Variabilidad en caracteres vinculados a la implantación en poblaciones espontáneas de Stapfochloa berroi (Arechav.) P. M. Peterson de la Pampa Deprimida

Abstract

Stapfochloa berroi is a spring-summer growing perennial grass, native to South America, which in the Pampa Deprimida (Buenos Aires, Argentina) is a key species due to its forage value and adaptation to environments that are restrictive (sodic soils, low organic matter content, waterlogging, drought) for other forage species. The reincorporation of selected native germplasm would be important both for increasing livestock productivity and for maintaining and/or recovering biodiversity in these agroecosystems. The objective was to analyze the variability in traits linked to the success of implantation in two spontaneous populations of S. berroi from the steppes of the halophyte of the Pampa Deprimida. Seed germination was evaluated and individual seed weight was recorded for both populations. Subsequently, seeds with their individual weights identified were sown in seedling trays with limiting substrate (low alkaline soil) and with nonlimiting substrate (horizon A from a typical Argiudol soil) in a greenhouse. The emergency was evaluated for 30 days. After 54 days, for each individual, the following traits were determined: height, total plant length and length of the longest adventitious root, number of adventitious roots, number of unfolded green leaves and number of tillers. The percentage of germination and cumulative emergence and an index of emergence speed were calculated, and aerial, root and total dry weight were determined. The variability found in key traits for establishment between S. berroi populations (e.g., germination, emergence), but mainly within populations (e.g., aerial, root and total dry weight) would be promising for an initial selection phase.