PRODUCTION OF HEALTHY SEED CANE IN TUCUMÁN, ARGENTINA

A.S. NOGUERA*, N. DEL V. PAZ*, M.E. DÍAZ*, M.F. PERERA*, C. DÍAZ ROMERO**, M.B. GARCÍA**, M.P. FILIPPONE, B. WELIN*, M.I. CUENYA** AND A.P. CASTAGNARO

Congreso; ISSCT CONGRESS; 2013

Since 2001, the Estación Experimental Agroindustrial Obispo Colombres (EEAOC) has been working on the ?Vitroplantas Project?. Annually, 50-80,000 sugarcane seedlings of commercial varieties are produced through in vitro meristem cultures. This micropropagation technique is widely used in order to eliminate systemic diseases, especially viral ones. It is well known that plant tissue in vitro culture can produce somaclonal variations, which consists of genetic modifications in cultured cells and tissues. In order to guarantee that seedlings are identical to parental varieties a molecular methodology based on molecular markers to quantify and detect somaclonal variation in the propagation scheme is routinely applied as a complement of the phenotypic evaluation in the field. Thus, this project guarantees the health and genetic purity of seedlings transferred to field propagation. The sanitation of plant material is achieved through in vitro culture of apical meristem from donor plants previously hydro-heat-treated and grown for 3 years in greenhouse conditions with anti-aphid screens. Systemic diseases are evaluated in both meristem donor plants and micropropagated seedlings by different molecular diagnostics. We are using PCR protocols to detect two bacterial diseases, ratoon stunting and leaf scald, and RT-PCR protocols for the detection of SCMV and SrMV, causing sugarcane mosaic disease. After propagation and testing, in vitro produced seedlings undergo an acclimatization process in a specially adapted greenhouse at the EEAOC. In order to avoid dehydration of plant seedlings, this process takes place in a greenhouse environment with very high relative humidity (RH=80-100%) and low light intensity during the first two weeks of the treatment. After a fortnight, HR is gradually reduced and the intensity of light gradually increased. In these conditions, the critical stage that defines the commercial viability of the whole process lasts on average about 90 days. After acclimatization two more stages of conventional field propagation (Basic, and Registered), are carried out before seed cane is finally being distributed among sugarcane growers. The implementation of the project ?Vitroplantas? has improved the health state of sugarcane production in general and contributed to improved production yields of up to 30% in some varieties and regions of the Province of Tucuman.