Root Morphological Traits of Seedlings Are Predictors of Seed Yield and Quality in Winter Oilseed Rape Hybrid Cultivars

Abstract

The root system is responsible for soil resources acquisition. Hence, optimizing crop root characteristics has considerable implications for agricultural production. This study evaluated a panel of twenty-eight European modern cultivars of oilseed rape (Brassica napus L.) cultivated in laboratory and field environments. Root morphology was screened using a high-throughput hydroponic growth system with two divergent nitrogen supplies. The panel showed an important diversity for biomass production and root morphological traits. Differences in root and shoot dry biomasses and lateral root length were mainly explained by the genotype, and differences in primary root length by nitrogen nutrition. The cultivars were tested in a pluriannual field trial. The field variation for yield and seed quality traits attributed to the genotype was more important than the year or the genotype × year interaction effects. The total root length measured at the seedling stage could predict the proportion of nitrogen taken up from the field and reallocated to seed organs, a component of the nitrogen use efficiency. The genetic interrelationship between cultivars, established with simple sequence repeat markers, indicated a very narrow genetic base. Positive correlations were found between the genetic distance measures, root morphological traits during nitrogen depletion and yield components. This study illustrates a root phenotyping screen in the laboratory with a proof of concept evaluation in the field. The results could assist future genetic improvements in oilseed rape for desirable root characteristics to reduce nutrient losses in the environment.

Natural Selection Under Conventional and Organic Cropping Systems Affect Root Architecture in Spring Barley

“…Nevertheless, the testing under eld condition could result an increased underestimation of root architectural parameters, therefore we complemented the eld trial with a hydroponic experiment, where the entire root system morphology could be estimated. As already shown in root morphological trials in Brassica, the root development in seedling stage is a reliable indicator for the following development stages 37 . We hypothesized that this is also true in barley.…”

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

“…To test parental lines of studied populations, 89 SSR primer pairs were used. Some of these primers were also tested in rapeseed genetic diversity studies [17,19,46,47]. After initial analysis, 43 markers proved to be polymorphic and were used to analyze all genotypes.…”

Nitrogen Uptake Efficiency, Mediated by Fine Root Growth, Early Determines Temporal and Genotypic Variations in Nitrogen Use Efficiency of Winter Oilseed Rape

“…These data are consistent with the results of Malagoli et al ( 2005a ), who reported a loss of 12% of plant N in fallen leaves. Some other studies assessing NUE include tap roots and sometimes fine roots, but not fully for each individual plant (Ulas et al, 2012 ; Hohmann et al, 2016 ; Yuan et al, 2016 , Dresbøll et al, 2016 ) or at each phenological stage, mainly targeting either the seedling or reproductive stages (Thomas et al, 2016 ; Wang et al, 2017 ; Louvieaux et al, 2020 ). To our knowledge, our study is the first to describe the NUE dynamics of winter oilseed rape so completely and accurately, by considering entire individual plants grown under canopy conditions at key phenological stages from sowing to seed maturity.…”

“…Alternatively, a genotypic analysis of the fine-root growth, seen as a proxy of root architecture, could provide some clues of NUE determinism. Indeed, Wang et al ( 2017 ) highlighted a strong correlation between root biomass and total root area on young plants of winter oilseed rape, and Louvieaux et al ( 2020 ) evidenced a positive correlation between primary root length early measured in hydroponics and seed yield measured in the field.…”

“…On the one hand, Balint and Rengel ( 2008 ) showed little consistency between the NUE of 12 oilseed rape varieties measured at the vegetative and maturity stages. On the other hand, Koscielny and Gulden ( 2012 ), as well as Louvieaux et al ( 2020 ), found that seedling root length could be used as an early indicator of potential yield in winter oilseed rape and Wang et al ( 2017 ) found QTL for root architecture traits that co-localized with QTL for NUE at the seedling stage.…”