[Effect of exogenous Ca2+ on protective infection of Pinellia ternata and accumulation of major components under high temperature stress].

OBJECTIVE: To study the effect of exogenous Ca2+ on protective infection of Pinellia ternata and accumulation of major components under high temperature stress. METHOD: The soilless cultivation experiment was applied, stress resistance index of P. ternata leaves, statistics the rate of lodge P. ternata,the content of oxalate in different places in the plant, the content of total alkaloids, total organic acids and glucosine in P. ternata tubers were measured based on different concentrations of exogenous Ca2+. RESULT: The test results showed that, at lower concentrations of Ca2+ treatments, the rate of lodge P. ternata was higher than that of the others. With Ca2+ concentration increasing, activities of SOD and POD initially increased and then decreased, however, proline level tended to be down then up. Soluble oxalic acid content was lower than the content of unhandled treatment in P. ternata leaves and tubers; with Ca2+ concentration increasing, soluble oxalic acidl content and yield showed a tendency of decrease after increase in the leaves and tubers. Compared with other treatments, spraying 400 mg x L(-1) Ca2+ significantly enhanced the accumulation of total alkaloid and guanosine in P. ternata tubers. At Lower concentrations of Ca2+, the content of total free organic acid was higher in the tuber. CONCLUSION: With the treatment of Ca2+ the capacity of heat resistance was improved in P. ternata plants, the rate of lodge P. ternata was postponed, growing period was extended and corresponding production has increased by spraying exogenous Ca2+.

[Effects of NH4(+)-N/NO3(-)-N ratio in applied supplementary fertilizer on nitrogen metabolism, photosynthesis and growth of Isatis indigotica].

OBJECTIVE: To study the effect of NH4(+)-N/NO3(-)-N ratios in the applied supplementary fertilizer on the growth, nitrogen metabolis related enzymes activity and photosynthetic characteristics of Isatis indigotica. METHOD: The sand culture experiment was conducted, and seedling of I. indigotica was fertilized with the mixed nutrition that containing the Hoagland's macro elements and the Aron's micro elements, the additional 63 mmol N was supplementary with the NH4(+)-N/NO3(-)-N ratio of 100:0, 75:25, 50:50, 25:75 and 0:100. RESULT: The biomass of I. indigotica increased at first when the supplementary N of NH4(+)-N/NO3(-)-N ratio changed from 100:0 to 50:50 and decreased afterwards. The maximum value was at 50:50 and the minimum at 100: 0. With increasing the ratio of NO3(-)-N, the activity of nitrate reductase and glutamine synthetase increased and then decreased and the relationship between the activity and the ratio could be described with an approximate parabola curve. The net photosynthetic rate of I. indigotica was the highest at the NH4(+)-N/NO3(-)-N ratio of 75:25 and the lowest at 100:0. CONCLUSION: Increasing the NO3(-)-N ratio properly was beneficial to promote the growth and improve the activity of nitrate reductase and glutamine synthetase and net photosynthetic rate of I. indigotica.

[Salt-tolerance evaluation of seedlings of medicinal Chrysanthemum morifolium cultivar].

OBJECTIVE: To evaluate salt tolerance of seedlings of 4 medicinal C. morifolium cultivars to be transplanted, and to expand the planting area. METHOD: Seedlings were cultivated in hoagland nutrient solution containing various concentrations of NaCl for 30 days. The height, dry weight and chlorophyll content were investigated. Identification index mainly in relative growth rate, the evaluation of NaCl effects on the growth, K+, Na+ and Cl- distribution in seedlings were surveyed. RESULT AND CONCLUSION: The salt tolerance was difference among four cultivars of C. morifolium. The salt tolerance of "Dabaiju" and "Changbanju" was weak, while "Hongxinju" and "Xiaobaiju" was strong. "Hongxinju" and "Xiaobaiju" may be planted in salinte soil area.