Research On Pollen Storage And Controlled Pollination Techniques Of Eucalyptus

Cross breeding is an important method for tree improvement of Eucalyptus. The use of heterosis plays an important part in breeding.Sexual hybridization and vegetative propagation can greatly increase the productivity of Eucalyptus. Cross breeding of Eucalyptus in China dated back to 60s, 20th, with a 50-years history, and cross breeding has went through a series innovation. This thesis through the phenology summary of Eucalyptus,research on building dwarfed breeding field,pollen storage and controlled pollination technical,comes to some conclusion:(1) According to 2 year's observation of phenology of Eucalyptus, together with experts'conclusion, the phenology of seven main species of Eucalyptus is summarized.According to the phenlogy table,we can make pollen collection and controlled pollination in time.(2) The thesis also concludes a whole set of feasible grafting technology of Eucalyptus , the growth retardant --- paclobutrazol is used to dwarf the plants. The result indicates that the appropriate temperature for grafting is 18～28℃, and the appropriate grafting type is splice graft.The effect of using paclobutrazol for dwarfing Encalyptus is obvious. Trees treated with paclobutrazol usually darker green in foliage colour.It acts by inhibiting cell elongation, the number of tillers is increased and the internodes compressed into a shoter length of stem. There are significant different reaction to paclobutrazol among clones.(3) The pollen vitality of Eucalyptus which was preserved in room temperature ,low temperature and super-low temperature was measured . The results indicated that: the best pollen culture medium for Eucalyptus was 20% cane sugar and 6%agar and 100ppm boric acid; Methods of pollen storage, species and storage time had significant affect on pollen vitality. After 30d,the pollen germination rate of E. urophylla and E. dunnii, which was preserved in room temperature, declined to 10%., whereas E. urophylla×E. dunnii and E. grandis's pollen need to be 50days.The pollen which was preserved in freezing low temperature and super-low temperature for one years, still had a high germination rate of more than 35%. Pollen germination rate was also affected by the method of thaw, and 38℃water thaw was the best method.(4) Controlled pollination technology mainly uses one stop pollination and artificially induced protogyny,compared with traditional three-visit controlled pollination, the result indicates that OSP treatment 1 has a higher capsule retention and No.of viable seeds than traditional controlled pollination technology; AIP technology has a higher capsule retention than traditional controlled pollination technolygy in dealing with yellow-colored buds and yellow-green buds, the capsule retention is 69.67%,65.84% and 24.12% respectively.