Establishment Of Tissue Culture And Rapid Propagation System Of ’Luqiu 1’ Catalpa Bungei

Catalpa bungei C.A.Mey.is a large deciduous tree of the genus Bonaloniaceae Juss,with a height of 30 m and a DBH of more than 1 m.It is a precious high-quality timber species and a famous ornamental tree species in China.Eucalyptus in the international use of materials are included in a class of wood,can create intercropping forest,timber forest,shelter forest,tree-shaped stalwart,beautiful color,leaf rich,known as the "wood king".Due to the incompatibility of self-pollination of eucalyptus,eucalyptus often flowers and is not strong;even if different clones are mixed together,the pollination by insects can be strong,but the fruiting is rare,the seed germination rate is very low,and the breeding is difficult.Eucalyptus is a difficult rooting tree species,and the survival rate of cutting propagation is low,and the existing cutting technology is high in operation requirements,or requires facility conditions,or labor and time and cost,and is not easy to be popularized in actual production.Although the root propagation is relatively easy,the root propagation depends on the relatively small amount of reproductive material,which objectively restricts the scale of breeding.When adopting the method of grafting and breeding,the rootstock must first be cultivated.At present,the rootstock cultivation adopts the eucalyptus sowing and seedling method,but it takes at least 2 years after sowing to reach the required thickness of the grafted rootstock,and there is a shortcoming of the long-term production period of the rootstock.In summary,the problem of rapid breeding of eucalyptus cannot be better solved.Tissue culture techniques can multiply seedlings in a short period of time within the limits of human control.Its biggest feature is its speed and high output.In this paper,the new varieties of "Luqiu 1" selected by Shandong Forestry Research Institute were used as experimental materials.The key technologies of eucalyptus tissue culture technology were systematically studied,and a high-efficiency and rapid propagation system was successfully established for new varieties.Below are key research findings:1.Screened out the most suitable vaccination explants for ’Lujing 1’ and the best disinfection method: The best explants are sprouted after hydroponic culture.The best explants are sprouted after hydroponics.The best disinfection method is to rinse with tap water for 30 min,then 75% alcohol disinfection on the ultra-clean workbench for 30 s,andsterile water rinse for 3~4 times,0.1 % Mercury chloride soak for 4 min,then rinse with sterile water for 3~4 times.Under this method,the contamination rate of explants is only 5%,the browning rate is 0,and the germination rate can reach 95%.2.In this experiment,the orthogonal test method was used in the start-up culture,and the medium,cytokinin and auxin were used as three factors,and three levels were set at the same time.The optimal culture formula for the primary culture was determined as: MS+6-BA 0.50mg/L+IAA 0.15 mg/L+sucrose 30 g/L+agar 7 g/L,pH 5.8-6.0.After 30 days of culture,the number of induced buds was as high as 3.30,and the bud length was 1.55.Because the browning of explants is related to the genotype and lignification degree of the explants,the addition of appropriate activated carbon will adsorb the enzymes that cause browning.The method of adding activated carbon is used to reduce the browning rate.When activated carbon was added to the medium at 1.00 mg/L,browning during explant initiation was reduced.3.In the proliferation stage,the orthogonal test was used to select the three factors of medium,cytokinin 6-BA and auxin NAA,and the different concentrations of different media and 6-BA and NAA were set at three levels.The optimal medium formulation for subculture was determined to be: N6+6-BA0.8 mg/L+NAA0.10 mg/L,and the adventitious bud proliferation coefficient was the highest 6.20.The tissue culture seedlings grew well and the leaves of the plants were bright green.4.At the rooting stage,three different basic media,different concentrations of cytokinin6-BA,and different concentrations of auxin NAA and IBA were used for the ratio test.The most suitable medium and auxin ratio in the root stage were selected: 1 /2MS+NAA 0.5mg/L+6-BA0.10 mg/L.The average rooting number reached 12.50,and the rooting rate reached 100%.It was also found that when the cytokinin concentration was higher than that of auxin,the plants tend to grow longer,and on the contrary,they are more conducive to rooting.5.Remolded seedling transplanting: 7 days of refining,the transplanting substrate is perlite: vermiculite: peat = 1:1:1 is most suitable for transplanting,the survival rate of tissue culture seedlings after transplanting is 90.1%,and the average seedling height can also be Up to 5.30 cm.