Effect of some applications on the physiological and morphological properties of Lilium (Lilium hybrida La.) grown by water stress conditions

Objective: With the decrease in the amount of water, studies on water stress began to gain importance among ornamental plants. The lilies, which has an increasing export share in the world, enables year-round production and has large flowers, is very sensitive to drought stress in the growth period of its life cycle, although it continues its life as a bulb during dormant periods. For these reasons, physiological and morphological changes in stress conditions should be determined in lilies under water stress and in the case of some chemicals application. The aim of the study is to determine the morphological and physiological effects of lilies by applying plant growth regulator and chemical compounds to the plants at limited water levels and to reveal the appropriate irrigation dose for cultivation. Materials and Methods: Lilium LA hybrid "Trebbiano Gerrit Zalm", Lilium LA hybrid "Ercolano" and Lilium LA hybrid "Pedara" varieties were used as plant material. In this research, a randomized block design was carried out; 5 different irrigation doses (25%, 50%, 75% and 0% (without water) and 7 different applications (35 combinations in total) with glycine betaine and L-proline from compatible solute, salicylic acid and epibrassinolide from plant growth regulators, nano silica and nano titanium dioxide from nanomaterials and control, 3 replicates and 12 lilies bulbs in each replicate. The study was carried out in 3 periods: 2017 Autumn trial, 2018 Spring trial and 2018 Autumn trial. Morphological measurements such as flower stalk lenght, number of flower buds, vase life, number of bulblets and physiological measurement values such as relative water content, electrolyte leakage, chlorophyll density and leaf surface temperature were determined in each period. Results: The highest values of flower stalk lenght, flower stalk diameter, length of leaves, fresh and dry weight of flower stalks, number of flower buds, flower buds diameter and vase life which are important criteria in terms of plant growth and flower quality were obtained from the lilies applied with 100% and 75% water dose. The lowest values were obtained from 0% water dose. When the values of the leaf relative water content are examined in general, it is seen that the lowest values are obtained in the plants where 0% and 25% water levels are applied. The values of electrolyte leakage and chlorophyll concentration showed differences according to the growing periods and the dates of measurement. When the leaf surface temperature values were evaluated in general, it was determined that the highest values were obtained from 0% water dose. The physiological effects of stress conditions on plants varied according to the applications. Conclusion: When the study is evaluated in general, 75% irrigation level (25% water deficit) makes high quality flower cultivation possible. It has been determined that nano silica applications have a positive effect on flower branch quality in the trials carried out in the autumn period. When the measurements made regarding the formation of bulblets are evaluated in general, if the aim is to increase the formation of bulblets rather than the size of the bulblets, 50% water dose may be preferred by the breeders. In this context, the sustainability of water resources will be ensured and the cost of water will be reduced. Key Words: Plant Growth Regulator, Flower Bulb, Nanomaterial, Compatible Solute, Water Deficit.