Título:	Coffee microspore cultivation to attain doubled-haploid stable plantlets.
Autoria:	ANGELO, P. C. da S. PEREIRA, L. F. P. SERA, G. H. SETA, T.
Afiliação:	PAULA CRISTINA DA SILVA ANGELO, CNPCa.
Ano de publicação:	2022
Referência:	INTERNATIONAL HORTICULTURAL CONGRESS, 31., 2022, Angers, França.
Conteúdo:	The aim of this study was to explore the potentials of progenies produced by the introgression of disease resistance from related Coffea species to C. arabica . In the IDR-Parana, Brazil, hybrids of C. arabica (tetraploid) x C. racemosa (diploid) were obtained. Self-pollination of some of these hybrids produced very mild yields, despite the backcros to C. arabica . In an attempt to regenerate stable double-haploids, anthers and isolated microspores were grown in vitro . It was assumed that chromosomes captured in a microspore after meiosis can acquire homo and/or homeologous stability faster in vitro than in vivo. C. arabica anthers served as control. Flowers were collected when the young microspores were uninucleated, and disinfected with 8% active chlorine. Microspores were extracted in 90 mM mannitol using a food mixer that worked for a few seconds, washed and centrifuged twice at 100xg and grown in modified N6 liquid medium (10 5 cells/mL in 35 mm diameter plates). Explants were grown continuously for six months on the same N6 medium containing 6.5 mg/L auxins, 1.0 mg/L cytokinins and 0.5 mg/L gibberellin (GA3), at 27 o C in the dark. Isolated microspores produced embryo-like structures or microcalli at very low frequencies (0.3 per plate). The anthers, on the other hand, produced embryogenic calli . One particular endogenous fungus infected 70% of the control anthers but 5% produced friable calli . Some of these were embryogenic, but arrested when compared to calli produced by the interspecific hybrid anthers. Regarding the hybrid anthers, 25% were infected by a same endogenous bacteria but 8% produced embryogenic tissue, with globular embryos multiplying and maturing simultaneously upon transfer to N6 medium without growth regulators. After 1.2 years, the photomorphogenesis has been induced under light, and auxin/cytokinin ratio = 2 plus GA3.
Thesagro:	Café Pólen Embriogénese Rubiaceae
NAL Thesaurus:	Embryogenesis Pollen
Digital Object Identifier:	10.17660/ActaHortic.2023.1359.14
Notas:	E-poster.
Tipo do material:	Resumo em anais e proceedings
Acesso:	openAccess
Aparece nas coleções:	Resumo em anais de congresso (SAPC)