STUDIES ON THE AGRONOMIC CHARACTERISTICS, YIELD, AND SAIKOSAPONIN CONTENT OF 2 BUPLEURUM SPECIES IN TAIWAN

Two Bupleurum species (Bupleurums spp.), i.e., B. falcatum L. cv. Tain ung No.1 and B. kaoi Liu, Chao, et Chuang, were compared for their dif ferences in seed germination, plant characteristics and root yield, an d saikosaponin content. Experimental data showed that the most suitabl e temperature for seed germination of the two species was 16 degrees C . Two treatments, cold stratification at 4 degrees C for 8 weeks and p resoaking by running water for 2 days, resulted in higher germination rates. Tainung No.1 possessed a higher 1,000-seed weight than B. kaoi. However, field survival rate was higher for B. kaoi than for Tainung No.1. Results from field experiments also revealed that stem diameter, leaf width and fresh weight of various plant parts except the root we re superior for Tainung No.1 to B. kaoi. On the contrary, tiller numbe r and root diameter and weight of B. kaoi were higher than those of Ta inung No. 1. Harvest date and elevation had significant effects on the agronomic performance of the two Bupleurum spp. Measurements of most traits of the 6 month-old plants were superior to those of the 3 and 1 0 month-old plants. Cultivation at higher elevation (850 m) favored th e development of leaf weight and root length, while cultivation at low er elevation (85 m) facilitated the development of plant height, root diameter, and root weight. Analysis of saikosaponin concentration in t he root tissue revealed that average contents of 3.19 and 3.80 mg/g, r espectively, for plants grown at the elevations of 850 m and 85 m. Com parison between the two species showed no significant difference in sa ikosaponin content, ranging from 3.45 to 3.55 mg/g.