This study attempted to understand the effects of BAP and ethrel on organogenesis of protocorm-like bodies (PLBs) in Dendrobium kingianum under white fluorescent lamps in vitro. BAP is the most effective cytokinin for multiplication in plant tissue culture. Ethrel regulates many aspects of plant morphogenesis. The highest number of PLBs (13.1) as against in control (8.1) and the highest number of developing shoots (2.1) was recorded in the medium containing 0.1 mg/l BAP combined with 1 mg/l ethrel. Increase in fresh weight showed higher values in same combination. Low concentration of BAP alone increased in the number of PLBs but showed inhibitory effects on shoot formation. On the other hand low concentration of ethrel alone increased both number of PLBs and shoots after 4 weeks in vitro.Dendrobium is popular in the international floriculture industry due to its floriferous flower sprays, wide spectrum of colors, sizes and shapes; year-round availability and long flowering life ( Kuehnle 2007, Khosravi et al. 2009). BAP is the most effective cytokinin for multiplication followed by Kn and 2-ip (Hu and Wang 1983, Schuch andErig 2005). Ethylene is unique among plant hormones; it is a simple hydrocarbon that affects growth, differentiation, and senescence in plants in concentrations as low as 0.01 µl/l (Reid 1995). Ethylene regulates many aspects of plant morphogenesis. Growth and development of cells cultured in vitro are largely dependent on the presence of phytohormones. Hence, modification of phytohormone composition and interaction in the nutrient medium has been the primary strategy to manipulate morphogenesis in vitro. Research on specific effects of ethylene on cell division is rather limited. From the

Throughout this study, the objective was to determine the most effective carbohydrate (CHO) sources under different light-emitting diodes (LEDs), and the impact of chlorocholine chloride (CCC), for the in vitro regeneration of the protocom-like bodies (PLBs) in Phalaenopsis ‘Fmk02010’. We applied 15 LEDs combined with three CHO sources and five CCC concentrations in the study. Organogenesis of PLBs was very poor in maltose both for the number of PLBs and their fresh weight (FW) compared to media containing sucrose and trehalose. Sucrose was the best CHO source under the red-white (RW) LED for the in vitro organogenesis of PLBs (PLBs: 54.13; FW: 0.109 g), while trehalose was best under the blue-white (BW) LED (PLBs: 36.33, FW: 0.129 g). The red-blue-white (RBW)-trehalose combination generated a suitable number of PLBs (35.13) with the highest FW (0.167 g). CCC at 0.01, 0.1, and 1 mgL−1CCC had no effect on PLB formation or FW, but 10 mg L−1 reduced both. RW-sucrose, BW-trehalose, and RBW-trehalose were the best combinations for PLB organogenesis. The addition of low concentrations of CCC in the plant culture medium are unnecessary.

An experiment on pinching (viz. P 0 ; without pinching and P 1 ; with pinching) with 3 replications showed the tallest (37.7 cm) and the shortest plant (33.4 cm) without pinching and with pinching, respectively. Maximum number of leaves (30.1) and flowers (58.7) per plant were recorded following pinching (P 1 ); and minimum number of leaves (26.8) and flowers (37.9) per plant were from without pinching (P 0 ).Key words: Pinching, Chrysanthemum indicum, Flower, Terminal bud, Growth, Yield Chrysanthemum (Chrysanthemum indicum L.) is a popular flower plant, belongs to Asteraceae. Chrysanthemum, commonly known as the Mum flower, is one of the most popular decorative flowers in the world. In recent years, demand for pot plants for house decoration and for use in amenity horticulture, in many countries in the world has steadily been increased for their outstanding aesthetic beauty, long lasting quality, and their good prospect of marketing as cut flowers and potted plants (Erler and Siegmund 1986). It is also very popular in floral bouquets and flower arrangements. A large number of chrysanthemum cultivars are the result of selection by growers and breeders in many centuries. The climatic condition of Bangladesh is well-adapted for cultivation of chrysanthemum but it's commercial production in Bangladesh is very low. It grows well in sandy loam soil with high light intensity.Pinching is removing the terminal growing portion of stem mainly for inducing branch and also to reduce the plant height. Pinching makes chrysanthemums compact, bushy plants, with more blooms. The plant height, stem diameter and number of inflorescences increase in the number of pruning's (Brum et al. 2007). In Bangladesh, only limited studies have been done on pinching for growth and yield of chrysanthemums. The present research work was undertaken to study the effects of pinching on growth and yield of chrysanthemum.The experiment was conducted at Horticulture Farm, Sher-e

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