VARIABILITY IN SALT TOLERANCE IN SEEDLINGS OF Panicum coloratum VAR. makarikariense L. IN HYDROPONICS

CARDAMONE L.; CUATRÍN A.; GRUNBERG K.; TOMÁS A.

Buenos Aires

Simposio; 5th International Symposium of Forage Breeding; 2015

Soil salinity is a major constraint to plant production and an increasing phenomenon in regionswith raising water tables. Improving germplasm for salinity tolerance could be a moresustainable solution than soil reclamation in subtropical areas. Panicum coloratum var.makarikariense is a warm-season perennial grass native to Africa used as forage in subtropicalareas of the world. Genetic improvement to increase salinity tolerance in the species could makeit a forage resource for areas with this edaphic restriction. In this study we searched forvariability in salinity tolerance in a collection of P. coloratum var. makarikariense to find suitablematerials to be included in a breeding program. A screening of 18 families from 4 populations(ER, DF, TS and UCB) was performed by culturing in hydroponic conditions, in a DBCA (2replicates, ten seedlings/replicate of each family) in a greenhouse setting. Treatments were:control (Hoagland solution, 0mM NaCl) and salinity (Hoagland solution + 200 mM NaCl). Plantswere cultivated for 35 days then divided into roots and aerial biomass at harvest. Tolerance wasevaluated as total biomass (TB) produced under salinity and by calculating the damage as thepercent reduction in growth in salt compared to the control setting. Data was analyzed byANOVA. PCA and clustering analysis were also used to discriminate susceptible from tolerantfamilies. Families ER3, ER6, ER9 and DF7 had the highest TB although differences were notsignificant. Nonetheless, clustering and PCA grouped the same families as more productive.Damage was estimated in: aerial fresh weight, root fresh weight, total fresh weight, aerial dryweight, root dry weight, total dry weight. Families ER3, ER6, ER10, TS23 and DF7 had thelowest damage in all of variables. PCA biplot and clustering based on damage distinguished;ER3, ER6, ER10, TS23 and DF7 as tolerant families while the rest were set as susceptible ones.Variability for salinity tolerance was found in the collection and promising materials weredetected to enter a breeding program to increase productivity under salt conditions.