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

Comparative study of four safflower oils (Carthamus tinctorius) varieties grown in eastern of Morocco

Safflower (Carthamus tinctorius) is an oilseed crop, which, for many years, has been grown on a relatively small scale in parts of North Africa and Middle East (Purdy and al., 1959)