Anatomical study of somatic embryogenesis in Glycine max (L.) Merrill

A comparative anatomical analysis of somatic embryogenesis in two soybean (Glycine max (L.) Merrill) genotypes was carried out. The somatic embryos were originated from cotyledonary explants obtained from immature zygotic embryos. The medium used fir somatic embryogenesis induction was Murashige and Skoog, 1962, salts and Gamborg et al., 1968, vitamins (MSB) supplemented with 0.8 mg.L-1 of 2,4-D for genotype PI 123439 and 40 mg.L-1 kof 2,4-D for 'Williams 82'. Globular structures, constituted by meristematic cells, originated from subepidermal cell divisions of the cotyledonary mesophyll. In P1 123439, the globular structures presented tracheary differentiation among meristematic cells and they could follow distinct morphogenetic process depending on their location along the explant. For 'Williams 82' it was observed globular structures along the cotyledonary explant surface. They gave rise to somatic embryos. These embryos showed different morphologies and they were classified based on their shape and number of cotyledons. The ability of these morphological types to convert to plantlets was discussed.