Polygonatum Odoratum Seed Multiplication And Drought Stress Research

Polygonatum odoratum geographical distribution widely,it has good growth ang adaptability in arid sandy habitats of Da Qing grassland.If It used in restoration of grassland vegetation,the ecological environment of Da Qing arid sandy habitats could be improved,the adversity plant resources could be increased.It is necessary to find out the best technical processes,evaluate quantitatively the ability of its drought tolerance.This paper mainly reseached growth and development rhythm of Polygonatum odoratum in Herbin;the effect on seed germination by15、20、25、30℃temperature treatment, stratification tretment and5%、10%、15%、20%、25%concentration PEG treatment; the effect on physical and photosynthetic characteristics by10%、20%and30%PEG indoor drought Stress and9、18、27、36、45d outdoor drought stress.The main results as follows:(1)Under the filed cultivation condition, Polygonatum odoratum has bud in early May when the minimum temperature reached5℃,above9℃flower bud formed;multi-flowering reached above a week after,be continued15d,the end of August or early September fruit gradually matured.In early October it gradually withered death when average temperature at1.4℃.Contrast with Da Q ing,its budding period、leaf stage has beforehand3-4d,wilting stage has delayed5-7d,the whole growth cycle has10d longer.(2) Polygonatum odoratum seed germination rate can reach88.89%under the condition of25℃dark condition after4℃stratification treatment25d.Mass production can use seed breeding.25℃is the optimum temperature of seed germination,15℃failed to germinate, stratification tretment can increase the germination rate.(3) With the different concentration PEG drought stress,the trauma of10%is least,20%and30%has suffered in the late stage of stress,it can not recover when rehydration. Polygonatum odoratum has self-regulating capacity under drought stress,can tolerate21h drought stress by20%～30%PEG.Ornamental value of Polygonatum odoratum vanish on42h、35h after stressed by20%、30%PEG Relative leaf water content has very significantly negative correlation to PEG concentrate and stress time, conductivity has very significantly positive correlation to PEG concentrate,MDA has very significantly positive correlation to stress time,and no significantly correlation to PEG concentrate. With the stress intensifies,chla and chlb show a downward trend,SOD enzyme activity first unchanged,then sharp rise and then decline, soluble protein content unaffected.Polygonatum odoratum is ability to resistance drought stress,it has self-regulating capacity to reduce the damage of cell membrane;can resist the membrane lipid peroxidation;improve SOD activity to decrese the reactive oxygen species.(4) With the outdoor water control drought stress, Polygonatum odoratum suffered stress after27d,can tolerate45d drought stress maximumly.After18d drough stress it can recover to normal. After36d drough stress it can not recover to normal.Polygonatum odoratum soil moisture has very significantly negative correlation to relative leaf water content,The trends of conductivity and Proline imply Polygonatum odoratum suffered drought injury,MDA and SOD trends can reflect the ability of drought tolerance, It shows the ability of Polygonatum odoratum resist drought stressed through self-regulation. Soluble protein content has no significantly correlation to PEG concentration and stress time, Can not be measured the ability of anti-drought.(5) Drought bring about Soil water content decreased, stomatal closede, transpiration rate decreased, photosynthetic pigment declined, water use efficiency has declined,finally Pn decreased.The reason is dual factors of stomatal factors and non-stomatal factors.On stress early period is stomatal factors dominant,later period the leading role is the non-stomatal factors.