Screening of Brazilian soybean genotypes with high potential for somatic embryogenesis and plant regeneration

Abstract

-The aim of this work was to identify Brazilian soybean (Glycine max) genotypes with potential to respond to in vitro culture stimuli for primary somatic embryo induction, secondary embryo proliferation and plant regeneration. Differences among eight tested cultivars were observed at each stage. Two cultivars, IAS-5 and BRSMG 68 Vencedora, were selected for the evaluation of the capacity for embryo differentiation and plant regeneration. These cultivars had high embryo induction frequencies, repetitive embryogenic proliferation, and low precocious embryo germination in the initial experiment. The effect of abscisic acid (ABA) and charcoal addition on plant regeneration was investigated. The addition of ABA to proliferation medium and of ABA and activated charcoal to maturation medium increased embryo differentiation rates, which resulted in a higher number of regenerated plants. The BRSMG 68 Vencedora cultivar was found to have a high potential for embryo induction, embryo proliferation and plant regeneration. The potential of this cultivar for somatic embryogenesis was similar to that observed for cultivar IAS-5, which is currently used for soybean transformation in Brazil. BRSMG 68 Vencedora may be a good alternative genotype for soybean genetic engineering via somatic embryogenesis protocols.Index terms: Glycine max, Brazilian cultivars, embryogenic potential, genetic engineering, soybean transformation. Seleção de genótipos brasileiros de soja com alto potencial para embriogênese somática e regeneração de plantasResumo -O objetivo deste trabalho foi identificar cultivares brasileiras de soja (Glycine max) com capacidade de resposta aos estímulos da cultura in vitro para a indução de embriões somáticos primários, proliferação de embriões secundários e regeneração de plantas. Foram observadas diferenças para cada estádio entre as oito cultivares testadas. Foram selecionadas duas cultivares, 'IAS-5' e BRSMG 68 Vencedora, para avaliação do potencial dos embriões quanto à diferenciação e conversão em plantas. Essas cultivares tiveram altas taxas de indução, proliferação embriogênica repetitiva e baixa germinação precoce dos embriões, no experimento inicial. Foi investigado o efeito da adição de ácido abscísico (ABA) e carvão sobre a regeneração. Os resultados mostraram que a adição de ABA ao meio de proliferação e de ABA e carvão ativado ao meio de maturação aumentaram as taxas de diferenciação dos embriões, o que resultou em maior número de plantas regeneradas. A cultivar BRSMG 68 Vencedora foi identificada como genótipo com alto potencial para indução e proliferação de embriões, bem como para regeneração de plantas. O potencial dessa cultivar quanto à embriogênese somática foi similar ao observado para a cultivar IAS-5, atualmente utilizada para transformação de soja no Brasil. A BRSMG 68 Vencedora pode ser um genótipo alternativo para a engenharia genética de soja via protocolos de embriogênese somática.Termos para indexação: Glycine max, cultivares brasileiras, potencial embriogênico, engenharia gené...

Strategies for Improvement of Soybean Regeneration via Somatic Embryogenesis and Genetic Transformation

“…Subsequently, several papers have reported the development of somatic embryos from cotyledons of immature embryos. But until today the measured frequencies at which these embryos convert into plants are significantly lower than that expected (Parrott et al, 1988;Meurer et al, 2001;Droste et al, 2001Droste et al, , 2010. Therefore, efforts have been directed towards developing and refining protocols for initiation, proliferation, and histodifferentiation/maturation of soybean somatic embryogenesis.…”

“…In soybean, considerable variation in embryogenic capacity was found to exist between individual genotypes (Komatsuda et al, 1991;Bailey et al, 1993a, b;Santos et al, 1997;Droste et al, 2001;Meurer et al, 2001;Tomlin et al, 2002;Hiraga et al, 2007;Yang et al, 2009;Droste et al, 2010) as will be discussed below (Genotype-dependent response and screening of highly responsive cultivars section).…”

“…Studies with soybean plants indicated that germination/conversion capacity is also greatly influenced by genotype (Komatsuda & Ohyama, 1988;Bailey et al, 1993;Santos et al, 1997;Droste et al, 2001Droste et al, , 2010.…”

“…Several studies have revealed the differences among soybean genotypes in their capacity to respond to the different steps of somatic embryogenesis (Bailey et al, 1993;Santos et al, 1997;Simmonds & Donaldson, 2000;Droste et al, 2001;Meurer et al, 2001;Tomlin et al, 2002;Hiraga et al, 2007;Yang et al, 2009;Droste et al, 2010). The efficiencies were shown to be different among cultivars at each SE phase: induction, proliferation, histodifferentiation/maturation, germination and conversion (Bailey et al, 1993;Santos et al, 1997).…”

“…Other studies also reported the high capacity of IAS-5 to produce somatic embryos (Santos et al, 1997;Di Mauro et al, 2000;Droste et al, 2001). More recently, Droste et al (2010) identified Brazilian soybean genotypes with potential to respond to in vitro culture stimuli for somatic embryo induction, embryo proliferation and plant regeneration. Somatic embryos were induced in all eight tested genotypes, but differences were observed at each stage.…”