A Primary Study On High Efficiency Propagation Technology Of Populus

Populus is an important forestation species in north China,and large numbers of its seedlings are required in the market.Currently,the choiceness species of Populus are mainly relied on asexual propagation,but plant tissue culture is the crucial technology for large scale multiplication of these species.The main objective of this study was to investigate the liquid culture of Populus alba×P,alba var.pyramidali and optimize the regeneration system.The results were obtained as following.1.The proper shoot propagation medium for Populus alba×P,alba var.pyramidali was obtained using MS+1.0mg/L6-BA+0.25mg/LIAA.The multiplication coefficient was significantly affected by 6-BA,IAA,and their interaction.The 6-BA accounted for the main effect.One generation of cycle 20～25d was deemed as suitable.The rooting medium experiment showed that 1/2MS+0.10mg/LIBA was so proper that rooting rate can reach 100%.2.Our research indicated that the multiplication coefficient of Populus alba×p.alba var. pyramidali growing on the liquid culture medium increased by 17.4%and 29.6%at the 7d and 14d,respectively,compared to growing on solid culture medium.Meanwhile,the rooting time needed by Populus alba×p.alba var.pyramidali growing on liquid culture medium was reduced by 1d to 3d days,compared to solid culture medium.However,severe hyperhydricity was observed on liquid culture medium,which has a great negative influence on the growth and development of Populus alba×P,alba var.pyramidali.Shoot hyperhydration is the lowest in temporary completeness immersion experiment compared to other immersion methods.3.The optimum immersion frequency and time by using Populus propagation system were 8 times/d and 5min/time.The plant size under lcm resulted in a signification higher shoot production rate compared with that of over 1.5cm,but shoot length and hyperhydricity were not affected by the plant size.The study of the influence of medium exchange on shoot propagation and rooting showed that there was no obvious advantages for higher quality shoot production and accelerate rooting.4.Shoot cultures from the liquid medium rooted normally and quickly with 100%rooting and the rooted plantlets matched well in the greenhouse.The time of domestication of the plantlets reduced by 3d compared to solid culture,and the transplantation rate is over 90%...