RESUMO
Spike fertility index (SF) has been well established as an ecophysiological trait related to grain number per unit area and a promising selection target in wheat breeding programs. Scarce information on the molecular basis of SF is available thus far. In this study, a preliminary molecular marker analysis was carried out in a RIL population derived from the cross between two Argentinean cultivars with contrasting SF to identify candidate genomic regions associated with SF. Twenty-four microsatellites and two functional markers that had been found to co-segregate with SF in a bulked-segregant analysis of the F3 generation of the population were analyzed. Phenotypic data were collected from three field experiments carried out during 2013, 2014 and 2015 growing seasons at Balcarce, Argentina. Two genomic regions associated with SF in chromosomes 5BS and 7AS were detected, which merit further investigation.
El índice de fertilidad de espiga (FE) ha sido propuesto como un carácter ecofisiológico asociado con el número de granos por unidad de área y como criterio de selección prometedor para los programas de mejoramiento de trigo. Sin embargo, la información sobre las bases moleculares de la FE aún es escasa. En este estudio, se realizó un análisis preliminar de marcadores moleculares en una población RIL derivada del cruce entre dos cultivares argentinos con FE contrastante con el objetivo de identificar regiones genómicas candidatas asociadas con el carácter. Se analizaron 24 microsatélites y dos marcadores funcionales que se había encontrado que se co-segregaban con la FE en un análisis de segregantes en "bulk" en la generación F3 de la población. Se recopilaron datos fenotípicos de tres experimentos de campo llevados a cabo durante las temporadas de cultivo 2013, 2014 y 2015 en Balcarce, Argentina. Se detectaron dos regiones genómicas asociadas con la FE en los cromosomas 5BS y 7AS, que mostraron ser estables a través de los años de evaluación. Este trabajo aporta información novedosa acerca de las bases moleculares de la FE, las cuales deberán ser estudiadas con mayor profundidad.
RESUMO
Callus growth and plant regeneration from long-term callus cultures were studied in two elite clones of Asparagus officinalis cv. Argenteuil, to establish a suitable protocol for a prospective in vitro selection program. Callus initiation and growth was evaluated on MS medium with 3
agar, 1 mg x l(-1) kinetin, and three levels of 2,4-D. The highest callus relative growth was obtained on medium with 1.5 mg x l(-1) 2,4-D and 1 mg x l(-1) kinetin. Shoot primordia (SP) induction from > 18-months-old calluses was evaluated on several media; the highest percentage of SP induction (89
) and average number of SP per callus (8.6) were obtained with clone [quot ]265[quot ] on MS medium with 5 mg x l(-1) 2iP, 1 mg x l(-1) IAA, 3
sucrose and 0.9
agar. The highest percentage of root induction (100
) was achieved with clone 265 on MS medium with 0.1 mg x l(-1) kinetin, 0.1 mg x l(-1) NAA, 1.32 mg x l(-1) ancymidol, 7
glucose and 0.8
agar. Important medium x genotype interactions were detected, pointing to the need of adjusting this and other in vitro protocols for specific asparagus genotypes.