Field Evaluation on Growth and Productivity of the Transgenic Sugarcane Lines Overexpressing Sucrose-Phosphate Synthase

Abstract

The development of new sugarcane cultivars using modern agricultural biotechnology is an important strategy in increasing sugar yield, which is directed toward sustainable agriculture. Genetic transformation has been demonstrated to be an effective engineering tool to introduce superior traits into plants. Overexpression of the SoSPS1 gene in sugarcane resulted in increased sucrose phosphate synthase activity, sucrose content, and biomass in the greenhouse experiment. However, performance evaluation in confined field trials in natural environments is an important step in selecting transgenic sugarcane with novel properties. In this study, transgenic sugarcane lines were cultivated in four experimental locations with different climates and soil types using a randomized block design with five replicates. We observed that transgenic sugarcane lines displayed higher tiller number and plant height than that of non-transgenic sugarcane. The cane yield, and percentage of Brix and Pol in the transgenic lines were also higher than those in non-transgenic sugarcane. Among the transgenic lines, SPS3 exhibited considerable growth and productivity in all field locations. Interestingly the cane yield was higher in locations supplied with normal irrigation. In contrast, Brix and Pol % were higher in less water-supplied or dry land cultivated canes. In addition, the transgenic sugarcane lines neither affected the bacterial diversity in the soil rhizosphere nor assisted in horizontal gene flow in the soil environment. Therefore, evaluating the growth and productivity of transgenic sugarcane during field trials aids in selecting the best sugarcane line for an appropriate agro-climate.