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Exploring Agronomic and Physiological Traits Associated With the Differences in Productivity Between Triticale and Bread Wheat in Mediterranean Environments

2019; Frontiers Media; Volume: 10; Linguagem: Inglês

10.3389/fpls.2019.00404

1664-462X

Ana María Méndez-Espinoza, Sebastián Romero‐Bravo, Félix Estrada, Miguel Garriga, Gustavo A. Lobos, Dalma Castillo, Iván Matus, Íker Aranjuelo, Alejandro del Pozo,

Soil Carbon and Nitrogen Dynamics

In Mediterranean climates soil water deficit occurs mainly during the spring and summer, having a great impact on cereal productivity. While previous studies have indicated that the grain yield (GY) of triticale is usually higher than bread wheat (Triticum aestivum L.), comparatively little is known about the performance of these crops under water-limited conditions or the physiological traits involved in the different yields of both crops. For this purpose, two sets of experiments were conducted in order to compare a high yielding triticale (cv. Aguacero) and spring wheat (cvs. Pandora and Domo). The first experiment, aiming to analyze the agronomic performance, was carried out in 10 sites located across a wide range of Mediterranean and temperate environments, distributed between 33°34' and 38°41' S. The second experiment, aiming to identify potential physiological traits linked to the different yields of the two crops, was conducted in two Mediterranean sites (Cauquenes and Santa Rosa) in which crops were grown under well-watered (WW) and water-limited (WL) conditions. The relationship between GY and the environmental index revealed that triticale exhibited a higher regression coefficient (Finlay-Wilkinson slope), indicating a more stable response to the environment, accompanied by higher yields than bread wheat. Harvest index was not significantly different between the two cereals, but triticale had higher kernels per spike (35%) and thousand kernel weight (16%) than wheat, despite a lower number of spikes per square meter and test weight. For the physiological traits evaluated at anthesis and grain filling, the GxE interaction was only significant for stomatal conductance (gs) and internal CO2 concentration (Ci) at grain filling. The environmental effect was highly significant for all traits and developing stages, except for maximum fluorescence (Fm). The higher yield of triticale was linked to higher values of leaf net photosynthesis (An), maximum rate of electron transport (ETRmax), photochemical quantum yield of PSII (Y(II)) and leaf water-use efficiency. These results revealed that, compared to bread wheat cv., the higher photosynthetic efficiency of triticale contributed to increased CO2 assimilation rates and overcame potential oxidative stress symptoms in triticale under stressful growth conditions.