[Study on growth rhythm in populations of Pinellia ternata (Thunb.) Breit].

OBJECTIVE: To study the genetic diversity of Pinellia ternata. the growth rhythm. METHOD: Sixteen populations of P. ternata. originated mostly from middle and lower reaches of Yangtze River valley were collected and cultivated in Weigang Experimental Farm of Nanjing Agricultural University with same cultural conditions, whose differences in growth rhythm have been observed and compared continuously for two years. RESULT AND CONCLUSION: There are obvious differences in sprouting, lamina spreading, bolting and "sprout tumble", Three times of "sprouting" and so-called "sprout tumble" and two fast-growing periods for plants in most of the populations in spring and autumn respectively were observed within a year, including mass bolting in May. But the starting time and duration are very different from population to population, with flowering being prior to sprouting in the population originated from Jurong county.

[Comparative study on three types of chemicals extracted from tubers of populations of Pinellia ternata (Thunb.) Breit].

OBJECTIVE: To study the genetic diversity of Pinellia ternata. on the chemical composition. METHOD: Fifteen populations of Pinellia ternata. originated mostly from middle and lower reaches of Yangtze River valley were collected and cultivated in Weigang Experimental Farm of Nanjing Agricultural University with same cultural conditions, and contents in three types of index chemicals extracted from tubers of the populations have been compared continuously. RESULT AND CONCLUSION: The difference in contents of beta-sitosterol and Val and Arg extracted from tubers of the populations has been observed, and those contents are also different with harvesting time. But the mean contents of each of the three types of chemicals in autumn are all higher than those in summer respectively.

A comparative study on essential oil components of wild and cultivated Atractylodes lancea and A. chinensis.

To clarify the variation in the pharmacologically active components of the essential oil contained in the rhizomes of Atractylodes lancea and A. chinensis growing in China, we transplanted the rhizomes of the wild plants from 18 populations, including A. koreana, in the same experimental field. After two or three years' cultivation, main essential oil components, i.e., the sesquiterpenes: elemol (1), atractylon (2), hinesol (3), beta-eudesmol (4), selina-4(14),7(11)-dien-8-one (5), and the polyacetylene of atractylodin (6) were determined by capillary gas chromatography. The analytical data of 306 cultivated plants were compared with plants collected in their habitat. A. lancea varied significantly in the contents of the components after cultivation; however, the correlation coefficient in the contents of 3, 4, and 6 between the wild and cultivated plants were 0.985, 0.954, and 0.945, respectively (p < 0.001). Compared to this, A. chinensis had constant content values. Three types of A. lancea and two types of A. chinensis, which are distinguished by the characteristics of the components in the wild conditions, were statistically recognized after cultivation. From these results, it was determined that the geographical variation in the components of these species mainly reflects genetic variability.

[Research on correlations between climatic factors and diosgenin content in Dioscorea zingiberensis Wright].

Dioscorea zingiberensis wright is native to China. In this paper correlations between seven climatic factors (mean annual temperature, mean annual relative humidity, mean annual 5 cm soil temperature, annual precipitation. Annual sunshine hours, mean annual sunshine percentage and annual greater than or equal to 10 degrees C accumulative temperature) and diosgenin content has been reported. It is annual precipitation and mean annual 5 cm soil temperature that are real principal factors affecting the diosgenin content. The most suitable climatic range for the biosynthesis and accumulation of diosgenin is as follows: Annual precipitation: 800-900 mm, 850 mm the best. Mean annual 5 cm soil temperature: 15-17 degrees C, 16 degrees C the best.