Bahiagrass Tetraploids Produced by making (Apomictic Tetraploid ✕ Diploid) ✕ Diploid Hybrids1
- Glenn W. Burton and
- Wayne W. Hanna2
A short, rapid spreading hybrid with 30 chromosomes was found among several hundred spaced plants established from seed of a facultative apomictic tetraploid (In = 40) of bahiagrass (Paspalum notatum Flögge) grown in isolation with a sexual diploid (In = 20) ‘Pensacola’ bahiagrass clone. This hybrid shed no pollen but set 34% seed when grown next to a large block of Pensacola bahia. Six hundred and forty-three plants established from open-pollinated seed of this triploid resulted in 508 maternal triploid plants and 135 40- chromosome plants that were similar in appearance but more vigorous than the triploid. It appeared that unreduced eggs from the triploid female united with 10 chromosome male gametes from Pensacola bahiagrass to produce fertile tetraploids. Thus, fertile tetraploid hybrids carrying 20 chromosomes from the apomictic tetraploid and 20 from the sexual diploid were created by hybridization. In the past, such tetraploid hybrids were produced only by doubling the chromosome number in the sexual diploid to make a sexual tetraploid that could then be hybridized with the apomictic tetraploid. The uniformity in the sterile triploids and within the progenies of 117 of the tetraploid hybrids indicated that apomixis had been transferred from the tetraploid parent to its offspring. The variability that occurred in progenies from later harvested seed from 10 of these genotypes indicated that the inherited apomixis was facultative as expected.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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