Obtaining and selecting sweet potato genotypes tolerant to drought stress, productive, and with root quality

• Grant number: 23/04264-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2023
• End date: April 30, 2027
• Field of knowledge: Agronomical Sciences - Agronomy
• Principal Investigator: Edgard Henrique Costa Silva
• Grantee: Dario Sousa da Silva
• Host Institution: Pró-Reitoria de Pesquisa e Pós-Graduação. Universidade do Oeste Paulista (UNOESTE). Presidente Prudente , SP, Brazil
• Associated research grant: 22/03120-6 - Development of drought-tolerant sweet potato genotypes, AP.PNGP.PI

Abstract

Sweet potato crop in Brazil has outstanding socioeconomic importance as it is the fourth most cultivated vegetable. In national territory, the state of São Paulo is the second largest producer of sweet potatoes and Western São Paulo has been a producing region and a national reference in the export of tuberous roots, even with soils with a predominance of sandy texture, a period of drought, and adoption of obsolete genotypes, reducing yield and consequently affecting the commercial standard. Water stress due to deficiency decreases yield, especially if it occurs in the establishment and root formation stages, and when very severe, it causes the death of the plants. The main technological challenge to be overcome is to obtain sweet potato genotypes that combines tolerance to water deficit, high yield, and root quality. The genotypes selected in the screening phase will be adopted in the polycrossing and the progenies that flower and produce at least 2,000 seeds will be effectively used in the breeding program. Seeds will be submitted to dormancy breaking and germination test placed in a B.O.D. The seedlings obtained will be transferred to polyethylene trays, placed in a greenhouse with irrigation for thirty days. After this period, the seedlings will be transplanted in open field to produce vines and subsequent cloning of individuals from a botanical seed. The clones obtained from random crossing will be evaluated in five cycles considering agronomic and quality characteristics, resistance to key pests, and root quality parameters. The first cycle will have augmented blocks with the control cultivars: 'Lilabath' and 'Resisto' as water deficit tolerance standard and 'Canadense' as commercial standard interspersed with water deficit tolerant genotypes obtained from polycrossing. Treatments will be randomized with restriction of relatedness. The remaining four cycles will be conducted in a randomized block design. After the cycle of approximately 120-150 days, the tuberous roots will be harvest and yield and quality traits will be assessed. It is expected to develop sweet potato genotypes that are tolerant to water deficit and present high yield and quality of tuberous roots, to help the producer to obtain better remuneration and the consumer to access to more sustainable food at a fair price.