Changes in oat (Avena sativa L.) flowers and inflorescences under conditions of copper deficiency

The anatomy and morphology of oat (Avena sativa L.) cv. 'Udycz Żółty' flowers and inflorescences formed at different copper levels (0, 5, 125 mg Cu/pot) was investigated. Considerable changes in the structure of the generative elements of oat flowers occurred under conditions of severe copper deficiency (Cu = 0): the stamens showed considerably smaller anthers, with changed shape; the anther chambers were significantly diminished in size and did not open after the formation of pollen; the pollen grains were sterile, deformed and of smaller dimensions. The pistils and ovules were also smaller; outgrowths on the pistil stigmas were smaller and of a different shape. A decrease in the dimensions of the inflorescences was observed in both early and later phases of development. In moderately copper-deficient plants (Cu = 5) the flowers were heteromorphic: functionally male - with great anthers and small pistils, functionally female - with great pistils and small anthers and hermaphrodite - with great pistils and anthers