Inducing genetic variability in Cenchrus ciliaris L. through chemical and physical mutations

LÓPEZ COLOMBA, E.; PRINA, A.; GRIFFA S.M; RIBOTTA, A.; CARLONI, E.; TOMASSINO, E.; LUNA, C.; BIDERBOST, E.; GRUNBERG, K.

Campo Grande , Matto Grosso do Soul, Brasil

Simposio; II Simpósio Internacional sobre Melhoramento de Forrageiras. Campo Grande :; 2009

Embrapa gado da Corte

Cenchrus ciliaris L., a forage grass of wide distribution in the north-west area of Argentina, is a tetraploid (4x 36) and an obligate apomictic species (Ozias-Akins, 2006; Miles, 2007). One way of obtaining a novel germplasm is by using non-conventional methods, such as induced mutations. Among the most widely used mutagenic agents are gamma rays, X rays, and ethyl methanesulfonate (EMS) (Ahloowalia and Maluszynski, 2001; Mohan Jain, 2005). Because of the random nature of mutagenic agents, it is necessary to use accurate techniques that, through morphological, physiological and/or molecular characters, enable to recover and characterize the new genotypes. In the search of individuals of improved behaviour under abiotic stress factors, selection methods are conducted under field and/or hydroponic conditions and are based on parameters related to production under control versus stress conditions (Munns et al., 2002; Verlues et al., 2006). The complex nature of these analyses along with the difficulty to test large populations has promoted the use of other types of methods, such as in vitro selection (Carretero et al., 2007), which has the advantage of being a rapid and efficient technique for screening numerous individuals in a small space and a short period and enables to incorporate selection agents into the culture media (Dziadczyk et al., 2003). The aim of this work was to evaluate whether the combination of induced mutations through chemical and physical agents and in vitro selection could be a useful approach within the framework of a genetic improvement program to increase genetic diversity, with emphasis on salinity and drought tolerance.