[Influence of body mass index on self-esteem of children aged 12-14 years]. / Influencia del índice de masa corporal en la autoestima de niños y niñas de 12-14 años.

INTRODUCTION: During the last decades, the increase in the rate of children and adolescents that are overweight or obese is alarming and it is related with a lower social competency, and low self-esteem. METHOD: A transversal study was conducted with a representative sample of 292 students enrolled in years 8 and 9 at secondary school (13.05±0.97 years) in the city of Jaen, Spain. RESULTS: Girls wanted a thinner figure than boys (P < .001). Regarding self-esteem we observed statistically lower values in the case of girls (P < .000) as compared to their male counterparts. Regarding the BMI, students with a healthy weight have a statistically higher self-esteem score than students that are overweight and these have a slightly higher score than those that are obese. Positive correlation exists between the perceived silhouette and the desired silhouette (r=.485) and a negative correlation between the BMI and self-esteem (r=-.248). CONCLUSION: It is necessary to plan actions aimed as reinforcing and increasing self-esteem, focusing on the group of girls and the group of young adults with overweight and obesity problems.

Genetic improvement of bread wheat yield and associated traits in Spain during the 20th century.

A collection of 26 wheat genotypes widely grown in Spain during the 20th century was evaluated in eight contrasting environments in order to quantify breeding achievements in yield and associated traits. From 1930 to 2000, yield increased at a rate of 35·1 kg/ha/yr or 0·88%/yr, but estimations of relative genetic gain (RGG) were environment-dependent. RGG estimated for yield were positively associated with the average minimum daily temperatures from sowing to heading in the testing environments (R(2) = 0·81; P < 0·01). The number of grains/spike and the number of spikes/m(2) increased at a rate of 0·60%/yr and 0·30%/yr, respectively, while grain weight remained unchanged. The present study detected two main episodes of yield improvement during the century. The first one coincided with the introduction, during the 1950s, of the first improved cultivars derived from intra-specific crosses, which increased the yield of landraces by 30% due to an increase of c. 58% in the number of grains/spike, accompanied by a 16% reduction in grain weight. These initial cultivars (termed 'old-bred' in a previous study by Sanchez-Garcia et al. 2012) exhibited a higher harvest index (HI), increased from 0·25 to 0·40, but maintained the same aboveground biomass at maturity as the landraces (despite reducing both plant height and the number of tillers/plant) due to increases in the proportion of tillers bearing spikes. The second yield gain occurred after the introduction, in the early 1970s, of semi-dwarf germplasm from CIMMYT (International Maize and Wheat Improvement Centre) and some French cultivars. This new germplasm further reduced plant height, improved HI up to 0·45 and increased the number of tillers/plant while maintaining their rate of fertility, thus resulting in a yield gain of c. 37%. The cultivars released during the last decade of the century did not contribute to significant yield improvements.

Cereal cyst nematode resistance conferred by the Cre7 gene from Aegilops triuncialis and its relationship with Cre genes from Australian wheat cultivars.

Cereal cyst nematode (CCN; Heterodera avenae Woll.) is a root pathogen of cereal crops that can cause severe yield losses in wheat (Triticum aestivum). Differential host-nematode interactions occur in wheat cultivars carrying different CCN resistance (Cre) genes. The objective of this study was to determine the CCN resistance conferred by the Cre7 gene from Aegilops triuncialis in a 42-chromosome introgression line and to assess the effects of the Cre1, Cre3, Cre4, and Cre8 genes present in Australian wheat lines on Spanish pathotype Ha71. Inhibition of nematode reproduction was rank-ordered as Cre1 >or = Cre4 > or = Cre7 >> Cre8 > Cre3. Lines carrying Cre1, Cre4, or Cre7 exhibited a significantly higher level of resistance than those carrying Cre8 or Cre3. Allelism tests indicated that Cre7 segregated independently of Cre1 on chromosome 2BL and Cre4 on chromosome 2DL, and these genes could consistently be combined in the same genotype, inducing a more durable resistance. Tests to determine the chromosomal location of Cre7 using addition lines were inconclusive.

A new Hessian fly resistance gene (H30) transferred from the wild grass Aegilops triuncialis to hexaploid wheat.

A new Hessian fly (Mayetiola destructor Say) resistance gene from Aegilops triuncialis and its transfer to hexaploid wheat via interspecific hybridisation is described. The transfer line TR-3531 (42 chromosomes), derived from the cross [(Triticum turgidum x Ae. triuncialis) x Triticum aestivum] and carrying the Heterodera avenae resistance gene Cre7, showed a high level of resistance to the M. destructor biotype prevailing in the SW of Spain. A single dominant gene (H30) seems to determine the Hessian fly resistance in this introgression line, and its linkage with an isozyme marker (Acph-U1) has also been studied. It has been demonstrated that the resistance gene H30 in the TR-3531 line is non-allelic with respect to the genes H3, H6, H9, H11, H12, H13, H18 and H21, present in wheat cultivars from the Uniform Hessian Fly Nursery (UHFN), as well as to H27, carried by the introgression line H-93-33. Advanced lines with the H30 gene were obtained by backcrossing the transfer line and different commercial wheats as recurrent parents. Several of them showed a high yield in tests carried out in the infested field. Electronic Supplementary Material is available if you access this article at http://dx.doi.org/10.1007/s00122-002-1182-z. On that page (frame on the left side), a link takes you directly to the supplementary material.

Biochemical and genetic studies of two Heterodera avenae resistance genes transferred from Aegilops ventricosa to wheat.

Two Heterodera avenae resistance genes, Cre2 from Aegilops ventricosa AP-1 and Cre5 from Ae. ventricosa #10, were shown to confer a high level of resistance to the Spanish pathotype Ha71. No susceptible plants were found in the F(2) progeny from the cross between the two accessions of Ae. ventricosa, suggesting that their respective resistance factors were allelic. However, genes Cre2 and Cre5 apparently were transferred to a different chromosomal location in the wheat line H-93-8 and in the 6M(v)(6D) substitution, respectively, as proved by F(2) segregation of their cross progeny. The induction of several defence responses during early infection by the same H. avenae pathotype in resistant lines carrying Cre2 or Cre5 genes was studied. Isoelectrofocusing (IEF) isozyme analysis revealed that peroxidase, esterase and superoxide dismutase activity increased after nematode infection, in roots of resistant lines in comparison with their susceptible parents. Differential induced isoforms were also identified when IEF patterns of resistant lines were compared. A DNA marker, absent in Cre5-carrying genotypes, was found to be linked, thought not very tightly, to the Cre2 gene in the H-93-8 line. The differences observed between the Cre2 and Cre5 genes with respect to their chromosomal location in wheat introgression lines, de-toxificant enzyme induction and behaviour against different pathotypes, suggest they are different H. avenae resistance sources for wheat breeding.

Resistance to the cereal cyst nematode (Heterodera avenae Woll.) transferred from the wild grassAegilops ventricosa to hexaploid wheat by a "stepping-stone" procedure.

Transfer of resistance toHeterodera avenae, the cereal cyst nematode (CCN), by a "stepping-stone" procedure from the wild grassAegilops ventricosa to hexaploid wheat has been demonstrated. The number of nematodes per plant was lower, and reached a plateau much earlier, in the resistant introgression line H93-8 (1-2 nematodes per plant) than in the recipient H10-15 wheat (14-16 nematodes per plant). Necrosis (hypersensitive reaction) near the nematode, little cell fusion, and few, often degraded syncytia were observed in infested H93-8 roots, while abundant, well-formed syncytia were present in the susceptible H10-15 wheat. Line H93-8 was highly resistant to the two Spanish populations tested, as well as the four French races (Fr1-Fr4), and the British pathotype Hall, but was susceptible to the Swedish pathotypes HgI and HgIII. Resistance was inherited as though determined by a single quasi-dominant factor in the F2 generations resulting from crosses of H93-8 with H10-15 and with Loros, a resistant wheat carrying the geneCre1 (syn.Ccn1). The resistance gene in H93-8 (Cre2 orCcn2) is not allelic with respect to that in Loros. RFLPs and other markers, together with the cytogenetical evidence, indicate that theCre2 gene has been integrated into a wheat chromosome without affecting its meiotic pairing ability. Introduction ofCre2 by backcrossing into a commercial wheat backgroud increases grain yield when under challenge by the nematode and is not detrimental in the absence of infestation.