IBS   24490
INSTITUTO DE BIOLOGIA SUBTROPICAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Microsporogenesis and seed fertility in Paspalum minus E. Fourn. and P. conduplicatum Canto-Dorow, Valls & Longhi-Wagner
Autor/es:
PERICHON M.C.; ANA I. HONFI; VALLS J.F.M.; RUA GABRIEL HUGO
Lugar:
FOZ DO IGUAZU
Reunión:
Congreso; 2018 INTERNATIONAL CONGRESS OF GENETICS; 2018
Institución organizadora:
INTERNATIONAL FEDERATION OF GENETICS, SOCIEDADE BRASILERA DE GENETICA, ASOCIACION LATINOAMERICANA DE GENETICA
Resumen:
Paspalum minus and P. conduplicatum are high polyploid, perennial species of the core-Notata group of Paspalum, P. conduplicatum endemic to southern Brazil and hexaploid (2n=6x=60), and P. minus with a wide distribution in America, with almost exclusively pentaploid cytotypes(2n=5x=50). The genetic system of accessions of P. minus from Caaguazú, Paraguay (GHR1180) and P. conduplicatum from Piraí do Sul, Paraná, Brazil (V16483) was studied. Meiosis was analyzed in pollen mother cells (PMCs) stained with 2% acetocarmine and pollen viability by in vivo germination with 0.1% aniline blue staining. Seed production in open- and selfpollination was estimated. Paspalum minus presented irregular meiosis, with most chromosomes as univalents and multivalents at diakinesis and metaphase I, with a range of 29-50I, 0-11II,0-2III, 0-4IV, 0-1V, and 39.24I, 4.36II, 0.32III, 0.8IV, 0.04V by PMC in average. First meiotic division arrested before telophase I and a restitution nucleus is formed, which is divided equationally in a second division. Microspore dyads are the result of meiosis, each with unreduced nucleus (2n). Low pollen viability (PV=16%) and a high seed production under both open- (96.74%) and self-pollination (98%) were registered. Pollen?pistil compatibility indicates that it is self-compatible (96%). Paspalum conduplicatum presented regular meiosis with formation of up to 30 bivalents in 37.5% of PMCs. Most frequent association was 28II+1IV in62.5% of PMCs. Pollen viability was 58% and in vivo germination of 84.21%. High seed production under open pollination (94%) was found. These results indicate allopolyploid origin for both species and full fertility.