Teruo Wada

Novel Methods to Generate Active Ingredients-Enriched Ashwagandha Leaves and Extracts.

Ashwagandha (Withania somnifera) is an Ayurvedic herb commonly used in world-renowned traditional Indian home medicine system. Roots of Ashwagandha have been traditionally known to possess a variety of therapeutic and health promoting potentials that have not been sufficiently supported by laboratory studies. Nevertheless, most, if not all, of the preventive and therapeutic potentials have been assigned to its bioactive components, steroidal alkaloids and lactones. In contrast to the traditional use of roots, we have been exploring bioactivities in leaves of Ashwagandha. Here, we report that the leaves possess higher content of active Withanolides, Withaferin-A (Wi-A) and Withanone (Wi-N), as compared to the roots. We also established, for the first time, hydroponic cultivation of Ashwagandha and investigated the effect of various cultivation conditions on the content of Wi-A and Wi-N by chemical analysis and bioassays. We report that the Withanone/Withaferin A-rich leaves could be obtained by manipulating light condition during hydroponic cultivation. Furthermore, we recruited cyclodextrins to prepare extracts with desired ratio of Wi-N and Wi-A. Hydroponically grown Ashwagandha and its extracts with high ratio of withanolides are valuable for cancer treatment.

Rice Cultivation by Direct Seeding into Untilled Dry Paddy Stubble: Proposal of a New Seeding Method and Germination Rate with That

Abstract We propose direct seeding into the previous years stubbles as a labor-saving rice cultivation method in untilled dry paddy fields. The effectiveness of this method was determined by conducting a seeding experiment. Three seeding holes at depths of 20 or 40 mm were bored per stubble, and 4 or 7 seeds were sown per stubble. Four sets of experiments were designed with different combinations of seeding depth and seeding number, and each set of conditions was replicated 3 times. Germination rate and stubble width were determined 1 month after seeding. Our results suggest that seeding in stubbles may be effective in preventing bird damage typically noted in shallow seeding but that deep seeding restricts seedling growth through shielding of sunlight.

Establishment of Hydroponic Cultivation of Ashwagandha for Active Ingredient Enriched Leaves

Hydroponics, growing plants in water with appropriate nutrients and other cultivation conditions including temperature and CO2, is a convenient way to (i) avoid the unpredictable extreme weather conditions that affect the cultivation of plants in soil, (ii) safe guard against environmental stresses including industrial pollutants and pesticides and (iii) ensure stable content of active components that are important for value of plants as either functional food or medicine. Considerable advances have been made in establishment of hydroponics cultivation conditions for a variety of leafy vegetables. However, their use has not expanded to medicinal herbs. In this chapter, we review the very first hydroponic cultivation of Ashwagandha, a medicinal herb.

Rice Cultivation by Direct Seeding into Untilled Dry Paddy Stubble: Panicle Number and Rice Yield

Abstract We hypothesized that direct seeding into the previous years stubbles in untilled dry rice fields would be a labor-saving rice cultivation method and sought to determine the effectiveness of this method. Three seeding holes (depth, 20 or 40 mm) were bored per stubble, and 4 or 7 seeds were sown in these holes. Four sets of experiments (performed in triplicate) were designed with different combinations of seeding depths and seed numbers. Each experimental plot (2 × 2 m) included 91 stubbles at 150-mm intervals with 300-mm inter-row distances. As a control, 7 seeds were sown in a ditch (depth, 20 mm). Productive panicle number and winnowed paddy yield were determined after harvesting. The experimental results demonstrate the effectiveness of our seeding technique.

Visualization of Vessels in Tomato Seedlings Using Girdling

A novel method for the easy and detailed visualization of water pathways (i.e., xylem vessels) involving girdling after staining is proposed. This technique was applied to intact seedlings as well as seedlings whose vessels were intentionally damaged to evaluate the effectiveness of the procedure. The applicability of the technique to grafted fruit-vegetable seedlings was tested using tomato seedlings (Lycopersicon esculentum Mill. ‘Momotaro’). The vessels were stained with congo red via the roots prior to girdling. This technique is unique in that it allows the visualization of the vessel network by a simple procedure as well as the continuous and unambiguous observation of the vertical and horizontal networks of vessels. Using the technique, we can observe a complex network of vessels, including vessel branching and vessel regeneration after damage.