Progress 10/01/04 to 09/30/05
Outputs
Transgenic male parental lines (TGM-AS-1 and TGM-AS-2) of 'Galia' muskmelon bearing an antisense ACC oxidase (ACO-1) gene were developed from cotyledon explants cultured in vitro. Transgenic fruits from the ACO-1 antisense male line produced less ethylene and had a longer shelf-life compared to wild-type fruits. The other postharvest quality characteristics of the transgenic fruit were similar to wild-type fruit. Transgenic T0F1 'Galia' was developed from the transformed male line and wild-type female parental line. During spring and fall 2004, transgenic T0F1 'Galia', wild-type 'Galia' and 'Gal-52', were grown in a passive-ventilated greenhouse in Citra, FL. In spring 2004, there was a severe powdery mildew (Sphaerotheca fulingea) epidemic. No significant differences in plant yield, quality, ethylene evolution and respiration were observed between transgenic plants and wild-type 'Galia', however, 'Gal-52' was significantly (P less than 0.05) firmer after storage for
5 days at 20 degrees C with fewer days to harvest. 'Gal-52' produced more ethylene and carbon dioxide than the other melons. In fall 2004, there was a significant difference in days to harvest for unselected transgenic T0F1 'Galia' compared to wild-type 'Galia' and 'Gal-52'. The transgenic 'Galia' remained on the vine an average of 5 days longer than wild-type 'Galia' and 7 days longer than 'Gal-52'. This 5 day window could help improve post-harvest shelf-life by allowing growers to harvest early and ship fruit to their destination. To potentially increase this window further, work is being done to improve the transgenic 'Galia' hybrid through improvement of both parental lines. Throughout 2004 and 2005 T2, T3 and T4 lines of the transgenic male populations (TGM-AS-1 and TGM-AS-2) were produced. The T1 and T2 lines exhibited delayed ripening as compared to wild-type fruit, remaining on the vine an average of 14 days longer than wild-type fruits. However in summer 2005, one of the T3
transgenic male lines (TGM-AS-2) did not exhibit delayed ripening. Fruit on this line performed as wild-type fruit while fruit, ready to harvest at 30 days post pollination. However, the other T3 transgenic line, TGM-AS-1 line continued to show delayed ripening, some fruit remaining on the vine 20 days longer than the wild-type. This line will be used as the final breeding male parental line. Although it was not possible to regenerate a transgenic (ACO-1) female 'Galia' parental line through biotechnology, this is now being done through traditional breeding methods using the 'backcross' method. T0F1 pollen was backcrossed to the wild-type female 'Galia' parental line in order to insert the antisense ACC oxidase (ACO-1) gene. The female transgenic backcross 2 (BC2) seeds were produced during the summer 2004 and BC3 and BC4 lines were produced in spring and summer 2005. In spring 2006, T4 male lines will be crossed to the BC4 female lines and a new transgenic hybrid will be created.
This hybrid will be grown in fall 2006 and compared to wild-type, commercial 'Galia' for yield and postharvest quality characteristics.
Impacts
Markets for greenhouse grown hydroponic vegetables are strong throughout the U.S. These markets continue to increase with diversification of the commodities grown. The 'Galia' muskmelon has brought billions of dollars to exporters of the fruit from Israel, Spain, Turkey, and Morocco, to Europe. Pilot sales in the U.S., including Publix supermarkets, has given similar potentials for fruit produced in the U.S. especially in warmer climates such as Florida and Puerto Rico. One of the major drawbacks to increased sales is soft fruit, as they must be harvested fully ripe for optimum flavor. Previous work has developed the protocol for transformation of both the male and female parents of 'Galia'. The research which is proposed will continue to develop seed stocks of both lines and characterize the phenotypes of each. F1 hybrid crosses will be made to develop 'Galia' cultivars with a reduced ability to produce ethylene and thus delay fruit softening. Initial studies with
the male line have shown that this transgenic system works. Once F1 hybrid seeds are available we will characterize the postharvest quality of the fruit including ethylene production, sugar content, firmness, color, volatiles, and aroma, as well as, fruit yield capabilities under commercial conditions in a passive-ventilated greenhouse.
Publications
- Mitchell, J. M., Cantliffe, D., Klee, H., Sargent, S., and Stoffella, P. 2005. Fruit quality characteristics of 'Galia' F1 Hybrid (Cucumis melo L. var. reticulatus Ser.) muskmelon developed from a transgenic male parent. Proc. III Inter. Cucurbit Symp. ActaHort. (In press).
- Nunez-Palenius, H., Cantliffe, D., Klee, H., and Huber, D. 2004. Extended shelf-life in transgenic Galia (Cucumis melo L. Var. reticulatus Ser.) HortScience. 39:861.
- Nunez-Palenius, H., Cantliffe, D., Klee, H. 2003. Transformation of Galia (Cucumis melo L. Var. reticulatus Ser.) melon with an antisense ACC oxidase gene. HortScience. 38:710.
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Progress 09/15/03 to 09/14/05
Outputs
Transgenic male parental lines (TGM-AS-1 and TGM-AS-2) of 'Galia' muskmelon bearing an antisense ACC oxidase (ACO-1) gene were developed from cotyledon explants cultured in vitro. Transgenic fruits from the ACO-1 antisense male line produced less ethylene and had a longer shelf-life compared to wild-type fruits. The other postharvest quality characteristics of the transgenic fruit were similar to wild-type fruit. Transgenic T0F1 'Galia' was developed from the transformed male line and wild-type female parental line. During spring and fall 2004, transgenic T0F1 'Galia', wild-type 'Galia' and 'Gal-52', were grown in a passive-ventilated greenhouse in Citra, FL. In spring 2004, there was a severe powdery mildew (Sphaerotheca fulingea) epidemic. No significant differences in plant yield, quality, ethylene evolution and respiration were observed between transgenic plants and wild-type 'Galia', however, 'Gal-52' was significantly (P less than 0.05) firmer after storage for 5
days at 20 degrees C with fewer days to harvest. 'Gal-52' produced more ethylene and carbon dioxide than the other melons. In fall 2004, there was a significant difference in days to harvest for unselected transgenic T0F1 'Galia' compared to wild-type 'Galia' and 'Gal-52'. The transgenic 'Galia' remained on the vine an average of 5 days longer than wild-type 'Galia' and 7 days longer than 'Gal-52'. This 5 day window could help improve post-harvest shelf-life by allowing growers to harvest early and ship fruit to their destination. To potentially increase this window further, work is being done to improve the transgenic 'Galia' hybrid through improvement of both parental lines. Throughout 2004 and 2005 T2, T3 and T4 lines of the transgenic male populations (TGM-AS-1 and TGM-AS-2) were produced. The T1 and T2 lines exhibited delayed ripening as compared to wild-type fruit, remaining on the vine an average of 14 days longer than wild-type fruits. However in summer 2005, one of the T3
transgenic male lines (TGM-AS-2) did not exhibit delayed ripening. Fruit on this line performed as wild-type fruit while fruit, ready to harvest at 30 days post pollination. However, the other T3 transgenic line, TGM-AS-1 line continued to show delayed ripening, some fruit remaining on the vine 20 days longer than the wild-type. This line will be used as the final breeding male parental line. Although it was not possible to regenerate a transgenic (ACO-1) female 'Galia' parental line through biotechnology, this is now being done through traditional breeding methods using the 'backcross' method. T0F1 pollen was backcrossed to the wild-type female 'Galia' parental line in order to insert the antisense ACC oxidase (ACO-1) gene. The female transgenic backcross 2 (BC2) seeds were produced during the summer 2004 and BC3 and BC4 lines were produced in spring and summer 2005. In spring 2006, T4 male lines will be crossed to the BC4 female lines and a new transgenic hybrid will be created.
This hybrid will be grown in fall 2006 and compared to wild-type, commercial 'Galia' for yield and postharvest quality characteristics.
Impacts
Markets for greenhouse grown hydroponic vegetables are strong throughout the U.S. These markets continue to increase with diversification of the commodities grown. The 'Galia' muskmelon has brought billions of dollars to exporters of the fruit from Israel, Spain, Turkey, and Morocco, to Europe. Pilot sales in the U.S., including Publix supermarkets, has given similar potentials for fruit produced in the U.S. especially in warmer climates such as Florida and Puerto Rico. One of the major drawbacks to increased sales is soft fruit, as they must be harvested fully ripe for optimum flavor. Previous work has developed the protocol for transformation of both the male and female parents of 'Galia'. The research which is proposed will continue to develop seed stocks of both lines and characterize the phenotypes of each. F1 hybrid crosses will be made to develop 'Galia' cultivars with a reduced ability to produce ethylene and thus delay fruit softening. Initial studies with the
male line have shown that this transgenic system works. Once F1 hybrid seeds are available we will characterize the postharvest quality of the fruit including ethylene production, sugar content, firmness, color, volatiles, and aroma, as well as, fruit yield capabilities under commercial conditions in a passive-ventilated greenhouse.
Publications
- Mitchell, J. M., Cantliffe, D., Klee, H., Sargent, S., and Stoffella, P. 2005. Fruit quality characteristics of 'Galia' F1 Hybrid (Cucumis melo L. var. reticulatus Ser.) muskmelon developed from a transgenic male parent. Proc. III Inter. Cucurbit Symp. ActaHort. (In press).
- Nunez-Palenius, H., Cantliffe, D., Klee, H., and Huber, D. 2004. Extended shelf-life in transgenic Galia (Cucumis melo L. Var. reticulatus Ser.) HortScience. 39:861.
- Nunez-Palenius, H., Cantliffe, D., Klee, H. 2003. Transformation of Galia (Cucumis melo L. Var. reticulatus Ser.) melon with an antisense ACC oxidase gene. HortScience. 38:710.
- Nunez-Palenius, H., Cantliffe, D., Klee, H., and Huber, D. 2004. Transformation of muskmelon parental line (Cucumis melo L. var. reticulatus Ser.) with an antisense ACC oxidase gene. Acta Horticulturae 659: 805-808.
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Progress 10/01/03 to 09/30/04
Outputs
Transgenic male parental lines of Galia muskmelon bearing an antisense ACC oxidase (ACO-1) gene were developed from cotyledon explants cultured in vitro. Transgenic fruits from the ACO-1 antisense male line produced less ethylene and had a longer shelf-life compared to wild-type fruits. The other postharvest quality characteristics of the transgenic fruit were similar to wild-type fruit. Transgenic T0F1 Galia was developed from the transformed male line and wild-type female parental line. It was not possible to regenerate a transgenic (ACO-1) female Galia parental line thus; T0F1 pollen was backcrossed to the wild-type female Galia parental line in order to insert the antisense ACC oxidase (ACO-1) gene. The female transgenic backcross 1 (BC1) seeds were produced during the summer 2004. During spring and fall 2004, transgenic T0F1 Galia, wild-type Galia and Gal-52, were grown in a passive-ventilated greenhouse in Citra, FL. In spring 2004, there was a severe powdery
mildew (Sphaerotheca fulingea) infestation. No significant differences in plant yield, quality, ethylene evolution and respiration were observed between transgenic plants and wild-type Galia, however, Gal-52 was significantly (P<0.05) firmer after storage for 5 days at 20 degrees C with fewer days to harvest. Gal-52 produced more ethylene and carbon dioxide than the other melons. In fall 2004, there was a significant difference in days to harvest for unselected transgenic T0F1 Galia compared to wild-type Galia and Gal-52. The transgenic Galia remained on the vine an average of 5 days longer than wild-type Galia and 7 days longer than Gal-52.
Impacts
We expect to provide data supporting the conclusion that we have created a new, improved variety of melon that has all of the positive aspects of Galia in terms of taste and consumer acceptance but now has the extended shelf life permitting widespread adoption in agriculture.
Publications
- Nunez-Palenius H, Cantliffe D, Klee H, Huber D. 2004. Extended shelf life in transgenic Galia melon (Cucumis melo L. var. reticulatus Ser.). HortScience 39: 861.
- Nunez-Palenius H, Cantliffe D, Klee H, Huber D. 2004. Transformation of muskmelon parental line (Cucumis melo L. var. reticulatus Ser.) with an antisense ACC oxidase gene. Acta Horticulturae 659: 805-808.
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