Multidimensional Analysis of Diversity in DH Lines and Hybrids of Winter Oilseed Rape (Brassica napus L.)

Abstract

Limited genetic variability is a major problem in rapeseed breeding, whose strict selection, limited geographical range and a short period of domestication has led to a reduction in genetic and phenotypic diversity. Assessing specific populations for the greatest genetic diversity for many traits simultaneously, requires the evaluation of multi-feature characteristics. The aim of this study was to estimate the variability of DH (doubled haploid) lines and two generations of winter oilseed rape hybrids. In addition, the relationship between the Mahalanobis distances of parental forms and the effect of heterosis in hybrids was investigated. The results of MANOVA showed that the genotypes and years as well as genotype × year interaction were significantly different (p < 0.001) for all eight observed traits. The first (V1) and the second (V2) canonical variate explained 38.57% and 27.55% of the total variation in 2015, and 50.19% and 31.84% in 2016, respectively Canonical variate analysis showed that the traits, flowering time and number of branches per plant had a very large influence on the differentiation of genotypes. Graphs demonstrated that the tested DH lines and hybrids are characterized by a similar, wide range of variability. It was observed, that when using a diverse population of DH lines for crossbreeding with only one CMS/Rfo line, there was no significant reduction of variation in hybrid generations and between these generations. The phenotypic distance values determined by the results of Mahalanobis analysis were similar in both years, but slightly wider in 2016. The observed minimum and maximum ranged from 1.324 to 22.356 in 2015, and from 1.105 to 27.792 in 2016, respectively. No significant correlation was observed between the hybrid heterosis effect and the Mahalanobis distance of the parental lines.

Identification of SSR Markers Associated with Yield-Related Traits and Heterosis Effect in Winter Oilseed Rape (Brassica Napus L.)

“…For studied phenotypic traits, we identified in total 354 significant associations, of which 168 in year 2015 and 186 in 2016, and only 36 of them were common in both years. Differences in the associations probably resulted from the influence of the environment on the observed features, which is also reflected in their variability [39]. There are few published studies about the association of SSR markers with phenotypic traits.…”

“…The following quantitative traits were evaluated: beginning of flowering (days), length of flowering (days), plant height (cm), the number of branches per plant, the number of siliques per plant, silique length (mm), the number of seeds per silique, and thousand seed weight (g). Phenotypic evaluation of measured agronomic traits and their variation was described in detail by Łopaty ńska et al [39].…”

Impact of Selected PSII Parameters on Barley DH Lines Biomass and Yield Elements

“…We have applied multivariate statistical analysis such as CVA in our studies. This type of analysis was applied in studies of Lopatynska et al [34] to detect differences in DH lines and hybrids of winter rapeseed e.g., in thousand seed weight and the first two canonical variates together explained from 66.12% to 82.03% of the total variation depending on the year, since in our experiment, CVA explained 44.14% of the entire variation.…”

“…If the parental form did not significantly differ from each other, there is a possibility to obtain from which possesses a heterosis effect. Such studies were conducted by Lopatynska et al [34] in winter rape and helped to choose the valuable genotypes for breeding programs. In our studies, we have found significant heterosis effect for CF parameters (Fv/Fm, Area, PI and ETo/CS), as well as for yield elements (TGW, GNP) and biomass.…”

Enhancing yield and oil content in oilseed rape hybrids: Insights from line × tester and SIIG approaches

“…Furthermore, understanding the genetic structure and mode of inheritance for target traits is crucial for improving hybrid or openpollinated varieties of oilseed rape. Additive gene effects indicate the efficiency of selection, while non-additive effects, such as dominance and overdominance, contribute to hybrid variety development (Amiri Oghan et al, 2018;Łopatyńska et al, 2021;Masood et al, 2019).…”