Banco de Germoplasma Activo de frutilla (BGA): modalidades de conservación.

ARIAS, M.E.; LEMME, M.C.; DEBES, M.A.; DÍAZ, M.; SALAZAR, S.M; LUQUE, A.C; CASTAGNARO, A.P.; DÍAZ RICCI J.C

Ciencia

Fac de Ciencias Exactas y Nat.

Año: 2010 vol. 5 p. 19 - 34

1668-2009

The BGA maintains different genotypes related to the cultivated strawberryFragaria x ananassa, that belong to the species: Duchesnea indica (twobotanical forms: indica and albocapout) Duchesnea chrysantha, Potentillatucumanensis, Fragaria chiloensis, Fragaria vesca, Fragaria virginiana, andnumerous cultivars and hybrids of Fragaria x ananassa. The mainobjectives of BGA are: to maintain biodiversity, conserve genotypes forbreeding programs and enable the development of many research lines(graduate, post-graduate and post-doctoral thesis). The BGA uses threeconservation modes: 1) in vitro multiplication of materials under laboratoryconditions, 2) in vivo multiplication -in Fitotrón- under controlledconditions and 3) in vivo multiplication, under nursery in field conditions.The in vitro multiplication is carried out from apices of stolons understerile conditions, in glass bottles using two different media: agar withsalts for rooting and agar with hormones for vegetal multiplication. InFitotrón, the material multiplied in vitro is removed from the artificialsubstrate and treated with contact fungicide by immersion, thentransferred to a sterile growth substrate soil/ perlome (2:1). Speedlings of3 cm diameter wells were used and placed in larger trays (containers).Watering is carried out every 48 hours with distilled water making a film of1 cm at the base of the tray. Trays are then covered with paper film for 30days to preserve dehydration stress of seedlings. After that, trays areuncovered gradually for rustication of seedlings. They were thentransplanted to individual pots with substrate: soil/perlome (2:1). Theconditions of the Fitotron are regulated for stolonization (16 hours lightand 28º C). Stolons with 2 leaves completely unfolded, are used for agamicpropagation. The material is conservated in field in two forms: in shadow(mother collection) and greenhouse (work collection). The first form permitsa better approximation to natural conditions. Plants are transferred to individual 250 cm2 quarries, direct to ground and separated 40-50 cmfrom one quarry to the other.The mother plants of the collection remain under shadow over the yearand as they get old and weak they are replaced by new plants of the samegenotype (obtained by agamic multiplication). The plants of the workcollectionare placed in 40 cm x 40 cm deep pots in substrate soil/perlome(2:1). In summer, the pots are transferred to the shadow to avoid excessivedehydration. These types of conservation enable keeping several replicas ofthe vegetal material and ensuring the preservation of genotypes in theBGA