Search

ABSTRACT Water stress is one of the limiting factors for obtaining maximum yield in soybean, which makes the identification of tolerant genotypes an important approach in breeding programs. The objectives of this work were evaluate soybean genotypes in conditions of water deficit, determine traits that allow the identification of genotypes tolerant to water deficit, and suggest promising crosses. Sixteen soybean genotypes were submitted to two osmotic potentials (0.0 MPa and -0.2 MPa) induced by PEG 6000 and the traits of germination and growing were evaluated. Genetic dissimilarity analysis was performed. There was genetic variability among genotypes for all traits, and significant interaction for root length, shoot and total fresh matter and dry root matter. Based on root length, it was possible to discriminate genotypes tolerant to water deficit. The cultivars BRS 7270 IPRO, TMG 2158 IPRO, UFUS Tikuna and UFU_P32 showed higher root length and stood out for dry root, fresh shoot and total fresh matter under water stress conditions and are indicated as promising parents in crosses.

Carrots (Daucus carota L.), a globally significant vegetable, lack extensive research on heterotic groups and diallel analysis to generate hybrid combinations. Thus, the objective of this study was to assess combining abilities and identify optimal carrot parents for producing hybrids suitable for tropical climates with elevated metabolite levels. Twenty carrot hybrids, ten parent plants, and three commercial cultivars were evaluated during the summers of 2020/2021 and 2021/2022. Agronomic evaluations were carried out and chlorophyll and carotenoid levels were determined, followed by a diallel analysis using Griffing’s Method III and GGE biplot analysis. There were significant general combining ability (GCA) effects for various agronomic traits, suggesting additive genetic effects. Based on GCA, cultivars 5, 4, and 2 were the most promising parents. Specific combining ability (SCA) revealed that hybrids 1 × 2 and 3 × 5 stood out in environment 1, whereas hybrids 1 × 5 and 5 × 3 performed well in environment 2. The GGE biplot analysis showed that hybrids 1 × 2 and 3 × 2 displayed larger average root diameters, belonged to the group with the best bolting percentages, and exhibited stability across environments. Moreover, hybrids 2 × 4, 3 × 1, 4 × 1, and 4 × 2 exhibited higher metabolite levels. These findings suggest the feasibility of obtaining superior hybrids tailored for the tropical carrot market.