Progress 08/01/02 to 09/30/06
Outputs
Marker assisted selection (MAS) was successfully employed to select the progeny from genetic crosses containing 3 disease resistance genes and to develop inbred tomato varieties that could be commercially grown in Hawaii. A genetic backcrossing strategy was employed for the development of different horticultural tomato types. Two donor beef steak type tomato parents, G8-5 was homozygous for Sw-5 that confers resistance to the tomato spotted wilt tospovirus (TSWV), Mi that confers resistance to the root knot nematode, and Tm2a that confers resistance to the tomato mosaic tobamovirus. The other parent (3-4#5) was homozygous for Sw-5 and the ripening-inhibitor (rin) mutation that yield fruits that fail to ripen. Markers employed included 3 co-dominant SCAR markers, UBC421 for Sw-5, Rex-1 for Mi, and Tm2 for Tm2a. A beefsteak-type F1 hybrid tomato suitable for commercial production in Hawaii was generated by crossing G8-5 and 3-4#5. A plum-type tomato inbred tomato
suitable for production in Hawaii was also developed in this program. In the development of this inbred line, a plum-type breeding line with homozygous resistance to TSWV and the root knot nematode was generated by a cross between G8-5 and an inbred plum variety derived from a F1 commercial hybrid, Supra. The resultant F1 hybrid was self-pollinated and progeny homozygous for both Sw-5 and Mi was selected after 2 self-pollinations. Cross pollinations were then made with the F3 generation materials and plum-type parental lines derived by self-pollinating and selecting desirable F5 plants from two commercial F1 hybrids, Classica VFFNA hybrid and Spectrum hybrid. Selection for horticultural type was made from field evaluations on the island of Maui and disease resistance selections were based upon marker assisted selection using molecular markers. A green zebra type tomato was also developed in this program. In the development of this inbred, a genetic cross between the variety Green
Zebra and 3-4#5 was generated and the progeny self-pollinated for 5 generations. During the selection process, MAS was used to select progeny homozygous for the Sw-5 gene and inbred line selected for commercial production selected based upon yield, fruit size and taste. A red grape tomato was developed in this program. In the development of this inbred a genetic cross between G8-5 and an inbred grape variety, derived from F1 Bright Pearl, was generated and self pollinated for two generations then backcrossed prior to self pollinating and selecting a commercial grape type tomato line resistant to Sw-5, Mi and Tm2a. The three tomato types are currently being distributed to growers in Hawaii. During the selection process, MAS was used to select progeny homozygous for the Sw-5, Mi and Tm2a genes and inbred line selected for commercial production selected based upon yield, fruit size and taste. The tomatoes developed are being distributed to Hawaii tomato growers.
Impacts
A breeding program has successfully developed a beeksteak, plum, zebra, and grape tomato types for commercial production in Hawaii. Modern marker assisted selection was employed to help identify tomatoes in the breeding to accelerate the development commercial tomatoes with multiple disease resistances to major pests in Hawaii. These tomatoes will allow Hawaiian growers to reduce their use of pesticides and make production more profitable.
Publications
- No publications reported this period
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Progress 10/01/04 to 09/30/05
Outputs
Several inbred tomato varieties were fixed for disease resistance and horticultural type during this period. Selection for horticultural type was made from field evaluations on the island of Maui and disease resistance selections were based upon marker assisted selection using molecular markers linked to 3 disease resistant genes. The 3 disease resistant genes included Sw-5 conferring resistance to the tomato spotted wilt tospovirus (TSWV), Mi that confers resistance to the root knot nematode, and Tm2a that confers resistance to the tomato mosaic virus. The tomatoes included: a green and yellow striped zebra tomato homozygous for the Sw-5 gene; a red and green striped zebra tomato homozygous for the Sw-5 and Mi genes; a yellow beefsteak tomato homozygous for the Sw-5, Mi and Tm2a genes; and a red cluster type tomato homozygous for the Sw-5, Mi and Tm2a genes.
Impacts
Several different horticultural type tomatoes with disease resistance to the tomato spotted wilt virus and 2 other diseases have been developed for the commercial Hawaiian market. Production of these tomatoes will allow growers to be able to economically produce tomatoes for the Hawaii market.
Publications
- No publications reported this period
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Progress 10/01/03 to 09/29/04
Outputs
No progress in this project because no funds were given for research.
Impacts
Parental tomato lines have been generated to produce multiple disease resistant red beefsteak tomatoes with an extended shelf life suitable for the commercial market in Hawaii.
Publications
- No publications reported this period
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Progress 10/01/02 to 09/30/03
Outputs
Inbred tomato lines are being generated for different tomato types. Inbred parents to generate a red beefsteak type tomato have been fixed. One parent is a semi-determinate red beefsteak tomato and resistant to the tomato spotted virus, the tomato mosaic virus and the root knot nematode. The other parent is a determinate large red beefsteak tomato that is homozygous for the mutant form of the rin gene that slows the ripening process in tomato. Genetic crosses between these two parents generates a multiple disease resistant with an increased shelf life red beefsteak tomato. Several tomato growers on Maui, Kauai and Hawaii are currently growing this hybrid for commercial tomato production. Marker assisted selection using molecular markers linked to all 3 disease resistant genes is being used to identify homozygous and heterozygous susceptible and resistant individuals in segregating populations. Use of this marker strategy has accelerated the development of useful
inbred lines. Currently susceptible inbred parents have been generated for a yellow beefsteak, red grape, red cherry, and red cluster tomato types. Resistant lines for all types have also been generated but their phenotype has not been fixed and further selfing and selection for both phenotype and genotype is required.
Impacts
Parental tomato lines have been generated to produce multiple disease resistant red beefsteak tomatoes with an extended shelf life suitable for the commercial market in Hawaii.
Publications
- No publications reported this period
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Progress 10/01/01 to 09/30/02
Outputs
An experiment has been planned to make hybrid tomatoes using a University of Hawaii inbred tomato line that contain the Sw5, Mi and Tm2a genes that confers disease resistance to TSWV, root knot nematode, and tomato mosaic virus, respectively and disease susceptible heirloom tomatoes.
Impacts
Development of multiple disease resistant tomato hybrids will allow Hawaiian growers to increase their production of tomatoes and become more self sufficient.
Publications
- No publications reported this period
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