SALINITY RESPONSE AND GENETIC VARIABILITY IN CLONES OF Panicum coloratum TO BREEDING PURPOSES

A RIBOTTA; LÓPEZ COLOMBA E; E.TOMASSINO; C.FIOL ; GRIFFA S,; M. QUIROGA; E. CARLONI; GRUNBERG K

Buenos Aires

Simposio; 5th International Symposium of Forage Breeding; 2015

ISFB

Panicum coloratum is a cross-pollinated perennial grass native of South Africa that has beenintroduced to different parts of the world including Argentina.In this country, this species hasbeen shown good forage quality and production. The continuous increase in the area dedicatedto agriculture has displaced livestock production to areas with adverse environmental conditions.Therefore, a breeding program to increase environmental stress tolerance in P. coloratum isactually been developed for INTA, with emphasis in enhancing salinity tolerance. The aim of thiswork was to evaluate salt response of clones through morpho-physiological traits and todeterminate genetic variability by ISSR markers. The plant material consisted of 18 clonesderived from two accessions of different source. These clones were previously selected for goodperformance of agro-morphological traits. The salt assay was conducted in a greenhouse underhydroponic conditions with two treatments (0 and 300 mMNaCl). Different traits contributing tobiomass productionand traits related to physiological state as malondialdehyde content, theability to reduce iron, chlorophyll content, total membrane integrity (MI),total soluble sugars, totalprotein, relative content of water (RCW) and ions Na+, K+ and Mg2+were evaluated. An index thatmeasure the effect generated by salt stress respect to control for each variable was estimatedanda multivariate Principal Components Analysis was performed.. Groups of differentialbehavior in salt stress conditions were obtained by this analysis. Groups with more biomassproduction were the least affected to salt stress, and this was related to lower damage in thetraits MI, CRA and Na+/K+. To performed DNA extraction, 100 mg of young leaves of each clonewere used. A total of 28 ISSR primers were screened initially and 23 ISSR primers thatproduced clear and reproducible fragments were selected. Of the total bands obtained, 443(95.67%) were polymorphic.The results obtained in this work showed differential response in saltstress and genetic diversity among clones of Panicum coloratum.This is important in a breeding