نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار بخش تحقیقات علوم زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی جنوب کرمان، سازمان تحقیقات، آموزش و ترویج کشاورزی، ایران.
2 کارشناس، بخش تحقیقات علوم زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی جنوب کرمان، سازمان تحقیقات، آموزش و ترویج کشاورزی، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Abstract
Objective
Genotypic and phenotypic correlation studies between plant traits are helpful in planning, evaluating, and determining selection criteria for desired traits in a breeding program. The present aimed to estimate the phenotypic and genotypic correlation coefficients between yield and its associated traits, investigate the direct and indirect effects of performance-related traits through path coefficient analysis, and identify superior lines using the selection index of ideal genotype (SIIG).
Materials and Methods
Seeds from 50 genotypes of sweet pepper were obtained from the Germplasm Department of the Institute of Plant Genetics and Crop Plant Research (IPK), Germany. Pure lines were developed through five generations of self-crossing. The seeds of these pure lines were cultivated in a completely randomized design with three replications under greenhouse conditions, and 12 quantitative and qualitative traits were evaluated. Variance analysis, correlation coefficients, regression analysis, and path analysis were conducted using OPSTAT software. The SIIG method was applied to select superior lines based on the integration of performance and the traits influencing it.
Results
The analysis of variance revealed a significant difference among the evaluated lines for all studied traits at a 1% probability level, indicating substantial genetic diversity among the lines. Fruit yield showed a positive and significant correlation with the number of fruits per plant, fruit diameter, fruit length, fruit tail length, pericarp thickness, dry matter percentage, and fruit weight. The regression model analyzed yield as the dependent variable, while other traits were independent. Five traits (fruit weight, fruit number, dry matter percentage, fruit length, and fruit diameter) were identified as the most influential factors affecting fruit yield. Path analysis further demonstrated that fruit weight and the number of fruits per plant had the most direct and positive effect on fruit yield, contributing 63% and 44%, respectively. Selection based on the selection index of the ideal genotype resulted in the identification of five superior lines 237, 334, 389, 296, 400, and 318, which exhibited the shortest distance from the ideal genotype.
Conclusion
The results of the path coefficient analysis indicate that selecting traits such as fruit weight, fruit length, number of fruits per plant, fruit diameter, and dry matter percentage can significantly enhance sweet pepper productivity. Additionally, employing the selection index ideal genotype (SIIG) enables the identification of lines and genotypes that exhibit optimal performance across these traits. Consequently, lines 318, 296, 400, 389, 324, and 237 have been identified as candidates for further studies aimed at hybrid seed production.
کلیدواژه‌ها [English]
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