Germination and Initial growth of pineapple half-sib progenies

Viable seeds are developed via natural or controlled cross-pollination among different cultivars of pineapple. Pineapple sexual reproduction allows random recombination of different alleles that control traits related to plant and fruit for genetic breeding. This study aimed to evaluate germination and measure the initial growth of seedlings in the half-sib progenies from IPA’s breeding program. This study was performed in the Experimental Station of Itambé, PE, Brazil. Seeds from three half-sib progenies ('Pérola', 'BRS Vitória' and 'MD-2') were obtained by pollination using a pollen mix from these same cultivars. Seeds were sowed in plastic trays with blotting paper as a substrate and moistened with distilled water. Trays were sealed with PVC film and kept inside a seed germination chamber with 25 °C and under continuous light. Germination (%) for up to 75 days after sowing was verified. Germinated seeds that emitted radicles when visible to naked eye were considered. These seedlings were individualized into black polyethylene bags (15 cm x 10 cm) containing 2/3 of soil plus 1/3 of tanned bovine manure, and maintained under full sun with micro-spray irrigation. Acclimatization period lasted for about 14 months, when 871 seedlings were evaluated for plant height (cm) - PH, stem diameter (mm) - SD, leaf number - LN, leaf length (cm) - LL, and leaf width (cm) - LW. A total of 3.109 seeds was obtained, 871 germinated, resulting in the overall average of 28.02%. The higher average germination of 32.32% was observed in the 'MD-2' progeny, followed by the 'BRS Vitória' and 'Pérola' progenies with 29.77% and 25.49%, respectively. Regarding the initial growth of seedling, the 'MD-2' progeny reached the higher averages for the NF (13.1), CF (22.1cm) and LF (2.9cm) traits. Progeny 'BRS Vitória' presented the highest average of 19.8 mm for DC, followed by 'MD-2' (19.2mm) and 'Pérola' (18.3mm) progenies. The highest average (21.7 cm) for PH was presented by 'Pérola' progeny, followed by 'BRS Vitória' (18.6 cm) and 'MD-2' (18.3 cm). In conclusion, evaluated progenies stand out with suitable germination and satisfactory initial growth for use by IPA’s breeding program.