Abstract

The dried over-ground parts of the plant Glechoma longituba are one of the important ingredients used in traditional Chinese medicine (TCM). In this study, five different watering treatments, namely 95 to100% (T1), 80 to 85% (T2), 65 to 70% (T3), 50 to 55% (T4) and 35 to 40% (T5) of field capacity were used to investigate the effects of water deficiency on the growth, physiological characteristics and total flavonoid content of G. longituba. The study found that epidermis, palisade tissue, spongy tissue and vascular cylinder thickness peaked in the T2 treatment and then decreased in the other treatments in anatomy structure of leaf. And anatomical structure analysis of the stem revealed that the thickness of the cortex and the vascular cylinder were the highest in the T2 treatment, too. Water stress increased the thickness of the vessel walls in the xylem and the size of the parenchyma cells in the cortex, whereas it decreased the size of the parenchyma cells in the pith. As the water stress intensified, the resulting changes found in physiological indices suggested that water stress stimulated the level of redox activity. In addition, the yield of total flavonoids in the T2 treatment was higher than in the other treatments. Our results suggested that 80 to 85% of field capacity is the most suitable watering treatment for the growth of G. longituba. This procedure would be suitable for the domestication of G. longituba.

Key words: Glechoma longituba, water treatment, physiological characteristics, total flavonoids.