Maturation and germination of somatic embryos of <i>Sorghum bicolor</i> (L.) Moench cultivar 'CIAP 132R-05'

Abstract

In sorghum [Sorghum bicolor (L.) Moench], developed protocols for plant regeneration via somatic embryogenesis do not include maturation stage. The present work was carried out with the aim of achieving the maturation and germination of sorghum somatic embryos in cultivar 'CIAP 132R-05'. It were studied four concentrations of sucrose (30, 50, 70 and 90 g l-1), two of abscisic acid (0.25 and 0.5 μM) and a control without this growth regulator. Germination initiation (days) and number of somatic embryos with complete germination were evaluated in three periods (1 - 7, 8 - 14 and 15 - 21 days of culture). In addition, the effect of 6-BAP (8.9, 17.8 and 26.6 μM) on somatic embryo germination was determined. The germination start time (days) and after 21 days the number of somatic embryos with complete germination and plants with malformations were determined. The addition of 70 g l-1 sucrose in the culture medium without abscisic acid increased the germination of the somatic embryos to 37.2 plants per embryo group (0.5 g of fresh mass). The highest number of somatic embryos germinated was obtained with 17.78 μM 6-BAP in the germination culture medium. It was demonstrated the need of a maturation stage in the sorghum somatic embryogenesis to increase the germination percentage. Keywords: somatic embryogenesis, sorghum, sucrose, 6-BAP