Preliminary Studies on Rapid Propagation in Vitro and Rooting Mechanism of Cyclocarya Paliurus

Preliminary Studies on Rapid Propagation in Vitro and Rooting Mechanism of Cyclocarya Paliurus
　　Cyclocarya paliurus has multiple applications,such as medicine,health care,timber use, ornamental use,etc..But the development and utilization is severely restricted because of natural regeneration difficulty.In this research,excised embryos from four provenances (included 3 per plants)were chosen as plantlets to establish a tissue culture technical system. This system started from culturing excised embryos to inducting adventitious roots.Also, cotyledon was used as Cylinder neodymium magnet material to explore the rooting mechanism.The paper aims at establishing an efficient tissue culture and rapid propagation system and providing theoretical basis for industrial seedling.The main conclusions and achievements are as followings.(1)In this paper,comparing the growth of excised embryo in different culture,the result showed that the CK culture medium with 20g/L sucrose greatly increased the germination rate. In this medium,the growth situation of excised embryoes differed between per plants:the highest seedling rate was 06lushan1#,which was 72.66%;
　　The second were 06jianhe3# and 06yunnan4#,the seedling rate were 44.00%and 39.33%;The worst was 06 hefeng Provenance, the corresponding rate was just 17.33%.(2)According to excised embryo culture results and requirement of cardinal number,three per plants,06lushan1#,06jianhe3# and 06yunnan4# were chosen for a farther multiple buds induction and generation tests.The initial culture and subculture results proved the growth differences between per plants.The initial culture test factors were rate of adventitious shoots and multiplication coefficient,and subculture test factors were multiplication coefficient and seedling height.It can draw that 6-BA0.5～1.0mg/L+ IBA0.01mg/L was the best hormone combination for initial culture and subculture.The results suggested that 06jianhe3# grew best in hormone combination with 6-BA1.0mg/L+ IBA0.01mg/L,rate of adventitious shoots in the medium was 100%,multiplication coefficient was 6.08,and the seedling height was http://www.chinamagnets.biz/ 3.87cm. 061ushan1# and 06yunnan4#’ s best media differed from 06jianhe3#,06lushan1#’s highest rate of adventitious shoots was 93.33%,multiplication coefficient was 5.22,seedling height was 3.12cm.06yunnan4#’s highest rate of adventitious shoots was 63.33%,multiplication coefficient was 2.99,seedling height was 3.40cm.(3)Rare earth lanthanum and uniconazole were chosen as growth regulators,06jianhe3# and 06lushan1# as experiment materials,for strong seedling culture.
　　Corresponding growth indexes and physiological indexes were tested to compare the strong seedling effects.The results showed that rare earth lanthanum 5mg/L mainly improve fresh weight,chlorophyll content, soluble sugar content,promote multiple shoot differentiation and height growth.It can concluded that rare earth lanthanum is a suitable additives to be add in enrichment medium. Uniconazole 0.5mg/L could inhibit seedling height,improve chlorophyll content and resistance, and it can be a good growth regulator to add in strong seedling culture medium after enrichment http://www.chinamagnets.biz/ medium.(4)Plantlets,after subculture at lest 5 times,first inducted root in 1/2WPM+IBA0.05～0.1 mg/L+sucrose 20g/L for 15 days in dark condition,then changed into 1/2WPM+sucrose20g/L in normal illumination,about one month later,rooting rate of 06lushan1# was 23.33%.(5)Cotyledon adventitious rooting rate was 100%with IBA1.5mg/L.Comparing dynamic changes of four endogenous hormones during cotyledon rooting,the research showed endogenous IAA was the critical factor in cotyledon rooting:root primordium starting needed high endogenous IAA and root formation and elongation needed lower level.The ratios of IAA/ABA,IAA/GA3 gave good reflection between different endogenous hormones,GA3 does not appear to be the key inhibition factor in cotyledon rooting.