[Dynamic studies on photosynthetic and growth characteristics of Angecila dahurcia].

Photosynthetic and growth characteristics of Angelica dahurica were studied in order to clarity the relations of photosynthesis, growth and root dry weight, and provide a theoretical basis for its cultivation. Photosynthesis and growth indexes were meas- ured every 25 days. The contents of chlorophyll a, b, a + b, soluble protein and the activities of Hill reaction, Ca(2+)-ATPase, Mg(2+)-ATPase had an increasing trend; They had the highest value in leaf high-speed growth period. Then, they were decreased in root high- speed growth period. The root dry weight showed negative corelation with photosynthetic characteristics indexes except stomatal con- ductance, however, the negative corelation only from net photosynthetic rate and Ca(2+)-ATPase were significant. The vegetative growth period of spring sowing A. dahuricia was divided into three phases: seedling period, leaf high-speed growth period and root high-speed growth period. The root dry weight showed a significantly positive corelation with the root diameter, leaf dry weight, shoot dry weight, aboveground dry weight. There was the competitive relation between aboveground and underground, so underground growth could be es- timated from leaf area and shoot dimeter.

[Study on the dynamic growth rhythm of Achyranthes bidentata under different densities].

OBJECTIVE: The experiment was conducted to study the dynamic growth rhythm of Achyranthes bidentata under different densities. METHOD: The plant samples were collected to measure the growth rate of each organ. RESULT: Under different densities, the growing dynamic rhythm of A. bidentata were similar. The growth of main root exhibited a trend of "slow-fast-slow" by stages. The increase of dry root weight was fastest during the period of 30-40 days before harvest. The dry-matter increasing rate of whole plant was fastest in the later period of branching stage. The differences of root yields among the plants growing under different densities were significant. CONCLUSION: For high yield and good quality, the density of planting of A. bidentata should be considered.

[Primary study on developmental speciality and cultural practices of Amphicarpaea edgeworthii].

OBJECTIVE: The experiments were conducted to study specialty of seed germinating, plant growing and developing and cultural practices of A. edgeworthii. METHOD: The germinating and sowing test, growth habitants, photosensitive reaction of seedling from subterraneous seeds and above ground seeds on A. edgeworthii were studied in this experiment. RESULT AND CONCLUSION: The results indicated that (1) The water could not be absorbed by seed from plant above ground; (2) The underground and above ground seeds could normally germinate, grow, blossom and bear fruits, A. edgeworthii sowed in early May, blossomed in early September and matured in the last ten days of October; (3) The seed leaf of seedling grew underground; (4) The underground seed was produced from subterraneous branch stem which developed from node of seed leaf; (5) A. edgeworthii was shade demanding, high-temperature sensible short-day light plant. The flowering could be greatly advantaged by short-day light treatment (12, 10, 8, 6 h). Cultural practices were studied also in this experiment.