Reproductive behavior of the Aapomictic Paspalum notatum hybrid cultivar Boyero-UNNE growing at field conditions in the Argentina temperate región

BALABÁN, DAVID; DELGADO LUCIANA; ANIBALINI, VERÓNICA; SOLIMAN, MARIANO; ORTIZ, JUAN PABLO AMELIO; BUSNELLI, VALERIA; MARTIN, B

Workshop; Proceedings of the 7th Series of Seminars on Advances in Apomixis Research; 2020

Paspalum notatum cv. Boyero-UNNE is an apomictic-hybrid cultivar developed at FCAUNNE,Argentina. Here we evaluated seed development and phenotypic/reproductivestability through successive generations of Boyero-UNNE in the argentine temperate region(pampas). Plots were established at the FCA-UNR, Zavalla, Argentina. The developmentof seeds was examined by collecting 20 inflorescences every 3 days during the floweringperiod (21 days in total) and observing 50 spikelets/plant with a binocular microscope.Proportions of small fertilized ovaries (SFO), immature caryopses (IC), filled caryopses (FC),necrotic ovaries (NO), and empty spikelets (ES) were scored. The stability of vegetativeand reproductive traits was evaluated in three F1 families (seeds collected in 2016, 2017,2018) by measuring plant height (PH), tiller number (TN), stem length (SL), bunch length(BL) and percentages of ovules carrying aposporous sacs (% OAES), meiotic sacs (% OMES)and aposporous + meiotic sacs (% OMIX). The vegetative traits were also examined inthe progeny of each F1 family. Seed development studies showed 18% SFO, 18% IC, 38%FC, 24% NO, and 2% ES. Non-significant differences were observed in vegetative traitsacross families and generations. The reproductive characterization showed, on average54.7% OAES, 15.4% OMES and 29.9% OMIX (total apomixis capacity: % OAES +% OMIX= 84.6%). Our results indicated that cv. Boyero-UNNE can form caryopses in up to 74%of the spikelets (18% SFO, 18% IC, and 38% FC). Moreover, considering that originalBoyero-UNNE reports notify a total apomictic capacity of 86?93%, both vegetative andreproductive traits can be considered stable across generations.