Advanced Clones Research Articles

Genetic bases of tomato and sweet pepper marker-assisted selection in Belarus

Molecular markers are important and valuable tools in crop breeding programmes to help in the discovery and manipulation of important genes governing resistance reaction. In potato, several biotic stresses hamper quantity and quality of tuber production. Availability of molecular markers and high throughput screening method provide an excellent opportunity to practice marker assisted selection for potato improvement without waiting for phenotypic screening. In this study, we developed 20 KASP markers related to late blight, PVY and PCN resistance traits to facilitate the screening at earlier stages of potato breeding programmes. Out of these 20 markers, nine KASP assays were validated and associated with the phenotype data on respective traits for reliability in their wider application. The validation was done in a panel of 1447 potato germplasm accessions including varieties from diverse provenience and advanced breeding clones. Among traits, the best association found related to KASP markers for late blight, namely markers snp ST00106, snp ST00020 and snp ST00023. Overall, the allele calls were conclusive for all the nine markers, and the results demonstrate the usefulness of SNP KASP markers in high throughput cost effective marker assisted selection (MAS) for important biotic stress traits in potatoes.

Combining ability of highland tropic adapted potato for tuber yield and yield components under drought.

Recurrent drought and late blight disease are the major factors limiting potato productivity in the northwest Ethiopian highlands. Incorporating drought tolerance and late blight resistance in the same genotypes will enable the development of cultivars with high and stable yield potential under erratic rainfall conditions. The objectives of this study were to assess combining ability effects and gene action for tuber yield and traits related to drought tolerance in the International Potato Centre’s (CIP’s) advanced clones from the late blight resistant breeding population B group ‘B3C2’ and to identify promising parents and families for cultivar development. Sixteen advanced clones from the late blight resistant breeding population were crossed in two sets using the North Carolina Design II. The resulting 32 families were evaluated together with five checks and 12 parental clones in a 7 x 7 lattice design with two water regimes and two replications. The experiment was carried out at Adet, in northwest Ethiopia under well-watered and water stressed conditions with terminal drought imposed from the tuber bulking stage. The results showed highly significant differences between families, checks, and parents for growth, physiological, and tuber yield related traits. Traits including marketable tuber yield, marketable tuber number, average tuber weight and groundcover were positively correlated with total tuber yield under both drought stressed and well-watered conditions. Plant height was correlated with yield only under drought stressed condition. GCA was more important than SCA for total tuber yield, marketable tuber yield, average tuber weight, plant height, groundcover, and chlorophyll content under stress. This study identified the parents with best GCA and the combinations with best SCA effects, for both tuber yield and drought tolerance related traits. The new population is shown to be a valuable genetic resource for variety selection and improvement of potato’s adaptation to the drought prone areas in northwest Ethiopia and similar environments.

Late blight and virus host-plant resistances, crossing ability and glycoalkaloids in Nordic potato germplasm

ABSTRACTOld potato cultivars from the Nordic Genetic Resource Center (NordGen) and advanced breeding clones from the Swedish University of Agricultural Sciences (SLU) were evaluated for susceptibility to Potato Virus Y (PVY) and Potato Leafroll Virus (PLRV), foliar and tuber resistance to late blight – caused by Phytophthora infestans – as well as for glycoalkaloid content and crossing ability. Enzyme-Linked Immunosorbant Assay (ELISA) tests were used for PVY and PLRV screening during two years that were characterized by intensive virus incidence and severity in the field, while foliar and tuber resistances to late blight were assessed under artificial inoculation with an aggressive Swedish isolate of P. infestans. Hybrid seeds were obtained by crossing cultivars such as ‘Kiva’, ‘Sarpo Mira’, ‘Rosamunda’ and ‘Superb’ with SLU advanced breeding clones and a selected clone of Solanum tuberosum Group Andigena. Some cultivars (‘Hårek’, ‘Sarpo Mira’) and breeding clones (04-2662, 04-2085) with late blight resistance did not show virus infection. The α-solanin and α-chaconin contents of some of the old Nordic potato cultivars and breeding clones were similar to the known Dutch table cultivar ‘Bintje’ after 3 years of testing. This research allows identification of promising Nordic potato cultivars and SLU breeding clones for further use in developing germplasm aiming at organic and conventional farming systems.

Genomic Analyses of Breast Cancer Progression Reveal Distinct Routes of Metastasis Emergence

A main controversy in cancer research is whether metastatic abilities are present in the most advanced clone of the primary tumor or result from independently acquired aberrations in early disseminated cancer cells as suggested by the linear and the parallel progression models, respectively. The genetic concordance between different steps of malignant progression is mostly unexplored as very few studies have included cancer samples separated by both space and time. We applied whole exome sequencing and targeted deep sequencing to 26 successive samples from six patients with metastatic estrogen receptor (ER)-positive breast cancer. Our data provide support for both linear and parallel progression towards metastasis. We report for the first time evidence of metastasis-to-metastasis seeding in breast cancer. Our results point to three distinct routes of metastasis emergence. This may have profound clinical implications and provides substantial novel molecular insights into the timing and mutational evolution of breast cancer metastasis.

In vitro screening of potato genotypes for osmotic stress tolerance

AbstractPotato (Solanum tuberosum L.) is a cool season crop which is susceptible to both drought and heat stresses. Lack of suitable varieties of the crop adapted to drought-prone areas of the lowland tropics deprives farmers living in such areas the opportunity to produce and use the crop as a source of food and income. As a step towards developing such varieties, the present research was conducted to evaluate different potato genotypes for osmotic stress tolerance under in vitro conditions and identify drought tolerant genotypes for future field evaluation. The experiment was carried out at the Leibniz University of Hannover, Germany, by inducing osmotic stress using sorbitol at two concentrations (0.1 and 0.2 M) in the culture medium. A total of 43 genotypes collected from different sources (27 advanced clones from CIP, nine improved varieties, and seven farmers’ cultivars) were used in a completely randomized design with four replications in two rounds. Data were collected on root and shoot growth. The results revealed that the main effects of genotype, sorbitol treatment, and their interactions significantly (P < 0.01) influenced root and shoot growthrelated traits. Under osmotic stress, all the measured root and shoot growth traits were significantly correlated. The dendrogram obtained from the unweighted pair group method with arithmetic mean allowed grouping of the genotypes into tolerant, moderately tolerant, and susceptible ones to a sorbitol concentration of 0.2 M in the culture medium. Five advanced clones (CIP304350.100, CIP304405.47, CIP392745.7, CIP388676.1, and CIP388615.22) produced shoots and rooted earlier than all other genotypes, with higher root numbers, root length, shoot and root mass under osmotic stress conditions induced by sorbitol. Some of these genotypes had been previously identified as drought-tolerant under field conditions, suggesting the capacity of the in vitro evaluation method to predict drought stress tolerant genotypes. Most of the genotypes collected from Ethiopia were found to be susceptible to osmotic stress, except one farmers’ cultivar (Dadafa) and two improved varieties (Zemen and Belete). Field evaluation of the tested materials under drought conditions would confirm the capacity of osmotic stress tolerant genotypes to perform well under drought-prone conditions and the potential interest of in vitro evaluation as a pre-screening component in potato breeding programs.

Evaluation and selection of potato hybrid clones (Solanum tuberosum) for yield and associated characters

The present study was undertaken to evaluate advanced generation potato clones comprised 183 genotypes obtained from true potato seed, for early bulking towards high yields and associated characters for development of new varieties and selection of promising lines for different traits using augmented design. This approach provides a very efficient means of screening test entries with replicated controls, at early stages of breeding when propagating material is restricted. Based on the analysis H23 was identified to have a significantly larger number of leaves per stem. Number of stems per plant was observed to be significantly high in H14, H172 and H175. Significantly, lesser undersized tubers were observed for lines H98, H167, H28, H54 and H34. The lines H37 and H162 were identified to be significantly superior giving a marketable yield of more than 1.16 kg/ plant. These lines with significantly high yield are considered for release as varieties after conducting replicated evaluation and based on the desirable characters may be suitably considered as parents in succeeding crossing programmes.

Tuber yield and processing traits of potato advanced selections

World potato production continuously requires new cultivars to satisfy farmers’ and consumers’ demand. Tuber yield and quality are some of the main potato breeding targets. In this study, 27 advanced potato clones from 7 hybrid families were evaluated for yield, tuber specific gravity and chipping ability. Variability in tuber yield was found between families as well as between clones. Forty-eight percent of clones showed higher productivity compared to the best control (Agria, 1.1 Kg). Families displayed significant differences also in terms of tubers specific gravity, with about 70% of clones with a score higher than 1.080, which was considered the minimum acceptable value for processing. Chipping ability was evaluated at harvesting time and after cold storage with and without reconditioning. The majority of studied clones showed a good chipping ability score (<4.5) at harvest; five samples chipped well after cold storage with reconditioning, while good chippers were not identified after cold storage without reconditioning. The use of an arbitrary index calculated for each clone is proposed to assist the selection of materials with a good trait combination.

Desempenho genotípico de clones de batata via modelos mistos

The aim of this work was to verify the genotypic performance of twelve potato genotypes in relation to yield components, using the mixed models. The experiments were carried out in the city of Canoinhas, SC, Brazil. Two advanced potato clones and two national cultivars developed by Embrapa, six advanced clones developed by Epagri, and two foreign commercial cultivars widely cultivated in the country were evaluated in the spring seasons of 2012 and 2013. A randomized complete block design with four replications of two single 10 plant plot was used. All plots were harvested 110 days after planting, and evaluated for yield components. The data were submitted to the individual and joint deviance analysis, and adaptability and stability. It was verified that the clones F48-07-06 (Embrapa), 308 (Epagri) and especially the 316 (Epagri), despite not having a high total number of tubers, they were better than the others for all the traits evaluated, combining high productivity, yield stability and adaptability.

Release of orange-fleshed sweetpotato (Ipomoea batatas [l.] Lam.) cultivars in Mozambique through an accelerated breeding scheme

SUMMARYSweetpotato breeding requires at least 5 years to obtain an advanced breeding clone for further testing with the goal of cultivar release. An accelerated breeding scheme (ABS) can be feasible if the genotype × year interaction is low. The objectives of the present study were to describe an ABS for sweetpotato and to investigate the efficiency of this breeding scheme for selecting high-yielding and well-adapted orange-fleshed sweetpotato (OFSP) cultivars with high β-carotene (BC) content. More than 198 500 seeds from two crossing blocks were germinated and rapidly multiplied for evaluation in observation trials at four breeding locations in Mozambique. Breeding clones with storage root yields above 10 t/ha were advanced to preliminary and advanced yield trials across four sites and for 3 years. As a result, 64 high-yielding OFSP breeding clones were selected and evaluated in four mega-environments following a randomized complete block design with three replicates at Angónia, Chókwè, Gurúè and Umbelúzi. Data from multi-environment trials were subjected to single site and combined analysis of variance as well as to stability analysis. The genotype × environment interaction was highly significant for storage root and vine yields, dry matter (DM) and BC content. Storage root yield and DM content for 15 OFSP breeding clones ranged from 14·9 to 27·1 t/ha and from 24·8 to 32·8%, respectively. BC content, iron and zinc ranged from 5·9 to 38·4, 1·6 to 2·1 and 1·1 to 1·5 mg/100 g dry weight, respectively. The OFSP breeding clones also met the culinary tastes required by local consumers in Mozambique. The proposed ABS seems to be an attractive scheme for genetic enhancement of sweetpotato.

Chipping ability, specific gravity and resistance to Pectobacterium carotovorum in advanced potato selections

ABSTRACTThe availability of potato varieties combining good tuber quality and resistance traits is very important for both processors and supermarkets. In the present study, post-harvest quality traits as well as resistance to tuber bacterial soft rot were evaluated in 42 advanced potato clones belonging to seven hybrid families. Differences in specific gravity were found among families and among clones, with about 30% of clones showing a high specific gravity (>1.080). Clones and varieties were assayed also for a comprehensive chipping profile. Overall, 43% of clones presented an acceptable chipping score (≤4.5) at harvest. In addition, following cold storage with and without reconditioning, various clones performed acceptably. Five clones from three families (Bolestra X MC 329, Spunta X Victoria and Majestic X Alcmaria) were classified as resistant to bacterial soft rot. An evaluation index is proposed to help identify clones with interesting combinations of traits.

Genetic Diversity and Relationship of Ethiopian Potato Varieties to Germplasm from North America, Europe and the International Potato Center

Potato is an increasingly important crop in Ethiopia, but the origin of local cultivars grown throughout the country is unknown. To evaluate the genetic diversity of Ethiopian potato cultivars, and to assess their relationship with germplasm from North America, Europe and the International Potato Center (CIP), 8303 SNP markers were used to characterize 44 local Ethiopian cultivars, as well as 26 CIP, 22 American and 17 European potato cultivars and advanced breeding clones. The marker data revealed that most of the local cultivars were duplicates; among the 44 cultivars tested, only 15 unique genotypes were observed. Principal component and neighbor-joining dendrogram analyses showed that American, European and CIP germplasm form three distinct clusters, with older Ethiopian cultivars overlapping the European cultivars, suggesting that the oldest local cultivars are of European descent. Local cultivars overall separated into two distinct clusters, suggesting that at least two distinct introductions gave rise to current local cultivars in Ethiopia. Ethiopian germplasm harbors comparable levels of genetic diversity to American, European, and CIP germplasm and could provide the foundation for a national potato breeding program.

Evaluation of potato (Solanum tuberosum L.) genotypes for resistance to late blight at Sinana Southeastern Ethiopia

Late blight caused by Phytophthora infestans (Mont.) de Bary, is one of the most significant constraints to potato production in Bale high lands and other regions of Ethiopia. Hence, this requires to develop high yielding and late blight resistant varieties. Therefore, this study was conducted to determine host resistance of potato against Phytophthora infestans in order to develop late blight resistant/tolerant genotypes. The experiment was laid out in randomized complete block design with three replications at Sinana Agricultural Research Center during 2014 main cropping season. The genotypes showed highly significant (P&lt;0.01) differences for all the characters studied. Genotypes exhibited wide ranges of mean values for all characters. The highest total tuber yield (46.1 t ha-1) was obtained from the advanced clone, CIP-392640.524 followed by Belete (41 t ha-1). Late blight appeared early on farmer's cultivar Kellacho (48 days after planting) and late on advanced clones CIP- 399062.102(74 days after planting). Percent severity index (PSI) and area under disease progress curve (AUDPC) ranged from 33.91 to 91.67% and 105 to 2370, respectively. Eleven newly introduced clones and the released variety "Belete" recorded PSI 33 to 39.7% and AUDPC 105 to 264.1. Hence, these genotypes can be categorized as moderately resistant. The study revealed the presence of considerable variability in tested genotypes for economically important traits and the higher chance of selecting genotypes with high yield and moderately resistant to late blight. However, it appears that further evaluation of genotypes across seasons and locations to identify genotypes that could be released as varieties seem to be quite pertinent.Int. J. Agril. Res. Innov. &amp; Tech. 6 (1): 21-25, June, 2016

Field Evaluation of Potato Genotypes for Resistance to Powdery Scab on Tubers and Root Gall Formation Caused by Spongospora subterranea

Spongospora subterranea causes root galls and powdery scab on potato tubers (Solanum tuberosum L.). Host resistance represents an economically suitable and long term approach for the management of the disease; however, the relationship between root and tuber symptoms may vary across potato genotypes. To assess susceptibility differences among genotypes, 30 potato cultivars and 83 advanced clones with varying skin type (market class) were evaluated for powdery scab and root gall formation. Five field experiments were conducted during 2011 and 2012 on naturally infested soils in Minnesota and North Dakota. Differences among genotypes in the degree of susceptibility to tuber and root symptoms were observed (P < 0.001, n = 33 to 80). Higher powdery scab pressure (P < 0.001, n = 90) was observed in North Dakota locations across years. Environmental conditions influenced the formation of root galls and the expression of powdery scab, with greatest variability among white- and red-skinned genotypes. Under high disease pressure, the estimates of broad-sense heritability for powdery scab incidence and severity were 0.76 and 0.63, respectively. Across environments, russet-skinned genotypes resulted in less disease on tubers, but yielded similar levels of root galls as red-skinned genotypes. Tuber scab and root gall formation indices were significantly associated (r = 0.42, P < 0.001, n = 80); however, high levels of disease in roots were observed in genotypes ranked resistant to powdery scab. Cultivars Dakota Trailblazer, Dakota Russet and Karu ranked highly resistant, whereas Shepody, Kennebec and Red LaSoda were highly susceptible to both phases of the disease. Cultivar selection is highly recommended for disease management.

Breeding for nutritional quality and pest resistance: potential of a set of non-commercial tetraploid potato cultivars with purple and red flesh

Potatoes are the most widely cultivated tubers and also a valuable source of nutrients and non-nutrient health-promoting compounds. Cultivars with pigmented skin and flesh are of especial interest due to the presence of high concentrations of carotenoids, anthocyanins, flavonoids and phenolic acids. Several investigations have focused on the characterization of native and wild potato accessions, particularly highly pigmented genotypes in order to broaden the overall genetic variation in terms of commercial and processing aptitude, pest resistance and nutritional quality. However, the incorporation of some of these traits into new breeding lines at the tetraploid level is hampered by the presence of detrimental traits as well as varying ploidy levels. Therefore, a set of ten highly-pigmented tetraploid cultivars (Solanum tuberosum L.) was selected and characterized on the basis of tuber morphology, pest resistance and nutritional related traits in order to select parental lines for breeding. Attractive colors and color patterns with potential for the potato snack industry have been identified. Varying degrees of resistance to Globodera spp. and Phythophora infestans, which are considered major threats for the crop, have been found among the collection of pigmented cultivars. Nutritional quality related parameters including significantly higher levels of phenolic compounds, anthocyanins, carotenoids, vitamin C and micronutrients (Zn and Fe) were found when compared with the commercial cultivars used as checks. These findings could assist in the selection of parents (progenitors) towards the introduction of interesting traits into new potato advanced clones at the tetraploid level, without the problems derived from ploidy levels and non-commercial characteristics.

Assessing zebra chip resistance of advanced potato clones under field conditions in the Toluca valley, Mexico

Zebra chip, also known as ‘potato purple-top’ and ‘internal tuber browning’ is threatening potato production in Mexico, Central America, the United States, and New Zealand. The disease is caused by the phloem-limited ‘Candidatus Liberibacter solanacearum’ (Lso), for which potato psyllid, Bactericera cockerelli is the vector. Currently, ZC management is mainly based on insecticide applications targeted against the potato psyllid, underscoring the need for development of potato varieties that are resistant to Lso and/or potato psyllid. A field study was carried out during three years in the Toluca Valley, Mexico, to assess the zebra chip resistance of six advanced potato clones. In addition, the commercial variety Fianna was included as a control. There were no significant differences in yield and number of potato psyllid nymphs per plant among the seven potato clones. However, significant differences were observed in the percentage of healthy tubers, area under disease progress curve in the foliage and in the severity of the internal tuber discoloration. The six potato clones showed higher tolerance to ZC symptoms than Fianna.

Selection of promising sweet potato clones using projective mapping

Increasing demand for sweet potato in regions with temperate climates has triggered interest in the development of new cultivars. Breeding of this crop should consider sensory characteristics in order to meet consumers' expectations. This requires the application of simple and cost-effective methodologies that allow quality evaluation from a sensory perspective. With the objective of identifying the key sensory characteristics of different sweet potato genotypes, two commercial cultivars and seven clones were evaluated during three consecutive years using projective mapping by an untrained consumer panel. This methodology allowed the discrimination of the genotypes, identifying similarities and differences among groups based on sensory terms selected by the assessors. Genotypes were differentiated in terms of texture and flavor characteristics (firmness, moisture, smoothness, creaminess, flavor intensity, sweetness and bitterness). Materials for future crossings were identified. The evaluation of the sensory characteristics of sweet potato clones and cultivars using projective mapping is a quick, cost-effective and reliable tool for the selection of new advanced sweet potato clones with superior sensory characteristics compared to the reference cultivars INIA Arapey and Cuarí. © 2016 Society of Chemical Industry.

Assessment of resistance to root-lesion and root-knot nematodes in Australian hybrid clones of sugarcane and its wild relatives

Root lesion nematode (Pratylenchus zeae) and root knot nematode (Meloidogyne javanica) are the two most important nematode pathogens of sugarcane in Australia. They cause significant yield loss but there are no known varieties with resistance. A research project commenced in 2011 to assess the level of nematode resistance in the progenies from clones derived from crosses between sugarcane (Saccharum spp.) and Erianthus spp. or Saccharum spontaneum Since standard methods of assessing nematode resistance in sugarcane clones were not available, the study aimed to develop rapid, effective and reliable methods for the screening of large numbers of clones for resistance to root lesion and root knot nematodes. A second objective was to determine the resistance of basic Saccharum spp., their wild relatives and some selected crosses to these two nematodes. Shoot and root biomass, reproduction factors (RF) and number of nematodes (or eggs) per g of roots were used to assess resistance levels. A visual rating of root galling was also used for root knot nematodes. The RF value, nematodes or eggs per g of roots, and visual rating (for root-knot nematode) were highly correlated. Resistant and susceptible clones were distinguished using any of these methods. It is concluded that the RF values can be used to detect nematode resistance in large numbers of clones. In the case of root-knot nematodes, visual gall ratings produced results that were similar to egg counts, and could be used as an alternative in future. For advanced clones, rating based on nematodes or eggs per g of root is likely to provide more accurate results. Basic S. spontaneum, E. arundinaceus clones and some progeny clones from crosses between these wild canes and commercial sugarcane clones, or from further backcrosses between these and sugarcane clones, were found to be resistant or moderately resistant to root-knot and root lesion-nematode. These clones are being further tested in the glasshouse and in the field, and should be useful sources of resistance for root-lesion and root-knot nematodes for sugarcane breeding programs.

Identification and reproducibility of diagnostic DNA markers for tuber starch and yield optimization in a novel association mapping population of potato (Solanum tuberosum L.).

Key messageSNPs in candidate genesPain-1,InvCD141(invertases),SSIV(starch synthase),StCDF1(transcription factor),LapN(leucine aminopeptidase), and cytoplasm type are associated with potato tuber yield, starch content and/or starch yield.Tuber yield (TY), starch content (TSC), and starch yield (TSY) are complex characters of high importance for the potato crop in general and for industrial starch production in particular. DNA markers associated with superior alleles of genes that control the natural variation of TY, TSC, and TSY could increase precision and speed of breeding new cultivars optimized for potato starch production. Diagnostic DNA markers are identified by association mapping in populations of tetraploid potato varieties and advanced breeding clones. A novel association mapping population of 282 genotypes including varieties, breeding clones and Andean landraces was assembled and field evaluated in Northern Spain for TY, TSC, TSY, tuber number (TN) and tuber weight (TW). The landraces had lower mean values of TY, TW, TN, and TSY. The population was genotyped for 183 microsatellite alleles, 221 single nucleotide polymorphisms (SNPs) in fourteen candidate genes and eight known diagnostic markers for TSC and TSY. Association test statistics including kinship and population structure reproduced five known marker–trait associations of candidate genes and discovered new ones, particularly for tuber yield and starch yield. The inclusion of landraces increased the number of detected marker–trait associations. Integration of the present association mapping results with previous QTL linkage mapping studies for TY, TSC, TSY, TW, TN, and tuberization revealed some hot spots of QTL for these traits in the potato genome. The genomic positions of markers linked or associated with QTL for complex tuber traits suggest high multiplicity and genome wide distribution of the underlying genes.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-016-2665-7) contains supplementary material, which is available to authorized users.

Heritability of target bioactive compounds and hydrophilic antioxidant capacity in purple- and red-fleshed tetraploid potatoes

Intensely pigmented potato tubers are desired for the speciality potato market because of the health-promoting effects of pigments and other related compounds. Although highly coloured potatoes show higher concentrations of carotenoids and anthocyanins and higher antioxidant capacity, the phytochemical composition is highly dependent on environmental factors. Thus, the effects of genotype, environment and genotype × environment interactions on monomeric anthocyanins, soluble phenolics, carotenoids and hydrophilic antioxidant capacity were evaluated in a set of cultivars selected on the basis of the contrasting flesh colour of tubers. Twenty-one tetraploid potato genotypes were grown in three different field trials at Arkaute and Iturrieta for 2 years. Genotype, environment and genotype × environment interactions were significant for all of the studied parameters (P ≤ 0.01). However, most of the variation was accounted for by clonal variation. Broad-sense heritabilities (and their 95% confidence intervals) were 0.947 (0.832–0.981) for total monomeric anthocyanins, 0.917 (0.852–0.952) for total soluble phenolics, 0.950 (0.911–0.975) for total carotenoids, and 0.887 (0.799–0.945) and 0.850 (0.734–0.927) for hydrophilic antioxidant capacity measured by ABTS and DPPH methods, respectively. Although certain instabilities were recorded for all of the studied traits, the high estimates of heritability support the main role of genetics in phytochemical composition and suggest that sufficient heritable genetic variation exists in tetraploid potato germplasm for the breeding of advanced clones with improved bioactive properties.

Bioethanol from poplar clone Imola: an environmentally viable alternative to fossil fuel?

BackgroundEnvironmental issues, e.g. climate change, fossil resource depletion have triggered ambitious national/regional policies to develop biofuel and bioenergy roles within the overall energy portfolio to achieve decarbonising the global economy and increase energy security. With the 10 % binding target for the transport sector, the Renewable Energy Directive confirms the EU’s commitment to renewable transport fuels especially advanced biofuels. Imola is an elite poplar clone crossed from Populus deltoides Bartr. and Populus nigra L. by Research Units for Intensive Wood Production, Agriculture Research Council in Italy. This study examines its suitability for plantation cultivation under short or very short rotation coppice regimes as a potential lignocellulosic feedstock for the production of ethanol as a transport biofuel. A life cycle assessment (LCA) approach was used to model the cradle-to-gate environmental profile of Imola-derived biofuel benchmarked against conventional fossil gasoline. Specific attention was given to analysing the agroecosystem fluxes of carbon and nitrogen occurring in the cultivation of the Imola biomass in the biofuel life cycle using a process-oriented biogeochemistry model (DeNitrification-DeComposition) specifically modified for application to 2G perennial bioenergy crops and carbon and nitrogen cycling.ResultsOur results demonstrate that carbon and nitrogen cycling in perennial crop–soil ecosystems such as this example can be expected to have significant effects on the overall environmental profiles of 2G biofuels. In particular, soil carbon accumulation in perennial biomass plantations is likely to be a significant component in the overall greenhouse gas balance of future biofuel and other biorefinery products and warrants ongoing research and data collection for LCA models. We conclude that bioethanol produced from Imola represents a promising alternative transport fuel offering some savings ranging from 35 to 100 % over petrol in global warming potential, ozone depletion and photochemical oxidation impact categories.ConclusionsVia comparative analyses for Imola-derived bioethanol across potential supply chains, we highlight priority issues for potential improvement in 2G biofuel profiling. Advanced clones of poplar such as Imola for 2G biofuel production in Italy as modelled here show potential to deliver an environmentally sustainable lignocellulosic biorefinery industry and accelerate advanced biofuel penetration in the transport sector.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-015-0318-8) contains supplementary material, which is available to authorized users.