The use of genomic in situ hybridization (GISH) to show transmission of recombinant chromosomes by a partially fertile bigeneric hybrid,Gasteria lutzii x Aloe aristata (Aloaceae), to its progeny

Takahashi, C.; Leitch, I. J.; Ryan, A.; Bennett, M. D.; Brandham, P. E.

The use of genomic in situ hybridization (GISH) to show transmission of recombinant chromosomes by a partially fertile bigeneric hybrid,Gasteria lutzii x Aloe aristata (Aloaceae), to its progeny

1997

Takahashi, C. | Leitch, I. J. | Ryan, A. | Bennett, M. D. | Brandham, P. E.

Genomic in situ hybridization (GISH) was used to study somatic chromosomes of parental and progeny plants (all 2n=2x=14) of the bigeneric hybrid betweenGasteria lutzii andAloe aristata (Aloaceae), which is partially fertile, a rare occurrence in plants. GISH successfully distinguished between the two parental geonomes in the F1 hybrid and revealed numerous genomic recombinations in chromosomes transmitted by the F1 to the back-cross progeny. The results indicate high levels of meiotic compatibility between the parental genomes, even though they differ in size by 20%. Recombination occurred at a frequency that was higher than that expected from the analysis of orcein-stained meiosis in the F1. The discrepancy suggests that terminalization may occur prior to or during metaphase I, reducing the apparent chiasma frequency, or possibly reveals an under-estimation caused by difficulties in resolving closely grouped chiasmata by eye.

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