| Summary: | 碩士 === 國立屏東科技大學 === 農園生產系所 === 100 === Guava (Psidium guajava L.) is a tropical fruit which belongs to the family Myrtaceae and the genus Psidium. It is an important economical fruit crop in Taiwan. To establish an efficient regeneration system for guava micropropagation, zygotic embryos for somatic embryogenesis and hypocotyls for organogenesis were used in this study. Among zygotic embryos with different week-old ages, the best induction rate of somatic embryogenesis was achieved with 10 week-old zygotic embryos from summer fruits. Regardless the week-old ages of zygotic embryos, the best induction rate occurred on MS medium supplemented with 3% sucrose and 2.3 or 4.5 μM 2,4-D, or MS medium supplemented with 5% sucrose and 2.3 μM 2,4-D for 10 day then transferring to PGR-free full-strength MS basal medium. Their somatic embryo induction rates were all above 60%. Furthermore, somatic embryo formation rate was also affected by seasons and genotypes. For hypocotyl organogenesis, the combined effect of NAA and BA was more efficient than either of them used alone. Extending the incubation time can further increase the proportion of hypocotyl producing adventitious shoots. In addition, BA treatment exhibited better effect on shoot proliferation of guava than of TDZ. Transferring proliferated shoots to MS medium without BA or with increased MS macro salt concentration can alleviate the problem of short shoot internodes. The 1/2 MS medium supplemented with 6.66 μM BA used in this experiment can also be applied to other guava genotypes for shoot proliferation. A high efficiency micropropagation system of guava not only provides a way for rapid proliferation of elite genotypes, but also offers a possibility to improve the genotype by genetic transformation.
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