Response of growth and photosynthetic characteristics of Polygonatum cyrtonema to shading conditions / 中国中药杂志

The purpose of this experiment was to study the effects of different shading conditions on the growth,physiological characteristics and biomass allocation of Polygonatum cyrtonema,which offered a theoretical basis for its cultivation.Different light environments(100%,80%,60% and 35% light transmittance) were simulated with shading treatments.Growth and photosynthetic indexes of P.cyrtonema were measured and the variances were analyzed.The results show that shading decreased superoxide anion radical(O-·2)production rate and hydrogen peroxide(H_2O_2) accumulation,kept the activity of SOD,POD and CAT enzyme at a high level.Furthermore,The content of chlorophyll a and chlorophyll b,net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),maximal photochemical efficiency of photosystem Ⅱ(Fv/Fm),photochemical quenching index(q P) and effective quantum yield of photosystem II(ΦPSⅡ) of P.cyrtonema were increased while the intercellular CO2 concentration(Ci),Foand NPQ were decreased by shading.Shading is beneficial to P.cyrtonema growth,can increase the total biomass P.cyrtonema.The allocation proportion of biomass on the aerial portion of P.cyrtonema increased but underground parts decreased with increasing shading conditions.In this study,P.cyrtonema can grow well in shading conditions,shading is beneficial to the formation of the yield and quality of the rhizomes of P.cyrtonema,especially in 65% light transmittance.

Effects of N and Zn interaction on growth, yield and active components of Agastache rugosa / 中国中药杂志

The study is aimed to explore the effect of combination use of nitrogen(N) and zinc(Zn) fertilizers on the growth, yield and the effective components of Agastache rugosa. A. rugosa was grown under two N application rate (120, 300 kg·hm⁻²) and five Zn levels (0, 20, 50, 100，150 kg·hm⁻²) under field condition. The effect of the treatments on the physiological indicators, distribution of nitrogen and zinc and volatile oil components of A. rugosa were studied. The results showed that the combination use of N and Zn could significantly affect the growth and development, yield and volatile oil components of A. rugosa. Under the test conditions, the highest yield of Agastaches Herba was obtained when 50 kg·hm⁻² of Zn fertilizer was applied with high N application rate of 300 kg·hm⁻². Under the same N application rate, the increase of Zn production was positively correlated with the amount of Zn application in a certain concentration range, but excessive Zn application led to the decrease of yield. With the increase of N application level, the content of Zn also significantly increased. The combination use of N and Zn increased the yield of Agastaches Herba. High level of N application was beneficial to the absorption and accumulation of N and Zn of A. rugosa. Zn fertilizer could also promote the absorption and accumulation of N of A. rugosa. The interaction between N and Zn had significant influence on the main chemical constituents of the volatile oil of A. rugosa. Among the volatile oil chemical constituents of A. rugosa the content of pulegone (34.56%-53.91%) and piperonyl methyl ether (18.86%-42.27%) were much higher. Under the same N application rate, different Zn application rates also had significant effects on the main chemical components of volatile oil.