Effect of altitude differences on seed germination and seedling growth in Rhododendron luteum Sweet

Abstract

The aim of this study is to encourage the use of Rhododendron luteum Sweet, distributed in high altitudes in its natural habitat, in planting designs and landscape architecture and to cultivate these plants by seed propagation. In this context, the effects of different altitudes on R. luteum germination and post-germination seedling growth were investigated. The germination success of R. luteum seeds collected at 3 different altitudes, 1,586 m, 1,760 m and 2,100 m a.s.l., was investigated under greenhouse conditions at a temperature of 25 ± 2 °C and humidity of 70 ± 2% and in soil, peat, soil + peat (5:5), peat + sand (7:3), soil + sand (7:3) and soil + peat + sand (4:4:2) propagation media. The post-germination seedling height, root length, and the number of leaves of the seedlings were determined. Different altitudes had significant effects (P < 0.05) on height, root length, and the number of leaves of the seedlings. The highest germination percentage was 76.69% with the seeds collected from 2,100 m. Furthermore, seedlings that grew from these seeds possessed the best seedling growth with a greater height, longer roots, and a greater number of leaves. Keywords: landscape architecture, Rhododendron luteum, seed propagation, variation