Study of Response Character to Seawater Treatments and Extracted Technics of Objective Matter of Aloe Vera
|School||Nanjing Agricultural College|
|Keywords||Aloe vera Seawater irrigation Growth Physiological characteristics Ion distribution Active substance|
The experiments were carried out to study the growth and physiological characteristics, inorganic ions distribution,anthraquinone substance and extracted conditions of anthraquinone substance in the seedlings of Aloe vera under seawater irrigation conditions. The results were as follows:1) The above-ground dry biomass and fresh biomass were slightly declined under the seawater treatments.Water contents of A.vera under the 30%concentration of seawater （W3）,40%（W4）,and 50%（W5） treatments were significantly lower than those in deion water treatments（control,W0） and 10%（W1）,suggesting A.vera grows better under 10% and 20%seawater irrigation.However,there were no significant differences in the longest leaf length and the net increased leaf numbers between seawater and control treatments. Moreover,there were no significant changes in the net plumule amount in 10%（W1） and 20%（W2） treatments,as compared with CK.However,the net plumule amount decreased significantly with the concentrations of seawater increasing.The leaf growth rate（leaf length,leaf width and leaf thickness） was gradually decreased with the increasing salinity of seawater,and the effect of plant growth mainly on leaf thickness,then the leaf width and the leaf length.The contents of total anthraquinone and aloin were not affected（p＜0.05） under seawater conditions.2) With the increasing of salt concentrations,root activity and chlorophyll contents were decreased,while leaf electrolytic leakage and MDA contents were increased;MDA decreased in the 10%（W1） and 20%（W2） treatments.However,there were no significant changes of root activities,chlorophyll contents,electrolytic leakage and MDA contents in plant leaves.And the soluble sugar and soluble protein increased with the seawater concentrations increasing,but the organic acid in mature leaves changed little except for 50%seawater treatment compared with CK.But soluble sugar and soluble protein in young and mature leaves were significantly higher than those in old leaves under seawater stress, but there were no significant changes in organic acid.3) The concentration increments of Na+ and Cl- in the eighth leaf were much higher than those in the fourth leaf,indicating Na+ and Cl- have a trend to be centralized in the water-stored tissues and old leaves in case of salt injury to young leaves.Simultaneously,Cl-concentration in sieve tube was higher than other tissues,showing Cl- was transported to roots for keeping from stress effects.Ca2+ and Zn2+ were transported to epidermal tissue as cell wall,showing ions were absorbed selectively in order to adapt to the salt stress conditions.4) Under 30%seawater irrigation,the effect of leaf yield of A.vera was of N＞P＞N×P; but,P accumulation was not affected（p＜0.05）under fertilize application,Mg2+ contents in young leaves had significant changes;but in old leaves,Mg2+ content was effected by N and N×P,and in mature leaves there was no significant changes.5) To anthraquinone in A.vera,the optimum extracting methods were investigated by the orthogonal design with hot water extraction,ultrasonic extraction and soxlet extraction. This results showed that the best method for anthraquinon extraction is ultrasonic extraction. The optimum conditions is aloe young leaf with a sieve passing through 0.33 mm and dipping in ethanol at 40℃for 45min under ultrasonic.