نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم و مهندسی باغبانی، دانشکده علوم کشاورزی، دانشگاه گیلان. رشت. ایران.
2 گروه مهندسی بیوسیستم، دانشکده علوم کشاورزی، دانشگاه گیلان. رشت. ایران
3 گروه گیاهپزشکی، دانشکده علوم کشاورزی، دانشگاه گیلان. رشت. ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
In order to study the resistance of cucumber to powdery mildew disease, 7 hybrids of cucumber were evaluated under two conditions: fungicide (Metalaxyl) application and no fungicide application. The experiment was conducted as a factorial based on a completely randomized design in three replications under greenhouse condition. Studied traits included the number of female and male flowers, the pedicle length, ovary length, the number of lateral branches, plant length, fruit length, average leaf area, average infected leaf area and number of fruits per plant. The results showed that under no fungicide application condition, the highest value of fruit number in the plant belonged to the genotype 39-2-2×36-5-2, while with the application of fungicide, the 36-5-2×22-3-4 and 39-2-2×36-5-2 genotypes had the highest number. In terms of the number of fruits per plant, the least amount of fluctuation in the two conditions and the highest stability belonged to the 50-2-3×36-5-2, respectively. The genotype 39-2-2×36-5-2 showed the highest number of female flowers in both conditions. Based on the results, among the studied genotypes, the 50-2-3×22-3-4 genotype with the lowest changes in performance traits and the highest stability was identified as a resistance genotype to powdery mildew disease and suitable for cultivation.
کلیدواژه‌ها [English]
Extended Abstract
Introduction
Cucumber is an important agricultural crop due to its large cultivated area and economic value, with hybrid seed production playing a crucial role in its yield and quality. Identifying superior parental combinations is one of the most important steps in hybrid seed production as it directly impacts the performance of the resulting hybrids. Cucumber powdery mildew is one of the important diseases in humid cucumber-growing regions and greenhouses, causing substantial yield and quality losses. Selecting resistant or tolerant cucumber cultivars is an effective strategy to reduce disease damage. This study aimed to investigate the response of seven cucumber hybrids to the application of fungicides against cucumber powdery mildew disease. These cucumber hybrids were created by crossing a native Guilan cucumber genotype with lines developed at University of Guilan, and afterwards by selecting plants using pedigree method over generations.
Materials and Methods
In order to investigate the resistance of cucumber hybrids to powdery mildew disease, two-leaves seedlings of seven cucumber hybrid genotypes were planted in pots containing cocopeat and perlite (1:1), in the polycarbonate greenhouse in the Faculty of Agricultural Sciences, University of Guilan. Powdery mildew disease was occurred naturally on plants in the greenhouse. An experiment conducted as a factorial based on completely randomized design with 3 replications, during summer 2022. The first factor was 7 genotypes and the second was application of fungicide (Metalaxyl 1 ml/L). The studied traits were the number of female and male flowers, pedicle length, ovary length, number of lateral branches, plant length, fruit length, leaf area, and infected leaf area.
Due to the difficulty of calculating the surface infected with leaf powdery mildew by traditional methods, image processing technique was used in this research. Imaging of the surface of the leaves was done using a scanner. A dark blue plastic plate was used during scanning to facilitate separation of the leaf from the background.
Images were saved in JPG format for preprocessing and processing. According to the appearance characteristics of powdery mildew spots, image processing was done in MATLAB software to detect this disease on cucumber plants.
Results and Discussion
The results showed that under no fungicide application condition, the highest value of fruit number in the plant belonged to the genotype 39-2-2×36-5-2, while with the application of fungicide, the 36-5-2×22-3-4 and 39-2-2×36-5-2 genotypes had the highest number. Untreated and treated plants of genotype 39-2-2×36-5-2 showed the highest number of female flowers. Genotype 50-2-3×36-5-2 with the lowest amount of fluctuation and the highest stability in number of fruits per plant traits at both conditions was identified for cultivation. The analysis of variance revealed that the interaction effect between genotype and fungicide on the trait “mean infected leaf area” was not statistically significant. However, a significant difference among genotypes for this trait was observed. The highest level of infection was recorded in the genotype 4-3-22 × 50-2-3, with 50.77% infected area. The lowest level of infection was observed in genotype 2-5-36 × 39-2-2, with only 24.84% infected area. In direct genotype selection, cultivars suited to specific conditions can be selected based on their yield performance. However, when selecting genotypes that perform well under both fungicide-treated and untreated conditions, preference should be given to those with minimal variation in yield and related traits. Among the genotypes evaluated in this study genotypes 2-5-36 × 3-2-52 and 4-3-22 × 2-2-39 showed the least variability and greatest stability in traits such as fruit number and average fruit weight. For fruit length, the genotype 4-3-22 × 2-5-36 demonstrated the highest stability and lowest performance fluctuation across conditions.
Conclusion
Based on the results of this study, the studied genotypes of cucumber showed different responses to the application of fungicide and resistance to powdery mildew disease. Comparing genotypes in both conditions (with and without application of fungicide) revealed that the least changes in the number of fruits per plant and fruit weight were observed in genotypes 52-2-3×36-5-5 and 39-2-2×22-3-4, and the least change in fruit length in genotype 36-5-2×50-2-3, and they can be introduced for cultivation as resistance genotypes to powdery mildew disease.
Author contributions
Conceptualization and project design: J.A. Olfati
Methodology and field experiment setup: K. Nazari
Data collection and phenotypic assessments: J.A. Olfati; K. Nazari; S. Mousanezhad and F. Rahimi Ajdadi
Statistical analysis and variance interpretation: J.A. Olfati; K. Nazari
Writing – Original draft: J.A. Olfati
Writing – Review & editing: A. Sahraroo, S. Musanezhad and F. Rahimi Ajdadi
Visualization and figure preparation: J.A. Olfati; F. Rahimi Ajdadi
Supervision and research guidance: J.A. Olfati, A. Sahraroo
Project administration and funding acquisition: J.A. Olfati
Data availability statement
The data supporting the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgements
The authors would like to express their sincere appreciation to the Agricultural Department, University of Guilan for their valuable support and collaboration throughout this research project. Special thanks are extended to the technical staff and greenhouse management team for their assistance in field experiments and data collection.
Ethical considerations
This study was conducted in accordance with national guidelines for agricultural research. No genetically modified organisms (GMOs), hazardous substances, or practices harmful to the environment were used during the study. The authors affirm that all data presented are original and were collected responsibly without fabrication, falsification, or plagiarism.
Conflict of interest
The authors declare that there is no conflict of interest related to the publication of this article. All research activities were conducted independently, without any commercial or financial relationships that could be construed as a potential conflict.
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