碩士 / 南台科技大學 / 生物科技系 / 92 / Calla lily (Zantedeschia spp.), a member of Arum family (Araceae), is a tuber flower crop originating from the southern regions of Africa. Two major production problems in calla lily industry are bacterial soft rot caused by Erwinia corotovora and viral disease infected either by cucumber mosaic virus (CMV) or by dasheen mosaic virus (DsMV). Therefore, disease resistance has been an important goal for calla lily breeding programs all over the world. Since hybridization incompatibility usually occurs in interspecific cross in Zantedeschia, it has been a difficulty in traditional breeding that trying to transfer disease tolerance characteristic from the white flower species Z. aethiopica to other species. Gene transformation, therefore, has been considered as a feasible way to circumvent this sexual reproduction barrier; and plantlet regeneration from transformed cell(s) is an essential step for this methodology. The purpose of this research is to investigate optimal conditions for callus induction and organ redifferentiation in calla lily, as well as to provide fundamental information for transgenic plant regeneration when using genetic engineering strategy for this crop improvement.
For callus induction, explants excised from petioles of ‘Pacific Pink’ calla lily performed better than those from blades; and half-strength MS is better than full-strength, These is no significant difference between half-strength MS and B5 treatment. The highest percentage of callus induction (80 ± 3.9 %) was obtained on half-strength MS medium supplemented with 1 mg/ L 2,4-D and 2 mg/ L TDZ after dark incubation for two months. Most calli induced by 2,4-D and TDZ is white friable type. They could be maintained and proliferated either on the induction medium mentioned above or on half-strength MS medium supplemented with 2 mg/ L Picloram and 0.5 mg/ L. No organogenesis from this type of callus was observed, even though various treatments have been tried in this research.
Most calli derived from petiole explants on half-strength MS medium with 2,4-D and BA showed yellow color and compact texture. The optimal combination of these two plant growth regulators for the callus induction was 1 mg/ L 2,4-D plus 1 mg/ L BA, though the percentage of callus induction only 53 ± 6.7 %. After subculture on half-strength MS medium with 2 mg/ L NAA and 0—0.5 mg/ L BA under light condition for two months, the yellow-compact calli redifferentiated into short-thick roots (diameter 1.5 ± 0.1 mm) with sparse root hairs. On the other hand, slender roots (diameter 0.74 ± 0.1 mm) with dense root hairs were formed if transferred this type of calli to the same medium with 0.05 mg/ L NAA, 1 mg/ L BA, and 0.5-2 mg/ L TDZ was utilized. Incorporation of 1 mM glutamine or 1000 mg/ L yeast extract in the rhizogenesis medium enhanced the number of root induction and their elongation.
No shoot formation was found among different treatments, including combining different plant growth regulators, modifying molar concentration of NH4NO3 to KNO3 ratio (15.5: 29.5 and 20.6: 39.4) of half-strength MS basal medium, or adding reduced nitrogen compound (1000 mg/ L casein hydrolysate, peptone, or yeast extract) for two months in light condition. However, yellow-compact calli inoculated on a medium based on half-strength MS plus 0.5 mg/ L 2,4-D, 1 mg/ L BA, and 0.5% sucrose developed green spots, which may have the potential for shoot regeneration.
| Identifer | oai:union.ndltd.org:TW/092STUT0111013 |
| Date | January 2004 |
| Creators | 林聖全 |
| Contributors | Wu Chun-Ta, 吳俊達 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 76 |
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