Studies on Chromosome Doubling of Fragaria hayatae Makino and Interspecific Hybridization with Fragaria ×ananassa Duch.
Date Issued
2010
Date
2010
Author(s)
Hsu, Chin
Abstract
Taiwan strawberry (Fragaria hayatae Makino) is a diploid strawberry with small fruit and some pest resistant characteristics native in Taiwan. Polyploids and interspecific hybridization should be made for this specise’s further use. Reciprocal crosses were made between F. hayatae and F. ×ananassa Duch. in order to obtaine pentaploids, and were F. hayatae treated with colchicine, in expecting to get tetraploid plants.
In the combination of Taiwan strawberry × cultivated strawberry, higher percentage of fruit set was obtained, and seed number /fruit set was higher. Progenies of the reciprocal cross between F. hayatae and F. ×ananassa were fewer than expected. To improve the survival rate of the offspring, germination test for F. hayatae and the hybrid seeds was made. Germination rate was promoted in stratified F. hayatae seeds. The seeds of stratification treatment and control of F. hayatae, both had more than 90% germination rate after sowing for 30 days. The effect of stratification and scarification were about the same in interspecific hybridization seeds. Low survival rate of interspecific hybridization seedlings was caused by low fertility seeds, especially the seeds with hollow heart might be the evidence of barrier in embryo and endosperm development.
Chromosome number of root tip in F. hayatae was investigated, which was 2n = 2x = 14, and in the 10 offsprings of F. ×ananassa ''Taoyuan No. 3'' × F. hayatae 4 of them were aneuploid, with the chromosome number ranging from 44 ~ 53, 5 of them were octoploid, and one plant was hexaploid. The octoploid hybrid progenies might be due to pollen contamination or apomixis. The other five aneuploidy plants suggest that there were due to disorder during miosis.
In meristem culture of F. hayatae, primary medium by 1/2 MS with 0.5 mg.L-1 BA was the best growth conditions for the proliferation medium was 1/2 MS + 0.5 mg.L-1 NAA + 0.5 mg.L-1 BA. Cultured plants subcultured into the proliferation medium with BA removed, could promote rooting.
Eight plantlets were obtained from a tissue culture test, which used the culture medium as further metioned with 50 mg.L-1 colchicine added. But the chromosome number of all of them were 2n = 2x = 14.
In the combination of Taiwan strawberry × cultivated strawberry, higher percentage of fruit set was obtained, and seed number /fruit set was higher. Progenies of the reciprocal cross between F. hayatae and F. ×ananassa were fewer than expected. To improve the survival rate of the offspring, germination test for F. hayatae and the hybrid seeds was made. Germination rate was promoted in stratified F. hayatae seeds. The seeds of stratification treatment and control of F. hayatae, both had more than 90% germination rate after sowing for 30 days. The effect of stratification and scarification were about the same in interspecific hybridization seeds. Low survival rate of interspecific hybridization seedlings was caused by low fertility seeds, especially the seeds with hollow heart might be the evidence of barrier in embryo and endosperm development.
Chromosome number of root tip in F. hayatae was investigated, which was 2n = 2x = 14, and in the 10 offsprings of F. ×ananassa ''Taoyuan No. 3'' × F. hayatae 4 of them were aneuploid, with the chromosome number ranging from 44 ~ 53, 5 of them were octoploid, and one plant was hexaploid. The octoploid hybrid progenies might be due to pollen contamination or apomixis. The other five aneuploidy plants suggest that there were due to disorder during miosis.
In meristem culture of F. hayatae, primary medium by 1/2 MS with 0.5 mg.L-1 BA was the best growth conditions for the proliferation medium was 1/2 MS + 0.5 mg.L-1 NAA + 0.5 mg.L-1 BA. Cultured plants subcultured into the proliferation medium with BA removed, could promote rooting.
Eight plantlets were obtained from a tissue culture test, which used the culture medium as further metioned with 50 mg.L-1 colchicine added. But the chromosome number of all of them were 2n = 2x = 14.
Subjects
polyploid
squash method
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