A case for crop wild relative preservation and use in potato.

Crop wild relatives (CWR) offer a critical resource to address food security needs by providing genetic diversity for crop improvement, leading to increased plasticity and productivity of farming systems. However, plant breeders typically have not developed systematic or comprehensive strategies for the characterization and use of CWR for cultivar improvement. Potato (Solanum tuberosum L.) provides an excellent case study for the use of CWR germplasm in addressing global food security needs. International cooperation and collaboration are critical to collect, characterize, and use CWR in anticipation of future production needs. Both ex situ and in situ preservation of wild potato species are essential to assure a comprehensive conservation plan. Top priorities include a coordinated inventory of gene bank holdings followed by re-collection of CWR and new collection where gaps exist. Access to CWR genetic diversity will continue to be critical as breeders face the challenge of developing cultivars that fit into new production systems, especially in response to climate change. With the advent of the genomics era, new visions of germplasm use strategies are emerging. In addition to filling gaps in collections, it will be important to expand efforts to characterize and use potato CWR. A systematic and integrated strategy is needed to evaluate CWR in gene banks for traits to continue breeding progress.Fil: Jansky, S. H.. University of Wisconsin; Estados UnidosFil: Dempewolf, H.. Viale delle Terme di Caracalla. Global Crop Diversity Trust; ItaliaFil: Camadro, Elsa Lucila. Universidad Nacional de Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Simon, R.. International Potato Center; PerúFil: Zimnoch Guzovska, E.. Młochów Research Center; PoloniaFil: Bisogin, D. A.. Federal Universidad de Santa Maria; BrasilFil: Bonierbale, M.. International Potato Center; Per

Embryo rescue from interspecific crosses in apple rootstocks Resgate de embriões a partir de cruzamentos interespecíficos em porta-enxerto de macieira

The objetive of this work was to rescue immature embryos of apple rootstocks Malus prunifolia (Marubakaido) and Malus pumila (M9) after 40-60 days of pollination and to put them into MS culture media supplemented with agar (6 g L-1) and casein hydrolysate (500 mg L-1). Embryos originated from interspecific crosses and open pollination showed differences in the in vitro responses, depending on the female parent, the developmental stage of the embryo, and the culture medium composition. Embryos of the M. pumila rootstock, rescued within 40 days after pollination and put in culture medium supplemented with indolacetic acid (IAA), gibberellic acid (GA3), kinetin and maltose, resulted in a normal development of plantlets. However, embryos originating from hand-pollination, cultivated in medium supplemented with 14 µM IAA, 5 µM kinetin and 1.5 µM Ga3 (MS1), mainly those of M. prunifolia x M. pumila, showed a high percentage of rusted embryos (96.2%). Embryos from open pollination of M. prunifolia and M. pumila formed calluses. It was possible to identify the influence of the female parent by the enhanced development of M. pumila shoots derived from open or hand-pollination. The crossing of responsive species and the use of the technique of embryo culture provided a rapid and uniform germination and, consequently, the development of fully normal seedlings.<br>O objetivo deste trabalho foi resgatar embriões imaturos de porta-enxertos de macieira Malus prunifolia (Marubakaido) e Malus pumila (M9) depois de 40 e 60 dias de polinização e colocá-los em meio de cultura MS suplementado com ágar (6 g L-1) e hidrolisado de caseína (500 mg L-1). Embriões originados do cruzamento interespecífico dirigido e de polinização aberta mostraram diferenças significativas in vitro, tendo sido observadas diferenças quanto ao progenitor feminino, quanto à fase de desenvolvimento do embrião e à composição do meio de cultura. Embriões do porta-enxerto M. pumila, resgatados aos 40 dias depois da polinização e colocados em meio de cultura suplementado com ácido indolacético (AIA), ácido giberélico (GA3), cinetina e maltose, resultaram em desenvolvimento normal das plantas. Porém, foi observada alta porcentagem de embriões oxidados (96,2%), originados de polinização dirigida, cultivados em meio com 14 µM de AIA, 5 µM de cinetina e 1,5 µM de GA3 (MS1), principalmente para o cruzamento M. prunifolia e M. pumila. Embriões de polinização aberta de M. prunifolia x M. pumila formaram calos. Foi possível identificar a influência do progenitor feminino, pelo incremento de brotações de M. pumila derivada de polinização aberta e dirigida. O cruzamento de espécies responsivas e o uso da técnica de cultura de embrião promoveram germinação rápida e uniforme e, por conseguinte, o desenvolvimento de mudas normais