Valentina Di Pauli1, Paola D Fontana1, Dalia M Lewi2, Arturo Felipe1, Luciana Martínez Calsina1 and Luis E Erazzú1
1National Institute of Agricultural Technology (INTA), Experimental Station Famaillá, Tucumán, Argentina; dipauli.valentina@inta.gob.ar
2National Institute of Agricultural Technology (INTA), Genetic Institute «Ewald A. Favret» (IGEAF), Buenos Aires, Argentina
The complexity of the sugarcane genome, the narrow genetic base of subtropical germplasm, and the extended breeding and selection cycle pose significant challenges to conventional breeding methods. In vitro mutagenesis offers an alternative approach to generating genetic variability by harnessing both somaclonal variation and induced mutations. An in vitro mutagenesis protocol, using the chemical mutagen EMS in an elite Argentine sugarcane cultivar, was developed. Additionally, the genetic variability generated through both somaclonal variation and induced mutagenesis was assessed in the field. Six-week-old embryogenic calli were treated with 8, 16, 32, and 48 mM EMS. Plants were regenerated from treated calli and then acclimatized in a greenhouse. LD25 and LD50 were calculated through linear regression analysis. LD50 for regeneration capacity was 31.68 mM EMS, whereas LD25 was 17.71 mM EMS. Based on these results, the plants from the 16 and 32 mM EMS treatments were phenotypically assessed in the field in both plant cane and first-ratoon crops. Field assessments showed that EMS treatments exhibited phenotypic variability due to genetic changes. Traits such as the number of stalks, stalk length, and stalk weight showed an increase in the population mean in the EMS treatments compared to the wild type. Some traits maintained changes from one year to the next, whereas others stabilized to the wild-type genotype values in the second year. The values obtained for the degree of genetic determination (DGD) are highly valuable for assessing the breeding potential of a base population. Based on agronomic traits, 23 mutant plants were selected and advanced to subsequent generations in INTA’s Sugarcane Breeding Program.