| Feijoa sellowiana Berg, also called'pineapple guava',is an evergreen shrub or small tree belonging to Feijoa genus of the Myrtaceae family. It is an emerging subtropical fruit tree with characteristics of edible, ornamental and landscaping in international fruit market in recent years. Feijoa shows a broad application prospect in food, medicine, cosmetic and many other fields. The fruit is sweet and delicious, containing soluble iodine and has a unique and rich aromas; the tree presents itself with a frutescent crown, bears green fruit, blooms unique and gorgeous flowers, having a strong ornamental function. Studies have showed that Feijoa can adapt itself to the climatic conditions in Hunan and retain its fruit quality and ornamental characteristics, so it has a great development potential. At present there is not a complete seedling reproduction technology for this tree in China yet; therefore, in order to promote the development of Feijoa industry, developing the seedling reproduction technology has become all the more important.The breeding ways of sowing, grafting, cutting and tissue culture of Feijoa were studied in this thesis. The results show that:(1) Seeding propagation. The seed of Feijoa has no obvious dormant period. When the mature seeds were sown in the matrix mixed with peat and perlite by a proportion of 5:1, the emergence rate of seeds could reach 93% after 36 h soaking in clean water. The emergence rate of seeds decreased gradually as the storage times lengthened, and it could be reduced to 8～10% for seeds stored over one year.(2) Grafting reproduction. Three-year old shoots with 4-6 buds were used as scionwood to make shoot graft in mid-May, and the highest grafting survival rate reached 34% by cut graft and 12% by in-bark graft. However, the highest grafting survival rate with bud graft was 22% by cut graft in mid-May and 12% by pull budding in mid-June, respectively.(3) Cutting propagation. The type of plant growth regulator, concentration, treatment time, matrix, cutting period, length of cuttings and the amount of leaves reserved all played important role in the cutting rooting and growth of the cuttings. In May or June, cutting the lower or middle crown shoots into 8-12 cm cuttings with 2 leaves (retaining more than two knobs) and planting the cuttings in vermiculite after soaking it in the 200 mg/L IBA solution, the best effect of cutting rooting and growth could be obtained, the mean rooting rate, number of roots taken per cutting, and the length of roots reached 62.8%,4.2 roots, and 14.2 cm, respectively. The root of Feijoa cuttings could be induced. There was no incubate root primordium in cuttings, and the adventitious root was developed from the induction root resulting from cutting. The induction of adventitious roots of cuttings produced and formation of callus was independent of each other.(4) Tissue culture. It was an appropriate tissue culture method to disinfect the explant in 0.1% HgCl2 solution for 9 min after soaking it in the 75% ethanol for 30 s. The appropriate culture medium for stem segments was MS+ 2.0 mg/L 6-BA+0.2mg/L NAA+1.5mg/L IBA and MS+2.0mg/L 6-BA+0.5 mg/L NAA+0.5mg/L IBA; the appropriate culture medium for induction callus of petals and anther was MS+1.0 mg/L 2,4-D+1.0 mg/L KT+0.5 mg/L 6-BA; and the appropriate culture medium for induction callus of ovary is MS+1.0 mg/L 2,4-D+0.5 mg/L KT+2.0 mg/L 6-BA. When the seed was used for inducing somatic embryogenesis, the best method of sterilization was soaking the seed in 1.0% NaCIO solution for 12 h. While the seeds were used for somatic embryogenesis, the induction of embryogenesis is indirect:firstly the callus grew from the seed, then the body embryos produced from callus, the rate of somatic embryogenesis was 46%; while the cotyledon was used for somatic embryogenesis, the induction of embryogenesis was direct, the rate of somatic embryogenesis reached 34%. |
PDF Full Text Request