Method for comparing aphid resistance of lily based on aphid life table

Abstract

The invention discloses a method for comparing lily aphid resistance based on an aphid life table, and belongs to the technical field of resistance breeding. According to the method, the influence of different lilies on age differentiation, development, reproduction and survival of the cotton aphid population is monitored by utilizing an age-age bisexual life table, and the aphid resistance between different varieties of lilies is analyzed on the basis. According to the method, the aphid resistance of lilies can be accurately and qualitatively evaluated, resistant varieties and sensitive varieties can be screened, the population number dynamic state can be better estimated, a population trend index model is established, and guidance is provided for formulating a targeted prevention and treatment strategy.

Description

Technical Field

[0001] The invention belongs to the technical field of resistance breeding, and in particular relates to a method for comparing aphid resistance of lilies based on an aphid life table. Background Art

[0002] Lilies, Lilium spp., are world-renowned bulbous flowers, not only ornamental as cut flowers, potted plants, and garden ornamentals, but also edible and medicinal. The cotton aphid, Aphis gossypii, is a major pest of lilies. It not only directly harms lily growth, causing leaf curling and deformation, and in severe cases, plant shrinkage, poor growth, and bud deformities, but is also a primary vector of several viruses, including lily mosaic virus (LMV), lily ringspot virus (LRSV), and lily cluster virus (LRV). Currently, chemical pesticides are the primary means of controlling lily aphids. However, long-term, excessive, and irrational use of chemical pesticides has led to aphids developing significant resistance to various pesticides, including organophosphates, carbamates, and pyrethroids, making aphid control more difficult. This, in turn, leads to numerous problems, including pesticide residues, damage to natural enemies, and ecological pollution. Breeding resistant lily varieties is an effective approach to combating this pest. However, the selection of resistant breeding parents, as well as resistance testing and screening of hybrid offspring, requires the development of accurate methods for identifying aphid resistance. Given this, it is crucial to develop a cost-effective, accurate, and reliable method for identifying lily aphid resistance. Currently, methods for identifying aphid resistance in plants in the field primarily include the aphid index method and fuzzy recognition methods. These methods are significantly affected by natural environmental conditions and require years of continuous observation to improve the accuracy of the results. Artificial inoculation methods for identifying aphid resistance primarily include the aphid population ratio method and probe potential mapping techniques. These methods require observation of the entire plant, which poses challenges for larger plants, such as the large space requirements and high costs. Summary of the Invention

[0003] To address the above-mentioned technical issues, the present invention provides a method for comparing lily aphid resistance based on an aphid life table. This method is simple, practical, low-cost, and provides accurate and reliable results for identifying lily aphid resistance. It achieves the goals of obtaining lily-resistant germplasm, shortening the aphid-resistant lily breeding cycle, and providing a scientific aphid control strategy for lilies, demonstrating both practicality and scientificity.

[0004] The object of the present invention is achieved through the following technical solutions:

[0005] The present invention provides a method for comparing the aphid resistance of lilies based on an aphid life table, comprising the following steps:

[0006] (1) Collection and processing of lily leaves:

[0007] After the lily bulbs were planted for 4 weeks, the newly expanded leaves were collected, and the petioles were wrapped with wet cotton balls and placed in plastic culture dishes. The purpose of this step was to obtain fresh lily leaves while maintaining their freshness and suitable growth environment, providing a good foundation for subsequent aphid inoculation and observation.

[0008] (2) Aphid inoculation and selection:

[0009] The apterous cotton aphid adults were inoculated onto the lily leaves in plastic culture dishes, and after observing the adults laying eggs, the cotton aphid adults and excess newly hatched nymphs were removed from the leaves with a small brush, leaving only one first instar nymph on the leaf for experimental observation. By selecting single first instar nymphs for observation, the accuracy and repeatability of the experiment were ensured, avoiding mutual interference and competition among multiple aphids, thus more accurately reflecting the influence of lily varieties on aphid growth and reproduction.

[0010] (3) Leaf replacement and preservation:

[0011] To maintain leaf freshness, fresh lily leaves were replaced every 2-3 days during the experiment, and the cotton balls wrapped around the petioles were kept moist. Regularly replacing leaves and keeping cotton balls moist was to simulate the growth state of lily leaves in natural environments, providing continuous suitable feeding and growth conditions for aphids, ensuring the reliability of experimental results.

[0012] (4) Control of culture conditions:

[0013] After labeling the culture dishes, they were placed in an indoor climate incubator with the following conditions: light L: D 16h: 8h, temperature (25±1)℃, humidity 60%±10%. L represents light, and D represents darkness. Strict control of culture conditions, including light, temperature, and humidity, was to ensure the stability and consistency of the experimental environment, making the comparison of aphid resistance among different lily varieties more fair and accurate, and reducing environmental factors that interfere with experimental results.

[0014] (5) Observation and recording of aphid growth

[0015] Aphid growth was observed at 8:00 am and 20:00 pm every day, and molting, egg laying, or death was recorded. After recording, the newly hatched nymphs were removed with a small brush, and the survival status of the aphids was checked until all the test aphids died. By regularly observing and recording the survival and reproduction data of aphids of different ages and stages, accurate data for subsequent aphid resistance evaluation were provided. At the same time, timely removal of newly hatched nymphs can avoid their impact on the growth and development of adult aphids, ensuring the accuracy of the experiment.

[0016] (6) Aphid resistance evaluation:

[0017] The TWOSEX software is used to calculate various parameters in the aphid population life table on different lily varieties, such as intrinsic growth rate, week limit growth rate, net propagation rate, average generation cycle and the like. The reproductive rate < 30 is a resistant variety, 30 < reproductive rate < 50 is a susceptible variety, and the reproductive rate > 50 is a highly susceptible variety. The calculation by using the TWOSEX software is an existing and mature calculation method, which can accurately analyze the life table parameters of the aphid population, thereby providing a scientific and quantitative basis for the evaluation of the aphid resistance of lily varieties. By setting a clear reproductive rate threshold to divide the aphid resistance grades of lily varieties, the evaluation result is more intuitive, easy to understand and apply.

[0018] The beneficial effects of the present application are:

[0019] 1. The present application uses the bisexual life table to analyze the population biological characteristics and calculate the life table parameters, which can not only accurately qualitatively evaluate the aphid resistance of lily, but also screen the resistant varieties and susceptible varieties, and better estimate the population quantity dynamics, establish a population trend index model, and provide guidance for formulating targeted control strategies.

[0020] 2. The present application is less affected by environmental and human factors, can accurately evaluate the population growth state of cotton aphids on different lily varieties, and the accuracy and scientificity of the identification result are outstanding. It is simple, low in cost and high in operability, and has outstanding practicability.

[0021] 3. The present application occupies a small space, and uses less plant materials, can continuously identify the aphid resistance of lily varieties and early screening of aphid-resistant lily varieties in large quantities, and shortens the breeding cycle of aphid resistance.

[0022] 4. The comparison of the aphid resistance of lily varieties can accurately calculate the population growth parameters of cotton aphids on different lily varieties, and identify and distinguish the aphid resistance of lily varieties. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a lily plant planting schematic diagram in the present application.

[0024] Figure 2 It is a lily aphid resistance identification schematic diagram in the present application. DETAILED DESCRIPTION

[0025] The present application will be described in detail below in combination with the drawings and examples.

[0026] Example: The present application is a method for comparing the aphid resistance of lily based on aphid life table, which comprises the following steps:

[0027] (1) Collection and treatment of lily leaves:

[0028] Four weeks after the lily bulbs were planted, newly unfolded leaves were collected. Cut them close to the plant stem with a scalpel, and the petioles were wrapped with moist cotton balls and placed in a plastic Petri dish. This step aims to obtain fresh lily leaves while maintaining their freshness and a suitable growth environment, providing a good foundation for subsequent aphid inoculation and observation.

[0029] (2) Aphid inoculation and screening:

[0030] Wingless cotton aphid adults were inoculated onto lily leaves in plastic petri dishes. After the adults were observed to lay pups, the adults and any extra newborn nymphs were removed from the leaves with a small brush, leaving only a single first-instar nymph on the leaf for observation. By selecting a single first-instar nymph for observation, the accuracy and repeatability of the experiment were ensured, interference and competition between multiple aphids were avoided, and the effects of lily varieties on aphid growth, development, and reproduction were more accurately reflected.

[0031] (3) Replacement and preservation of leaves:

[0032] To keep the leaves fresh, fresh lily leaves were replaced every 2 to 3 days during the experiment, and the cotton balls wrapped around the petioles were kept moist. Regularly replacing leaves and keeping the cotton balls moist was intended to simulate the growth conditions of lily leaves in the natural environment, providing aphids with continuous and suitable feeding and growth conditions, and ensuring the reliability of the experimental results.

[0033] (4) Control of culture conditions:

[0034] After labeling the culture dishes, they were placed in an indoor climate incubator under the following conditions: a light intensity ratio of 16 h:8 h, a temperature of (25 ± 1)°C, and a humidity of 60% ± 10% (where L represents light and D represents darkness). Strict control of the culture conditions, including light intensity, temperature, and humidity, ensures the stability and consistency of the experimental environment, making comparisons of aphid resistance among different lily varieties more fair and accurate and reducing the impact of environmental factors on the experimental results.

[0035] (5) Observation and recording of aphid growth

[0036] Observe twice a day, 12 hours apart, for example, at 8:00 a.m. and 8:00 p.m. to observe the growth of aphids and record molting, birthing, or death. After recording, use a small brush to brush away newborn nymphs and check the survival status of aphids until all the test cotton aphids are dead. By regularly observing and recording the growth and development of aphids in detail, you can obtain rich data and provide an accurate basis for subsequent aphid resistance evaluation. At the same time, timely removal of newborn nymphs can avoid their impact on the growth and development of mother aphids, ensuring the accuracy of the experiment.

[0037] (6) Aphid resistance evaluation:

[0038] The TWOSEX software is used to calculate output various life table parameters and statistical results, to obtain the population growth and development and reproduction parameters of cotton aphids on different lily varieties, and the reproduction force < 30 is a resistant variety, 30 < reproduction force < 50 is a susceptible variety, and the reproduction force >= 50 is a high-susceptible variety. Among them, according to the development time and reproduction number of cotton aphids at different ages, the software will calculate and analyze according to the input data, and output various life table parameters and statistical results; the cotton aphid molts once, and the age period is 1 time. The time required for the cotton aphid to grow for 1 year (1 age) on different lily varieties can be determined, and the shorter the time required, the more suitable the lily variety is for the growth of the cotton aphid. The time required for the cotton aphid to grow for 1 year (1 age) on different lily varieties can be determined, and the shorter the time required, the more suitable the lily variety is for the growth of the cotton aphid. The death condition is the death time of the test cotton aphid, and the survival time of the test cotton aphid on the lily is recorded.

[0039] The above method of the application is applied to compare the aphid resistance of 5 lily varieties'red core', 'wood door','sabon', 'talisia' and 'weiyiyanna', and the research results show that the resistance of the 5 varieties to cotton aphids is'red core' >'sabon' > 'talisia' > 'wood door' > 'weiyiyanna', and at the same time, the growth and development of cotton aphids on the 5 lily varieties (table 1) and the population parameters (table 2) are determined, and the reproduction force is used to evaluate the resistance of lily to aphids.

[0040] Table 1 Influence of 5 lily varieties on the growth and reproduction of cotton aphids

[0041]

[0042]

[0043] Note: The table is the average value ± standard error, and the letters after the data in the same row are different, indicating that the difference is significant, and the difference is significant at the level of P < 0.05 by SPSS test, and the letters are the same, indicating that the difference is not significant, and the letters are different, indicating that the difference is significant.

[0044] Table 2 Influence of 5 lily varieties on the population parameters of cotton aphids

[0045]

[0046] Note: The table is the average value ± standard error, and the letters after the data in the same row are different, indicating that the difference is significant, and the difference is significant at the level of P < 0.05 by Paired bootstrap test.

[0047] The parts not described in detail in the application are all existing conventional technologies, and here, no further description is given.

[0048] It can be understood that the above specific description of the present application is only for illustrating the present application and is not limited to the technical solutions described in the embodiments of the present application. Those skilled in the art should understand that the present application can still be modified or replaced equivalently to achieve the same technical effects. As long as the use needs are met, it is within the protection scope of the present application.

Claims

1. A method for comparing the aphid resistance of lilies based on an aphid life table, characterized in that: The following steps are involved: (1) After 4 weeks of planting, collect the newly unfolded young leaves of the lily bulbs. Cut them close to the plant stem with a scalpel. Wrap the petiole with moist cotton balls and place it in a plastic culture dish. (2) Wingless cotton aphid adults were inoculated onto lily leaves in a plastic petri dish and reared until the adults were observed to lay pups. The cotton aphid adults and excess newborn nymphs were then removed from the leaves using a small brush, leaving only one first-instar nymph on the leaf for experimental observation. (3) To keep the leaves fresh, replace the corresponding fresh lily leaves every 2 to 3 days during the experiment, and keep the cotton balls wrapped around the petioles moist; (4) After the culture dishes are labeled, they are placed in an indoor climate incubator under the following conditions: light intensity (L:D) of 16 h:8 h, temperature (25 ± 1) °C, and humidity of 60% ± 10% (L represents light and D represents darkness). (5) Observe the growth of aphids twice a day, with an interval of 12 hours between each observation. Record the molting, birth, or death of cotton aphids. After recording, use a small brush to brush away the newly born nymphs and check the survival status of the test cotton aphids until all the test cotton aphids die. (6) TWOSEX software was used to calculate and output various life table parameters and statistical results, and the growth, development and reproduction parameters of cotton aphid populations were obtained. Reproductivity <30 was a resistant variety, 30≤reproductivity <50 was a susceptible variety, and reproductivity ≥50 was a highly susceptible variety.

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