Effect of drought stress and mycorrhizal inoculation on the growth, photosynthetic activity and water use efficiency of leek ( Allium porrum L. ‘Gigante Suizo’)

JEZDINSKÝ, A., PETŘIKOVA, K., SLEZAK, K., POKLUDA, R.: Eff ect of drought stress and mycorrhizal inoculation on the growth, photosynthetic activity and water use effi ciency of leek (Allium porrum L. ‘Gigante Suizo’). Acta univ. agric. et silvic. Mendel. Brun., 2012, LX, No. 8, pp. 101–108 During the experiments it was examined two irrigation levels: 1. optimal water supply – the irrigation activation by available water capacity (AWC) < 65 %; 2. drought stress – irrigation activation by AWC < 45 %) and inoculation of plants by the vesicular-arbuscular mycorrhizal fungus Glomus in leek culture. The eff ect of treatments on the photosynthetic rate (A), transpiration rate (E), water use effi ciency (WUE), biomass production (weight, dry matter content of diff erent plant part), size of pseudostem, leaf area and specifi c leaf area (SLA) was observed. The drought stress had eff ect on all observed parameters: it decreased the photosynthetic and transpiration rate (A: from 5.04–5.37 to 3.33–3.43 μmol CO 2 .m −2 . s −1 , E: from 1.78–1.91 to 0.99–1.03 mmol H 2 O. m −2 . s −1 in the average of 5 measuring date), the weight total fresh weight of plants: from 355–453 g to 152–255 g), and the leaf area, the length and diameter of pseudostem, too. The WUE, the dry matter content and the thickness of leaves increased under stress. In the most parameters, the water supply had stronger eff ect than the inoculation. The inoculation had positive eff ect mainly under drought stress: it improved the WUE at 3 measuring time (from 3.45 to 3.50 μmol CO 2 .mmol H 2 O −1 , in the average of 5 measuring date), increased the weight (total fresh weight of plants: from 152 g to 255 g) and the leaf area (from 0.16 to 0.12 m 2 ). leek, Glomus, inoculation, morphology, photosynthetic rate, specifi c leaf area, water use effi ciency (WUE)