| Pinellia ternata?Thunb.?Breit.is a precious herbal medicine in Chinese.Pinellia tuber contains many chemical ingredients,which have the functions of removing dampness to reduce phlegm and relieving vomiting in stomach.Pinellia tuber is frequently used in traditional Chinese medicines.However,in the cultivation process of Pinellia ternata,the growing environments are required to avoid strong illumination,drought,waterlogging and high temperature.In addition,excessive collection leads to the shortage of high-quality resources.Therefore,in order to improve the medicinal quality of Pinellia tuber,it is necessary to study the effects of the factors on the quality of Pinellia tubers.This experiment explored the effects of particle size,allelopathy,temperature,illumination intensity and UV-B radiation on Pinellia tuber,which could provide theoretical basis for improving the quality of Pinellia tuber and rationally exploiting and utilizing of Pinellia resources.The results were as follows:1.Effects of different tuber sizes on active ingredients,nutritional ingredients and antioxidant capacity of Pinellia tuber.The materials were divided into four grades according to the diameter of Pinellia tuber.The tuber diameters of I,II,III and IV were d?1 cm,1 cm<d?1.5 cm,1.5 cm<d?2 cm and 2 cm<d?2.5 cm,respectively.The experimental results showed:?1?the contents of alkaloids,?-sitosterol,free amino acid and soluble sugar in I size tuber were the highest.Flavone,protein and vitamin C content in III size tuber was the highest.Vitamin C content was highest in IV size tuber.?2?The superoxide radical scavenging activity and hydroxyl radical scavenging ability reached the most value in III size tuber?1.5 cm<d?2 cm?and II size tuber?1 cm<d?1.5 cm?,respectively.However,DPPH radical scavenging activity decreased with the increase of tuber diameter.2.Effects of tuber extract and soil extract of Pinellia ternata on the germination and tuber quality.Each extract had four levels of mass concentrations?25,50,75,100 mg/mL?with 0 mg/mL as the control group.The results showed that:?1?tuber extract significantly inhibited the germination of Pinellia;The low concentration?25 and 50 mg/mL?of soil extract promoted the germination of Pinellia,while showing an inhibitory effect at high concentration?75 and 100 mg/mL?.?2?tuber extract significantly reduced the alkaloid content in tuber.The soil extract significantly increased the alkaloid content.Both treatments significantly reduced the contents of flavone,protein and soluble sugar.3.Effects of temperature and illumination intensity on the germination and active ingredients and nutritional ingredients in Pinellia ternata.The experiment included three levels of temperature gradients?20°C,25°C,30°C?and three levels of illumination intensity gradients?2000 Lux,4000 Lux,6000 Lux?.The results showed that:?1?it was most suitable for the germination of Pinellia ternata when the temperature is 25°C and the illumination intensity was 6000 Lux,but the content of active and nutritional ingredients was relatively low in tuber after harvest.?2?when the temperature was 30°C and the illumination intensity was 4000 Lux,the contents of flavonoid,protein,vitamin C and free amino acid in Pinellia tuber were the highest.Considering the active and nutritional ingredients.It is helpful for accumulation of many ingredients in tuber when temperature was 30°C and the illumination intensity was 4000 Lux.4.Effects of ultraviolet-B?UV-B?on physiological characteristics,active ingredients and nutritional ingredients of postharvest tuber.The UV-B radiation intensities in the experiment were:0?U0?,200?U1?,400?U2?and 600?W cm-2?U3?,respectively.Enhanced UV-B radiation significantly increased the rate of superoxide radical production,the activities of phenylalanine ammonia lyase enzyme,cinnamic acid-4-hydroxylase,4-Coumarate CoA ligase enzyme,ant the contents of alkaloid,flavone,protein,vitamin C and free amino acid in Pinellia tuber.The higher UV-B radiation?U2 and U3?significantly decreased soluble sugar content in tuber.?-sitosterol content was only significantly increased by U3 treatment over the control.The results showed that enhanced UV-B radiation could promote the secondary metabolism of postharvest tubers and increase the contents of active and nutritional ingredients?except for soluble sugar?in tuber.This experiment explored the effects of particle size,allelopathy,temperature,illumination intensity and UV-B radiation on the quality of Pinellia ternata were explored,which supplied theoretical basis for the selection of,accumulation of medicinal ingredients and the development and utilization of Pinellia resources. |
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