Flowering Induction in Paspalum plicatulum Michx, a Sexual Tetraploid and Sexual Plant

NOVO P.; RUIZ DÍAZ G.; QUARIN CL; VIDOZ ML; ESPINOZA, F

Rosario

Workshop; Proceedings of the 7th Series of Seminars on Advances in Apomixis Research; 2021

Paspalum plicatulum is an experimental sexual autotetraploid plant (4×S) obtained by colchicine doubling chromosomes from a wild 2×plant. 4×S had already produced interspecific hybrids in crossing with tetraploid apomictic species (4×A) of the Plicatula group. However, the 4 × S plant blooms in early summer and there are some 4 × A species in this group which bloom in late April, preventing crossbreeding. The objective of this study was to delay the flowering of 4 × S by controlling the photoperiod and temperatureandtohybridizewith4×AspeciesofthePlicatulagroupthatflowerinApril. Theexperimentswerecarriedoutinachamberwithcontrolledlight(14h)andtemperature (25 ◦C±2◦) and were repeated twice. We used 16 4×S clones in a 4-treatment design: (1) control (in greenhouse, natural light), (2) light intensity of 170 µmol m−2 s−1 of; (3) light intensity of 350 µmol m−2 s−1; and (4) light intensity of170 µmol m−2 s−1 + 25 µg GA3 en 10 µL of ethanol 95% (v/v). The control did not flower, while all the chamber treatments started flowering at 90 days. Using these plants as pistillate, hybrids were obtained after crossing with cv. Cambá and line U44 of P. atratum and with cv. Chané of P. guenoarum. Thus, the delay in flowering of the 4×S plant allowed obtaining new interspecific hybrids to be achieved within the Plicatula group of Paspalum. This will permit expanding the use of germplasm from other apomictic species in the genetic improvement program for native forages.