The allelic variation at seven prolamin loci involved in quality has been studied in a set of durum wheat landraces from all the Spanish regions where this crop has been traditionally cultivated. The genetic variability was higher than that found in other germplasm collections. All the loci, except Glu-B2, displayed a genetic variability higher than 0.62, with Glu-3 the most polymorphic. In total, five alleles were studied at Glu-A1, nine at Glu-B1, 15 at Glu-A3, 18 at Glu-B3, two at Glu-B2, and eight at Gli-A1 and Gli-B1. New allelic variants not previously identified in durum wheat were detected. The 30 different genotypes of B low-molecular-weight (B-LMW) glutenin subunits analysed, of which 25 are novel, provide an important source of genetic variability for quality breeding. Protein patterns for convars. durum and turgidum, and for the North and South of Spain were identified for the loci with significant influence on quality. Higher variability was observed in convar. turgidum and in the North zone than in convar. durum and the South, respectively, mainly for the Glu-B1 and Glu-B3. Also, convar. turgidum appeared to be a valuable source for new alleles for the LMW glutenin subunits. Wheats from the South were, however, more diverse for prolamins encoded at Glu-A3.Additional key words: convar. durum, convar. turgidum, germplasm, LMW patterns, prolamin alleles, quality breeding. ResumenVariación genética de las gluteninas y gliadinas asociadas con calidad en variedades locales españolas de trigo duro (Triticum turgidum L. ssp. turgidum) Se ha estudiado la variación alélica en siete loci de prolaminas relacionados con la calidad en un grupo de variedades locales de trigo duro procedentes de todas las provincias españolas donde se cultivaba tradicionalmente. La variabilidad genética encontrada fue mayor que la observada en otras colecciones de germoplasma. Todos los loci, excepto el Glu-B2, mostraron una variabilidad genética mayor que 0,62, siendo los Glu-3 los más polimórficos. En total se estudiaron cinco alelos en el Glu-A1, nueve en el Glu-B1, 15 en el Glu-A3, 18 en el Glu-B3, dos en el Glu-B2 y ocho en el Gli-A1 y Gli-B1. Se han detectado variantes alélicas nuevas que no se habían identificado antes. Los 30 genotipos diferentes analizados de subunidades B de gluteninas de bajo peso molecular (B-LMW), de los cuales 25 son nuevos, representan una fuente importante de variabilidad genética para la mejora de la calidad. Se identificaron patrones de proteínas para las convars. durum y turgidum, y para el norte y sur de España para los loci con influencia significativa en calidad. En la convar. turgidum y en el norte se observó mayor variabilidad que en la convar. durum y en el sur, respectivamente, principalmente en el Glu-B1 y Glu-B3. Además, la convar. turgidum parece ser una fuente valiosa de nuevos alelos para las subunidades LMW de gluteninas. Sin embargo, los trigos del sur son más diversos para las prolaminas codificadas en el Glu-A3.

In this work gliadin proteins were used to analyse the genetic variability in a sample of the durum wheat Spanish collection conserved at the CRF-INIA. In total 38 different alleles were identified at the loci Gli-Al, . All the gliadin loci were polymorphic, possessed large genetic diversity and small and large differentiation within and between varieties, respectively. The GH-A2 and Gli-B2 loci were the most polymorphic, the most fixed within varieties and the most useful to distinguish among varieties. Alternatively, Gli-Bl locus presented the least genetic variability out of the four main loci Gli-Al, Gli-Bl, GH-A2 and GH-B2. The Gli-Bl alleles coding for the gliadin y-45, associated with good quality, had an accumulated frequency of 69.7%, showing that the Spanish germplasm could be a good source for breeding quality. The Spanish landraces studied showed new gliadin alleles not catalogued so far. These new alleles might be associated with specific Spanish environment factors. The large number of new alleles identified also indicates that durum wheat Spanish germplasm is rather unique.

Haploids in apple were induced using anther culture and in situ parthenogenesis followed by in vitro culture of immature embryos or cotyledons. In addition to an earlier characterization of the zygosity state using isozymes, the purpose of this work was an analysis of simple sequence repeats (SSRs) to describe the homozygosity more comprehensively. Five previously described SSR primer combinations were applied. Initially, polymerase chain reaction amplification with the primer pairs was performed on the donor genotypes ‘Alkmene’ and ‘Remo’ and on a further four apple cultivars. Only those primer pairs that amplified two different contrasting alleles could be used for investigation of the zygosity state. According to these analyses both the androgenic and parthenogenic regenerated shoots are homozygous.

A core subset of Spanish durum wheat landraces was evaluated at two nitrogen levels (80 and 220 kg/ha) to identify landrace genotypes adapted to low N production. Yield differences were statistically significant between N levels and among genotypes at both levels. Fiftyone per cent of the landraces yielded significantly more at low than at high N (low-N varieties) while 26% had a positive (high-N varieties) and 23% an indifferent (indifferent-N varieties) response to N fertilizer. No significant agromorphological differences were found among low and high-N varieties at low N level that conferred some advantage to low-N varieties. In contrast, high-N varieties possessed longer grain-filling period under high N level. Phenological characters showed an important influence on yield and on the performance of the varieties within each subgroup. The traits affecting grain yield most positively, mainly the low-N varieties, were long filling period and earliness. Five entries were selected for prebreeding to low N adaptation.

Three Quercus simple sequence repeat (SSR) markers were amplified by polymerase chain reaction (PCR) from nuclear DNA extracts of trees and in vitro-induced haploid embryos from anther cultures of Quercus suber L. These markers were sufficiently polymorphic to identify 10 of 12 trees located in two Spanish natural areas. The same loci have been analyzed in anther-derived haploid embryos showing the parental tree allele segregation. All the alleles were present in the haploid progeny. The presence of diverse alleles in embryos derived from the same anther demonstrated that they were induced on multiple microspores or pollen grains and they were not clonally propagated. Also, diploid cultures and mixtures of haploid-diploid tissues were obtained. The origin of such cultures, either somatic or gametic, was elucidated by SSR markers. All the embryos showed only one allele, corroborating a haploid origin. Allelic composition of the haploid progeny permitted parental identification among all analyzed trees.