Propagation of three important medicinal plants in Aacanthaceae; <em>Andrographis paniculata</em>, <em>Barleria prionitis</em> and <em>Rhinacanthus polonnaruwensis</em>

Abstract

High demand has increased the exploitation of medicinal plants from the wild. Insufficient information on germination and seedling development hinders the propagation of such plants. Thus, seed germination and seedling development of three medicinal species in the family Acanthaceae were studied. Seeds were collected during their peak dispersal period. Seed moisture content (SMC) was determined using the oven dry method. Seed germination and effect of 500 ppm GA treatment and dry storage on germination were studied. Seedlings were transferred to three potting media, viz, sand: coir dust: compost, sand: compost, sand: coir dust and sand: garden soil (in equal ratio) and raised until 45 days in a greenhouse. Number of leaves and height of plants were measured in 7-day intervals. Fresh weight, root, shoot and leaf dry weights were measured after 45 days. SMC of all the studied species was < 15%, revealing that they are orthodox. Thus, no special conditions are needed to store them. Rhinacanthus polonnaruwensis seeds had a T50 < 30 days, indicating that they have no dormancy. Barleria prionitis and Andrographis paniculata seeds were dormant as the T50 was > 30days. Germination increased > 80 % after GA3 treatment and dry storage. Therefore, seeds of B. prionitis and A. paniculata have non-deep physiological dormancy. Dry storage for 1 and 3 months could be recommended for these two species, respectively. Seedlings of all three-study species showed high growth performance in the sand: garden soil potting medium which could be recommended to grow these species. These information will be useful to germinate and grow these three species for large-scale commercial pursoses.

Keywords

• germination, growth parameters, physiological dormancy, seed dormancy, seedling development