Water deficit increases the frequency of hybrid citrus with polyembryonic female parents

Abstract

The aim of this study was to develop a methodology that uses water deficit induction to increase the frequency of hybrids in Citrus varieties that have a high and an intermediate level of polyembryony, respectively. The experiment examined the ‘Sunki Tropical’ mandarin and ‘Rangpur Santa Cruz’ lime genotypes at three water stress intensities: 20, 40 and 100% of the pot capacity (PC). The generated fruits were harvested, and the seeds were counted. After germination, the number of nucellar and hybrid seedlings was determined. For ‘Rangpur Santa Cruz’ lime genotype, the highest hybrid frequency generated was 64.2%, which occurred at a PC of 40% and exceeded by 12% that occurring at a PC of 100%. For ‘Sunki Tropical’ mandarin, the highest observed hybrid frequency was 21.75%, which occurred at a PC of 20% and was more than double the hybrid frequency of 8.57% observed at 100% of the PC.