Three decades of breeding research on willow trees in Argentina

GRANDE JORGELINA; FERNANDEZ PATRICIA; VILLAVERDE RAUL; LUQUEZ VIRGINIA; THOMAS ESTEBAN; GARCIA, ARACELI; CERRILLO TERESA; MONTEOLIVA SILVIA; FOSCO IGNACIO; LOVAL SABRINA

Buenos Aires

Simposio; VII IUFRO International Poplar Symposium; 2018

In a global context, Argentina is displayedprominently in productivity of willowplantations for sawing, paper pulp,particleboards, and potential for otherapplications, as bioenergy and environmentalservices, dueto favorable environmentalconditions for cultivation development. TheParaná River Delta (located between 32º5 · - 34º 29, S and 58° 22, - 60º 45, W} is thecore region of willow production. Otherregions have good potential, such as the NorthPatagonia (between 39º 01' 12" S. and67º 40' 04" W} and the Salado River Basin(35º 44' S and 57º 21' W}. The country hasdeveloped research to improve willow traits.First strategies were carried out by INTAin 1952, obtaining improved willow clones forfarmers and industries. According to newneeds of industries and foresters, a newupdated breeding program was developed atthe end of the 1980's, with public-privatearrangements. The Breeding Program has~een developed in connection with pathology,wood technology, ecophysiology andbiotechnology as a consolidated team. More than20.000 seedlings were developed bycrossing parents of Salix alba L., S.amygdaloides Anders, S. bondplandiana H.B.K., S.babylonica L., S. jessoensis Seemen, S.matsudana Koidtz, S. nigra Marsh. Main traitsconsidered for selection were volume yield,disease and pest resistance, floodingtolerance and wood quality. Molecular geneticmarkers proved to be efficient tools forindividual identification; microsatellites(SSR} fit best to requirements of testingsystems. Mpre than 200 genotypes were evaluatedin field trials, after previousselection phases. As a result, 9 new clones ofthe S. matsudana x S. alba and S.matsudana x S. nigra inter-specific taxa, alongwith open-pollinated selections of S.alba, S. nigra and S. matsudana; 7 wereregistered and are being adopted by forestcompanies and small landholders. In 10-yearsold trials, in medium-quality sites in Deltaregion, the improved clones showed a meanannual increase in volume (MAi} of22m3.ha-1.yr-1, that represents an increase of45% compared to traditional clones.There are experimental clones in differentselection stages; in 5-years old trials,genotypes originated from S. matsudana, S.alba, S. nigra and S. amygdaloides speciesshowed the best performance in Delta; S.matsudana x S. albataxon in North Patagoniaand S. nigra and S. matsudana x S. nigra in theSalado River Basin. A rapid replacementof cultivars is relevant to improveproductivity in the upcoming years, to achieve a goodlevel of volume and quality for wood productionin a sustainable production system.