Elisa Salas

Given the widespread micronutrient deficiencies in vulnerable populations, crop biofortification has been proposed as a solution to increase nutrient concentrations. This study aimed to determine the effect of combining biofortification strategies on the agronomic characteristics and nutritional composition of potato. The effect of foliar fertilization (FF) with zinc (Zn) on five potato genotypes (G): four biofortified clones developed through conventional breeding with different Zn levels (high, medium, and low in Zn, and one high in Fe and Zn) and a commercial variety (‘Yungay’) were evaluated. At harvest, the number of tubers per plant, the weight of tubers per plant, and the average tuber weight were evaluated as yield components, and tuber samples were collected for micronutrient determination. For yield components, the analysis with linear mixed models showed no significant G × D interaction effects, but highly significant differences were observed among G. The Zn concentration in tubers showed a highly significant effect in the G × D interaction. The simple effects analysis showed that biofortified genotypes responded to FF with Zn by significantly increasing the tuber Zn concentrations by an average of 43% (range 28–61%), despite growing in alkaline soils. In contrast, the ‘Yungay’ variety showed a 6% increase. Clones biofortified through conventional genetic improvement responded better to agronomic FF with Zn compared to the non-biofortified commercial variety, demonstrating that both are synergistic strategies that can achieve a significant increase in Zn concentrations in tubers. The result of this study might be used to further biofortification efforts and decrease nutritional deficiencies.

SUMMARY: Potato (Solanum tuberosum L.) is one of the world's most important crops, but it is facing major challenges due to climatic changes. To investigate the effects of intermittent drought on the natural variability of plant morphology and tuber metabolism in a novel potato association panel comprising 258 varieties we performed an augmented block design field study under normal irrigation and under water‐deficit and recovery conditions in Ica, Peru. All potato genotypes were profiled for 45 morphological traits and 42 central metabolites via nuclear magnetic resonance. Statistical tests and norm of reaction analysis revealed that the observed variations were trait specific, that is, genotypic versus environmental. Principal component analysis showed a separation of samples as a result of conditional changes. To explore the relational ties between morphological traits and metabolites, correlation‐based network analysis was employed, constructing one network for normal irrigation and one network for water‐recovery samples. Community detection and difference network analysis highlighted the differences between the two networks, revealing a significant correlational link between fumarate and plant vigor. A genome‐wide association study was performed for each metabolic trait. Eleven single nucleotide polymorphism (SNP) markers were associated with fumarate. Gene Ontology analysis of quantitative trait loci regions associated with fumarate revealed an enrichment of genes regulating metabolic processes. Three of the 11 SNPs were located within genes, coding for a protein of unknown function, a RING domain protein and a zinc finger protein ZAT2. Our findings have important implications for future potato breeding regimes, especially in countries suffering from climate change.

A main breeding target of the International Potato Center (CIP) has been the biofortification of potato (Solanum tuberosum L.) with the essential micronutrients iron and zinc. This study assessed the broad‐sense heritability (H²) and genetic gains (ΔGs) achieved for iron and zinc concentrations in potato tubers and their relationships with yield components through three cycles of recurrent selection at the diploid level. Sixty genotypes comprising 17 Andean landraces from a base population called Cycle 0, 21 genotypes from Cycle II, and 22 from Cycle III were grown in field trials over 2 yr to compare micronutrient concentrations and agronomic performance. The effects of cycles and cycles × location interactions were both significant (P < .01) for all characters except tuber yield. High phenotypic and genotypic coefficients of variation along with high H² (0.81 ± 0.19 for both iron and zinc) suggested that these parameters were under the control of additive gene effects and could be effectively manipulated by recurrent selection. Large gains of more than 29% iron and 26% zinc were demonstrated. There were slight decreases in dry matter (DM) content of 2 and 5% in Cycles II and III, respectively. Iron concentration had the greatest positive direct effect on total number of tubers per plant, and zinc had a weak negative direct effect on average tuber weight. Selected iron‐ and zinc‐dense genotypes with high, positive general combining ability were identified for use in an interploidy (4x–2x) breeding scheme aimed at increasing the iron and zinc contents of stable, high‐yielding disease and stress‐resistant varieties.

One of the future challenges to produce food in a Mars environment will be the optimization of resources through the potential use of the Martian substratum for growing crops as a part of bioregenerative food systems.In vitroplantlets from 65 potato genotypes were rooted in peat-pellets substratum and transplanted in pots filled with Mars-like soil from La Joya desert in Southern Peru. The Mars-like soil was characterized by extreme salinity (an electric conductivity of 19.3 and 52.6 dS m⁻¹under 1 : 1 and saturation extract of the soil solution, respectively) and plants grown in it were under sub-optimum physiological status indicated by average maximum stomatal conductance 2O m⁻²s⁻¹even after irrigation. 40% of the genotypes survived and yielded (0.3–5.2 g tuber plant⁻¹) where CIP.397099.4, CIP.396311.1 and CIP.390478.9 were targeted as promising materials with 9.3, 8.9 and 5.8% of fresh tuber yield in relation to the control conditions. A combination of appropriate genotypes and soil management will be crucial to withstand extreme salinity, a problem also important in agriculture on Earth that requires more detailed follow-up studies.

Tuber appearance is highly variable in the Andean cultivated potato germplasm. The diploid backcross mapping population ‘DMDD’ derived from the recently sequenced genome ‘DM’ represents a sample of the allelic variation for tuber shape and eye depth present in the Andean landraces. Here we evaluate the utility of morphological descriptors for tuber shape for identification of genetic loci responsible for the shape and eye depth variation. Subjective morphological descriptors and objective tuber length and width measurements were used for assessment of variation in tuber shape and eye depth. Phenotypic data obtained from three trials and male–female based genetic maps were used for quantitative trait locus (QTL) identification. Seven morphological tuber shapes were identified within the population. A continuous distribution of phenotypes was found using the ratio of tuber length to tuber width and a QTL was identified in the paternal map on chromosome 10. Using toPt-437059, the marker at the peak of this QTL, the seven tuber shapes were classified into two groups: cylindrical and non-cylindrical. In the first group, shapes classified as ‘compressed’, ‘round’, ‘oblong’, and ‘long-oblong’ mainly carried a marker allele originating from the male parent. The tubers in this group had deeper eyes, for which a strong QTL was found at the same location on chromosome 10 of the paternal map. The non-cylindrical tubers classified as ‘obovoid’, ‘elliptic’, and ‘elongated’ were in the second group, mostly lacking the marker allele originating from the male parent. The main QTL for shape and eye depth were located in the same genomic region as the previously mapped dominant genes for round tuber shape and eye depth. A number of candidate genes underlying the significant QTL markers for tuber shape and eye depth were identified. Utilization of a molecular marker at the shape and eye depth QTL enabled the reclassification of the variation in general tuber shape to two main groups. Quantitative measurement of the length and width at different parts of the tuber is recommended to accompany the morphological descriptor classification to correctly capture the shape variation.

The BioMart Community Portal (www.biomart.org) is a community-driven effort to provide a unified interface to biomedical databases that are distributed worldwide. The portal provides access to numerous database projects supported by 30 scientific organizations. It includes over 800 different biological datasets spanning genomics, proteomics, model organisms, cancer data, ontology information and more. All resources available through the portal are independently administered and funded by their host organizations. The BioMart data federation technology provides a unified interface to all the available data. The latest version of the portal comes with many new databases that have been created by our ever-growing community. It also comes with better support and extensibility for data analysis and visualization tools. A new addition to our toolbox, the enrichment analysis tool is now accessible through graphical and web service interface. The BioMart community portal averages over one million requests per day. Building on this level of service and the wealth of information that has become available, the BioMart Community Portal has introduced a new, more scalable and cheaper alternative to the large data stores maintained by specialized organizations.

Micronutrient malnutrition is a global health problem. An improved understanding of the genetic variation of important micronutrient traits within a potato breeding population will help devise breeding strategies for the biofortification of this important food staple. The dataset consisted of 556 individuals from 17 full‐sib diploid families grown in 2006 in Huanuco, Peru, and 1329 individuals from 32 full‐sib families grown in 2009 in Ayacucho, Peru. Genetic parameters were estimated using univariate and multivariate individual Bayesian models for micronutrient tuber content including Fe and Zn. Genetic variance was additive and heritability estimates were moderate (0.36 to 0.57) and inflated if the common environment of full‐sibs was not taken into account. Posterior modes of genetic correlation estimates between minerals, when analyzed on a dry‐weight basis, were all positive (0.04 to 0.72) and between minerals and tuber dry matter were negative (−0.14 to −0.38). On a fresh‐weight basis, genetic correlations between minerals and tuber dry matter were small but positive (0.05 to 0.18). The implications and challenges for selective breeding to enhance micronutrient content in potato tubers are discussed.