Chromosomal analysis of Nicotiana asymmetric somatic hybrids by dot blotting and in situ hybridization

1990 ◽  
Vol 222 (1) ◽  
pp. 97-103 ◽  
Author(s):  
William C. Piastuch ◽  
George W. Bates
1992 ◽  
Vol 2 (6) ◽  
pp. 863-874 ◽  
Author(s):  
A. S. Parokonny ◽  
A. Y. Kenton ◽  
Y. Y. Gleba ◽  
M. D. Bennett

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 726-735 ◽  
Author(s):  
A. M. A. Wolters ◽  
H. C. H. Schoenmakers ◽  
S. Kamstra ◽  
J. van Eden ◽  
M. Koornneef ◽  
...  

Chromosome numbers were determined in metaphase complements of root-tip meristems of 107 tomato (+) potato somatic hybrids, obtained from five different combinations of parental genotypes. Of these hybrids 79% were aneuploid, lacking one or two chromosomes in most cases. All four hybrids that were studied at mitotic anaphase of root tips showed laggards and bridges, the three aneuploids in a higher frequency than the single euploid. Hybrid K2H2-1C, which showed the highest percentage of aberrant anaphases, possessed 46 chromosomes. Fluorescence in situ hybridization with total genomic DNA showed that this hybrid contained 23 tomato, 22 potato, and 1 recombinant chromosome consisting of a tomato chromosome arm and a potato chromosome arm. The potato parent of K2H2-1C was aneusomatic in its root tips with a high frequency of monosomic and trisomic cells and a relatively high frequency of cells with one fragment or telosome. Meiotic analyses of three tomato (+) potato somatic hybrids revealed laggards, which occurred most frequently in the triploid hybrids, and bridges, which were frequently present in pollen mother cells (PMCs) at anaphase I of hypotetraploid K2H2-1C. We observed putative trivalents in PMCs at diakinesis and metaphase I of eutriploid A7-82A and quadrivalents in part of the PMCs of hypotetraploid K2H2-1C, suggesting that homoeologous recombination between tomato and potato chromosomes occurred in these hybrids. All three hybrids showed a high percentage of first division restitution, giving rise to unreduced gametes. However, shortly after the tetrad stage all microspores completely degenerated, resulting in exclusively sterile pollen.Key words: tomato, potato, symmetric somatic hybrids, chromosomal irregularities, genomic in situ hybridization.


Genome ◽  
1997 ◽  
Vol 40 (5) ◽  
pp. 666-673 ◽  
Author(s):  
F. Garriga-Calderé ◽  
D. J. Huigen ◽  
F. Filotico ◽  
E. Jacobsen ◽  
M. S. Ramanna

To increase the potential for establishing a complete series of tomato chromosome addition–sbstitution lines in a potato background, six new BC1 progeny were produced. All of them originated from crosses between three different hexaploid potato (+) tomato fusion hybrids. Three different somatic hybrids, viz., C31-17-5, C31-17-24, and C31-17-51, were used as female parents, and four different tetraploids, viz., Katahdin, Frieslander, 6704-1, and AM66.42 were used as male parents. A characterisation of the genomes of the three fusion hybrids and the six BC1 progenies (6739, 2001, 2002, 2003, 2004, and 2005) through genomic in situ hybridization and restriction fragment length polymorphism (RFLP) analysis indicated that there was preferential tomato chromosome elimination in the fusion hybrids. Similar analyses of the six BC1 progeny indicated that a variable number of the alien tomato chromosomes (6–11) were present in individual plants. RFLP analysis using chromosome specific DNA probes indicated that BC1 progenies had retained all 12 tomato chromosomes, albeit in different individual plants. This means that the available BC1 progenies have the potential for establishing a complete series of tomato chromosome addition–substitution lines in a potato background.Key words: protoplast fusion hybrids, Solanum tuberosum, Lycopersicon esculentum, BC1 progeny, in situ hybridization, RFLP analysis.


Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 987-992 ◽  
Author(s):  
F Dong ◽  
R G Novy ◽  
J P Helgeson ◽  
J Jiang

Four somatic hybrids derived from a diploid wild species Solanum etuberosum and a diploid tuber-bearing Solanum clone 463-4, together with five BC1 and three BC2 plants, were analyzed by genomic in situ hybridization (GISH). None of the four somatic hybrids had the expected chromosome constitutions, i.e., 24 chromosomes from each fusion parent. Either one chromosome from S. etuberosum or one from the potato parent 463-4 was lost in the hybrids. Three BC1 plants had exactly one set of S. etuberosum chromosomes. The other two BC1 plants either had one extra or one fewer S. etuberosum chromosome, possibly because their somatic hybrid parents had an extra or had lost one S. etuberosum chromosome. The presence of one set, or close to one set, of S. etuberosum chromosomes in all BC1 plants suggests a preferential pairing and segregation of the S. etuberosum chromosomes in the somatic hybrids. Two of the three BC2 plants had 52 chromosomes, deviating significantly from the expected chromosome number of 48. These results suggest poor pairing between S. etuberosum and S. tuberosum chromosomes in the BC1 plants. The present study demonstrates the importance of combining GISH and DNA marker analysis for a thorough characterization of potato germplasm containing chromosomes from different species.Key words: potato germplasm, Solanum etuberosum, molecular cytogenetics.


Genome ◽  
1998 ◽  
Vol 41 (5) ◽  
pp. 691-701 ◽  
Author(s):  
Marina Skarzhinskaya ◽  
Jan Fahleson ◽  
Kristina Glimelius ◽  
Armand Mouras

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