HIBRIDOS INTERESPECIFICOS DE "PASPALUM NOTATUM" X "P. MODESTUM"

CAMILO L. QUARIN

doi:10.30972/bon.521-298297

Autores/as

CAMILO L. QUARIN Instituto de Botánica del Nordeste (CONICET-UNNE)

DOI:

https://doi.org/10.30972/bon.521-298297

Resumen

A highly sexual white stigma Bahiagrass: Paspalum notatum clone SWSB (2n=4x=40) was crossed withP.modestum (2n=2x=20) in or- der to investígate the cytogenetic relations between these species.Fi- ve seedlings were recovered from 196 P. notatum SWSB spikelets that were emasculated and pollinated with P.modestum pollen. Chromo- some counts in root tips revealed that all were hybrids with 2n=3x=30 chromosomes associated during diakinesis and metaphase I, mainly as 10 univalents and 10 bivalents, with a mean of 10 univalents, 9,73 bivalents, 0,09 trivalents, and 0,07 quadrivalents per cell. Becausethe highly sexual SWSB Bahiagrass clone as well as the apomictic Com - mon Bahiagrass types are autotetraploids (2n=4x=40, NNNN) it is suggested that P. notatum brought into the hybrids two pairs of ho- mologous genomes NN, whereas P. modestum1 contributed withadif- ferent genome, which is tentatively named P, since this species has been included in the Plicatula group of Paspalum, according to its morphological characteristics. Thus, the meiotic chromosome assoda- tions in the hybrids would indicated that P.notatum and P.modestum have different genomes, remainig unknown the genomic relations of P.modestum. Only l’our hybrids produced inflorescences.Anthesis occurred only in few spikelets, but anthers did not dehisce. None of the hybrids produced seeds.

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