Modern Cultivars Research Articles

Evaluation of standard physico‐chemical and rheological parameters in predicting bread‐making quality of durum wheat (Triticum turgidum L. ssp. durum [Desf.] Husn.)

SummaryThe efficacy of empirical rheological methodology for modern Triticum aestivum L. in predicting bread‐making quality in Triticum turgidum L. ssp. durum is warranting of attention. The present study was aimed at providing a comparative evaluation of an array of standard rheological tests in predicting bread quality in three modern cultivars (Core, Sant’Agata and Simeto) and three durum wheat landraces (Ruscìa, Timilìa and Tumminia SG3). Gluten strength, alveograph dough strength and tenacity/extensibility ratio, farinograph stability and mixograph peak dough height and overall score, were significantly higher in the modern cultivars, and distinctive in accounting for the variance between modern and old genotypes, using principal component analysis. Quality bread‐making parameters, including bread volume, height and specific volume, were significantly higher in the durum wheat landraces. Standard rheological parameters were ineffective in predicting bread quality, necessitating the requisite in redefining rheological parameters to meet the increasing interest in heritage durum wheat genotypes for bread‐making.

Using Unmanned Aerial Vehicle and Ground-Based RGB Indices to Assess Agronomic Performance of Wheat Landraces and Cultivars in a Mediterranean-Type Environment

The adaptability and stability of new bread wheat cultivars that can be successfully grown in rainfed conditions are of paramount importance. Plant improvement can be boosted using effective high-throughput phenotyping tools in dry areas of the Mediterranean basin, where drought and heat stress are expected to increase yield instability. Remote sensing has been of growing interest in breeding programs since it is a cost-effective technology useful for assessing the canopy structure as well as the physiological traits of large genotype collections. The purpose of this study was to evaluate the use of a 4-band multispectral camera on-board an unmanned aerial vehicle (UAV) and ground-based RGB imagery to predict agronomic traits as well as quantify the best estimation of leaf area index (LAI) in rainfed conditions. A collection of 365 bread wheat genotypes, including 181 Mediterranean landraces and 184 modern cultivars, was evaluated during two consecutive growing seasons. Several vegetation indices (VI) derived from multispectral UAV and ground-based RGB images were calculated at different image acquisition dates of the crop cycle. The modified triangular vegetation index (MTVI2) proved to have a good accuracy to estimate LAI (R2 = 0.61). Although the stepwise multiple regression analysis showed that grain yield and number of grains per square meter (NGm2) were the agronomic traits most suitable to be predicted, the R2 were low due to field trials were conducted under rainfed conditions. Moreover, the prediction of agronomic traits was slightly better with ground-based RGB VI rather than with UAV multispectral VIs. NDVI and GNDVI, from multispectral images, were present in most of the prediction equations. Repeated measurements confirmed that the ability of VIs to predict yield depends on the range of phenotypic data. The current study highlights the potential use of VI and RGB images as an efficient tool for high-throughput phenotyping under rainfed Mediterranean conditions.

Vernalization (VRN) and Photoperiod (PPD) Genes in Spring Hexaploid Wheat Landraces

The heading time in wheat and some other cereals is mainly determined by the genetic system of VRN (vernalization response) and PPD (photoperiod response) genes. Using diagnostic DNA markers, we analyzed VRN-A1, VRN-B1, VRN-D1, and PPD-D1 allelic diversity in a set of landraces representing seven hexaploid spring wheat species from several regions of Eurasia. The determination of the spring growth habit was found to be variable: in 55.3% accessions, it was controlled monogenically by a VRN gene; in 30.3% accessions, by a combination of two VRN genes; and in 2.6% accessions, trigenically. The dominant Ppd-D1a allele was almost completely absent (only 2.6%) in the landraces, which suggests it being secondary to the recessive ppd-D1b allele as well as increase in its frequency during the recent “green revolution.” In species T. aestivum, Т. compactum, T. petropavlovskyi, and T. tibetanum, the Vrn-D1a frequency was shown to increase eastward with maximum concentration in the regions of Afghanistan, India, and China. In species with a compact ear (T. antiquorum, T. sphaerococcum, and Asian forms of Т. compactum), the spring growth habit is controlled by a single Vrn-B1a allele, which indicates their possible initial distribution in the same gene pool. The European and Asian T. spelta subspecies, despite the very fragmented distribution range, have the same Vrn-A1b and Vrn-B1c alleles, which genetically unites these subspecies. A common set of alleles of the VRN genes in landraces and modern cultivars have provided the adaptability of wheat to diverse environmental conditions during the long period of its cultivation. The newly detected DNA fragments in the first intron of VRN-D1 and PPD-D1 loci may mark new alleles and be of interest for further examination and use in breeding programs.

Fertilizer nitrogen recovery of irrigated spring malt barley

AbstractWell‐defined nitrogen (N) management in irrigated two‐row malting barley (Hordeum vulgare L.) is critical for yield and quality and to minimize environmental impacts. Data on fertilizer N recovery efficiency (FNRE) and the fate of fertilizer‐N in the soil are lacking. The study objective was to determine uptake and partitioning of 15N‐labeled urea in the plant and soil. Urea was either surface applied or incorporated at a total N rate (inorganic‐N + applied N) of 214 kg N ha–1 at planting. Three malt cultivars were grown, and samples were collected four times during the growing season (Feekes growth stages 4/5, 10.0, 11.2, and 11.4). Barley plants at Feekes 11.2 and 11.4 were separated into vegetative tissue and spikes. Plant N accumulation was lowest at Feekes 4/5 and reached a maximum at Feekes 11.2, whereas FNRE was greatest at Feekes 10.0. Nitrogen was redistributed from vegetative tissue to the spike from Feekes 11.2 to 11.4. Plant FNRE averaged 43% at Feekes 11.4. Total plant–soil FNRE for the surface application was 66%, which was less than the incorporated FNRE of 77%. Results provide evidence of the increased plant–soil system FNRE of incorporated applications in high‐input barley production systems compared with surface applications despite no yield difference. Similar FNRE as compared to previous work with lower yields was measured, and modern cultivars out‐yielded an older cultivar with no reduction in FNRE. Results of the study indicate that a relatively high plant–soil system FNRE of irrigated malting barley was achieved under high‐input, irrigated conditions common in southern Idaho.

Three founding ancestral genomes involved in the origin of sugarcane.

Background and AimsModern sugarcane cultivars (Saccharum spp.) are high polyploids, aneuploids (2n = ~12x = ~120) derived from interspecific hybridizations between the domesticated sweet species Saccharum officinarum and the wild species S. spontaneum.MethodsTo analyse the architecture and origin of such a complex genome, we analysed the sequences of all 12 hom(oe)ologous haplotypes (BAC clones) from two distinct genomic regions of a typical modern cultivar, as well as the corresponding sequence in Miscanthus sinense and Sorghum bicolor, and monitored their distribution among representatives of the Saccharum genus.Key ResultsThe diversity observed among haplotypes suggested the existence of three founding genomes (A, B, C) in modern cultivars, which diverged between 0.8 and 1.3 Mya. Two genomes (A, B) were contributed by S. officinarum; these were also found in its wild presumed ancestor S. robustum, and one genome (C) was contributed by S. spontaneum. These results suggest that S. officinarum and S. robustum are derived from interspecific hybridization between two unknown ancestors (A and B genomes). The A genome contributed most haplotypes (nine or ten) while the B and C genomes contributed one or two haplotypes in the regions analysed of this typical modern cultivar. Interspecific hybridizations likely involved accessions or gametes with distinct ploidy levels and/or were followed by a series of backcrosses with the A genome. The three founding genomes were found in all S. barberi, S. sinense and modern cultivars analysed. None of the analysed accessions contained only the A genome or the B genome, suggesting that representatives of these founding genomes remain to be discovered.ConclusionsThis evolutionary model, which combines interspecificity and high polyploidy, can explain the variable chromosome pairing affinity observed in Saccharum. It represents a major revision of the understanding of Saccharum diversity.

Functional gene assessment of bread wheat: breeding implications in Ningxia Province

BackgroundThe overall genetic distribution and divergence of cloned genes among bread wheat varieties that have occurred during the breeding process over the past few decades in Ningxia Province, China, are poorly understood. Here, we report the genetic diversities of 44 important genes related to grain yield, quality, adaptation and resistance in 121 Ningxia and 86 introduced wheat cultivars and advanced lines.ResultsThe population structure indicated characteristics of genetic components of Ningxia wheat, including landraces of particular genetic resources, introduced varieties with rich genetic diversities and modern cultivars in different periods. Analysis of allele frequencies showed that the dwarfing alleles Rht-B1b at Rht-B1 and Rht-D1b at Rht-D1, 1BL/1RS translocation, Hap-1 at GW2-6B and Hap-H at Sus2-2B are very frequently present in modern Ningxia cultivars and in introduced varieties from other regions but absent in landraces. This indicates that the introduced wheat germplasm with numerous beneficial genes is vital for broadening the genetic diversity of Ningxia wheat varieties. Large population differentiation between modern cultivars and landraces has occurred in adaptation genes. Founder parents carry excellent allele combinations of important genes, with a higher number of favorable alleles than modern cultivars. Gene flow analysis showed that six founder parents have greatly contributed to breeding improvement in Ningxia Province, particularly Zhou 8425B, for yield-related genes.ConclusionsVarieties introduced from other regions with rich genetic diversity and landraces with well-adapted genetic resources have been applied to improve modern cultivars. Founder parents, particularly Zhou 8425B, for yield-related genes have contributed greatly to wheat breeding improvement in Ningxia Province. These findings will greatly benefit bread wheat breeding in Ningxia Province as well as other areas with similar ecological environments.

Pheno-genetic studies of apple varieties in northern Pakistan: A hidden pool of diversity

Apple (Malus × domestica) is a main fruit crop of cold temperate regions and traded globally. Despite being a comparatively well documented plant cultigen, available germplasm in many remote regions is still unexplored and threatened. Increasing market demands for modern cultivars and farmers’ preference for high yields may lead to the gradual loss of indigenous varieties. Gilgit-Baltistan in northern Pakistan – a mountainous and remote apple growing region – was selected to study local cultigen diversity by assessing varietal richness and diversity, arboriculture activities as well as phenotypic and genotypic characters of available germplasm. In total, 106 individual apple trees were sampled, and 35 tree owners from seven villages of the two valleys Ishkoman and Baltistan were interviewed. Dendrometric parameters, fruit traits (qualitative and quantitative), and varietal diversity in each village were measured. Genetic variation was estimated using eleven SSR markers and synonyms and homonyms were identified based on cluster analysis.Sixty-one multi-locus genotypes (MLG; mean genotype diversity: 58 %) and 18 putative clones (comprising 2 to 9 ramets) were identified. Varietal diversity was highest in Baltistan where even a wild apple relative (Malus baccata) was discovered. Mean genetic diversity was moderate (He = 0.677), while negative inbreeding coefficients indicated excess of heterozygotes in three genetic clusters. A moderate correlation (r = 0.627, p = 0.001) between phenotypic and genetic dendrograms suggested genetically linked fruit traits, which merits further exploration.Considering the high genetic and phenotypic variability, Gilgit-Baltistan appears a promising source of apple germplasm for future breeding programs. The promotion of local varieties may allow farmers to diversify their produce and derived sources of income as well as to maintain a historically important bio-cultural heritage of Gilgit-Baltistan. To this end, comprehensive conservation strategies combined with further participatory research will be needed.

Gluten Protein Compositional Changes in Response to Nitrogen Application Rate

Field trials were conducted to evaluate the effect of nitrogen level on wheat protein content and composition in 16 cultivars over two years at three locations. The nitrogen treatment comprised two nitrogen levels, 0 kg ha−1 as low and 100 kg ha−1 as high nitrogen, applied as top dressings of 50 kg nitrogen per ha at tillering and stem extension growth stages. Increased nitrogen level generally enhanced grain protein by 11.3% (11.5% vs. 12.8%). Considering protein composition determined by reversed phase–high-pressure liquid chromatography, higher nitrogen supply generally enhanced the proportion of total gliadins, α-gliadins, γ-gliadins and high-molecular-weight glutenin subunits by 1.1%, 2.0%, 3.7%, 0.6% and 0.9%, respectively, and reduced albumins and globulins, ω-gliadins, total glutenins and low-molecular-weight glutenin subunits by 1.1%, 1.7%, 1.9% and 3.2%. Under a high nitrogen level, the historical cultivars Libellula, San Pastore and U-1 had a higher protein content (13.1–15.2%) with significantly higher total gliadins, which resulted in a significantly higher gliadin/glutenin ratio (1.68–1.92). In the modern cultivars, protein content varied between 11.4% and 14.6% with a well-balanced gliadin/glutenin ratio (1.08–1.50), except for cultivar MV Nemere which had a high gliadin/glutenin ratio at both nitrogen levels (1.81 vs. 1.87). In summary, increasing nitrogen level enhanced grain protein content while the composition of gliadin and glutenin fractions was changed to a lesser extent and was largely cultivar specific and therefore should be considered for wheat baking quality assessment and breeding purposes.

Leaf productivity and persistence have been improved during soybean (Glycine max) domestication and evolution.

Artificial and natural selection improved the leaf photosynthetic rate of soybean (Glycine max (L.) Merr. subsp. max). This change may be accompanied by unconscious, undesired changes in other leaf traits, such as decreased leaf persistence, if a finite resource was shared by two or more leaf traits-i.e., if they were traded off. We investigated leaf traits related to productivity (leaf photosynthetic rate, leaf nitrogen content, and stomatal conductance) and those related to persistence (leaf lifespan, leaf mass per unit area, and leaf bulk density) in one wild soybean line and three domesticated soybean lines (a landrace, an old cultivar, and a modern cultivar) in a three year experiment. Some leaf trait values increased while others did not change significantly during domestication and evolution. These results indicate that productivity-related leaf traits and persistence-related leaf traits are not negatively correlated. It was also found that the changes in productivity-related leaf traits and persistence-related leaf traits occurred at different times. Our results indicate that the productivity-related leaf traits and the persistence-related leaf traits have been independently selected for in soybean, and that they were not traded off. Combination of high leaf productivity and high leaf persistence would lead to higher lifetime leaf carbon gain and increased soybean yield.

Wheat cultivars with small root length density in the topsoil increased post-anthesis water use and grain yield in the semi-arid region on the Loess Plateau

Large distribution of roots in topsoil layers allow more uptake of soil water and nutrients during the vegetative growth, but it may be disadvantageous if soil water deficit develops during the reproductive stage. The relationship between the distribution of roots in topsoil (0–0.4 m) and soil water use, dry matter and nitrogen (N) accumulations, and grain yield was examined in winter wheat (Triticum aestivum L.) with contrasting root size in the topsoil. Two old landraces (CW134 and JM47, larger root length and biomass in the topsoil) and two modern wheat cultivars (CH58 and LH7, smaller root system size in the topsoil), were grown in the field during two seasons (2016–2017 and 2017–2018) under rainfed and irrigation conditions in the semi-arid farmland on the Loess Plateau. Root biomass and root length density (RLD) in topsoil (0–0.4 m) was significantly higher in the old landraces than in the modern cultivars (P < 0.05) under rainfed and irrigation in both seasons (no such difference in subsoil, 0.4–1.0 m). The modern cultivars had significantly higher grain yield, grain N concentration, water-use efficiency (WUE), and 1000-grain weight (P < 0.05). Seasonal water use was similar among all cultivars, but post-anthesis water use was higher in the modern cultivars, particularly under rainfed conditions in both seasons. Root biomass and RLD in the topsoil was positively correlated with pre-anthesis water use, but negatively correlated with after anthesis water use. Post-anthesis water use was closely related to post-anthesis dry matter, N accumulation, yield and WUE under rainfed conditions. To conclude, large distribution of roots in the topsoil had non-advantage for wheat grown under rainfed conditions. The small distribution of roots in the topsoil (characteristics of modern wheat cultivars) enhanced post-anthesis water use, increased post-anthesis dry matter and N accumulation, and hence attained higher grain yield and grain N when grown in the semi-arid environment.

Metabolic profiling of historical and modern wheat cultivars using proton nuclear magnetic resonance spectroscopy

To determine changes in the grain components between historical and modern wheat (Triticum aestivum L.) cultivars, wholemeal flours from 19 wheat cultivars and 2 landraces released or introduced between 1870 and 2013 and grown over two crop years were extracted using hydroalcoholic solution and analyzed using one dimensional 1H NMR spectral profiling. Grain yield, grain volume weight (GVW), and grain protein concentration were also measured. Grain yield increased while protein concentration decreased by release year (p < 0.001). Increasing trends (p < 0.01) were observed for tryptophan, sum of the measured amino acids, chlorogenic acid, ferulic acid, vanillic acid, and sum of the measured phenolic acids. Grain yield, phenolic acids, and tryptophan were mainly associated with modern cultivars, whereas grain protein concentration and GVW were associated with historical cultivars. The findings from this study showed changes in concentration of grain components over a century of breeding that may have implications for grain quality and human health.

The Genetic Basis of Tomato Aroma.

Tomato (Solanum lycopersicum L.) aroma is determined by the interaction of volatile compounds (VOCs) released by the tomato fruits with receptors in the nose, leading to a sensorial impression, such as “sweet”, “smoky”, or “fruity” aroma. Of the more than 400 VOCs released by tomato fruits, 21 have been reported as main contributors to the perceived tomato aroma. These VOCs can be grouped in five clusters, according to their biosynthetic origins. In the last decades, a vast array of scientific studies has investigated the genetic component of tomato aroma in modern tomato cultivars and their relatives. In this paper we aim to collect, compare, integrate and summarize the available literature on flavour-related QTLs in tomato. Three hundred and fifty nine (359) QTLs associated with tomato fruit VOCs were physically mapped on the genome and investigated for the presence of potential candidate genes. This review makes it possible to (i) pinpoint potential donors described in literature for specific traits, (ii) highlight important QTL regions by combining information from different populations, and (iii) pinpoint potential candidate genes. This overview aims to be a valuable resource for researchers aiming to elucidate the genetics underlying tomato flavour and for breeders who aim to improve tomato aroma.

Ancient genomes reveal early Andean farmers selected common beans while preserving diversity.

All crops are the product of a domestication process that started less than 12,000 years ago from one or more wild populations1,2. Farmers selected desirable phenotypic traits (such as improved energy accumulation, palatability of seeds and reduced natural shattering3) while leading domesticated populations through several more or less gradual demographic contractions2,4. As a consequence, the erosion of wild genetic variation5 is typical of modern cultivars, making them highly susceptible to pathogens, pests and environmental change6,7. The loss of genetic diversity hampers further crop improvement programmes to increase food production in a changing world, posing serious threats to food security8,9. Using both ancient and modern seeds, we analysed the temporal dynamics of genetic variation and selection during the domestication process of the common bean (Phaseolus vulgaris) in the southern Andes. Here, we show that most domestic traits were selected for before 2,500 years ago, with no or only minor loss of whole-genome heterozygosity. In fact, most of the changes at coding genes and linked regions that differentiate wild and domestic genomes are already present in the ancient genomes analysed here, and all ancient domestic genomes dated between 600 and 2,500 years ago are highly variable (at least as variable as modern genomes from the wild). Single seeds from modern cultivars show reduced variation when compared with ancient seeds, indicating that intensive selection within cultivars in the past few centuries probably partitioned ancestral variation within different genetically homogenous cultivars. When cultivars from different Andean regions are pooled, the genomic variation of the pool is higher than that observed in the pool of ancient seeds from north and central western Argentina. Considering that most desirable phenotypic traits are probably controlled by multiple polymorphic genes10, a plausible explanation of this decoupling of selection and genetic erosion is that early farmers applied a relatively weak selection pressure2 by using many phenotypically similar but genetically diverse individuals as parents. Our results imply that selection strategies during the past few centuries, as compared with earlier times, more intensively reduced genetic variation within cultivars and produced further improvements by focusing on a few plants carrying the traits of interest, at the cost of marked genetic erosion within Andean landraces.

Nitrogen allocation and remobilization contributing to low-nitrogen tolerance in stay-green maize

Nitrogen (N) efficient cultivars can achieve relatively high grain yield under reduced N input. Normally modern stay-green maize cultivars are high-yielding and more N efficient than the old senescent cultivars. However, less is known about the genotypic difference in N use efficiency (NUE) among stay-green high-yielding cultivars. This information is crucial for further genetic improvement in NUE of the modern stay-green cultivars. In the present study, two stay-green hybrids with different NUE, Zhengdan958 (ZD958, N-efficient) and Liangyu99 (LY99, N-inefficient), were grown under 60 (LN) and 180 kg N ha−1 (HN) conditions in a 4-year field experiment with split-design. The two hybrids did not differ in grain yield under HN. Under LN, grain yield and grain N content of LY99 was 23.6 % and 30.3 % lower compared to that of ZD958, respectively. LY99 had few grain number per row than ZD958. Correspondingly, floret primordia number decreased by 17.7 %, and grain abortion increased by 12.7 % in LY99 compared to ZD958. During critical period around silking, N concentration in the young ear of LY99 is lower than that in ZD958. Also, the maximum absolute ear growth rate and exponential duration of LY99 were 22.2 % and 6.0 % lower than that of ZD958 under LN, respectively. In LN conditions, the two hybrids did not differ in post-silking N accumulation. However, N remobilization from vegetative organs to grains in LY99 was 41.3 % lower than that in ZD935. In conclusion, NUE in stay-green cultivars could be improved by efficient N allocation into the young ear and vegetative-N remobilization during post-silking period under insufficient N supply.

Differences in Weed Suppression between Two Modern and Two Old Wheat Cultivars at Different Sowing Densities

Crop losses to weeds can be exacerbated in modern agricultural systems because modern crop cultivars have high population yields but low individual competitiveness. High density cropping systems offer the possibility of effectively suppressing weeds by increasing the initial size-asymmetric advantage of crops over the weeds. We tested this hypothesis in an outdoor mesocosm experiment with two old (Cultivar Heshangtou (HST) and Jinbaoyin (JBY)) and two modern (Xihan2 (XH2) and Xihan3 (XH3)) cultivars of spring wheat (Triticum aestivum L.), grown in a uniform pattern at four sowing densities under high weed pressure. Two annuals (Brassica napus and Linum usitatissimum) were used as model weeds sown at the same density in all treatments. Weed growth decreased and wheat yield increased with increasing crop density for all the cultivars, although yield levelled off at the highest densities. The old cultivars suppressed weeds better than the new cultivars at low density, reflecting the decline in individual competitiveness in modern cultivars. At high crop density, however, the modern XH3 suppressed the weeds as well as the old cultivars, supporting the hypothesis that traits that promote weed suppression are different at low vs. high density. Increasing crop density can be an effective way to suppress weed growth in many agricultural systems, and there is great potential for developing genotypes that can do this and produce high yields much better than the cultivars currently available.

Adaptive potential of durum wheat (Triticum durum Desf.) varieties of Azerbaijan

Background. Studies into the adaptability of the genetic diversity of cultivated plants and their wild relatives to various environments are induced by global climate change. Introduction of adaptive wheat cultivars resistant to environmental stressors is the basis for stable harvests. This article presents the results of a research into the adaptive value of indigenous durum wheat varieties and improved cultivars released in different years in Azerbaijan.Materials and methods. The experiments were carried out in the foothills of Mountainous Shirvan under unsecured non-irrigation at Gobustan Experiment Station of the Research Institute of Crop Husbandry. In 2012–2014, contrasting in weather conditions, levels and structure of yield were analyzed. VIR’s guidelines were used to study 42 durum wheat varie ties, including 10 landraces. The years of study differed sharply in rainfall. Selyaninov’s hydrothermal coefficient was used to assess the conditions of growing seasons.Results. Mostly modern cultivars of the semi-intensive type were distinguished for a set of agrobiological traits. Adaptability coefficients (0.81–1.23) showed that the response of the studied varieties to unfavorable conditions was highly expressed. Indigenous landraces ‘Ag bughda’ and ‘Bozak’, old breeding varieties ‘Arandani’, ‘Ag bughda 13’, ‘Kahraba’ and ‘Mirbashir 50’, and new cultivars ‘Karagilchig 2’ and ‘Barakatli 95’ had the highest adaptability coefficients. The first of them demonstrated stable yield, and the latter two were also resistant to stressors.Conclusion. Durum wheat yields under the conditions of moderately continental climate in Mountainous Shirvan depended on the number and weight of grains per ear. The varieties identified for the best adaptability are recommended to be included in crosses to develop new plastic cultivars of durum wheat.

Early production of table olives at a mid-7th millennium BP submerged site off the Carmel coast (Israel)

We present here the earliest evidence for large-scale table olive production from the mid-7th millennium BP inundated site of Hishuley Carmel on the northern Mediterranean coast of Israel. Olive pit size and fragmentation patterns, pollen as well as the architecture of installations associated with pits from this site, were compared to finds from the nearby and slightly earlier submerged Kfar Samir site. Results indicate that at Kfar Samir olive oil was extracted, while at Hishuley Carmel the data showed that large quantities of table olives, the oldest reported to date, were prepared. This process was most probably facilitated by the site’s proximity to the Mediterranean Sea, which served as a source of both sea water and salt required for debittering/pickling/salting the fruit, as experimentally demonstrated in this study. Comparison of pit morphometry from modern cultivars, wild-growing trees and the archaeological sites, intimates that in pit morphology the ancient pits resemble wild olives, but we cannot totally exclude the possibility that they derive from early cultivated trees. Our findings demonstrate that in this region, olive oil production may have predated table olive preparation, with each development serving as a milestone in the early exploitation of the olive.

Leaf photosynthetic and biomass parameters related to the tolerance of Vicia faba L. cultivars to salinity stress

Faba bean (Vicia faba L.) is an important pulse crop in the Mediterranean region. Salinity is one of the most devastating abiotic stresses that alter the growth and development of plants and affect the crop yield, especially in arid and semi-arid area such as Tunisia. To surmount the damaging effect of salinity, it is important to develop tolerant cultivars of faba bean. In this study, we examined the behavior of four faba bean cultivars in response to salinity stress. Plants were grown in hydroponics at 0, 75 and 150 mM of NaCl, and 16 morphological, photosynthetic and physiological parameters were assessed. Our data showed a significant genotypic variation for salt tolerance in faba bean among the studied cultivars. All measured parameters were affected by salinity at moderate salt concentration (75 mM), while there was a more pronounced reduction of all parameters at severe salt concentration (150 mM). The statistics analysis revealed that photosynthetic and biomass parameters were the least altered in cv. ‘Najeh’. Based on the results, cv. ‘Najeh’ can be considered to be a tolerant cultivar and to attract great interest in future breeding programs for modern cultivar improvement.

Seasonal arbuscular mycorrhiza colonization dynamic displays genotype-specific pattern in Iris sibirica L.

Arbuscular mycorrhiza (AM) is a widespread symbiotic association between plants and Glomeromycota fungi, that brings nutritional-derived benefits for phytobiont. Influence of plant breeding on arbuscular mycorrhiza susceptibility is a topic of current interest that can have many practical implications. Insights into whether new cultivars have a lower mycorrhizal potential, are critical for optimization of AM use. Aim of this research was to conduct a comparative assessment of AM colonization across a phenophase gradient in two Iris sibirica genotypes: one displaying the wild traits versus a modern reblooming cultivar with double flowers. Analysis showed that both Iris sibirica genotypes developed Paris-morphotype. Results indicated that on average the genotype with simple flowers had a higher AM colonization frequency (84.44±2.15) compared to the new cultivar with double flowers (52.22±6.09). Significant influence was exercised both by genotype (p&lt;0.001) as well as by phenophase (p=0.0013), over colonization frequency. The genotypes displayed contrasting colonization dynamics: highest AM frequency level occurred in spring for the genotype with simple flowers, and in autumn for the one with double flowers. Results suggest that host metabolic state has regulating role over functionality of established AM-symbiotic association according to plant nutritional requirements, while fungi might also respond to increased or decreased carbon flux in the plant, associated with geophyte phenology.

The Resistance of Narrow-Leafed Lupin to Diaporthe toxica Is Based on the Rapid Activation of Defense Response Genes.

Narrow-leafed lupin (Lupinus angustifolius L.) is a grain legume crop that is advantageous in animal nutrition due to its high protein content; however, livestock grazing on stubble may develop a lupinosis disease that is related to toxins produced by a pathogenic fungus, Diaporthe toxica. Two major unlinked alleles, Phr1 and PhtjR, confer L. angustifolius resistance to this fungus. Besides the introduction of these alleles into modern cultivars, the molecular mechanisms underlying resistance remained unsolved. In this study, resistant and susceptible lines were subjected to differential gene expression profiling in response to D. toxica inoculation, spanning the progress of the infection from the early to latent phases. High-throughput sequencing of stem transcriptome and PCR quantification of selected genes were performed. Gene Ontology term analysis revealed that an early (24 h) response in the resistant germplasm encompassed activation of genes controlling reactive oxygen species and oxylipin biosynthesis, whereas in the susceptible germplasm, it comprised induction of xyloglucan endotransglucosylases/hydrolases. During the first five days of the infection, the number of genes with significantly altered expressions was about 2.6 times higher in resistant lines than in the susceptible line. Global transcriptome reprogramming involving the activation of defense response genes occurred in lines conferring Phr1 and PhtjR resistance alleles about 4–8 days earlier than in the susceptible germplasm.