evaluated has no precipitation generation for a very long time, and the color of the solution is blue, so that the wheat harvest time is not subjected to rainfall disasters; on the contrary, the reaction system to be evaluated generates a large amount of precipitates in a very short time, and the color of the solution is brick red, so that the degree of rainfall disasters encountered in the harvest period of wheat is the heaviest.

Technical Field

The invention relates to the field of agricultural disaster evaluation, in particular to a method for evaluating the disastrous performance of rainfall encountered in the harvest period of wheat.

Background

When winter wheat is subjected to rainy and humid climate in the mature period, the germination phenomenon of wheat grains on ears is called ear germination, and the ear germination is a global climate disaster. According to the statistics of the food and agriculture organization of the united nations, the annual loss caused by the sprouting of the ears accounts for about 20 percent of the total wheat yield in the world, which is equivalent to the annual total wheat yield in China. In China, about 85% of wheat production areas have the hidden danger of ear sprouting. In the Huang-Huai-wheat area and the middle-lower wheat area of Yangtze river in China, large-area ear sprouting disasters occur for many times, and in the southwest winter wheat area and the northeast spring wheat area, ear sprouting disasters also occur frequently.

After wheat ears germinate, the yield is reduced, and the quality is seriously deteriorated, even the edible value and the processing value are lost. The external cause of the germination disaster is humid rainy weather because: when wheat encounters rainy days in the mature period, proper germination conditions can be formed, the consumption of stored substances in the seeds is triggered, and substances and energy are provided for the germination of the seeds; the internal cause of the germination disaster is the resistance of the wheat variety itself because: the resistance of wheat to sprouting is a quantitative character controlled by multiple genes, and the sprouting resistance of different wheat varieties is different. Thus, ear germination is the result of a combination of environmental conditions and the self-resistance of the variety.

The germination resistance of the wheat seeds is not brought into the important basis of whether the wheat seeds can pass the approval or not in the current approval standard of the wheat varieties, so that the germination resistance of the wheat seeds for production has great difference, and the germination degrees of the wheat seeds among different varieties have diversity. In addition, in production, various uncertain factors exist in the aspects of rainfall amount, rainfall time, rainfall intermittence and the like, and the diversity of the degree of the sprouting of the ear of grain is further increased. Therefore, the degree of the germination of the ear is influenced by the germination resistance of the ear and the humid environment, and the evaluation of the degree of the germination disaster of the ear is related to the development of disaster reduction work and the reasonable utilization of the harvested wheat grains.

The current method for evaluating the germination degree of the wheat head mainly comprises the step of observing the appearance change of grains and adopting a 10-grade standard evaluation method (namely, grade 1: no germination sign of the appearance of the seeds; grade 2: white exposure, 1-2 mm long of germ roots; grade 3: appearance of coleoptile; grade 4: 1 mm long of germ sheaths; grade 5: 2-3 mm long of germ sheaths; grade 6: 4-9 mm long of germ sheaths; grade 7: 10-19 mm long of germ sheaths; grade 8: 20-29 mm long of germ sheaths; grade 9: 30-39 mm long of germ sheaths; grade 10: more than 40 mm long of germ sheaths, and entering a leaf stage). In fact, since the germination of the ear is the result of the combined effect of the self-resistance of the variety and the humid environment factors, the continuous rainy weather is not common in the real production, and the wheat is resistant to the germination of the ear in the long-term natural selection process. Therefore, in actual production, the degree of germination of the ear is often on the order of 1, and thus it is difficult to determine the degree of germination of the ear by visual observation using the conventional method. With the development of quality detection technology, the quality detection means is used as an auxiliary method and applied to the evaluation of the germination degree of the ear. However, the quality detection and evaluation method is to evaluate the wheat head germination degree by multiple indexes such as protein content, wet gluten content, flour yield, sedimentation value, water absorption, volume weight, stabilization time, formation time, maximum resistance to elongation, ductility and stretching area, and the quality detection and evaluation method not only needs expensive precise instruments, but also has complex test process and has more requirements on the number of the indexes to be measured, and along with the increase of variety number, the quality detection method can greatly increase the workload, consume a large amount of resources and seriously increase the cost. Therefore, the evaluation of the germination degree of wheat ears by a quality detection method cannot be widely applied to production.

Disclosure of Invention

Aiming at the fact that the phenomenon of pre-harvest sprouting does not occur in rainfall during the wheat harvesting period, the disaster degree of rainfall on wheat cannot be effectively evaluated by the aid of the prior art scheme, the method for evaluating the disaster degree of rainfall during the wheat harvesting period is characterized in that when the wheat is exposed to rainy humid weather, the content of reducing sugar generated by storage substances in seeds due to the influence of varieties and rainfall conditions is different, and the reducing sugar and a Banner reagent are subjected to color reaction, so that the disaster degree of rainfall during the wheat harvesting period is evaluated.

In order to achieve the purpose, the invention adopts the technical scheme that:

1. a method for evaluating the disastrous rainfall encountered in the harvest period of wheat is characterized by comprising the following steps:

s1 selecting more than 50 complete ears randomly for 3 times in the year of raining or humid climate before wheat is mature and is harvested;

s2, taking the seeds on the upper part of the spike in S1 as a control group, taking the seeds in the middle part as a disaster evaluation material, and threshing the seeds in the upper part and the middle part respectively to be marked as a control group and an evaluation group respectively;

s3, weighing 5g of seeds of the control group and the evaluation group respectively, then putting the seeds of the control group and the evaluation group into different test tubes filled with boiling water, and keeping the seeds in the boiling water at 100 ℃ for 10 min;

s4, respectively putting the seeds of the control group and the evaluation group which are boiled in the S3 in a mortar, adding a small amount of quartz sand into the mortar, then adding 2ml of leaching liquor, and respectively grinding the seeds of the control group and the evaluation group into paste;

s5, filtering the pasty substances of the control group and the pasty substances of the evaluation group in the S4 into 50ml volumetric flasks respectively, and adding distilled water to fix the volume to scale marks to obtain control kernel filtrate and kernel filtrate to be evaluated;

s6, respectively adding 0.5ml of contrast grain filtrate and grain filtrate to be evaluated into different test tubes, and then respectively adding 5ml of Banner reagent into the test tubes to respectively obtain a contrast reaction system and a reaction system to be evaluated;

s7, placing the test tube containing the control reaction system and the reaction system to be evaluated in the S6 into a boiling water bath for heat preservation;

s8 observing and recording the color change of the reaction system, the initial time of the precipitate and the amount of the precipitate in S7, and recording the color change time, the color difference, the depth and the amount of the precipitate in detail;

s9, evaluating the disaster of rainfall in the harvest period of the wheat according to the result recorded in S8, when the recorded results of the comparison reaction system and the reaction system to be evaluated are completely the same, evaluating the disaster of rainfall in the harvest period of the wheat according to the following table:

note: according to the grading standard of the disaster degree, the disaster of the rainfall encountered in the harvest period of the wheat is evaluated, wherein the disaster degree of the wheat is gradually increased from the I level to the VI level, namely: grade I, no disaster; grade II, the disaster degree is the lightest; grade III, the disaster degree is light; grade IV, moderate disaster degree; grade V, the disaster degree is heavy; grade VI, the most severe disaster.

2. The method for evaluating the disastrous rainfall at the harvest time of wheat according to claim 1, wherein when the number of spikelets of the wheat head is even, 2 grains are respectively taken from the top row and the bottom row; and when the number of wheat ears is odd, selecting 4 grains in the middle.

3. The method as claimed in claim 1, wherein the selection of 4 kernels from the top kernel of the spike is performed in the control group.

4. The method as claimed in claim 1, wherein the leaching solution added during the kernel grinding is sodium citrate-sodium carbonate.

5. The method for evaluating the disaster of the rainfall encountered during the harvest period of the wheat according to claim 1, wherein the ratio of the Banner reagent to the control kernel filtrate to the kernel filtrate to be evaluated is 10: 1.

6. The method as claimed in claim 1, wherein the pH of the control reaction system and the pH of the reaction system to be evaluated are maintained at 7.5 or higher.

7. The method for evaluating the disastrous occurrence of rainfall during the harvest time of wheat according to claim 1, wherein the temperature of the control reaction system and the reaction system to be evaluated in a boiling water bath is kept for 3-5 min.

8. The method according to claim 1, wherein the reaction system to be evaluated has no precipitation generation for a very long time, and the color of the solution is blue, so that the wheat harvest time is not subjected to rainfall disasters; on the contrary, the reaction system to be evaluated generates a large amount of precipitates in a very short time, and the color of the solution is brick red, so that the degree of rainfall disasters encountered in the harvest period of wheat is the heaviest.

The invention has the following beneficial effects:

the technical scheme provides a method for evaluating the disastrous rainfall encountered in the harvest period of wheat, and solves the problem that the prior art has a certain limitation in evaluating the disaster degree of the rainfall on the wheat. According to the technical scheme, seeds on the upper part of the wheat ear are used as a reference, the interference of mature seeds containing reducing sugar on an evaluation result is eliminated, different amounts of reducing sugar are generated in storage substances in the seeds by utilizing the difference of seeds at different parts of the same wheat ear in the germination process of the wheat ear in rainy weather, and the disastrous degree of rainfall in the harvest period of the wheat is evaluated through the color reaction of the reducing sugar and the Banner reagent.

Detailed Description

In order that the objects and advantages of the invention will be more clearly understood, the invention is further described in detail below with reference to examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.