Studies On Tissue Culture Plantlets Of Disease-resistant Pinus Elliottii

This thesis aimed to study on the organogenesis of disease-resistant Pinus elliottii in lateralbud proliferation, root formation and domestication transplanting. Using the immature zygoticembryos of disease-resistant Pinus elliottii to study the somatic embryogenesis. The requirementsof cryopreservation to embryogenic callus of disease-resistant Pinus elliottii were studied. Themain results were as followed:The optimal combination of axillary buds induction was GD medium supplemented with1.5-2.0mg/L6-BA,0.15mg/LNAA,20g/Lsucrose. Shoots were elongated obviously on DCR mediumcontaining20g/Lsucrose and0.5g/L activated charcoal. The optimal combination of root formationwas WPM medium supplemented with2mg/L IBA and0.07mg/L NAA. But the survival rate ofdomestication transplanting is not high. Different genotypes had a decisive impact on the rate oflateral bud proliferation, root formation and domestication transplanting.The field experiment of disease-resistant Pinus elliottii regeneration plants was builded inAnhui Quanjiao. There were differences among different clones of the plant regeneration growthstate. The average survival rate of afforestation was53.82%after32months. The growth status ofdifferent families and clones were of significant difference, the best growth clones were8#8, theworst growth clones were8#61. Inoculation of ectomycorrhizal fungi Be and bacteria HB12wouldpromoted tissue culture plants growth. HB12is more effective.With the immature zygotic embryos as explants, the main factors affecting initiation,maintenance and proliferation, development and maturation of somatic embryos were studied. Thezygotic embryos collected in June28thand July5thwere already in stage2-4, which were the bestfor ESM initiation. The best medium for ESM induction was LP medium supplemented with10mg/L2,4-D and3mg/L6-BA, or with2mg/L2,4-D,4mg/L6-BA and2.5mg/L KT, or with2.2mg/L2,4-D and1mg/L6-BA, or with8mg/L2,4-D and4mg/L6-BA. PEG6000was not goodfor maturation. It is better to supplement AC2g/L and AgNO36mg/L in the later maturation stage.Studies on cryopreservation of disease-resistant Pinus elliottii embryogenic callus have beendone. The survival rate of callus after cryopreservation was higher with pretreatment for36h,0.6mol/L sorbitol and15%DMSO as cryoprotectants,30-40water℃bath heater after3d. Theaverage survival rate of callus after recovery culture was slow.