Title: Eventos embriogêncos em tecidos estaminais de Glycine max (L.) Merril
Abstract: Soybean [Glycine max (L.) Merrill, 2n=40] anther culture began in the 1970’s in order to obtain haploids and double-haploids androgenic plants. However, only in rare occasions, culture conditions allowed embryogenic development to proceed as far as plant regeneration. In the present study, culturing heterozygous anthers to a codominant molecular marker, it was recorded that some segregating genotypes originated embryo-like structures from either microspores or anther diploid tissues. Subsequently, through histological analysis, it was recorded callogenesis and somatic embryogenesis from the connective, middle layer and epidermis in cultured anthers of four soybean cultivars, under culture conditions known to trigger an androgenic response. Morphogenic responses from anther walls and connective tissue was favoured by 2,4-dichlorophenoxyacetic acid (2,4-D) and induction under light. Embryogenic potential of the connective tissue provided the possibility of using staminal tissue as a new source of explants, from individuals that have reached the reproductive phase, when the morphogenic response has been considered unsuccessful in soybean. Multinucleate pollen grains formation was not an exclusive response to culture: both anther culture and 4oC treatment increased symmetrical and extra nuclei frequencies in pollen grains, including atypical extra nuclei with a fragmented shape. On the whole, results indicated that, under recommended conditions, anther culture is a limited system to trigger androgenesis in soybean. Thus, a sequence of tests was carried out aiming to establish isolated microspores in vitro. It was developed a technique that allowed to obtain viable microspores suspensions at appropriate density and, subsequently, to establish cultures. The effects of medium constitution and genotypes were tested. This technique may be useful for further studies aiming to identify factors that are important to stimulate soybean androgenesis. In this study, morphogenic limitations and potentialities of soybean anther culture were identified. In consequence, it is proposed a new approach to study androgenesis, through the culture of isolated microspores and pollen grains. 7
Publication Year: 2004
Publication Date: 2004-01-01
Language: en
Type: article
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot