Study On Tech Niques For Asexual Propagation Of Nitraria Tangutorum

Nitrat ia tangutorum Bobr.was one of the main afforesting tree species for biological fixed-sand method in the arid area of our country.But the differentiation for the subgeneration of its seed was very great.In order to realize high-quality degree of seedling for Nitratia tangutorum Bobr.Using different treatments for hormone and concentration,Techniques for tender branch cutting and hard wood cutting of Nitratia tangutorum Bobr.were studied in this paper.The main research results were as follows:(1) In comparison with contrast treatment,through treatments for five hormones(ABT, NAA,GA,IAA,IBA) and four concentrations(100mg/L,250mg/L,500mg/L,750mg/L), survival rate for seedling of tender branch cutting was improved by 2.5-20.0%,1.3-17.3%, 13.3-17.3%,6.0-12.0%and 4.0-11.3%respectively,among them,the survival rate for association of ABT250mg/L can reach 56.75%and was the best.Average survival rate of 4 kinds of concentration showed GA(51.8%)＞ABT(48.7%)＞NAA(44.5%)＞IAA(41.6%)＞IBA (41.3%)＞CK(36.8%).The influence degree of 5 kinds of hormone on quantitative character(the number of root and leaf) for seedling of tender branch cutting was larger than their qualitative character(root length,root diameter,new branch length and leaf length). Different kinds of hormone had different synergy to seedling of tender branch cutting.Among them,IBA and IAA obviously promoted the growth of root and leaf respectively,NAA play a important role on the growth of new branch length,leaf length and root diameter and IAA had obvious effect on the growth of root.There were close relations between hormone and growth state for seedling of tender branch cutting.(2) After treating through five hormones(ABT,NAA,IAA,IBA,NAA+IBA),four concentrations(100mg/L,250mg/L,500mg/L,750mg/L) and their combination,their survival rate for seedling of hard wood cutting was improved obviously,among them,the survival rate for association of NAA+400mg/L accounted for 87.5%and was the highest,and the survival rate for association of IBA 100mg/L and NAA+IBA 100mg/L was 82.5%and 77.5% respectively,The three were 2.69 times,2.54 times and 2.39 times of the check treatment separately.On the whole,all growth indicators for the cutting seedlings were higher than that of the check treatment and had significant difference between the two.In terms of seedling height(63.6cm),ground diameter(1.38cm),above ground biomass(620.4g) and under ground biomass(80.8g),the association of NAA+IBA was the best.In respect of root length(78.3cm) and root number(69.6),IBA was the best.NAA and ABT were with branch number(3.8) at base best.IAA was with maximum branch length(125.5cm) best.In all growth indicators for seedling of hard wood cutting,the association of NAA+IBA(400mg/L) was the best.