Response of yield and oil fatty acid composition to the temperature and intercepted solar radiation of traditional and high oleic canola sown in Argentine: New findings of the behavior of spring canola.

ALBERIO, C.; IZQUIERDO N.G; CANTARERO, M; AGUIRREZÁBAL, L.A.N.

Nyon

Simposio; GCIRC Technical Meeting,; 2013

Agroscope

Response of yield and oil fatty acid composition to the temperature and intercepted solar radiation of traditional and high oleic canola sown in Argentine New findings of the behaviour of spring canola Authors: Constanza Alberioa, Natalia G. Izquierdoa, Marcelo Cantarerob, Luis A.N. Aguirrezábala. aFacultad Ciencias Agrarias, Universidad Nacional de Mar del Plata ? CONICET. Ruta 226, km 74,5. bFacultad de Ciencias Agrarias, Universidad Nacional de Córdoba. Av. Haya de la Torre s/n. Contact: e-mail : aguirrezabal.luis@inta.gob.ar, phone number +54 02266 439100 Text Vegetable oils with a high relative amount of unsaturated fatty acids are of great significance for human health. As in other crops, rapeseed genotypes were developed to produce oils with differentiated quality. Canola (Canadian Oil Low Acid) is one of the most widespread and is characterized by low concentrations of erucic acid, low glucosinolate concentration and low content of saturated fatty acids. But there are also other canola varieties like high oleic, low linolenic, and so on. Previous works showed that fatty acid composition and yield are affected by environmental conditions in winter traditional rapeseed, being the main factors the temperature and the intercepted photosynthetically active radiation (PAR). There are not data about the effects of these factors on fatty acid composition of spring traditional and high oleic rapeseed genotypes. Thereby the objective was to study the effect of temperature and intercepted PAR during seed filling on the fatty acid composition of rapeseed oil in spring traditional and high oleic cultivars. Experiments were performed at different latitudes, Balcarce (Buenos Aires Argentine, 37ºS; 58ºW) and Córdoba (Córdoba, Argentina, 32ºS; 64ºW), and sowing dates in order to modify the solar radiation and temperature. Four spring rapeseed cultivars were grown at these locations, one traditional genotype, Hyola 61, provided by Advanta Semillas SAIC, and three high oleic genotypes, Nexera 8450, Nexera 170 and DN05 1874, provided by Dow AgroSciences. There were three sowing dates in Balcarce (12 May 2011, 1 June 2011 and 11 July 2011) and one sowing date in Córdoba (31 May 2011). In Córdoba and the third sowing date of Balcarce three treatments to modify the intercepted PAR were applied: shading 80%, thinning plants and control. Treatments were applied in G2 according to the phenological CETIOM scale. The cultivars were isolated to prevent cross-pollination. Experiments were performed under optimum water and nutrient conditions. Weeds, insects and diseases were adequately controlled. Samples were collected at maturity and fatty acid composition was analysed by gas chromatography and the yield and weight per grain were calculated. Yield for the traditional cultivar ranged between 106.7 and 167.28 gr/m2 and between 72.0 and 138.6 gr/m2 for the high oleic cultivars depending on the location, sowing date and genotype. Also weight per grain in the high oleic cultivars differed between locations but not between sowing dates. Nevertheless shading treatments in Balcarce reduced almost 30% yield and grain weight per plant in all genotypes. Also, in Córdoba weight per grain was reduced significantly by shading in both genotypes; however yield only showed significantly differences among radiation treatments in the traditional one. The oleic acid concentration ranged in Balcarce between 68.7 and 71.0% for the traditional cultivar and between 79.4 and 82.7% for high oleic cultivars depending on the genotype and sowing date. For each genotype, these variations were not associated to mean temperature during grain filling. In Córdoba, cultivars Hyola 61 and Nexera 8450, both sown in the two studied locations, presented similar fatty acid composition than in Balcarce, although there was a difference of 2 °C between locations. In all genotypes, a higher concentration of oleic acid was associated with a lower concentrations of linoleic acid. Saturated fatty acids presented narrow ranges of variation, between 3.16-3.8% (palmitic) and 1.2-2.4 (stearic) respectively. In both locations, shading treatments did not modify the concentrations of oleic and linoleic fatty acids. However, there was an increase of three and two percentage points in palmitic and stearic fatty acids respectively in both, traditional and high oleic varieties, when the shading treatments were applied. The stability of oil composition as it was shown by the studied genotypes, regardless of the environmental conditions and yields, suggest that to obtain a given oil quality would be only necessary to select the appropriate cultivar, considering also its potential illness, crop cycle and tolerance to different biotic and abiotic stresses. Management practices could be adapted to this purpose.