نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشگاه علوم کشاورزی و منایع طبیعی خوزستان
2 دانشگاه علوم کشاورزی و منابع طبیعی خوزستان
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background & Objectives: The study was conducted to analyze the causality between grain yield and related traits in spring rapeseed genotypes.
Materials and Methods: The research was carried out in November 2019 at the research farm of Khuzestan University of Agricultural Sciences and Natural Resources at latitude 31 degrees 36 minutes, longitude 48 degrees 53 minutes and 22 meters above sea level. In terms of climate, the studied area is one of the hot and dry areas. The experiment was performed as a split plot in the form of a randomized complete block design in three replications. The main factor in this study consisted of three levels: no irrigation interruption, interruption of irrigation during the flowering stage up to 50% of flowering (flowering stress), and interruption of irrigation until harvest (silique stress). Irrigation was done during the growing season based on the plant's water needs and autumn rainfall, and in the final stages of growth, irrigation was stopped based on the growth stage of the variety. Ten spring rapeseed genotypes were included in the study: Long pod (late growth type, Iran), Aram, RGS003, Jancom, Solar, Hayola 4815, Mahtab, Jolios, Agamex, and Sala. These genotypes were placed as the second factor in sub-plots. The correlation between traits was calculated using step-by-step regression using SPSS software version 22, and the causality between traits was examined using route analysis using R software version 2.2.4.
Results: The results of stepwise regression analysis for rapeseed genotypes demonstrate that under drought stress at the end of the season, oil yield and harvest index (tension applied in the stage of silique to harvest) and harvest index and biological performance (stress applied at the flowering stage up to 50% of silique), respectively, are the two most crucial variables that determine grain yield. There is a high and positive simple correlation in the first stress condition between 1000 seed weight (0.52), biological yield (0.78), grain oil content (0.64) and the number of pods per plant (0.74) with the grain yield. And in the stress conditions of the second stage, a high and positive correlation was observed between grain yield and oil yield trait with a value of (0.97), harvest index with a value of (0.78) and biological yield with a value of (0.64). The results of genotypic causality analysis in the stress conditions of the first and second stages showed that the most negative direct effect of silique length with a value of (-0.917) and the growth period maturation with a value of (-0.793) and the most positive effect in the stress of the first stage From the 1000 seed weight with a value of (0.678) and the stress of the second stage of grain oil yield with a value of (0.379), the highest effect of phenotypic correlation in both applied stresses was observed from the characteristics of the harvest index in the first stress and The second one was obtained with the values (0.734-1.00) respectively.
Conclusion: The results showed that in the correlation analysis and causality analysis, harvest index traits, grain oil yield, 1000 seed weight, silique length and the growth period maturation in both stress conditions of flowering stage up to 50% grain yield and grain yield to harvest have the highest correlation with the amount of grain yield. Therefore, the mentioned traits can be used to improve rapeseed genotypes.
کلیدواژهها [English]
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