Pineapple breeding: development of new pineapple cultivars without leaf spines and resistant to fusariosis
摘要
Almost all pineapple crops in Brazil are grown using the cultivar Perola. This scenario can be changed through the development of new cultivars with better fruit quality and resistance. The novel approach of the present study was to select pineapple clones that combine both resistance to fusariosis and characteristics related to plant and fruit quality as alternatives to the traditional cultivar Perola. Therefore, the objectives of this work were to estimate genetic parameters and select clones through the REML/BLUP methodology, based on morpho-agronomic characteristics and resistance to fusariosis. Thus, a selection index was used for quantitative characteristics and, later, for qualitative characteristics, such as fruit quality, presence or absence of leaf spines, and resistance to fusariosis. Significant differences were found for most variables, denoting genetic variability among the evaluated clones. Fruit weight with and without crown and D-leaf length presented the highest heritability estimates (above 50%); however, fruit length, mean fruit diameter, soluble solids, titratable acidity, plant height, and number of active leaves presented the lowest heritability estimates due to greater residual variances. Characteristics related to plant and fruit development are strongly affected by the environment and may result in phenotypic changes. Dominance variance was higher than additive variance, which enables the obtaining of heterosis through vegetative propagation. Eleven out of the 20 superior selected clones presented absence of leaf spines and multiple crowns, higher fruit weight and soluble solids content, and desirable fruit shape and pulp color; seven of them showed resistance to fusariosis, making them suitable for final testing for release as new cultivars.