Abstract
For the improving regeneration and conservation of medicinal B. polystachya, stem cuttings were obtained from trees in Aseer area, Saudi Arabia, and two experiments were conducted to investigate factors affecting rooting (season and auxin type and concentration) and assessing growth performance of rooted cuttings. To test rooting factors, cuttings were collected during autumn, winter, and spring and treated with 500, 1000, and 2000 ppm indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and naphthyl acetic acid (NAA) during each season. Following the evaluation of rooting, the second experiment was conducted using the best rooted cuttings, to test growth performance of seedlings under the effect of different auxins and four types of growth media. Cuttings collected during spring and treated with IBA had the highest rooting percentage (91%-98%), number of roots (23-29 roots cutting(-1)), and root length (26-39 cm). Regarding seedling growth, planting cuttings in growth substrate containing clay, sand, and peat moss (1:1:1 v/v) resulted in highest quality seedlings in terms of leaf number, stem height and relative growth rate. We concluded that spring cuttings collection treatment with 1000 ppm IBA, and transplantation to fertile growth media can be a useful technique for mass production of B. polystachya