Selection of Eggplant Genotypes Tolerant to High Temperatures

Abstract

In the northeast of Brazil, the yield of eggplant has been unpredictable, especially when the flowering coincides with the hottest period of the year. The objective of this study was to evaluate eggplant genotypes for tolerance to high temperatures and to identify correlations between traits that aid the indirect selection of genotypes tolerant to high temperatures. Twenty-two genotypes were arranged in a randomized block design with four replications conducted in a greenhouse and in the open field, both located at the Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil, between December 2016 and May 2017. Positive correlations were obtained for the pairs, number of fruits per plant (NFP) x fruit fixation index (FFI), NFP x production per plant (PP) and PP x FFI and negative for the pair NFP x PP. The associations among the traits pollen viability (PV), FFI, NFP and PP were low and/or negative for all pairs in both environments and indicates that the indirect selection for FFI and PP through PV is not efficient. Higher values for PV, NFP, PP were observed in greenhouse cultivation, while in the field the genotypes had the best performance for fruit weight (FWe) FFI, fruit length (FL), fruit width (FWi) and length/width ratio of fruit (FLWR). In high temperature conditions, the genotypes CNPH 135, CNPH 93, CNPH 79, CNPH 84, CNPH 71, CNPH 71, CNPH 668, Ajimurasaki F1 and Kokushi Onaga F1 with good FFI and CNPH 135 with the highest FFI, PP, PV and PWe. The FFI in 45.4% of the genotypes under high temperatures was low, around 21.3 and 40.5%. In the field, genotypes CNPH 84 and CNPH 668 stood out with the best FFI (> 60%).