Avaliação de genótipos de batata-doce biofortificados em Resposta ao déficit hídrico (Ipomoea batatas L.)

Abstract

Water is one of the most important elements for the development of vegetables, including sweet potato (Ipomoea batatas L.), an herbaceous dicotyledonous plant with an edible tuberous root rich in fiber, carbohydrates, vitamins, proteins and sugars. Thus, the objective of this study was to select sweet potato genotypes tolerant to water deficit. For this, nine genotypes were used (Brazlândia Branca, FSC-FW-42, UFSCLW- 102, UFSC-LO-66, UFSC-LP-46, UFSC-FP-40, UFSC-LP-115, UFSC-FP-39, UFSC-LP-75).The plants were subjected to two water levels: irrigation with 80% of the substrate retention capacity (control, well-irrigated), and total water restriction between 30 and 51 days after planting (DAP), and harvested at 120 DAP. The experiment was carried out in a greenhouse located in the experimental area of the Seedling Production Laboratory, belonging to the Center for Human, Social and Agrarian Sciences of the Federal University of Paraíba (CCHSA/UFPB), in Bananeiras, Paraíba, Brazil. The experimental design was completely randomized, in a 2 × 9 factorial scheme (water conditions × genotypes), with 6 replicates. Wilting symptoms, biomass production, gas exchange, chlorophyll index, chlorophyll fluorescence, relative water content and electrolyte leakage were evaluated. Water deficit caused oxidative stress, increasing electrolyte leakage and reducing growth and productivity in all genotypes evaluated. The genotypes UFSC-FW-42, UFSC-LW-102 e UFSC-LP-115 were those that presented the highest productivity under water deficit, and the UFSC-FW-42 and UFSC-LP-115 genotypes also presented lower electrolyte leakage and higher FV/FM, suggesting a greater antioxidant capacity of these genotypes. In this context, the genotypes that presented the greatest tolerance to water deficit were UFSCFW-42 and UFSC-LP-115, which present cream and purple colored pulp, respectively. These results represent an important advance for the continuation of breeding programs with these materials aiming at tolerance to water deficit.