Effects Of Rehydration Under Drought Stress And Mycorrhizal Inoculation On Physiology And Secondary Metabolites Of Cannabis Sativa L.

Cannabis sativa L.is an annual cannabis plant belonging to genus Cannabis,family Moraceae Gaudich.As an upright herb,it is a very good cash crop.The fruits can enrich the intestine,the flowers can cure ill wind,amenorrhea and amnesia,and can even relieve nerve diseases such as glaucoma and migraine,which is of high value in both industry and medicine.In recent years,due to the influence of human activities and global warming,drought has become increasingly serious,which has a great impact on the growth and development of plants and their yield.Arbuscular mycorrhiza can form symbiotic relationship with plants and regulate the damage caused by stress on plants.In order to investigate the drought stress tolerance of C.sativa L.vulcanis and the content changes of secondary metabolites after inoculation and rehydration.In this paper,3 months old C.sativa seedlings as the research object in the way of soil culture pot cultivation,normal watering C.sativa seedlings as the control(CK),compared and analyzed the stress group at 0,3,5,7,9 day(d)after stress and after rehydration changes in physiological characteristics,photosynthesis and secondary metabolites.By inoculating arbuscular mycorrhiza,the damage caused by different degrees of drought stress on C.sativa was alleviated,so as to find out the program that is beneficial to the content of active substances used in C.sativa,and provide scientific basis for high-yield cultivation and utilization of secondary metabolites of C.sativa,as well as theoretical basis for efficient water-saving irrigation of C.sativa.The research results of this experiment mainly include the following aspects:(1)With the increase of stress days,drought stress increased the damage degree of cell membrane,photosynthesis inhibition was obvious,photosynthetic pigment content increased,water content of leaves continued to decrease,the activities of four antioxidant enzymes increased,SOD,POD,APX enzyme activities all reached the highest level at day 7,then decreased,and recovered to normal level after rehydration.Moderate drought stress can increase the activity of antioxidant enzymes in C.sativa.(2)With the increase of drought stress days,EWU firstly increased and then decreased,and the contents of total flavone,total phenol and total terpene in the flame were significantly increased to reduce the damage of reactive oxygen species on plants,while the content of CBD was decreased.After rehydration on specific days,the contents of total flavone,total phenol and total terpene tended to be normal,and the content of CBD in the leaves of the three groups was higher than that of CK.When moderate stress takes a certain time to rehydrate,the damage to plants can be alleviated,and it is conducive to the synthesis and accumulation of CBD.Among the three groups of different leaf positions,the more tender the leaves were,the higher the CBD content was,which provided data support for the development and utilization of the renewable resources.(3)With the increase of drought stress,the water content of leaves decreased,photosynthesis inhibited significantly,cell membrane damage increased,photosynthetic pigment content increased,osmotic regulatory substances increased,POD enzyme activity increased,SOD and APX enzyme activities increased first and then decreased,water utilization rate increased,total flavonoid and total phenol content in C.sativa increased first and then decreased.CBD levels continued to decrease.(4)After inoculation with arbuscular mycorrhiza,compared to uninoculated plants,the water-holding capacity,photosynthetic intensity,content of light and pigment,and content of osmotic regulatory substances were improved,the activity of antioxidant enzymes was increased,the content of MDA was reduced,the damage degree of cell membrane was reduced,the water utilization rate was increased,and the contents of total flavonoids,total terpenes and total phenols were increased.Inoculation of partial arbuscular mycorrhiza could increase the content of cannabidiol and reduce the decrease of damage.In general,arbuscular mycorrhizal inoculation increased the drought resistance of C.sativa and reduced the damage caused by drought,which provided data support for planting and breeding of C.sativa.