Breeding Short-Day Strawberry Genotypes for Cultivation in Tropical and Subtropical Regions

Abstract

The main strawberry cultivars grown in tropical regions originated from breeding programs developed in temperate countries, which limit the expression of their maximum productive potential when grown in warm climates. Additionally, strawberry cultivation in these regions depends almost entirely on imported strawberry young plants, increasing production costs. Obtaining adapted cultivars with a lower requirement for the accumulation of chilling hours is the main objective of breeding programs in the southern hemisphere. Thus, the objective of this study was to evaluate short-day strawberry genotypes, pre-selected based on yield and fruit quality components through multivariate analysis, for cultivation in tropical conditions. Two experiments were performed. In the first one, 36 pre-selected genotypes and their parents were assessed based on productive traits (total fruit mass, commercial fruit mass, and mean mass of commercial fruits), soluble solids content, and fruit firmness. For selection, multivariate analysis was applied using the genotype (ideotype) selection index and principal component analysis. In the second experiment, the fruit of the best-ranked genotypes, the parents, and the Camarosa and Dover cultivars were assessed for soluble solids (SS), titratable acidity (TA), SS/TA ratio, ascorbic acid, phenolic compounds, and total anthocyanins. To identify the most promising genotypes, the data were analyzed using principal component analysis. The RVFS06CR-105, RVDA11CR-61, RVDA11CR-125, and RVCS44CR-130 were the most promising genotypes for cultivation in tropical conditions, based on yield and fruit quality components. The means found for these genotypes were higher than the commercial cultivars Dover, Camino Real, and Camarosa. The use of multivariate analysis was efficient in selecting the genotypes, with repeatability of information between the methods guaranteeing consistency in the information. The selected genotypes had higher yields than those used as the control, which is a promising result considering the independence in relation to genetic material, mainly in the expansion of the cultivation area in the tropical regions of the southern hemisphere. In addition, these genotypes are being evaluated in different tropical climate regions with the aim of validating them for submission to the registration and release process for farmers. Additionally, they are being used as a source of genes for crossings and new selections.

Keywords

• <i>Fragaria</i> × <i>ananassa</i>
• floral induction
• selection index
• multivariate analysis
• breeding