Determination method for resistance of rice-stem borers

Abstract

The invention discloses a method for measuring the resistance of rice-stem borers, and belongs to the technical field of resistance identification. The invention discloses a method for indoor determination of Chilo suppressalis resistance, which comprises the following steps: selecting 10-14-day-old rice seedlings, wrapping the roots of the seedlings, and fixing the seedlings in a culture container; inoculating weighed chilo suppressalis larvae into each container, sealing the opening of the container, and culturing under the condition of a lower light source. And observing and recording the death conditions of the rice and the chilo suppressalis larvae, when the death rate of the to-be-controlled variety is higher than 80%, counting the survival rate of the rice of each tested material, the chilo suppressalis weight growth inhibition rate and the chilo suppressalis larva correction death rate, and evaluating the resistance level of the tested rice material. According to the method, resistance determination is carried out by taking seedling-stage rice as an object indoors, rice-stem borer resistance determination can be rapidly and efficiently carried out, the period of rice-stem borer resistance determination in the past is greatly shortened, and manpower and material resources are saved.

Description

Technical Field

[0001] The invention belongs to the technical field of resistance identification, and particularly relates to a method for determining resistance to rice stem borer. Background Art

[0002] As one of the main food crops in my country and many other countries in the world, the high yield and high quality of rice are of great significance to the national economy and food security of my country. The Chilo suppressalis (Walker) belongs to the family of Pyralidae in the order Lepidoptera and is one of the most important rice pests in Asia, North Africa and Southern Europe. The larvae bore into rice by boring, which can cause dead hearts in the seedling and tillering stages, and white ears and shriveled rice in the heading stage, seriously affecting the yield and quality of rice. The Chilo suppressalis occurs widely and causes serious damage in my country. It is a type of crop pest that is difficult to prevent and control, especially in the Yangtze River Basin and rice-growing areas to the south. With the warming of the climate and the changes in the tillage and cultivation system, the Chilo suppressalis habitat continues to expand northward. In recent years, it has also occurred frequently in northern rice-growing areas, causing serious economic losses.

[0003] The main reasons for the continued damage of the Chilo suppressalis and even its outbreak in some local areas in some years include the increasing resistance of the Chilo suppressalis to chemical pesticides, the weak resistance of the main rice varieties to the Chilo suppressalis, climate change, and changes in rice planting and cultivation patterns. Cultivating and mining Chilo suppressalis-resistant rice germplasm resources is the most economical and lasting prevention and control measure, but the Chilo suppressalis-resistant rice resources currently available are still very rare. Therefore, exploring a rapid and simple method for determining the resistance of rice Chilo suppressalis to accelerate the identification of the resistance of existing and newly cultivated rice materials to the Chilo suppressalis is of great significance for the development and utilization of rice Chilo suppressalis-resistant germplasm resources.

[0004] At present, the identification of rice resistance to the Chilo suppressalis is mainly carried out by artificial inoculation indoors and artificial inoculation or natural inoculation in the field. Artificial inoculation or natural inoculation in the field evaluates the resistance of rice to the Chilo suppressalis by investigating and calculating the dead heart index of rice in the tillering stage and the white panicle index in the panicle stage. At the same time, the number of live Chilo suppressalis and pupae is checked. The experimental cycle is long, the human and material resources required are large, the weather and external environmental conditions have a great impact on the experimental results, and each rice variety needs to be planted in an area of ​​more than 10 square meters, which makes it difficult to carry out large-scale identification of a large number of germplasms. Indoor artificial inoculation is carried out at the base of the rice plant in the tillering stage. The base is cut and the ant borer is inserted. After 7 days of inoculation, the rice plant is peeled off to investigate the larval mortality rate, and the resistance of the rice plant is evaluated by the larval corrected mortality rate. It takes a long time to cultivate rice to the tillering stage. During the experiment, the rice nutrient solution needs to be replaced and new rice plants need to be added. Therefore, this method also has the disadvantages of being time-consuming and complicated to operate. Summary of the invention

[0005] The purpose of the present invention is to provide a method for determining resistance to rice stem borer, which can quickly and efficiently determine resistance to rice stem borer by taking rice seedlings as the object indoors, greatly shortening the cycle of previous determination of resistance to rice stem borer and saving manpower and material resources.

[0006] The present invention provides a method for determining resistance to rice stem borer, comprising the following steps:

[0007] (1) Selecting a number of 10- to 14-day-old seedlings of the test rice materials and the insect-susceptible control varieties, respectively wrapping the roots and fixing them in culture containers, inoculating the 2nd-instar larvae of the Chilo suppressalis, sealing the culture containers and culturing them under a low light source; the 2nd-instar larvae of the Chilo suppressalis are weighed before inoculation;

[0008] (2) when the seedling mortality rate of the susceptible control variety is higher than 80%, statistical data is collected, mainly using the rice survival rate to evaluate the resistance of the tested rice material to the striped stem borer;

[0009] Rice survival rate (%) = number of surviving rice seedlings per treatment / total number of rice seedlings per treatment × 100%, formula I;

[0010] Seedling mortality (%) = number of rice seedlings that died in the susceptible control variety / total number of rice seedlings in the susceptible control variety × 100%, formula II.

[0011] Preferably, in step (1), 50 to 70 seedlings of each material are selected for measurement.

[0012] Preferably, the root wrapping and fixing in step (1) comprises wrapping the roots with absorbent cotton soaked in nutrient solution and fixing them in the culture container.

[0013] Preferably, the nutrient solution includes Kimura B nutrient solution.

[0014] Preferably, the sealing in step (1) comprises sealing the culture container with gauze and black cloth.

[0015] Preferably, the culture container in step (1) is made of a transparent material, and the height of the culture container is higher than the height of the rice seedlings.

[0016] Preferably, in step (1), 50 to 70 seedlings are fixed in each of the culture containers, and 10 to 20 second-instar larvae of Chilo suppressalis are inoculated to infest for 7 to 10 days.

[0017] Preferably, the statistical data in step (2) also includes statistical data on the corrected mortality of the Chilo suppressalis and statistical data on the inhibition rate of the weight growth of the Chilo suppressalis by each rice material;

[0018] Inhibition rate of insect weight growth (%) = (1-weight gain of the test group of striped borers / weight gain of the control group of striped borers) × 100%, formula III, wherein the weight gain of the striped borers = the average weight of each head at the end of the experiment - the average weight of each head before the experiment;

[0019] Corrected mortality (%) = (mortality of larvae feeding on the test variety - mortality of larvae feeding on the susceptible control) / (100 - mortality of larvae feeding on the control variety) × 100%, formula IV.

[0020] Preferably, in step (2), when the rice survival rate is greater than 85%, it is a highly resistant variety; when the rice survival rate is less than 70% and is ≤85%, it is a resistant variety; when the rice survival rate is less than 55% and is ≤70%, it is a moderately resistant variety; when the rice survival rate is less than 40% and is ≤55%, it is an insect-resistant variety; when the rice survival rate is less than 20% and is ≤40%, it is an insect-susceptible variety; and when the rice survival rate is less than 20%, it is a highly susceptible variety.

[0021] Preferably, in step (2), when the rice survival rate is greater than 85%, and the insect weight growth inhibition rate is greater than 85% or the corrected mortality rate of the rice stem borer is greater than 85%, the rice is a highly resistant variety;

[0022] When the rice survival rate is 70%<85%, and the insect weight growth inhibition rate is 70%<85% or the corrected mortality rate of Chilo suppressalis is 70%<85%, it is considered an insect-resistant variety.

[0023] When the rice survival rate is 55%<70%, and the insect weight growth inhibition rate is 55%<70% or the corrected mortality rate of the Chilo suppressalis is 55%<70%, it is considered a medium-resistant variety.

[0024] When the rice survival rate is 40%<55%, and the insect weight growth inhibition rate is 40%<55% or the corrected mortality rate of Chilo suppressalis is 40%<55%, it is considered an insect-resistant variety.

[0025] Varieties with a survival rate of 20%<rice≤40%, and a growth inhibition rate of insect weight of 20%<40% or a corrected mortality rate of Chilo suppressalis≤40% are considered susceptible varieties.

[0026] When the rice survival rate is ≤20%, and the insect weight growth inhibition rate is ≤20% or the corrected mortality rate of the rice stem borer is ≤20%, it is a highly susceptible variety.

[0027] Beneficial effects: The present invention discloses a method for indoor determination of resistance of different rice varieties to striped stem borer, which uses rice seedlings to inoculate young striped stem borer larvae for rapid identification, comprising the following steps: after different varieties of rice are cultivated into 10-14 day old seedlings, 50-70 rice seedlings with the same growth are selected, their roots are wrapped with absorbent cotton soaked in nutrient solution and fixed in a transparent culture device; weighed second-instar striped stem borer larvae are inoculated in each culture device, and sealed with gauze and black cloth. When the mortality rate of the susceptible control variety is greater than 80%, the survival rate, striped stem borer weight growth inhibition rate and corrected mortality rate of rice seedlings of each variety are counted. The present invention compares the differences in striped stem borer resistance of different rice varieties through the survival rate of rice seedlings after striped stem borer infestation, and the development and survival of striped stem borers after feeding on rice. Compared with traditional methods, the present invention conducts resistance testing on rice in the seedling stage indoors, which can easily and quickly test the resistance of rice to the striped stem borer, greatly shortening the cycle of previous rice striped stem borer resistance testing, reducing the space required for the experiment, saving manpower and material resources, and facilitating large-scale resistance identification of a large number of rice germplasms. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the operation process; A in the figure: a block of eggs of the Chilo suppressalis that are about to hatch; B: when the Chilo suppressalis eggs are about to hatch, the rice seeds are treated with disinfectant and then germinated; C: when the rice grows to 10-14 days old, the roots are wrapped with absorbent cotton soaked in nutrient solution and fixed to the bottom of the container, at which time the Chilo suppressalis develops to the second age; D: the Chilo suppressalis is weighed and inserted into the rice seedlings in the container, and the container is sealed with two layers of gauze and one layer of black cloth, and cultured under the condition of low light source;

[0029] Figure 2 Rice seedlings after 7 days of feeding; from left to right are TN1, Xiushui 11 and KMD. DETAILED DESCRIPTION

[0030] The present invention provides a method for determining resistance to rice stripe borer, comprising the following steps: (1) selecting a plurality of 10- to 14-day-old seedlings of a test rice material and an insect-susceptible control variety with the same growth, wrapping the seedlings at the root and fixing them in a culture container, inoculating 2nd-instar stripe borer larvae, sealing the culture container and placing the container under a lower light source for culture; the 2nd-instar stripe borer larvae are weighed before inoculation;

[0031] (2) when the seedling mortality rate of the susceptible control variety is higher than 80%, statistical data is collected, mainly using the rice survival rate to evaluate the resistance of the tested rice material to the striped stem borer;

[0032] Rice survival rate (%) = number of surviving rice seedlings per treatment / total number of rice seedlings per treatment × 100%, formula I;

[0033] Seedling mortality (%) = number of rice seedlings that died in the susceptible control variety / total number of rice seedlings in the susceptible control variety × 100%, formula II.

[0034] The present invention has no special limitation on the rice varieties, and preferably includes conventional rice varieties used in production and new rice materials created using genetic engineering technology.

[0035] The rice seedlings of the present invention are preferably obtained by nutrient solution cultivation, specifically including: after the seeds germinate, the seedlings are cultivated with Kimura B rice nutrient solution. When the present invention is carried out, the desired seeds are preferably first disinfected with 30 times diluted 84 disinfectant (disinfectant: water = 1:29) for 30 minutes, which can effectively kill the pathogens carried by the seeds and promote more uniform germination of the seeds; then rinse with water three times to wash away the residual disinfectant, and wrap the container with black plastic cloth to keep it moist, and after the seeds germinate (about two days), add rice nutrient solution for cultivation. The cultivation conditions of the present invention preferably include: placing in a culture room with a temperature of 27±1°C, a humidity of 70%, and a light of 14 hours / day.

[0036] The Kimura B rice nutrient solution of the present invention is purchased from Beijing Coolaibo Technology Co., Ltd., diluted and mixed according to the instructions, and adjusted to pH 5.6 with hydrochloric acid (Sinopharm Chemical Reagent Co., Ltd., purity 36.0-38.0%), and its components include: (NH4)2SO448.2 mg / L, KH2PO424.8 mg / L, KNO318.5 mg / L, K2SO415.9 mg / L, MgSO4·7H2O135.1 mg / L; Ca(NO3)2·4H2O 86.4 mg / L, MnCl2·4H2O 1.81 mg / L, H2MoO4·H2O 0.09 mg / L, H3BO32.86 mg / L, ZnSO4·7H2O0.22 mg / L, CuSO4·5H2O 0.08 mg / L, Na2EDTA7.45 mg / L, FeSO4·7H2O 5.57mg / L and Na2SiO3·9H2O 200mg / L.

[0037] The present invention preferably takes seedlings of 10 to 14 days old for the experiment, and the seedlings are more preferably 12 days old. The present invention preferably takes 50 to 70 seedlings of each variety for the determination, and before the determination, preferably uses cotton wool soaked in Kimura B nutrient solution to wrap the roots and place them in a transparent culture container. The culture container is preferably a transparent plastic cup, the height should be greater than the rice plant, and the size should be suitable for accommodating and fixing the rice plant. The container should be transparent to facilitate the cultivation of rice and rice stem borer and subsequent observation. The size of the plastic cup used in the embodiment of the present invention is 5 cm in diameter and 12 cm in height. In the present invention, the number of rice plants per treatment can be adjusted according to the size of the culture container. If there are too many seedlings, it is easy to mold, and if there are too few, the insects are easy to run away. 50 to 70 plants are suitable.

[0038] The present invention wraps the roots of the rice seedlings with absorbent cotton soaked in nutrient solution and fixes them in a plastic cup, which is beneficial to the survival of the rice plants on the one hand, and can prevent the occurrence of diseases and drowning caused by direct contact of the rice nutrient solution by the striped stem borer on the other hand. The present invention preferably inoculates 10 to 20 2nd-instar larvae of the striped stem borer in each container, and conducts experiments with the 2nd-instar larvae, which can reduce mechanical damage to the insect body caused by the inoculation operation and is beneficial to subsequent observation. After testing, 10 2nd-instar larvae of the striped stem borer cause damage for 7 to 10 days, and the mortality rate of 60 susceptible rice seedlings is 80 to 95%. The actual operation can be adjusted according to this insect-seedling ratio.

[0039] The present invention preferably takes 10 2nd instar larvae of the striped stem borer, weighs them and places them on the rice seedlings in a plastic cup, covers the cup mouth with two layers of gauze and one layer of black cloth, and fixes them with a rubber band, and repeats this process more than 4 times for each rice variety. More preferably, a lower light source is turned on in the culture room to prevent the striped stem borer from escaping, while meeting the needs of plant growth. The lower light source referred to in the present invention means that the lamp is below the culture container, and the upper light source used for most plant and insect culture, that is, the lamp is above the plant or insect feeding device; while the top of the striped stem borer experimental device needs to be covered with a black cloth, and the light cannot be shone from above; but rice growth requires light, so a lower light source is provided; the striped stem borer has a tendency to light, and the lower light source can also reduce the escape of the striped stem borer.

[0040] The present invention preferably takes the survival rate of rice as a necessary condition, and only when one of the insect weight growth inhibition rate or the corrected mortality rate is satisfied at the same time can its resistance level be determined. If the latter two do not meet the requirements of the level, the overall resistance level will be reduced by one level based on the level determined according to the rice survival rate.

[0041] The statistical data of the present invention includes statistics on rice survival rate, corrected mortality rate of Chilo suppressalis and inhibition rate of each rice material on weight growth of Chilo suppressalis;

[0042] Inhibition rate of insect weight growth (%) = (1-weight gain of the test group of striped borers / weight gain of the control group of striped borers) × 100%, formula III, wherein the weight gain of the striped borers = the average weight of each head at the end of the experiment - the average weight of each head before the experiment;

[0043] Corrected mortality (%) = (mortality of larvae feeding on the test variety - mortality of larvae feeding on the susceptible control variety) / (100 - mortality of larvae feeding on the susceptible control variety) × 100%, formula IV.

[0044] Table 1 Identification of resistance level of rice stem borer

[0045]

[0046]

[0047] In order to further illustrate the present invention, a method for determining resistance to rice stem borer provided by the present invention is described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present invention.

[0048] Example 1

[0049] The indica conventional rice varieties Taichung Zaila 1 (TN1), Yangdao 6 (9311) and Kasalath, the japonica conventional rice Xiushui 11 (information on the above four rice varieties can be obtained from the National Rice Data Center) and the rice material KMD (Cry1Ab insect-resistant gene transferred into Xiushui 11, Wu Gang et al., Chinese Agricultural Science, 34(5):465-468, 2001) which is known to be highly resistant to the striped stem borer were used as materials for the determination of striped stem borer resistance.

[0050] 1. Seedling cultivation: Place rice seeds in clean plastic cups, soak them for 30 minutes with 30-fold diluted 84 disinfectant (disinfectant: water = 1:29), pour out and rinse with clean water three times, then cover with black plastic cloth for 48 hours to germinate. After the seeds germinate, remove the black plastic cloth and add Kimura B nutrient solution (the ingredients of the nutrient solution are described above) to maintain the growth of rice seedlings, and cultivate them in a cultivation room with a temperature of 27±1℃, a humidity of 70%, and 14h light / 10h dark. (Cultivating seedlings when the eggs of the stem borer are gray-black can match the seedling age with the insect age)

[0051] 2. Take 12-day-old rice seedlings, wrap their roots with cotton wool soaked in Kimura nutrient solution, and place them in plastic cups, 60 plants per cup, 4 cups per variety, e.g. Figure 1 .

[0052] 3. Inoculation: Artificial inoculation of rice seedlings with Chilo suppressalis was performed. Ten weighed 2nd-instar Chilo suppressalis were placed in each cup. The cup was covered with two layers of gauze and one layer of black cloth and fixed with a rubber band. Figure 1One plastic cup was used as one replicate, and each rice variety was set up with 4 replicates. During the replication, a rubber-tipped dropper was used to add nutrient solution to the absorbent cotton (it is better to moisten the absorbent cotton with the nutrient solution).

[0053] 4. When the mortality rate of seedlings of the susceptible control variety TN1 was greater than 80% (7 days after inoculation), the relative survival rate of rice seedlings of different varieties and the corrected mortality rate of the Chilo suppressalis larvae were counted; the surviving Chilo suppressalis larvae were weighed, and the inhibition rate of Chilo suppressalis weight growth was counted. The rice seedling survival rate was used as the primary indicator, and the inhibition rate of insect weight growth and the corrected mortality rate of Chilo suppressalis larvae were used as auxiliary indicators to determine the resistance level of rice to Chilo suppressalis (Table 1). For example: 9311, the rice survival rate was 52.1%, the corrected mortality rate of Chilo suppressalis was 42.5%, and the resistance level was 5 insect-resistant; Kasalath, the rice survival rate was 41.1%, the inhibition rate of Chilo suppressalis weight growth was 40.9%, and the resistance level was 5 insect-resistant; Xiushui 11, the rice survival rate was 42.9%, but the inhibition rate of insect weight growth and the corrected mortality rate did not meet the requirements of level 5, so its resistance level was 7 insect-susceptible (Table 2).

[0054] Table 2 Resistance levels of different rice varieties to Chilo suppressalis

[0055]

[0056] Example 2

[0057] The resistance of indica conventional rice varieties Taichung Zaila 1 (TN1), Yangdao 6 (9311) and Kasalath was determined in accordance with the Jiangxi Provincial Standard DB36 / T951-2017.

[0058] 1. Seedling cultivation: The rice seeds were surface disinfected with 30-fold diluted 84 disinfectant and then germinated for 48 hours (same as in Example 1). After the seeds germinated, they were sown in the soil for seedling cultivation and cultured in an insect-proof net room under natural light and temperature conditions. The 20-day-old rice seedlings were transplanted into a culture frame (56 cm×42 cm×19 cm, 7 plants / row×4 rows) until the rice grew to the tillering stage.

[0059] 2. Inoculation: Wash 40-day-old rice seedlings and remove excess tillers (retain only the main stem), place in a 30cm high, 3cm diameter glass test tube, add 25ml Kimura nutrient solution, pick 10 newly hatched Chilo suppressalis larvae with a fine brush and inoculate them on the rice stems, seal the tube mouth with absorbent cotton plugs and mark. The experiment was carried out in an artificial climate chamber: 28±1℃, relative humidity: 70%±10%, light: dark 14h:10h.

[0060] 3. Ten days after inoculation, take out the rice in the test tube and place it on absorbent paper. Use your fingers to gently peel off the rice sheaths and stems. Use a brush to pick all the larvae of the striped stem borer in each tube and put them into a clean culture dish. Count the number of surviving larvae of the striped stem borer and calculate the corrected mortality rate of the larvae of the striped stem borer (Formula IV, with TN1 as the control variety) to determine the resistance level of the rice to the striped stem borer.

[0061] The results are shown in Table 3. The mortality rate of newly hatched larvae of Chilo suppressalis after being raised on 9311 rice for 10 days was 54.6%, the corrected mortality rate was 41.4% (%), and the resistance level was 5; for Kasalath, the mortality rate of Chilo suppressalis was 67.2%, the corrected mortality rate was 57.7%, and the resistance level was 5 (Table 3).

[0062] Table 3 Resistance levels of different rice varieties to Chilo suppressalis

[0063]

[0064]

[0065] The results obtained by identifying the resistance level of the three rice materials to the striped stem borer using the Jiangxi Provincial Local Standard DB36 / T951-2017 are consistent with the results obtained by the method of the present invention. Using the method described in DB36 / T951-2017, the rice seedlings need to be cultivated to the tillering stage (about 40 days), inoculated with insects for 7 to 10 days, and the test cycle takes about 50 days. However, the method described in the present invention only takes 17 to 24 days from cultivating rice seedlings to the end of the test, which greatly shortens the test cycle.

[0066] Although the above embodiment describes the present invention in detail, 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 protection scope of the present invention.

Claims

1. A method for determining resistance to rice stem borer, characterized in that: The following steps are involved: (1) Selecting a number of 10- to 14-day-old seedlings of the test rice materials and the insect-susceptible control varieties, respectively wrapping the roots and fixing them in culture containers, inoculating the 2nd-instar larvae of the Chilo suppressalis, sealing the culture containers and culturing them under a low light source; the 2nd-instar larvae of the Chilo suppressalis are weighed before inoculation; (2) when the seedling mortality rate of the susceptible control variety is higher than 80%, statistical data is collected, mainly using the rice survival rate to evaluate the resistance of the tested rice material to the striped stem borer; Rice survival rate (%) = number of surviving rice seedlings per treatment / total number of rice seedlings per treatment × 100%, formula I; Seedling mortality (%) = number of rice seedlings that died in the susceptible control variety / total number of rice seedlings in the susceptible control variety × 100%, formula II.

2. The measuring method according to claim 1, characterized in that: In step (1), 50 to 70 seedlings of each material are selected for measurement.

3. The determination method according to claim 2, characterized in that: The root wrapping and fixing in step (1) includes wrapping the roots with absorbent cotton soaked in nutrient solution and fixing them in the culture container.

4. The determination method according to claim 3, characterized in that: The nutrient solution includes Kimura B nutrient solution.

5. The determination method according to claim 2, characterized in that: The sealing in step (1) includes sealing the culture container with gauze and black cloth.

6. The determination method according to claim 5, characterized in that: The culture container in step (1) is made of transparent material, and the height of the culture container is higher than the height of the rice seedlings.

7. The determination method according to claim 5, characterized in that: Step (1) 50 to 70 seedlings are fixed in each of the culture containers, and 10 to 20 second-instar larvae of Chilo suppressalis are inoculated to infest for 7 to 10 days.

8. The determination method according to claim 1, characterized in that: The statistical data in step (2) also includes statistical data on the corrected mortality of the Chilo suppressalis and statistical data on the inhibition rate of the weight growth of the Chilo suppressalis by each rice material; Inhibition rate of insect weight growth (%) = (1-weight gain of the test group of striped borers / weight gain of the control group of striped borers) × 100%, formula III, wherein the weight gain of the striped borers = the average weight of each head at the end of the experiment - the average weight of each head before the experiment; Corrected mortality (%) = (mortality of larvae feeding on the test variety - mortality of larvae feeding on the susceptible control) / (100 - mortality of larvae feeding on the control variety) × 100%, formula IV.

9. The measuring method according to claim 1, characterized in that: In step (2), when the rice survival rate is greater than 85%, it is a highly resistant variety; when the rice survival rate is less than 70% and is ≤ 85%, it is a resistant variety; when the rice survival rate is less than 55% and is ≤ 70%, it is a moderately resistant variety; when the rice survival rate is less than 40% and is ≤ 55%, it is an insect-resistant variety; when the rice survival rate is less than 20% and is ≤ 40%, it is an insect-susceptible variety; and when the rice survival rate is less than 20%, it is a highly susceptible variety.

10. The determination method according to claim 8, characterized in that: In step (2), if the rice survival rate is greater than 85%, and the insect weight growth inhibition rate is greater than 85% or the corrected mortality rate of the rice stem borer is greater than 85%, the rice is considered to be a highly resistant variety; When the rice survival rate is 70%<85%, and the insect weight growth inhibition rate is 70%<85% or the corrected mortality rate of Chilo suppressalis is 70%<85%, it is considered an insect-resistant variety. When the rice survival rate is 55%<70%, and the insect weight growth inhibition rate is 55%<70% or the corrected mortality rate of the Chilo suppressalis is 55%<70%, it is considered a medium-resistant variety. When the rice survival rate is 40%<55%, and the insect weight growth inhibition rate is 40%<55% or the corrected mortality rate of Chilo suppressalis is 40%<55%, it is considered an insect-resistant variety. Varieties with a survival rate of 20%<rice≤40%, and a growth inhibition rate of insect weight of 20%<40% or a corrected mortality rate of Chilo suppressalis≤40% are considered susceptible varieties. When the rice survival rate is ≤20%, and the insect weight growth inhibition rate is ≤20% or the corrected mortality rate of the rice stem borer is ≤20%, it is a highly susceptible variety.

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