Studies On The Cutting Propagation Technique Of Tetraena Mongolica Maxim.

Tetraena mongolica Maxim., an endemic arid shrub with fleshy leaves in China, now is in endangerment. In order to promote its idioplasm protection and enlarge its population, this paper did research on its cutting propagation firstly.The results of experiments showed :Firstly, Tetraena mongolica Maxim.cuttings with leaves could root in growth season, which were formed from callus.Secondly,cuttings treated by different root-promoting hormone with the same concentrations showed:ABT No.1 rooting powder(ABT1) got the best results,followed by NAA(1-naphthy acetic acid),GGR No.6 and ABT No.2 rooting powder(ABT2),while water got the worst result.ABT1 with different concentrations had significant effects on the rooting percentage and roots quantity.After treated by 500 mgl-1 ABT1,cuttings'average rooting rate was 83.3 percantage, roots number was 4.2 and length was 1.9 cm.The rooting quality of cuttings treated by 250 mgl-1 was less than 500 mgl-1,which was the most suitable concentration for ABT1 as growth hormone in foresty practice.Except callus-formed rate and average length, significant differences (significance level was 0.01) of other indicators were observed between different concentrations for ABT2.Among them, 500 mgl-1 obtained the best results, and 2000 mgl-1 ranked the second,difference didn't almost exsist between their Index of Rooting Quality(IRQ) .Thirdly,among different leaf retention,significance level was 0.01 for callus-formed rate,0.05 for rooting rate and roots quality,no significant difference exsisted for average length and maximum length.Compared with leaf retention of 1/4 and 1/2,all rooting indicators along with IRQ for 3/4 came to maximum.Rooting ability of cutings with 10cm,15cm and 20cm long had no significant difference,and rooting quality of cuttings with branches was higher than that with no branch.Finally, August was more suitable for Tetraena mongolica Maxim. Cuttage.high temperature and humidity benefited roots occurrence,which might play key roles in the rooting course.