Abstract

MORANT, AE; MERCHAN, HD  and  LUTZ, EE. Selection of double purpose wheat genotypes: Vernalization requirements. Phyton (B. Aires) [online]. 2011, vol.80, n.1, pp.5-8. ISSN 1851-5657.

This study aimed to characterize wheat cultivars for their chilling requirements for differentiation and their relationship to flowering time, to establish a dual purpose ideotype. Seeds of eight genotypes (cultivars and advanced lines) of bread wheat were exposed to constant temperature (4 °C) in germination chambers for 8, 6, 4 and 2 weeks. A control treatment was kept at room temperature. Four replicates of each treatment were placed in the greenhouse in 250 cc pots containing 4 seedlings each, with irrigation and natural photoperiod, following a randomized complete block design. The greenhouse temperature was constant (20 °C) and the natural photoperiod ranged from the time of transplanting (22 June; 10:28 h) to flowering (12:57 h). We measured the variable "days to flowering"' when the peg of the main stem of the first plant of each treatment reached the state of anthesis. We confirmed the existence of variability between genotypes in terms of their requirements for low temperatures to flowering, which would imply differences in its agricultural management for grazing. In genotypes with a more pronounced response to vernalization (E3082, Longhorn, Super), days to flowering increased significantly between treatments with none to total requirements of chilling. At the other extreme, V223 and Charrúa showed little or no response between 8 and 0 weeks of cold. B1073, C2 and Karl showed a greater demand (supposedly photoperiod) with increasing days to flowering after widely covering its low temperature demands. Measuring only the response to vernalization is not sufficient as a method for classifying wheat varieties when the purpose is to obtain two productions (grass and grain) on the same crop.

Keywords : Double purpose wheat; Triticum aestivum; Vernalization.

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