A Comparative Study on Root Traits of Spring and Winter Canola (Brassica napus L.) under Controlled and Water Stressed Conditions

Abstract

Root system in canola (Brassica napus L.) varies largely in different growth habit types. A study was conducted with five winter and five spring types of canola germplasm. The objective was to identify the gradual change of root traits at different growth habits stages under controlled and water stressed conditions. Two experiments, controlled and water stressed, were conducted in a greenhouse. Data on different root traits were collected at 30, 40, 50 and 60 days after planting. In controlled experiment, no significant difference was observed for root traits between winter and spring types at 30 days after planting. However, significant variations were appeared for taproot length (F = 10.17***) and root dry weight (F = 16.96***) between winter and spring types at 40 days after planting. All other root parameters such as basal taproot diameter (F = 22.14***), bottom taproot diameter (F = 4.59*), primary root branches (F = 78.70***) and root vigor (F = 47.18***) were significantly higher in the winter types compared to those of the spring types at 60 days after planting. Growth pattern curves indicated that all the root traits of spring types increased in a steady fashion, where the root traits of winter types increased rapidly after 40 days of planting. In water stressed experiment, the water stress was applied from 20 to 60 days after planting, and data was taken at 60 days after planting. All the root parameters except taproot length were significantly (P < 0.001) lower in the stressed spring and winter plants compared to the control plants. The root growth reduction in stressed winter type germplasms was higher. Basal taproot diameter, bottom taproot diameter, primary root branches, root vigor, and root dry weight were decreased by 43%, 63%, 19%, 31% and 53%, respectively in stressed winter type plants. In contrast, the root growth reduction of the spring type germplasms were relatively lower. This study indicated that winter type canola generates vigorous root system in comparison to spring types under normal growing conditions, but ceases its root growth rate more than the spring types under water stressed conditions.

Genetic control of root morphology in response to nitrogen across rapeseed diversity

“…The winter-type (along with winter fodder and semi-winter) accessions were characterized by greater biomass production and larger root system size compared to the spring-type ones (Figure 2). Superior root features were already reported for these genotypes having a longer life cycle that necessitates vernalization (Rahman & McClean, 2013;Thomas et al, 2016a;Arifuzzaman & Rahman, 2017).…”

Genome-wide association studies of root system architecture traits in a broad collection of Brassica genotypes

“…Root architectural traits can serve as a focal point for enhancement and optimization, tailored to meet the specific requirements dictated by soil conditions (Arifuzzaman and Rahman, 2017). For example, Thomas et al (2016) examined the root structure of various growth types of B. napus and determined that root morphology has the potential to enhance crop yield, provided that appropriate genetic markers associated with agronomic traits can be identified (Arifuzzaman and Rahman, 2017). The findings from this study revealed that root traits dynamics were significantly influenced by the genotype and species, highlighting the significant role of genetic factors in RSA.…”

“…Root architectural traits can serve as a focal point for enhancement and optimization, tailored to meet the specific requirements dictated by soil conditions ( Arifuzzaman and Rahman, 2017 ). For example, Thomas et al.…”