Publicaciones


Publicaciones 2010

Havananda T., Brummer E.C., Maureira-Butler I.J., J.J. Doyle. (2010). Relationships among diploid members of the Medicago sativa (Fabaceae) species Complex based on chloroplast and mitochondrial DNA sequencesSystematic Botany. 35; 1; 140-150.

Resumen

The Medicago sativa species complex includes tetraploid cultivated alfalfa and several other diploid and tetraploid taxa that are recognized either as subspecies of M. sativa or as separate species. The two principal diploid taxa are “caerulea,” with purple flowers and coiled pods, and “falcata” with yellow flowers and falcate pods. To understand the evolutionary relationships among taxa in the complex, sequence variation in two noncoding regions of cpDNA (rpl20—rps12 and tmS—tmG spacers) and three regions of mitochondrial DNA (mtDNA: nad4 intron, nad7 intron, and rpS14—cob spacer) were surveyed from 48 (37 for mtDNA) individuals representing these and other diploid taxa in the complex. These sequences afforded independent perspectives on the evolutionary history of the group, because mtDNA is maternally inherited in Medicago whereas cpDNA is biparentally inherited with strong paternal bias. Twenty and 21 haplotypes were identified for cpDNA and mtDNA, respectively. Haplotype networks were constructed and tests of differentiation were conducted. Results from cpDNA sequences supported the recognition of “caerulea” and “falcata” as differentiated taxa, despite the presence of some shared haplotypes, in agreement with morphological characters. In contrast, no significant evidence of mtDNA haplotype differentiation was observed. Incongruence between cpDNA and mtDNA is more likely explained by introgression of the mitochondrial genome than by incomplete lineage sorting of mtDNA haplotypes, given the expected smaller effective population size for uniparentally inherited mtDNA than for biparentally inherited cpDNA. Moreover, the two taxa are readily crossable, making natural hybridization possible. The long-time disagreement on whether to recognize “falcata” as a separate species or a subspecies of M. sativa s. 1. is due to the common problem of unequal rates of differentiation for different characters during speciation.

Inostroza-Blancheteau C, Soto B, Ibáñez C, Ulloa P, Aquea F, Arce-Johnson P, Reyes-Diaz M. (2010). Mapping aluminum tolerance loci in cereals: A tool available for crop breeding. Electronic Journal of Biotechnology.  13; 4.

Resumen

Aluminum (Al) toxicity is the main factor limiting crop productivity in acidic soils around the world. In cereals, this problem reduces crop yields by 30-40%. The use of DNA-based markers linked to phenotypic traits is an interesting alternative approach. Strategies such as molecular marker-assisted selection (MAS) in conjunction with bioinformatics-based tools such as graphical genotypes (GGT) have been important for confirming introgression of genes or genomic regions in cereals but also to reduce the time and cost of identifying them through genetic selection. These biotechnologies also make it possible to identify target genes or quantitative trait loci (QTL) that can be potentially used in similar crops to increase their productivity. This review presents the main advances in the genetic improvement of cereals for Al-tolerance.

Marcus T. Brock, Jennifer M. Dechaine, Federico L. Iniguez-Luy, Julin N. MaloofJohn R. Stinchcombe, Cynthia Weinig. (2010). Floral Genetic Architecture: An Examination of QTL Architecture Underlying Floral (Co)Variation Across Environments, 
Resumen

Genetic correlations are expected to be high among functionally related traits and lower between groups of traits with distinct functions (e.g., reproductive vs. resource-acquisition traits). Here, we explore the quantitative-genetic and QTL architecture of floral organ sizes, vegetative traits, and life history in a set of Brassica rapa recombinant inbred lines within and across field and greenhouse environments. Floral organ lengths were strongly positively correlated within both environments, and analysis of standardized G-matrices indicates that the structure of genetic correlations is ∼80% conserved across environments. Consistent with these correlations, we detected a total of 19 and 21 additive-effect floral QTL in the field and the greenhouse, respectively, and individual QTL typically affected multiple organ types. Interestingly, QTL × QTL epistasis also appeared to contribute to observed genetic correlations; i.e., interactions between two QTL had similar effects on filament length and two estimates of petal size. Although floral and nonfloral traits are hypothesized to be genetically decoupled, correlations between floral organ size and both vegetative and life-history traits were highly significant in the greenhouse; G-matrices of floral and vegetative traits as well as floral and life-history traits differed across environments. Correspondingly, many QTL (45% of those mapped in the greenhouse) showed environmental interactions, including approximately even numbers of floral and nonfloral QTL. Most instances of QTL × QTL epistasis for floral traits were environment dependent.

Parra Gonzalez L.B., Straub S.C.K. Doyle J.J., Mora Ortega P.E., Salvo Garrido H.E., Maureira Butler I.J. (2010). Development of microsatellite markers in Lupinus Luteus (Fabaceae) and cross-species amplification In other lupine species. American Journal of Botany. 97; 8; e72-e74.

Resumen

Premise of the study: Microsatellite primers were developed in Lupinus luteusL., an emerging temperate protein crop, to investigate genetic diversity, population structure, and to facilitate the generation of better yellow lupine varieties.

Methods and Results: Thirteen polymorphic primer sets were evaluated in a European and Eastern European accession collection of L. luteus. The primers amplified di-, tri-, and tetranucleotide repeats with 2–4 alleles per locus. These revealed a moderate to low level of genetic variation, as indicated by an average observed heterozygosity of 0.0126. Select loci also amplified successfully in the closely related species L. hispanicus Boiss. & Reut. and in the New World species L. mutabilis Sweet.

Conclusions: These results indicate the utility of primers for the study of genetic diversity across L. luteus populations and related lupine species. The use of these microsatellite markers will facilitate the implementation of several molecular breeding strategies in yellow lupine.

Shene, C, Leyton, A, Esparza, Y., Flores, L, Quilodrán, B, Hinzpeter, I, & Rubilar, M. (2010). Microbial oils and fatty acids: effect of carbon source on docosahexaenoic acid (C22:6 n-3, DHA) production by thraustochytrid strains. Journal of soil science and plant nutrition.  10; 3;  207-216.

Resumen

Thraustochytrids are marine protists found throughout the world in estuarine and marine habitats. These microorganisms have attracted interest, because their lipids contain different long chain polyunsaturated fatty acids (PUFAs). Those able to produce docosahexaenoic acid (C22:6 n-3, DHA) are the most studied because of the physiological importance of this PUFA in human beings. Their heterotrophic cultivation offers several challenges since biomass, lipid content, and fatty acid profile are dependent on growth conditions. In this work the effects of C source and its concentration on DHA production by different thraustochytrid strains are reviewed. Results obtained by different investigators on the use of alternative and low cost nutrient sources for production of DHA by thraustochytrids are also presented.

Costoya, N.; Sineiro, J.; Pinelo, M.; Rubilar, M.; Nuñez, M. J. (2010). Enzyme-aided extraction of polyphenols from grape pomace.  Electronic Journal of Environmental, Agricultural and Food Chemistry, 9; 4; 696-705.

Resumen

Nowadays, grapepomace is frequently used as a source of polyphenols. With the aim of enhancing the yield of the extraction, the capacity of three commercial enzymatic preparations, Cellubrix® (cellulase and β-glucosidase activities), Neutrase® (protease and α-amylase activities) and Viscozyme® (cellulase, hemicellulase and pectinase activities) was tested in this study. Individually applied, none of the enzymatic formulations was able to improve the efficiency of the aqueous extraction (control). However, acting in combination, a significant increase in the yields of soluble solids (∼20-45%), and phenols (∼25-65%), so as a notable improve in antiradical activity DPPH, with the subsequent decrease when measured as EC 50 (∼53-70%) was detected either in a white variety (Garnatxa). as in a red one (Cabernet Sauvignon). Synergistic effect at different dosages (0-30 g Enzyme/Kg substrate) and incubation times (1-2h) was further studied. Significance of dosage was found to be dependent on the grape variety and on the nature of the pomace (pressing, distillation). The highest phenolic yields (2.6-2.8 g/Kg of dry raw material) were obtained when distilled Cabernet Sauvignon pomace was treated with the mixture in a dosage level of 30 g/Kg.

Rubilar, M, Gutiérrez, C, Verdugo, M, Shene, C, & Sineiro, J. (2010). Flaxseed as a Source of Functional Ingredients. Journal of soil science and plant nutrition. 10; 3; 373-377.

Resumen

Nowadays, grapepomace is frequently used as a source of polyphenols. With the aim of enhancing the yield of the extraction, the capacity of three commercial enzymatic preparations, Cellubrix® (cellulase and β-glucosidase activities), Neutrase® (protease and α-amylase activities) and Viscozyme® (cellulase, hemicellulase and pectinase activities) was tested in this study. Individually applied, none of the enzymatic formulations was able to improve the efficiency of the aqueous extraction (control). However, acting in combination, a significant increase in the yields of soluble solids (∼20-45%), and phenols (∼25-65%), so as a notable improve in antiradical activity DPPH, with the subsequent decrease when measured as EC 50 (∼53-70%) was detected either in a white variety (Garnatxa). as in a red one (Cabernet Sauvignon). Synergistic effect at different dosages (0-30 g Enzyme/Kg substrate) and incubation times (1-2h) was further studied. Significance of dosage was found to be dependent on the grape variety and on the nature of the pomace (pressing, distillation). The highest phenolic yields (2.6-2.8 g/Kg of dry raw material) were obtained when distilled Cabernet Sauvignon pomace was treated with the mixture in a dosage level of 30 g/Kg.

Gutiérrez, C, Rubilar, M, Jara, C, Verdugo, M, Sineiro, J, & Shene, C. (2010). Flaxseed and Flaxseed cake as a source of compounds for food industry. Journal of soil science and plant nutrition. 10; 4;  454-463.

Resumen

Nowadays, grapepomace is frequently used as a source of polyphenols. With the aim of enhancing the yield of the extraction, the capacity of three commercial enzymatic preparations, Cellubrix® (cellulase and β-glucosidase activities), Neutrase® (protease and α-amylase activities) and Viscozyme® (cellulase, hemicellulase and pectinase activities) was tested in this study. Individually applied, none of the enzymatic formulations was able to improve the efficiency of the aqueous extraction (control). However, acting in combination, a significant increase in the yields of soluble solids (∼20-45%), and phenols (∼25-65%), so as a notable improve in antiradical activity DPPH, with the subsequent decrease when measured as EC 50 (∼53-70%) was detected either in a white variety (Garnatxa). as in a red one (Cabernet Sauvignon). Synergistic effect at different dosages (0-30 g Enzyme/Kg substrate) and incubation times (1-2h) was further studied. Significance of dosage was found to be dependent on the grape variety and on the nature of the pomace (pressing, distillation). The highest phenolic yields (2.6-2.8 g/Kg of dry raw material) were obtained when distilled Cabernet Sauvignon pomace was treated with the mixture in a dosage level of 30 g/Kg.

Federico L. Iniguez-Luy, Maria L. Federico. (2010). The Genetics of Brassica napus. Plant Genetics and Genomics: Crops and Models. 9; 291-322.
Resumen

Brassica napus L. belongs to the Brassicaceae family of the Kingdom Plantae and is considered to be a newly formed species (5,000–10,000 mya) probably originating from independent and spontaneous inter-specific hybridizations between genotypes of turnip rape (Brassica rapa; AA, 2n = 20) and cabbage/Kale (Brassica oleracea; CC, 2n = 18). Genetically, B. napus is an allopolyploid (AACC, 2n = 38) exhibiting disomic inheritance. Within the species, two botanical varieties have been defined: B. napus L. var rapifera (DC) Metzger (2n = 4×= 38) and B. napus L. var oleiferaDelile (2n = 4×= 38). The latter has taken much of the attention and has become the second most cultivated oilseed crop (rapeseed) worldwide, after soybean. The appearance of annual and biannual rapeseed lines with low erucic acid (<2% in the oil) and low glucosinolates (B. napus, genetics/genomic tools for the species, and specific target traits affecting B. napus oil production and quality.