Development of Growth Models Based on Years for Salep Orchid Planted in Natural Environment

Abstract The orchids that produced tuber are known as salep orchids and have been collected from nature for centuries as a medicinal and aromatic plant. These orchids are endangered species because of their limited vegetative and generative production possibilities. Salep orchids, seed germination has been achieved with in-vitro studies, but no source has been found regarding the development of germinated seeds over the years. In this study, Dactylorhiza euxina (Nevski) Czerep. was used as research material. Seeds that were determined to germinate in nature were observed to develop in their own environment for five years and some morphological characteristics (plant height, number of leaves, leaf length, leaf width, total weight, tuber width, and tuber weight) were determined at the end of each vegetation year. Plants that start to develop with seed germination produce one leaf and a tuber of 0.115 g in the first year. When the tubers obtained from the first year were planted again, the plants was obtained 2-3 leaves and they were formed 0.465 grams of tubers. In the third year plants bloom for the first time. The period until flowering in the plant was called maturity period and Dactylorhiza euxina (Nevski) Czerep. was found to have a 3-year maturity period. Plants produced tuber 0.850 g in the third year, 1.585 g in the fourth year and 2.522 g in the fifth year. According to the mathematical modeling, the relationship between year (Y) and fresh tuber weight (FTW) was found Y = 1.22 + (1.61 × FTW) and there was a significant relationship among year, fresh tuber weight, and total biomass (TBM). This equation Y = 1.05 + (0.76 × FTW) + (0.14 × TBM) shows us the mathematical relations of year, fresh tuber weight, and total biomass. The mathematical relations among to fresh tuber weight, total biomass, and plant height (PH) was produced Y = 1.74 - (0.11 × FTW) + (0.57 × TBM) - (0.09 × PH). R2 values were found 0.95-0.99. All R2 values and standard errors were found to be significant at the p < 0.01 level.