Transgenic Researches Of Wheat,Maize And Hyacinth

Culture system of wheat hypocotyl segments, immature spikes and immature embryos were established and plants were regenerated. The frequency of embryonic callus formation reached the maximum when the explant were cultured in 25±1℃, dark and on MS medium. Keeping in 4±1℃ and dark was beneficial to preservation of the calluses and without any remarkable influence on the capacity of embryogenesis. The callus conversion frequency was improved by drying treatment. Genotype had obvious effect on callus induction of immature embryo. Four varieties, Xinong 1376, 85+1-3, Baofeng 7228 and Yan 2, were determined with high differentiation frequency from fourteen genotypes.Transformation of wheat hypocotyl segments, immature spikes and immature embryos mediated by Agrobacterium tumefaciens LBA4404-Y24 resulted in the expression of the foreign gene in the calluses, which were confirmed by PCR assay, but the transformed calluses could not differentiate. The order of factors affecting transformation frequency were: Triton X-100 > pretreatment > AS >light .Transformation of embryonic calluses derived from wheat immature embryos was performed via microprojectile bombardment and resistant calluses were obtained. Green-buds were regenerated when the resistant calluses were cultured on differentiation medium. But the green-buds could not grow any longer and transgenic plant was not produced.Transformation of maize immature embryos by microprojectile bombardment resulted in production of resistant calluses and regeneration of plants.The best callus induction medium of buld was MS medium supplementd with 3.0mg/L 2,4-D, 0.5mg/L 6-BA and 0.4mg/L NAA in hyacinth. Only the calluses with globular evection had the capacity of differentiation and the differentiation frequency was 85%. The differentiation medium was MS supplemented with 0.5mg/L 6-BA and 1.0mg/L KT.Transformation of hyacinth scale, flower stalk, flower bud and regeneration plantlet mediated by Agrobacterium rhizogenes A4 resulted in regeneration of buds. The buds were rooted in subculture process and plantlet were regenerated. Triton X-100 had positive effect on hyacinth transformation.