the Symposium on Wheats for More Tropical Environments - cimmyt

,36• Produce grain of high industrial andcommercial quality for both nationaland international markets.Genetic variability was introduced as aresult of 200 crosses made each year inMexico and at <strong>the</strong> Marcos JuarezRegional Experiment Station inCordoba, using progenitors with goodadaptation for nor<strong>the</strong>rn Argentina.Individual selection from F2 to F4populations for disease resistance,agronomic characters, grain type andindustrial quality was conducted at <strong>the</strong>Presidencia Roque Saenz Peiia RegionalExperiment Station. Mass selectionswere made beginning with <strong>the</strong> FSpopulations.Shuttle breeding of F3 populations wasalso accomplished through <strong>the</strong> Balcarcesummer nursery at <strong>the</strong> BalcarceRegional Experiment Station, BuenosAires. The goals of this off-seasonnursery were:• Develop lines with better adaption;• Develop lines with resistance to stemrust;• Achieve homozygoscity in feweryears;• Evaluate advanced lines inpreliminary comparative yield trials;• Evaluate lines to be included inregional comparative trials at SaenzPefia and Colonia Benitez, as well asin various parts of <strong>the</strong> pampasregion;• Evaluate advanced internationallines for good agronomic charactersand disease resistance;• Evaluate commercial bread wheatvarieties through comparative yieldtrials at Saenz Pena, at ColoniaBenitez and Las Brenas ExperimentStations in Chaco, and at EI ColoradoExperiment Station in Formosa, and• Identify different biotypes(Virulences) of stem and leaf rust byobserving varietal differences at <strong>the</strong>various testing sites.ConclusionsThe cultivar Chaqueno Inta wasreleased as a result of this program; itspedigree is Son64-P4160E x CT244. Ithas high yield potential, intermediateto-latematurity, good agronomiccharacters, disease resistance and goodbread-making quality. Chaqueno Intaand Marcos Juarez [nta are <strong>the</strong>predominant cultivars grown innor<strong>the</strong>ast Argentina. O<strong>the</strong>r commercialvarieties adapted to <strong>the</strong> region areLeones [nta, Buck Pangare, CargillTrigal 800 and Klein Chamaco. Severaladvanced lines are almost ready forrelease and have shown increased yieldpotential over <strong>the</strong> best check varieties,have better disease resistance and haveacceptable industrial quality (Table 2).Potential areas for wheat cultivation inrotation with o<strong>the</strong>r crops have beendetermined, and an additionalsubtropical area in nor<strong>the</strong>ast Argentinahas been found to hold promise forwheat cultivation within a soybeanwheatrotation. This is <strong>the</strong> area ofTucuman, Salta and Jujuy in Santiagodel Estero province. At present, wheatis grown <strong>the</strong>re on only about 20,000hectares, but high yields have beenobtained under irrigation.