Search

Seed longevity is influenced by many factors, a widely discussed one of which is the seed lipid content and fatty acid composition. Here, linear and non-linear regressions based on machine learning were applied to analyse germinability and seed composition of a set of 42 oilseed rape (Brassica napus L.) accessions grown under the same single environment and at the same time following a period of up to 31 years storage at 7°C. Mean viability was halved after 27.0 years of storage, but this figure concealed a major influence of genotype. There was also wide variation with respect to fatty acid composition, particularly with respect to oleic, α-linolenic, eicosenoic and erucic acid. Linear regression (r L) revealed significant correlation coefficients between normal seedling appearance and the content of α-linolenic acid (+0.52) and total oil (+0.59). Multivariate regression using artificial neural networks including a radial basis function (RBF), a multilayer perceptron (MLP) and a partial least square (PLS) recognized underlying structures and revealed high significant correlation coefficients (r M) for oil content (+0.87), eicosenoic acid (+0.75), stearic acid (+0.73) and lignoceric acid (+0.97). Oil content or a combination of oleic, α-linolenic, arachidic, eicosenoic and eicosadienoic acids and glucosinolates resulted in highest model fitting parameters R 2 of 0.90 and 0.88, respectively. In addition, the glucosinolate content, predominantly in the Brassicaceae family and ranging from 4.6 to 79.5 µM, was negatively correlated with viability (r L = ‒0.43). Summarizing, oil content, some fatty acids and glucosinolates contribute to variations in average half-life (15.2 to 50.7 years) of oilseed rape seeds. In contrast to linear regression, multivariate regression using artificial neural networks revealed high associations for combinations of parameters including underestimated minor fatty acids such as arachidic, stearic and eicosadienoic acids. This indicates that genetic and seed composition factors contribute to seed longevity. In addition, multivariate regressions might be a successful approach to predict seed viability based on fatty acids and seed oil content. [ABSTRACT FROM AUTHOR]

Although oilseed rape has become one of the most important oil crops in Europe, little is known regarding the viability of its seed under conditions of long-term storage. We report here an examination of oilseed rape seed longevity performed on a set of 42 accessions housed at the German ex situ genebank at IPK, Gatersleben. A comparison of germination between the accessions stored for 26 years showed that viability was in part genetically determined, since it ranged between 42 and 98%. An attempt was made to define the genetic basis of viability by subjecting a mapping population of doubled haploids to three artificial ageing treatments. Quantitative trait loci (QTL) were detected on six chromosomes: N6, N7, N8, N15, N16 and N18. The chromosomal locations of these QTL were compared with their syntenic regions in Arabidopsis thaliana in order to explore what genes might underlie genetic variation for longevity. [ABSTRACT FROM AUTHOR]