Reaction of some rapeseed (Brassica napus L.) genotypes to different drought stress levels during germination and seedling growth stages☆

Drought is a major abiotic stress that affects seed germination and plant growth in arid and semi-arid regions. Rapeseed is an oilseed crop adapted to Mediterranean area; however, it is reported that it is sensitive to water stress occurring during seed germination. In this study, we investigated how seed germination and early seedling growth of six rapeseed genotypes were influenced by different water stress levels. In addition to the control (absence of drought stress), three drought levels were simulated using three osmotic potentials of polyethylene glycol (PEG-6000), −9, −10 and −11 bars. A completely randomized design with three replications was used for this experiment. Germination percentage (GP), shoot length (SL), root length (RL), shoot elongation rate (SER) and root elongation rate (RER) were determined to evaluate the genotypes response to PEG-induced drought stress. Results showed drought stress, genotype and interaction stress × genotype had a significant effect on the studied parameters. GP decreased with the increase in stress level. The genotype ‛Nap9’ was the most interesting, having the highest GP values, namely 63.33, 62.67 and 28% under the stress levels −9, −10 and −11 bars, respectively. The genotype ‛H2M-5’, which ranked second with respect to this parameter, was statistically comparable to ‛Nap9’. Also, SL, RL, SER and RER decreased with the increase in drought stress level. However, the studied genotypes reacted differently to various water stress levels. Once again, the genotype ‛H2M-5’ exhibited the highest average RL and RER under all drought levels. Particularly, for severe drought conditions (−11 bars), ‛H2M-5’ had an average RL of 1.54 cm and RER of 0.36 cm/d. Field evaluation under controlled conditions is needed to confirm findings of the present experiment. The mutant ‛H2M-5’ could be a valuable and promising germplasm for developing a performant and adapted variety to be designed for harsh environments particularly characterized by early drought coinciding with germination and seedling growth stages

Tocoferoles y fitoesteroles en semillas de girasol para consumo directo

Sunflower seeds for the human food market are derived from both oilseed-type cultivars, with black achenes and low hull proportion, and confectionery-type cultivars, with striped achenes and high hull proportion. The objective of this research was to evaluate tocopherol and phytosterol contents in the seeds of both types of cultivars. Five oilseed-type and seven confectionery-type cultivars were evaluated in replicated field trials in two locations of Morocco and Spain. Large variations were found in hundred-kernel weight (2.6 to 5.5 g), kernel oil content (42.7 to 67.5%), tocopherol content (203 to 397 mg kg–1 kernel), and phytosterol content (2179 to 3555 mg kg–1 kernel). Both types of cultivars did not differ for kernel weight, kernel oil content, or tocopherol and phytosterol profiles. However, oilseed-type cultivars had significantly greater average tocopherol and phytosterol contents, though confectionery-type cultivars with levels of tocopherols and phytosterols similar to the best oilseed-type cultivars were identified. The large variations in kernel tocopherol and phytosterol contents found in this research suggest that there is room for breeding for increased levels of these compounds in order to develop healthier sunflower cultivars for the human food market.Las semillas de girasol para consumo directo proceden tanto de cultivares oleaginosos, con aquenios negros y baja proporción de cáscara, como de cultivares de consumo directo, con aquenios de colores claros o rayados y elevada proporción de cáscara. El objetivo de este trabajo fue evaluar el contenido en tocoferoles y fitoesteroles en semillas de ambos tipos de cultivares. Se evaluaron cinco cultivares oleaginosos y siete cultivares de consumo directo en ensayos de campo replicados en dos localidades de Marruecos y España. Se identificó gran variación para peso de 100 semillas (aquenios descascarillados; 2.6 a 5.5 g), contenido en aceite en la semilla (42.7 a 67.5%), contenido en tocoferoles (203 a 397 mg kg–1 semilla), y contenido en fitoesteroles (2179 a 3555 mg kg–1 semilla). No se observaron diferencias entre ambos tipos de cultivares para peso de semilla, contenido de aceite en la semilla, o perfiles de tocoferoles y fitoesteroles. Sin embargo, los cultivares oleaginosos presentaron mayor contenido medio de tocoferoles y fitoesteroles, aunque se identificaron cultivares de consumo directo con niveles de estos compuestos similares a los mejores cultivares oleaginosos. La gran variación encontrada para contenido en tocoferoles y fitoesteroles sugiere la posibilidad de elevar los niveles de estos compuestos mediante mejora genética con el objetivo de desarrollar cultivares de girasol de consumo directo más saludables

Germination and Seedling Growth of a Set of Rapeseed (Brassica napus) Varieties under Drought Stress Conditions

Drought stress is one of the major abiotic factors affecting seed germination and plant growth especially in arid and semi-arid regions. In this study, we investigated the effects of drought stress on seed germination and seedling growth of five varieties of rapeseed. Seven drought stress levels of zero (control), -3, -5, -7, -9, -11 and -13 bars were performed using polyethylene glycol-6000 (PEG-6000). A completely randomized design with three replications was used for this experiment. Germination percentage (GP), germination rate (GR), mean germination time (MGT), root length (RL) and shoot length (SL) were measured to evaluate the varieties response to PEG-induced drought stress. Drought stress, variety and the interaction drought × variety had a significant effect on all studied parameters. GP and GR decreased with the increase in stress level, while MGT increased. There were no seeds germinated for all varieties at -11 bars and -13 bars. Shoot length decreased with increasing drought stress but different varieties show different performance under stress environment. Root length decreased with increasing level of severe drought stress. However, the presence of moderate drought stress could even improve the root growth of the investigated varieties. The varieties ‘INRA-CZH2' and ‘INRA-CZH3' exhibited the highest germination percentage and the best early seedling growth. Thus, they could be recommended for environments with early cropping cycle drought

Genetic relationship and diversity among some Moroccan and introduced rapeseed (Brassica napus L.) varieties as revealed by molecular markers☆

Rapeseed (Brassica napus L.) crop can be a lever for the development of oilseed sector in Morocco due to its adaptation to local conditions and its major economic and food importance. Genetic diversity and selection of valuable crossing parents are the key to successful breeding and improvement of this crop. In this regard, genetic variation within the existing germplasm must be explored and characterized. Therefore, the present study was carried out to investigate the genetic diversity among 22 varieties from Morocco as well as other origins, using twenty ISSR primers. The selected primers have generated a total of 319 markers. Polymorphic amplified bands varied from 8 to18, with an average of 13 per primer. The diversity index (PIC value) ranged from 0.295 to 0.509, with a mean value of 0.37 per primer, indicating a good genetic diversity level for the primers used. The average similarity coefficient was 0.31, fluctuating between 0.176 and 0.456, and the pairwise comparison of the studied varieties showed a great discriminating power of primers and a large genetic diversity among accessions. A total of eight ISSR primers could be identified as key to rapeseed varietal determination. Hierarchical classification allowed identifying three groups with some phylogeographic structuring. This is the first report of molecular characterization of rapeseed germplasm in Morocco and Africa. The obtained results have important implications for management of this germplasm to conserve the existing genetic diversity and use it properly in breeding programs in Morocco as well as in other Mediterranean and African countries

Tocoferoles y fitoesteroles en semillas de girasol para consumo directo

[EN] Sunflower seeds for the human food market are derived from both oilseed-type cultivars, with black achenes and low hull proportion, and confectionery-type cultivars, with striped achenes and high hull proportion. The objective of this research was to evaluate tocopherol and phytosterol contents in the seeds of both types of cultivars. Five oilseed-type and seven confectionery-type cultivars were evaluated in replicated field trials in two locations of Morocco and Spain. Large variations were found in hundred-kernel weight (2.6 to 5.5 g), kernel oil content (42.7 to 67.5%), tocopherol content (203 to 397 mg kg -1 kernel), and phytosterol content (2179 to 3555 mg kg -1 kernel). Both types of cultivars did not differ for kernel weight, kernel oil content, or tocopherol and phytosterol profiles. However, oilseed-type cultivars had significantly greater average tocopherol and phytosterol contents, though confectionery-type cultivars with levels of tocopherols and phytosterols similar to the best oilseed-type cultivars were identified. The large variations in kernel tocopherol and phytosterol contents found in this research suggest that there is room for breeding for increased levels of these compounds in order to develop healthier sunflower cultivars for the human food market.[ES] Las semillas de girasol para consumo directo proceden tanto de cultivares oleaginosos, con aquenios negros y baja proporción de cáscara, como de cultivares de consumo di - recto, con aquenios de colores claros o rayados y elevada proporción de cáscara. El objetivo de este trabajo fue evaluar el contenido en tocoferoles y fitoesteroles en semillas de am - bos tipos de cultivares. Se evaluaron cinco cultivares oleagi - nosos y siete cultivares de consumo directo en ensayos de campo replicados en dos localidades de Marruecos y Espa - ña. Se identificó gran variación para peso de 100 semillas (aquenios descascarillados; 2.6 a 5.5 g), contenido en aceite en la semilla (42.7 a 67.5%), contenido en tocoferoles (203 a 397 mg kg –1 semilla), y contenido en fitoesteroles (2179 a 3555 mg kg –1 semilla). No se observaron diferencias entre ambos tipos de cultivares para peso de semilla, contenido de aceite en la semilla, o perfiles de tocoferoles y fitoesteroles. Sin embargo, los cultivares oleaginosos presentaron mayor contenido medio de tocoferoles y fitoesteroles, aunque se identificaron cultivares de consumo directo con niveles de estos compuestos similares a los mejores cultivares oleagi - nosos. La gran variación encontrada para contenido en toco - feroles y fitoesteroles sugiere la posibilidad de elevar los ni - veles de estos compuestos mediante mejora genética con el objetivo de desarrollar cultivares de girasol de consumo di - recto más saludables.The research was partially supported by the Consejo Superior de Investigaciones Científicas (CSIC), Spain and Centre National pour la Recherche Scientifique et Technique (CNRST), Morocco, project number 2007MA0059.Peer Reviewe

Performance and seed quality of Moroccan sunflower varieties and Spanish landraces used for confectionery and snack food

Sunflower seeds are one of the most important sources of vegetable oil in the world. Additionally, they are used for confectionery and snack food, as well as for bird and pet food. Sunflower germplasm used for food differs between Morocco and Spain. Whereas sunflower seeds used for food in Morocco are mainly obtained from oilseed-type cultivars with black achenes and low hull proportion, those used in Spain derive from confectionery-type cultivars with black and white striped achenes and high hull proportion. The objective of this research was to evaluate the performance and seed quality of Moroccan and Spanish sunflower germplasm used for food. Six cultivars from Morocco and six landraces from Spain were evaluated in replicated field trials in Aïn Taoujdate (Morocco) and Córdoba (Spain) in 2009. Seed yield, hundred-achene weight, hundred-kernel weight, achene oil content, kernel oil content, and fatty acid profile were measured. The results showed that confectionery-type and oilseed-type cultivars did not differ in seed yield, hundred-kernel weight and kernel oil content. Since confectionery-type cultivars from Spain performed similarly to local oilseed-type cultivars, they could be introduced to diversify the offer of in-shell sunflower seed snack in Morocco.The research was partially supported by Consejo Superior de Investigaciones Científicas (CSIC), Spain and Centre National pour la Recherche Scientifique et Technique (CNRST), Morocco, project number 2007MA0059.Peer Reviewe

Aceite de semilla de mostaza etiope con alto contenido en ácido linolénico

Referencia OEPM: P200301617.-- Fecha de solicitud: 04/07/2003.-- Titular: Consejo Superior de Investigaciones Científicas (CSIC).Aceite de semilla de mostaza etiope con alto contenido en ácido linolénico. Aceite vegetal obtenido de semillas de mostaza etíope (Brassica carinata) modificadas mediante un proceso de mejora genética convencional. Este aceite carece de ácido erúcico y presenta un elevado contenido en ácido linolénico, lo que le confiere propiedades de aceite secante de gran valor en la fabricación de tintas, barnices, pinturas, lacas, etc., así como en la industria oleoquímica.Peer reviewe