Correlation and path analysis in winter oilseed rape (Brassica napus L.) cultivars based on yield and phenotypic traits

The aim of this study was to access variability of different cultivars of winter oilseed rape for yield, yield components and seed quality traits by multivariable statistical method. Traits including seed yield, silique length, number of seeds per siliques, weight of 1000 seeds, content of oil in the seeds, two unsaturated fatty acids (linoleic, linolenic) and glucosinolate content in seed meal (gluconapine, glucobrassicanapine, progoitrine and total glucosinolates) were investigated. Seven cultivars of oilseed rape were evaluated in a randomized block design, with four replicates at two locations in two growing seasons. The tested genotypes displayed wider genetic variability for studied traits in all environments. The results of canonical variate analyses explained from 79.2% in 2004 (Bor4) to 93.7% in 2004 (Ziel3) of total variability. The first (V 1 ) and the second (V 2 ) canonical variate explained 74.4% and 15.9% of the total variation in Borowo (2003), 61.8% and 17.4% in Borowo (2004), 74% and 19.7% in Zielęcin (2003) and 56.4% and 26.1% in Zielęcin (2004), respectively. The traits that had the greatest impact on seed output across all settings were weight of 1000 seeds, silique length, oil content, linolenic fatty acid, and gluconapine, according to path analyses based on correlation matrices. Heat maps extended with the results of the cluster analysis for selected traits showed which genotypes are the most desirable for cultivation. As a results, cultivars Kaszub, Mazur as well as Pomorz demonstrated good average values of observed traits and higher stability to changeable environmental conditions.