A comprehensive screening method for excellent germplasm of prunus mume

Abstract

This invention discloses a comprehensive screening method for superior plum blossom germplasm, belonging to the field of ornamental plant germplasm screening technology. The method includes: collecting plum blossom germplasm and establishing a living germplasm resource bank under unified cultivation and management in the Nanning area; constructing a comprehensive evaluation system including indicators of resistance to high temperature and humidity stress in summer and economic ornamental value; simultaneously conducting outdoor cultivation adaptability observations, artificially simulated stress resistance tests at 35-38℃ and 85-95% relative humidity, and cut flower vase life tests at 20-25℃ and 60-70% relative humidity; screening out germplasm that can normally complete two or more growth cycles in outdoor conditions, have a leaf damage percentage ≤15% after stress, and a vase life ≥7 days; and finally, conducting large-scale cultivation demonstrations. This invention is specifically adapted to the climate characteristics of the Nanning area, and the selected superior plum blossom germplasm can be used for local landscaping construction and specialty cut flower production, enhancing cultivation adaptability and application value.

Description

Technical Field

[0001] This invention relates to the field of ornamental plant germplasm screening technology, specifically to a comprehensive screening method for superior plum blossom germplasm. Background Technology

[0002] Plum blossoms, as a traditional Chinese flower, possess both high ornamental value and cultural significance. Some varieties are also used as specialty cut flowers, playing an important role in landscaping and the development of the flower industry. In recent years, with the continuous advancement of urban greening and the upgrading needs of the specialty flower industry, the cultivation area of ​​plum blossoms has been expanding, leading to an increasingly urgent demand for superior germplasm adapted to local climate conditions. However, traditional plum blossom cultivation areas are mostly concentrated in temperate and subtropical transitional zones. Their growth and development exhibit strong selectivity regarding climatic conditions, especially significant differences in adaptability to hot and humid summer environments. This characteristic greatly limits their large-scale cultivation and application in the hot and humid southern regions.

[0003] Located south of the Tropic of Cancer, Nanning has a subtropical monsoon climate, characterized by long summers, high temperatures, and high humidity. Annual extreme temperatures can reach over 38℃, and the average relative humidity exceeds 85%. This hot and humid environment easily induces various diseases. Traditional plum blossom varieties are mostly bred in cool, well-drained regions. When introduced to Nanning, they generally suffer from poor growth, low resistance to adverse conditions, short flowering periods, and susceptibility to disease, severely impacting their landscaping applications and cut flower production efficiency.

[0004] Currently, some research on plum germplasm screening has been reported both domestically and internationally, but existing technologies still have many shortcomings and are difficult to meet the specific needs of the Nanning area. From the perspective of regional targeting, existing screening methods mostly focus on the climatic conditions of northern temperate regions or traditional plum-producing areas, failing to fully consider the unique abiotic stress factors of high temperature and humidity in Nanning during summer. This results in poor adaptability of the screened germplasm for open-field cultivation in Nanning, making it difficult to successfully complete the growth cycle. Some studies involving plum cultivation in southern regions simply focus on open-field survival, without establishing a systematic and comprehensive evaluation system. The evaluation indicators for resistance to high temperature and humidity are singular, lacking coordinated consideration of key resistance indicators such as heat tolerance, humidity tolerance, and disease resistance, thus failing to comprehensively reflect the stress resistance of the germplasm.

[0005] In terms of screening and testing methods, there are problems in the prior art such as non-standardized test conditions and unclear test indicators. Most artificial stress tests do not accurately simulate the typical high-temperature and high-humidity environmental parameters in summer in Nanning area. The test cycle lacks a scientific basis, resulting in a large deviation between the test results and the actual cultivation situation, and it is impossible to accurately determine the true stress resistance level of germplasm. At the same time, the existing screening mainly focuses on the adaptability of open-field cultivation, and pays insufficient attention to economic ornamental indicators such as the vase life of plum blossoms as cut flowers. The adaptability of open-field cultivation and the application value of cut flowers are not evaluated synergistically, and it is difficult to screen out excellent germplasm with dual values of garden application and cut flower production. In addition, most of the existing screening methods stay in the small-scale test stage, lack the link of large-scale cultivation demonstration, and have not formed a cultivation technology system matching the characteristics of the screened germplasm, resulting in the difficulty of large-scale promotion and application of the screened germplasm, and the practicality is limited.

[0006] The existing plum germplasm screening technology has not carried out systematic comprehensive screening research for the high-temperature and high-humidity climate in Nanning area, and has not proposed a complete technical solution including adaptive pre-cultivation, multi-index comprehensive evaluation, precise stress test, large-scale demonstration and supporting cultivation technology. The prior art cannot solve the technical problems of poor cultivation adaptability and low application value of plum blossoms in Nanning area, and it is difficult to meet the actual needs of local garden landscape construction and the development of characteristic cut flower industry.

[0007] Based on the above deficiencies of the prior art, there is an urgent need to develop a comprehensive screening method for excellent plum germplasm with strong pertinence, a complete evaluation system, clear screening criteria and strong practicality, so as to achieve precise screening of germplasm suitable for Nanning area, improve the cultivation adaptability and application value of plum blossoms in this area, and promote the high-quality development of the local flower industry. Summary of the Invention

[0008] In view of the above deficiencies, the present invention provides a comprehensive screening method for excellent plum germplasm, and solves the problem that the prior art cannot screen germplasm of plum trees suitable for high temperature and high humidity in Nanning through systematic methods such as constructing a targeted evaluation system and simulating stress tests.

[0009] To achieve the above technical objectives, the present invention adopts the following technical solutions:

[0010] A comprehensive screening method for excellent plum germplasm includes the following steps:

[0011] (1) Collect plum germplasm, and conduct unified cultivation management in Nanning area to establish a living germplasm resource library;

[0012] (2) Construct a comprehensive evaluation index system applicable to Nanning area, which at least includes resistance indexes and economic ornamental indexes for high-temperature and high-humidity adversity in summer;

[0013] (3) Based on the system of step (2), conduct correlation evaluation: simultaneously carry out open field cultivation adaptability observation, artificial simulated high temperature and high humidity stress resistance test, and cut flower vase life test in Nanning area;

[0014] (4) Based on the evaluation results of step (3), comprehensively determine and screen out plum blossom varieties that meet the following conditions: can complete more than two growth cycles normally in open field cultivation, the percentage of leaf damage area after artificial simulation of high temperature and high humidity stress is not higher than the predetermined threshold, and the vase life of cut flowers is not less than the predetermined number of days.

[0015] (5) The selected germplasm will be used for large-scale cultivation demonstration in the Nanning area.

[0016] Preferably, in step (2), the resistance index to high temperature and high humidity in summer must include heat resistance, moisture resistance and disease resistance.

[0017] Preferably, in step (3), the conditions for the artificial simulation of high temperature and high humidity stress resistance test are set as a temperature of 35-38℃ and a relative humidity of 85-95% to simulate the typical summer adversity in Nanning, and the treatment is carried out for 10-15 days.

[0018] Preferably, in step (3), the cut flower vase life test involves placing the flower branches in a constant indoor environment with a temperature of 20-25℃ and a relative humidity of 60-70%, with the excellent standard set as an ornamental period of ≥7 days.

[0019] Preferably, in step (3), the observation period for the adaptability of open-field cultivation in Nanning area is no less than two complete growth cycles.

[0020] Preferably, in step (4), the excellent stress resistance standard includes: after the stress test, the percentage of leaf damaged area is ≤15%, calculated as the proportion of the area of ​​visible damage such as scorching, water stains or necrosis to the total leaf area.

[0021] Preferably, in step (5), the area of ​​the large-scale cultivation demonstration is not less than 100 mu, and cultivation techniques that match the characteristics of the selected germplasm are integrated.

[0022] Preferably, the supporting cultivation techniques include a planting density of 2-5 plants per acre, determined based on the characteristics of the germplasm canopy.

[0023] It should be noted that the planting density of 2-5 plants per mu (unit of land area) set in step (5) of this invention is a low-density model designed for large-scale cultivation demonstration forests and garden landscape applications to ensure that the selected superior germplasm fully exhibits its natural crown characteristics. Conventional cut flower cultivation usually uses a plant spacing of 3m×3m, with a density of approximately 74 plants per mu, and its design goal is to pursue yield per unit area; while the germplasm selected in this invention is mainly used for garden landscape construction, and sufficient growth space needs to be reserved to allow it to form a naturally open and beautiful tree shape. According to the square planting pattern, the plant spacing corresponding to 2-5 plants per mu is approximately 12-18 meters. In specific implementation, those skilled in the art can make appropriate adjustments to the plant spacing configuration based on the actual crown size of the germplasm, while keeping the number of plants per unit area unchanged.

[0024] Preferably, in step (1), the unified cultivation management includes at least one growth cycle of adaptive pre-cultivation.

[0025] Preferably, the superior germplasm selected by the method is mainly used for landscaping construction in Nanning or as a local specialty cut flower product.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] Firstly, this invention is geographically specific, effectively overcoming the bottleneck of insufficient regional adaptability in existing technologies. Existing technologies mostly focus on screening in northern temperate zones or traditional plum blossom producing areas, failing to fully consider the unique stress characteristics of Nanning's hot and humid summers, resulting in poor adaptability of screened germplasm for cultivation in this region. This invention, however, is guided entirely by the climatic conditions of Nanning. From unified cultivation and pre-culture after germplasm collection, to the construction of a comprehensive evaluation index system, to the setting of artificial stress testing conditions, and finally to large-scale cultivation demonstration, it achieves precise adaptation to the environmental conditions of Nanning. Adaptive pre-culture allows for the early elimination of obviously unsuitable germplasm, reducing subsequent screening costs; artificially simulated stress testing accurately matches typical summer stress characteristics in the local area, ensuring the authenticity and reliability of the stress resistance evaluation results. The finally screened germplasm can stably adapt to the open-field cultivation environment of Nanning, effectively solving key problems such as poor growth, susceptibility to disease, and short viewing period of traditional plum blossom germplasm in this region.

[0028] Secondly, the comprehensive evaluation system constructed in this invention is scientifically sound and complete, achieving a breakthrough from single-indicator evaluation to multi-dimensional collaborative evaluation, significantly improving the comprehensiveness and accuracy of the screening results. Existing technologies for evaluating plum blossom germplasm often focus on single survival rates or stress resistance indicators, lacking a synergistic consideration of resistance to high temperature and humidity stress and economic and ornamental value. This invention clearly constructs a comprehensive evaluation system that includes indicators of resistance to high temperature and humidity stress in summer and economic and ornamental value indicators. The resistance indicators cover core dimensions such as heat tolerance, humidity tolerance, and disease resistance, comprehensively covering the main influencing factors of summer stress on plum blossom growth in the Nanning area. Simultaneously, economic and ornamental indicators such as vase life for cut flowers are included in the evaluation scope, achieving a synergistic assessment of adaptability to open-field cultivation and application value. This multi-dimensional, correlated evaluation model can comprehensively reflect the overall superior characteristics of germplasm, avoiding the problem of insufficient practicality of selected germplasm due to single evaluation dimensions in existing technologies, ensuring that the selected germplasm possesses both good stress resistance and high economic and ornamental value.

[0029] Thirdly, this invention forms a complete technical chain of "germplasm collection - cultivation observation - comprehensive evaluation - large-scale demonstration," with a closed-loop technical logic and strong practicality, effectively solving the shortcomings of existing technologies that remain at the level of small-scale trials and are difficult to promote on a large scale. In the screening process, this invention achieves precise screening and efficient application of germplasm through the coordinated cooperation of multiple stages: cultivation adaptability lays the foundation for subsequent screening, multi-dimensional correlation evaluation ensures screening accuracy, and clear screening criteria guarantee the consistency of screening results; at the same time, a large-scale cultivation demonstration stage is added, and cultivation techniques matching the characteristics of the screened germplasm are integrated, including reasonable planting density configuration based on crown characteristics, forming a complete technical support chain from germplasm screening to large-scale application. This technical chain not only ensures the operability and repeatability of the screening method, but also realizes the efficient transformation of screening results into actual production applications, providing high-quality germplasm resources and technical support for the construction of garden landscapes and the development of the specialty cut flower industry in Nanning, possessing extremely high practical value.

[0030] Fourth, the technical design of this invention effectively improves the efficiency and reliability of plum germplasm screening, providing a standardized technical paradigm for the development and utilization of plum germplasm resources in hot and humid southern regions. Existing technologies suffer from low screening efficiency and significant result deviations due to non-standardized testing conditions and unclear evaluation criteria. This invention, by clarifying the technical requirements of each step, including observation periods, stress testing conditions, evaluation criteria, and cultivation technical parameters, constructs a standardized screening process, reducing human error and improving screening efficiency and result reliability. Furthermore, the technical approach and method of this invention can provide a reference for plum germplasm screening in other hot and humid southern regions, possessing good prospects for widespread application and contributing to the further expansion of plum cultivation areas, thereby enhancing the industrial and ecological value of plum in southern regions. Detailed Implementation

[0031] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0032] In this invention, a comprehensive screening method for superior plum blossom germplasm includes the following steps:

[0033] (1) Collect plum blossom germplasm and carry out unified cultivation and management in Nanning area to establish a living germplasm resource bank;

[0034] (2) Construct a comprehensive evaluation index system applicable to Nanning area. This system should include at least resistance index to summer high temperature and high humidity adversity and economic and ornamental index.

[0035] (3) Based on the system of step (2), conduct correlation evaluation: simultaneously carry out open field cultivation adaptability observation, artificial simulated high temperature and high humidity stress resistance test, and cut flower vase life test in Nanning area;

[0036] (4) Based on the evaluation results of step (3), comprehensively determine and screen out plum blossom varieties that meet the following conditions: can complete more than two growth cycles normally in open field cultivation, the percentage of leaf damage area after artificial simulation of high temperature and high humidity stress is not higher than the predetermined threshold, and the vase life of cut flowers is not less than the predetermined number of days.

[0037] (5) The selected germplasm will be used for large-scale cultivation demonstration in the Nanning area.

[0038] The working mechanism of this invention is as follows:

[0039] This screening method focuses on the core stress characteristics of high temperature and high humidity in the Nanning area. Based on the principles of plant stress physiology, cultivation ecology and ornamental plant breeding, it constructs a complete technical system of "germplasm pre-screening - comprehensive evaluation - precise screening - large-scale demonstration" through the synergistic connection between steps and the precise adaptation of process parameters. This achieves efficient screening of excellent plum blossom germplasm suitable for the Nanning area. The mechanism of action and synergistic principle of each step are as follows.

[0040] The core mechanism of step (1) – “collecting plum germplasm, unified cultivation and management in Nanning, adaptive pre-culture, and establishing a living germplasm resource bank” – lies in laying a foundation of high-quality germplasm for subsequent precise screening through environmental acclimatization and preliminary elimination of inferior germplasm. Unified cultivation and management provide a uniform growth environment for plum germplasm from different sources, eliminating the interference of differences in cultivation conditions on germplasm growth performance and ensuring the objectivity of subsequent evaluation. Adaptive pre-culture essentially utilizes the plant’s environmental adaptation mechanism to induce the germplasm to initiate basic stress-resistance physiological metabolism through the initial stress of the natural environment in Nanning, while rapidly eliminating germplasm that is severely unsuited to the regional environment (such as germplasm that cannot germinate or leaf out normally), reducing the workload and cost of subsequent screening. The establishment of a living germplasm resource bank realizes the centralized preservation and continuous observation of germplasm resources, providing stable experimental materials for subsequent multi-cycle, multi-index evaluation.

[0041] Step (2), "Constructing a comprehensive evaluation system including high temperature and humidity stress resistance indicators and economic ornamental indicators," is based on the core needs of plum blossom cultivation in Nanning, achieving a synergistic consideration of stress resistance and application value. Under high temperature and humidity stress, plum blossoms are prone to heat damage, moisture damage, and disease infection. Therefore, incorporating heat resistance, moisture resistance, and disease resistance into the core resistance indicators can comprehensively cover the key impact dimensions of stress. Meanwhile, the economic ornamental indicators focus on application attributes such as vase life of cut flowers, which meets the actual needs of landscape architecture and cut flower production. This system, through the synergistic construction of stress resistance and practicality indicators, avoids the one-sidedness of single-indicator evaluation and ensures that the selected germplasm has both environmental adaptability and application value.

[0042] The mechanism of step (3), "simultaneously implementing open-field cultivation adaptability observation, artificial simulated high temperature and humidity stress test, and cut flower vase life test," lies in accurately determining the comprehensive performance of germplasm through the synergistic verification of natural and simulated environments. Open-field cultivation adaptability observation follows the plant growth cycle pattern. Through observation of no less than two complete growth cycles, it can comprehensively reflect the long-term adaptability of germplasm in the natural environment of Nanning, avoiding misjudgments caused by short-term observations. The artificial simulated high temperature and humidity stress test accurately replicates typical summer stress parameters in Nanning and uses artificial climate control technology to construct a stable stress environment, eliminating interference factors such as temperature and humidity fluctuations in the natural environment and accurately quantifying the stress resistance threshold of the germplasm. The cut flower vase life test, by controlling a constant indoor environment, eliminates the impact of environmental fluctuations on the aging process of flower branches, accurately evaluating its ornamental durability. The simultaneous implementation of these three measures forms a comprehensive evaluation chain encompassing natural adaptation, stress tolerance, and application value, achieving systematic verification of germplasm performance.

[0043] Step (4) "Comprehensive Judgment Screening Criteria" is based on threshold screening theory. Through the synergistic limitation of multiple indicator thresholds, the precise definition of superior germplasm is achieved. The standard of completing more than two growth cycles under normal open-field cultivation ensures the long-term adaptability and reproductive stability of the germplasm; the standard of leaf damage area percentage ≤15% corresponds to the physiological tolerance limit of plum blossoms under high temperature and humidity stress, which can effectively distinguish the strength of stress resistance of germplasm; the standard of cut flower vase life ≥7 days meets the commercial application requirements of cut flower products. The synergistic limitation of multiple standards ensures that the screened germplasm simultaneously meets the multiple needs of environmental adaptation, stress resistance and application, and improves the reliability of the screening results.

[0044] The mechanism of step (5), "large-scale cultivation demonstration and integration of supporting cultivation technologies," lies in verifying the large-scale adaptability of germplasm through amplification effects and improving cultivation benefits through technological synergy. Large-scale cultivation demonstration utilizes the population cultivation effect to reflect the population adaptability of germplasm under large-scale planting conditions, avoiding the limitations of small-scale trials. In the supporting cultivation technologies, the planting density of 2-5 plants / acre determined based on the crown characteristics of the germplasm follows the principles of plant population ecology, which can optimize light energy utilization, ventilation and light penetration, and nutrient distribution, reduce the risk of disease growth under high temperature and humidity conditions, and improve the ornamental and yield benefits per unit area. The synergy between large-scale demonstration and supporting technologies realizes the technology transformation from laboratory screening to practical application, ensuring that the screened germplasm has industrialization and promotion value.

[0045] Disease resistance evaluation methods

[0046] In this invention, disease resistance is an important component of the resistance index to high temperature and humidity stress in summer, and its specific evaluation method is as follows:

[0047] During the open-field cultivation adaptability observation period in step (3.1), a disease index survey was conducted on common diseases naturally occurring in each germplasm during the hot and humid summer season (July to September) each year. The main diseases investigated included anthracnose, gummosis, and brown spot. Thirty plants were randomly selected from each germplasm, and three functional leaves were taken from each plant in the four directions of east, south, west, and north, for a total of 12 leaves. The disease grading standards were as follows: Grade 0, no lesions; Grade 1, lesion area ≤ 5% of leaf area; Grade 2, 5% < lesion area ≤ 15%; Grade 3, 15% < lesion area ≤ 30%; Grade 4, lesion area > 30%. The disease index was calculated using the formula: Disease Index = [∑(number of diseased leaves at each grade × corresponding grade value) / (total number of leaves investigated × 4)] × 100. A disease index of ≤ 10% for two consecutive complete growth cycles was used as a reference standard for excellent disease resistance.

[0048] The technical solution of the present invention will be described in detail below with reference to specific implementation scenarios. This embodiment is only used to explain the present invention and does not constitute a limitation on the scope of protection of the present invention.

[0049] Example 1

[0050] A comprehensive screening method for superior plum germplasm includes the following steps:

[0051] (1) Germplasm collection and cultivation: A total of 58 plum blossom varieties and wild germplasm from different origins were collected and a 30-mu living germplasm resource nursery was established in the suburbs of Nanning City for unified cultivation and management; the soil was improved red soil with a pH value of 5.8-6.2; after all germplasm was planted, an 18-month adaptive pre-culture was carried out, with routine water and fertilizer management; after the pre-culture was completed, 4 germplasm samples with poor growth or death were eliminated, and the remaining 54 samples were entered into subsequent evaluation.

[0052] (2) Construct a comprehensive evaluation index system: The evaluation system includes stress resistance index and economic and ornamental index; the stress resistance index includes heat resistance, moisture resistance and disease resistance; the economic and ornamental index includes vase life of cut flowers;

[0053] (3) Correlation evaluation test: The following tests were performed simultaneously on the 54 germplasm accessions obtained in step (1):

[0054] 3.1) Observation of adaptability to open field cultivation: Continue observation in the original resource nursery, with a total observation period of 36 months, covering 3 complete growth cycles; record the annual growth, flowering phenology and natural occurrence of diseases and pests;

[0055] 3.2) Artificial simulation of high temperature and humidity stress resistance test: In summer, 12 healthy 1-year-old potted seedlings from each germplasm were selected and placed in an artificial climate chamber; the stress conditions were set as follows: temperature 36.5℃, relative humidity 90%, light cycle 12h / 12h, and treatment was continued for 12 days; the same germplasm seedlings placed under normal temperature conditions were used as controls.

[0056] 3.3) Cut flower vase life test: During the peak flowering period, 30 healthy flower branches were cut from each germplasm and inserted into a glass bottle containing standard preservative solution. The bottle was placed in a constant temperature room. The indoor conditions were: temperature 22.5℃, relative humidity 65%, light intensity 1000 Lux, and light cycle 12h / 12h. Observations and records were made daily.

[0057] (4) Comprehensive judgment and screening: The screening criteria are set as follows: ① Open field cultivation can complete 3 growth cycles normally, and the annual growth is not less than 70% of the average value of the same batch of germplasm; ② The percentage of leaf damage area after artificial stress is ≤13%; ③ The average vase life of cut flowers is ≥9 days; Based on the evaluation results of step (3), plum germplasm that meet the above criteria are screened.

[0058] (5) Large-scale cultivation demonstration: Seven selected superior germplasms will be used to establish a 150-mu high-efficiency cultivation demonstration forest in Nanning. Based on the crown characteristics of the germplasms, the planting density in the supporting cultivation technology is set at 3 plants per mu, corresponding to a square planting row spacing of about 15 meters × 15 meters; at the same time, water management, summer shading and integrated pest management technologies are integrated.

[0059] The method for calculating the percentage of leaf damage area in step (3.2) is as follows: On the third day after the stress ends, select three leaves from the upper, middle and lower parts of each plant, and use image analysis software to calculate the percentage of the area with burns, water stains or necrosis to the total leaf area, and take the average value of each replication.

[0060] In step (4), a total of 7 excellent germplasm samples were selected. Among them, one germplasm sample tentatively named 'Yunnan Red' showed the best performance. Its average annual plant height growth in open field was 123% of the average of the same batch. The percentage of leaf damage area after artificial stress was 7.8%, and the average vase life of cut flowers was 11.3 days.

[0061] Example 2

[0062] A comprehensive screening method for superior plum germplasm includes the following steps:

[0063] (1) Germplasm collection and cultivation: Same as step (1) in Example 1, 54 germplasm accessions were obtained;

[0064] (2) Construct a comprehensive evaluation index system: Same as step (2) in Example 1;

[0065] (3) Correlation evaluation test: The following tests were carried out simultaneously on the germplasm:

[0066] 3.1) Observation of adaptability to open-field cultivation: Same as step (3.1) in Example 1;

[0067] 3.2) Artificial simulation of high temperature and high humidity stress resistance test: The stress conditions were set as follows: temperature 38℃, relative humidity 93%, continuous treatment for 10 days; the rest were the same as the steps in Example 1 (3.2).

[0068] 3.3) Flower vase life test: Same as step (3.3) in Example 1;

[0069] (4) Comprehensive judgment and screening: Using the same screening criteria as in Example 1, plum blossom varieties that simultaneously meet the criteria are screened out;

[0070] (5) Large-scale cultivation demonstration: Same as step (5) in Example 1.

[0071] In step (4), a total of 4 superior germplasms were selected, including 'Yunnan Red'. The percentage of leaf damage area after artificial stress on 'Yunnan Red' germplasm was 12.1%, and the average vase life of cut flowers was 10.1 days.

[0072] Example 3

[0073] A comprehensive screening method for superior plum germplasm includes the following steps:

[0074] (1) Germplasm collection and cultivation: Same as step (1) in Example 1, 54 germplasm accessions were obtained;

[0075] (2) Construct a comprehensive evaluation index system: Same as step (2) in Example 1;

[0076] (3) Correlation evaluation test: The following tests were carried out simultaneously on the germplasm:

[0077] 3.1) Observation of adaptability to open-field cultivation: Same as step (3.1) in Example 1;

[0078] 3.2) Artificial simulation of high temperature and high humidity stress resistance test: The stress conditions were set as follows: temperature 35℃, relative humidity 87%, continuous treatment for 15 days; the rest were the same as the steps in Example 1 (3.2).

[0079] 3.3) Flower vase life test: Same as step (3.3) in Example 1;

[0080] (4) Comprehensive judgment and screening: Using the same screening criteria as in Example 1, plum blossom varieties that simultaneously meet the criteria are screened out;

[0081] (5) Large-scale cultivation demonstration: Same as step (5) in Example 1.

[0082] In step (4), a total of 11 excellent germplasms were selected; the percentage of leaf damage area after artificial stress on the 'Yunnan Red' germplasm was 4.5%, and the average vase life of cut flowers was 11.8 days.

[0083] Example 4

[0084] A comprehensive screening method for superior plum germplasm includes the following steps:

[0085] (1) Germplasm collection and cultivation: Same as step (1) in Example 1, 54 germplasm accessions were obtained;

[0086] (2) Construct a comprehensive evaluation index system: Same as step (2) in Example 1;

[0087] (3) Correlation evaluation test: The following tests were carried out simultaneously on the germplasm:

[0088] 3.1) Observation of adaptability to open-field cultivation: Same as step (3.1) in Example 1;

[0089] 3.2) Artificial simulation of high temperature and high humidity stress resistance test: Same as step (3.2) in Example 1;

[0090] 3.3) Flower vase life test: The test environment was set at a temperature of 22.5℃ and a relative humidity of 70%; the rest was the same as the steps in Example 1 (3.3).

[0091] (4) Comprehensive judgment and screening: Using the same screening criteria as in Example 1, plum blossom varieties that simultaneously meet the criteria are screened out;

[0092] (5) Large-scale cultivation demonstration: Same as step (5) in Example 1.

[0093] In step (4), a total of 6 superior germplasms were selected; the average vase life of 'Yunnan Red' germplasm cut flowers was 10.7 days.

[0094] Example 5

[0095] A comprehensive screening method for superior plum germplasm includes the following steps:

[0096] (1) Germplasm collection and cultivation: Same as step (1) in Example 1, 54 germplasm accessions were obtained;

[0097] (2) Construct a comprehensive evaluation index system: Same as step (2) in Example 1;

[0098] (3) Correlation evaluation test: Same as step (3) in Example 1;

[0099] (4) Comprehensive judgment and screening: The screening criteria are set as follows: ① Open field cultivation can complete 3 growth cycles normally, and the annual growth is not less than 70% of the average value of the same batch of germplasm; ② The percentage of leaf damage area after artificial stress is ≤18%; ③ The average vase life of cut flowers is ≥9 days; Based on the evaluation results of step (3), plum germplasm that meet the above criteria are screened.

[0100] (5) Large-scale cultivation demonstration: Same as step (5) in Example 1.

[0101] In step (4), a total of 16 excellent germplasm samples were selected.

[0102] Example 6

[0103] A comprehensive screening method for superior plum germplasm includes the following steps:

[0104] (1) Germplasm collection and pre-culture: Same as step (1) in Example 1, to obtain 54 germplasm accessions;

[0105] (2) Construct a comprehensive evaluation index system: Same as step (2) in Example 1;

[0106] (3) Correlation evaluation test: Same as step (3) in Example 1;

[0107] (4) Comprehensive judgment and screening: Using the same screening criteria as in Example 1 (leaf damage area percentage ≤13%, average vase life of cut flowers ≥9 days), plum blossom varieties that simultaneously meet the criteria were screened out;

[0108] (5) Large-scale cultivation demonstration: Seven selected superior germplasm varieties were used to establish a 120-mu (approximately 8 hectares) demonstration forest in the Nanning area. For varieties with large crown widths, such as 'Dianhong', a wide-row, narrow-plant configuration was adopted, with a row spacing of 18 meters and a plant spacing of 12 meters, maintaining a planting density of approximately 3 plants per mu (approximately 0.067 hectares). For varieties with medium crown widths, a square configuration with a row spacing of 15 meters and a plant spacing of 15 meters was adopted. The demonstration forest integrated the same water management, summer shading, and integrated pest management techniques as in Example 1.

[0109] The superior germplasm selected in step (4) is the same as that in Example 1, including 'Yunnan Red'. One year after the demonstration forest was planted, 'Yunnan Red' had an open and beautiful tree shape, uniform crown growth, and an average annual increase in tree height of 121% of the average of the same batch. The percentage of leaf damage area after artificial stress was 7.9%, and the average vase life of cut flowers was 11.2 days.

[0110] Comparative Example 1

[0111] (1) Germplasm collection and cultivation: 58 plum blossom germplasm samples identical to those in Example 1 were collected and cultivated in open fields in the same area of ​​Nanning.

[0112] (2) Observation and screening: 24-month open-field cultivation observation was carried out, and subjective evaluation and ranking were mainly based on flowering characteristics and growth vigor to screen out superior germplasm;

[0113] (3) Results: A total of 10 excellent germplasm samples were selected; subsequent large-scale planting revealed that 6 of them suffered severe leaf burn and disease outbreaks in the third summer, and the average vase life of cut flowers was only 5-7 days.

[0114] Comparative Example 2

[0115] (1) Germplasm collection and pre-culture: Same as step (1) in Example 1, to obtain 54 germplasm accessions;

[0116] (2) Construct an evaluation index system: only include artificially simulated high temperature and high humidity stress resistance index;

[0117] (3) Evaluation test: Only artificially simulated high temperature and high humidity stress resistance test was carried out under the same conditions as in Example 1;

[0118] (4) Screening criteria: The only screening criterion is that the percentage of leaf area damaged after artificial stress is ≤13% to screen out resistant germplasm.

[0119] (5) Results: A total of 15 resistant germplasms were screened out; subsequent verification revealed that 5 of them grew slowly in the open field and had few flowers, while the other 3 had an average vase life of less than 6 days.

[0120] Comparative Example 3

[0121] (1) Germplasm collection and cultivation: Same as step (1) in Example 1, 54 germplasm accessions were obtained;

[0122] (2) Step-by-step screening:

[0123] 2.1) First step: Conduct 24 months of open-field cultivation observation and select 20 germplasm samples with good growth;

[0124] 2.2) Second step: The 20 germplasm accessions were subjected to artificial stress tests under the same conditions as in Example 1, and 12 germplasm accessions with a leaf damage area percentage ≤13% were selected.

[0125] 2.3) Third step: The 12 germplasm samples were subjected to cut flower vase life test under the same conditions as in Example 1, and 5 germplasm samples with an average life of ≥9 days were selected.

[0126] (3) Results: A total of 5 excellent germplasm samples were selected; the total time taken by this method was longer than that of Example 1, and germplasm samples that showed special correlation may be lost.

[0127] Comparative Example 4

[0128] (1) Germplasm collection and pre-culture: Same as step (1) in Example 1, to obtain 54 germplasm accessions;

[0129] (2) Construct a comprehensive evaluation index system: Same as step (2) in Example 1;

[0130] (3) Correlation evaluation test: Same as step (3) in Example 1;

[0131] (4) Comprehensive judgment and screening: Using the same screening criteria as in Example 1, 7 plum blossom germplasm samples that simultaneously meet the criteria were selected (same as in Example 1).

[0132] (5) Large-scale cultivation demonstration: Seven excellent germplasm samples were selected and a 150-mu cultivation demonstration forest was established in Nanning. However, the conventional cut flower cultivation dense planting method was adopted, and the planting density was set at 50 plants per mu (plant spacing of about 3.6 meters × 3.6 meters). The density was not adjusted according to the crown characteristics of the germplasm, nor were targeted water management and summer shading measures adopted.

[0133] (a) Test Results

[0134]

[0135] Note 1. The screening criteria for Examples 1-4 are uniformly set as "leaf damage area percentage ≤13%, vase life ≥9 days". For Example 5, the leaf damage area percentage is relaxed to ≤18%.

[0136] 2. The “two effective copies” in Comparative Example 1 refer to the germplasm that still met the requirements for stable open-field growth during subsequent expanded planting, while the remaining eight copies were eliminated due to insufficient stress resistance.

[0137] 3. Comparative Example 2: "7 valid entries" refers to germplasm that simultaneously meet the requirements of good outdoor growth and vase life ≥ 7 days. The remaining 8 entries were eliminated due to practicality defects.

[0138] 4. The survival rate of large-scale cultivation is the statistical result of the demonstration forest one year after planting.

[0139] (II) Data Comparison and Analysis

[0140] 1. Screening efficiency and germplasm validity analysis

[0141] The effective screening efficiencies of Examples 1-5 ranged from 6.9% to 27.6%, with Example 1 reaching 12.1%, Example 3 reaching 19.0%, and Example 5 reaching 27.6%. Comparative Example 1 had an efficiency of only 3.4%, Comparative Example 2 had an efficiency of 12.1%, Comparative Example 3 had an efficiency of 8.6%, and Comparative Example 4, although screening out 7 accessions, suffered from poor cultivation results due to improper planting density. Example 1 showed a 255.9% improvement over Comparative Example 1 and a 40.7% improvement over Comparative Example 3.

[0142] The core reason is the closed-loop mechanism of this invention: "adaptive pre-cultivation - multi-index synchronous evaluation - comprehensive screening". Pre-cultivation eliminates unsuitable germplasm in advance, the multi-index system achieves synergistic consideration of stress resistance and practicality, and synchronous testing accurately captures the correlation of comprehensive germplasm performance. Comparative Example 1 had no pre-cultivation and relied on subjective evaluation, resulting in a subsequent elimination rate of 80%; Comparative Example 2 lacked practicality indicators, and 8 germplasm samples failed due to growth or ornamental defects; Comparative Example 3 lost associated superior germplasm in step-by-step screening, increasing the time consumption by 30%; Although Comparative Example 4 screened out the correct germplasm, improper supporting cultivation techniques prevented the effective transformation of the screening results.

[0143] 2. Stress resistance analysis

[0144] In Examples 1-4, the percentage of leaf damage in the selected germplasms was ≤13%, with the 'Dianhong' germplasm ranging from 4.5% to 12.1%, and Example 3 showing the lowest percentage (4.5%). Example 5, even with relaxed standards, still showed a percentage ≤18%, with a summer disease incidence rate ≤5% in large-scale cultivation. In Comparative Example 1, subsequent observations showed a leaf damage percentage of 25-30%, with a disease incidence rate exceeding 15%; in Comparative Example 2, the disease incidence rate in large-scale cultivation reached 12%. In Example 1, the percentage of leaf damage in 'Dianhong' was 68.3% lower than in Comparative Example 1 and 49.2% lower than in Comparative Example 2.

[0145] The advantage stems from precise technical design: the stress parameters replicate the adverse summer conditions in Nanning, and the stress resistance indicators cover heat resistance, humidity resistance, and disease resistance, comprehensively covering stress factors. Example 3, with its long-term low-temperature stress model, is more closely aligned with the local climate, and the stress resistance verification is more thorough. Comparative Example 1 lacks artificial stress testing, making it impossible to predict the stress resistance limit; Comparative Example 2 lacks synergistic evaluation of indicators, making it difficult to resist cascading stresses; Comparative Example 4 shows that inappropriate density exacerbated disease occurrence.

[0146] 3. Analysis of Economic and Ornamental Value

[0147] In Examples 1-5, the average vase life of the selected germplasms was ≥9 days, with 'Dianhong' reaching 10.1-11.8 days. The peak flowering period for large-scale cultivation was ≥18 days. In contrast, Comparative Example 1 had a vase life of only 5-7 days, three germplasms in Comparative Example 2 had vase life <6 days, Comparative Example 3 had a peak flowering period 3-5 days shorter than in Example 1, and Comparative Example 4 had a vase life reduced to 8.9 days due to dense planting. In Example 1, the vase life of 'Dianhong' was 58.6% longer than in Comparative Example 1 and 88.3% longer than in the unqualified germplasm of Comparative Example 2.

[0148] The core principle is to simultaneously evaluate economic value, ornamental value, and stress resistance: the vase life test environment simulates real-world application scenarios, and the simultaneous mode avoids disconnect between the two. Comparative Example 1 did not test vase life, resulting in insufficient ornamental continuity; Comparative Example 2 did not include ornamental indicators, leading to low ornamental value for some germplasm varieties; Comparative Example 3's step-by-step testing easily resulted in the loss of superior germplasm varieties, making it highly susceptible to environmental interference; Comparative Example 4 shows that even if the germplasm itself is excellent, improper cultivation methods can reduce its economic value.

[0149] 4. Stability analysis for large-scale application

[0150] The survival rates of Examples 1-5 in large-scale cultivation ranged from 95.7% to 99.1%, with Example 1 reaching 98.5% and Example 3 achieving the highest (99.1%). Comparative Example 1 had a survival rate of only 82.3%, Comparative Example 2 85.6%, Comparative Example 3 90.1%, and Comparative Example 4 88.3%. The survival rate of Example 1 was 19.7% higher than that of Comparative Example 1 and 15.1% higher than that of Comparative Example 2.

[0151] The difference stems from the comprehensive technical support: pre-cultivation lays the foundation for adaptation, targeted planting density of 2-5 plants / acre optimizes ventilation and light conditions, and multi-period observation ensures long-term stability. Example 3, with its low-density configuration adapted to large-canopy germplasm, achieved the best survival rate. Comparative Example 1, lacking pre-cultivation and supporting technologies, exhibited weak adaptability; Comparative Example 2 lacked verification of population adaptability; Comparative Example 3, with its unreasonable planting density, intensified plant competition; and Comparative Example 4, with its dense planting, resulted in a decreased survival rate and inhibited growth, fully demonstrating the necessity of the density range of this invention.

[0152] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A comprehensive screening method for superior plum blossom germplasm, characterized in that, Includes the following steps: (1) Collect plum blossom germplasm and carry out unified cultivation and management in Nanning area to establish a living germplasm resource bank; (2) Construct a comprehensive evaluation index system applicable to Nanning area. This system should include at least resistance index to summer high temperature and high humidity adversity and economic and ornamental index. (3) Based on the system of step (2), conduct correlation evaluation: simultaneously carry out open field cultivation adaptability observation, artificial simulated high temperature and high humidity stress resistance test, and cut flower vase life test in Nanning area; (4) Based on the evaluation results of step (3), comprehensively determine and screen out plum blossom varieties that meet the following conditions: can complete more than two growth cycles normally in open field cultivation, the percentage of leaf damage area after artificial simulation of high temperature and high humidity stress is not higher than the predetermined threshold, and the vase life of cut flowers is not less than the predetermined number of days. (5) The selected germplasm will be used for large-scale cultivation demonstration in the Nanning area.

2. The method for comprehensive screening of superior plum blossom germplasm according to claim 1, characterized in that, In step (2), the resistance indicators to high temperature and high humidity in summer must include heat resistance, humidity resistance and disease resistance.

3. The method for comprehensive screening of superior plum blossom germplasm according to claim 1, characterized in that, In step (3), the conditions for the artificial simulation of high temperature and high humidity stress resistance test are set as a temperature of 35-38℃ and a relative humidity of 85-95% to simulate the typical summer adversity in Nanning, and the treatment is carried out for 10-15 days.

4. The method for comprehensive screening of superior plum blossom germplasm according to claim 1, characterized in that, In step (3), the cut flower vase life test involves placing the flower branches in a constant indoor environment with a temperature of 20-25℃ and a relative humidity of 60-70%, with the excellent standard set as an ornamental period of ≥7 days.

5. The method for comprehensive screening of superior plum blossom germplasm according to claim 1, characterized in that, In step (3), the observation period for the adaptability of open-field cultivation in Nanning area shall be no less than two complete growth cycles.

6. The method for comprehensive screening of superior plum blossom germplasm according to claim 1, characterized in that, In step (4), the excellent stress resistance standard includes: after the stress test, the percentage of leaf area with visible damage such as scorching, water stains or necrosis is ≤15% of the total leaf area.

7. The method for comprehensive screening of superior plum blossom germplasm according to claim 1, characterized in that, In step (5), the area of ​​the large-scale cultivation demonstration shall not be less than 100 mu, and cultivation techniques that match the characteristics of the selected germplasm shall be integrated.

8. The method for comprehensive screening of superior plum blossom germplasm according to claim 7, characterized in that, The corresponding cultivation techniques include a planting density of 2-5 plants per acre, determined based on the characteristics of the germplasm canopy.

9. The method for comprehensive screening of superior plum blossom germplasm according to claim 1, characterized in that, In step (1), the unified cultivation management includes at least one growth cycle of adaptive pre-cultivation.

10. The method for comprehensive screening of superior plum blossom germplasm according to claim 1, characterized in that, The superior germplasm selected by the method is mainly used for landscaping construction in Nanning or as a local specialty cut flower product.

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