Biostimulatory Action of Arbuscular Mycorrhizal Fungi Enhances Productivity, Functional and Sensory Quality in ‘Piennolo del Vesuvio’ Cherry Tomato Landraces

Arbuscular mycorrhizal fungi (AMF) are a promising tool to improve plant nutrient use efficiency (NUE) and tolerance against abiotic stresses. Moreover, AMF can potentially increase plant productivity and reduce the negative externalities of the agricultural sector. Our study aimed to elucidate whether AMF (containing Rhizoglomus irregulare and Funneliformis mosseae) could positively affect not only tomato growth and productivity but also the nutritional and nutraceutical quality of yellow-pigmented type (‘Giagiù’) and red-pigmented type (‘Lucariello’) tomatoes (Solanum lycopersicum L.). These cherry tomatoes are landraces of the Protected Designation of Origin (PDO) ‘Pomodorino del Piennolo del Vesuvio’ (PPV), one of the most typical agricultural products of the Campania region (Southern Italy). AMF rose fruit yield by increasing the number of fruits per plant (+49% and +29% in ‘Giagiù’ and ‘Lucariello’, respectively) but not of the fruit mean mass. AMF increased lycopene (+40%), total ascorbic acid (TAA; +41%), alanine (+162%), gamma-Aminobutyric acid (GABA; +101%) and branched-chain amino acids (BCAAs; +53%) in ‘Lucariello’. In ‘Giagiù’, AMF increased calcium (+63%), zinc (+45%), ASP (+70%), GABA (+53%) and the essential amino acids arginine (+58%) and lysine (+45%), also indicating a genotype-specific response. In both landraces, AMF improved nutrient uptake and biosynthesis of important molecules involved in the control the oxidative stress and cellular pH. In addition to the beneficial effects of human health, the molecules influenced by the AMF treatment are expected to extend the shelf life of tomato fruits, thus further promoting the useful agronomic application of AMF for premium tomatoes marketed fresh or in pendulums (‘piennoli’)

Adapting Agriculture to Climate Change: A Synopsis of Coordinated National Crop Wild Relative Seed Collecting Programs across Five Continents

The Adapting Agriculture to Climate Change Project set out to improve the diversity, quantity, and accessibility of germplasm collections of crop wild relatives (CWR). Between 2013 and 2018, partners in 25 countries, heirs to the globetrotting legacy of Nikolai Vavilov, undertook seed collecting expeditions targeting CWR of 28 crops of global significance for agriculture. Here, we describe the implementation of the 25 national collecting programs and present the key results. A total of 4587 unique seed samples from at least 355 CWR taxa were collected, conserved ex situ, safety duplicated in national and international genebanks, and made available through the Multilateral System (MLS) of the International Treaty on Plant Genetic Resources for Food and Agriculture (Plant Treaty). Collections of CWR were made for all 28 targeted crops. Potato and eggplant were the most collected genepools, although the greatest number of primary genepool collections were made for rice. Overall, alfalfa, Bambara groundnut, grass pea and wheat were the genepools for which targets were best achieved. Several of the newly collected samples have already been used in pre-breeding programs to adapt crops to future challenges.info:eu-repo/semantics/publishedVersio

Characterization of durum wheat genetic resources and evaluation under Cyprus conditions

Ο γενετικός χαρακτηρισμός γενετικών πόρων αποτελεί σημαντική προϋπόθεση για την βελτιστοποίηση των στρατηγικών διατήρησης γενετικού υλικού και την αξιοποίηση του σε προγράμματα βελτίωσης. Η φαινοτυπική αξιολόγηση κάτω από διαφορετικά περιβάλλοντα επιτρέπει την εκτίμηση της παραλλακτικότητας για σημαντικά αγρονομικά και φυσιολογικά χαρακτηριστικά και τον υπολογισμό των συσχετίσεων τους με την απόδοση. Οι τεχνολογίες υψηλής απόδοσης, όπως η τηλεπισκόπηση, έχουν αποκτήσει ιδιαίτερο ενδιαφέρον για τη φαινοτύπηση φυτών επειδή είναι γρήγορες και φτηνές μέθοδοι. Οι κύριοι στόχοι αυτής της διδακτορικής διατριβής ήταν: (1) ο γενετικός χαρακτηρισμός 55 καταχωρήσεων σκληρού σιταριού, συμπεριλαμβανομένων μοντέρνων ποικιλιών από διαφορετικά προγράμματα βελτίωσης και παραδοσιακών ποικιλιών προερχόμενων από την Κύπρο και άλλες περιοχές της Μεσογείου με μικροδορυφόρους, (2) η αξιολόγηση 20 μοντέρνων ποικιλιών για απόδοση και άλλα σημαντικά αγρονομικά χαρακτηριστικά κάτω από διαφορετικές εδαφο-κλιματικές συνθήκες, και (3) η αξιολόγηση της χρησιμότητας μεθόδων υψηλής απόδοσης τηλεπισκόπησης για μαζική φαινοτύπηση κάτω από ένα ξηρό και θερμό περιβάλλον. Οι μικροδορυφόροι κατέδειξαν την ύπαρξη μεγάλης γενετικής παραλλακτικότητας. Οι παραδοσιακές ποικιλίες δημιούργησαν ξεχωριστές ομάδες και παρουσίασαν μεγαλύτερη γενετική παραλλακτικότητα από τις μοντέρνες ποικιλίες ενισχύοντας τη δυνατότητα αξιοποίησης τους στα προγράμματα βελτίωσης. Η μεγαλύτερη γενετική παραλλακτικότητα παρατηρήθηκε στις κυπριακές παραδοσιακές ποικιλίες υποδεικνύοντας την πιθανή ύπαρξη μοναδικής ποικιλομορφίας εντός αυτής της γενετικής δεξαμενής. Μεγάλη γενετική παραλλακτικότητα παρατηρήθηκε και εντός της κυπριακής παραδοσιακής ποικιλίας «Κυπερούντα». Η γενετική ποικιλομορφία ήταν μεγαλύτερη εντός των καταχωρήσεων που διατηρούνται ως ξεχωριστές γραμμές προερχόμενες από ένα στάχυ. Η γενετική διαφοροποίηση των καταχωρήσεων της «Κυπερούντας» και η διαφορετική κατάταξη των καταχωρήσεων με ίδιο όνομα στην ανάλυση συστάδων υποδεικνύει ότι τα δεδομένα συλλογής δεν είναι αξιόπιστος τρόπος για περιορισμό διπλών δειγμάτων. Η φαινοτυπική αξιολόγηση κατέδειξε την ύπαρξη σημαντικής γενετικής παραλλακτικότητας για όλα τα χαρακτηριστικά που εξετάστηκαν, παρόλα αυτά, για τα περισσότερα η επίδραση του περιβάλλοντος ήταν μεγαλύτερη. Παρατηρήθηκαν στατιστικά σημαντικές συσχετίσεις μεταξύ του αριθμού σπόρων ανά τ.μ. και της απόδοσης στα περισσότερα περιβάλλοντα και οι συσχετίσεις ήταν μεγαλύτερες στα δύο περιβάλλοντα με τη χαμηλότερη απόδοση. Ο αριθμός σπόρων ανά στάχυ ήταν το χαρακτηριστικό που συστηματικά συσχετιζόταν σημαντικά με τον αριθμό σπόρων ανά τ.μ. Παρατηρήθηκαν επίσης αρνητικές συσχετίσεις μεταξύ των συστατικών απόδοσης. Οι ποικιλίες είχαν διαφορετικές στρατηγικές διαμόρφωσης της απόδοσης. Οι δύο ποικιλίες με την μεγαλύτερη παραγωγή είχαν το μεγαλύτερο αριθμό γόνιμων αδελφιών ανά τ.μ. σε συνδυασμό με ψηλό αριθμό σπόρων ανά στάχυ, ή βάρος χιλίων κόκκων, αντίστοιχα. Οι ποικιλίες διέφεραν μεταξύ τους ως προς την πλαστικότητα τους για τα περισσότερα χαρακτηριστικά. Σε ορισμένες περιπτώσεις, παρατηρήθηκαν σημαντικές συσχετίσεις μεταξύ των πλαστικοτήτων των ποικιλιών ή μεταξύ των πλαστικοτήτων και των μέσων όρων των ποικιλιών για διαφορετικά χαρακτηριστικά. Παρατηρήθηκαν στατιστικά σημαντικές διαφορές μεταξύ των ποικιλιών για τους Δείκτες Βλάστησης υπολογιζόμενους με ανάλυση φωτογραφίας προερχόμενη από μη επανδρωμένα σκάφη. Σε ορισμένες περιπτώσεις, η απόδοση συσχετιζόταν σημαντικά με τους δείκτες βλάστησης. Οι συσχετίσεις ήταν θετικές ή αρνητικές υποδεικνύοντας ότι οι περιβαλλοντικές συνθήκες κατά τη διάρκεια του γεμίσματος του σπόρου μπορούν να επηρεάσουν το πρόσημο των συσχετίσεων. Η υπολογιστική ικανότητα της απόδοσης των Δεικτών Βλάστησης επηρεάστηκε από τη διαφορετική φαινολογία των ποικιλιών. Οι συσχετίσεις της απόδοσης με τους Δείκτες Βλάστησης ήταν μεγαλύτερες όταν οι συσχετίσεις του χρόνου ξεσταχυάσματος με τους Δείκτες Βλάστησης ήταν μικρότερες ή μη σημαντικές. Τα αποτελέσματα αναδεικνύουν την δυνατότητα χρήσης των Δεικτών Βλάστησης, υπολογιζόμενοι από φωτογραφία προερχόμενη από μη επανδρωμένα σκάφη, για φαινοτύπηση σκληρού σιταριού σε Μεσογειακά περιβάλλοντα χαμηλής απόδοσης.Breeders need to intensify their efforts to meet the challenges arising from the growing population and from climate change. Genotypic characterization, phenotypic evaluation and exploitation of high throughput technologies will be crucial in order to achieve their goals. The main objectives of this doctoral dissertation were (1) to characterize a set of 55 durum wheat accessions, including modern varieties from different breeding programs and landraces originated from Cyprus and other Mediterranean areas using microsatellites, (2) to evaluate a subset of twenty modern varieties for grain yield and other important agronomic traits under diverse climatic conditions, and (3) to evaluate the usefulness of high throughput, remote sensing techniques for plant phenotyping under a water limited and heat stressed environment. High genetic diversity was detected. Landraces formed distinct groups and depicted higher genetic variability than modern varieties reinforcing their potential use to plant breeding. The highest genetic variability was observed in Cypriot landraces suggesting the existence of unique genetic diversity within this genepool. High genetic diversity was also detected in Cypriot landrace ''Kyperounda''. The genetic diversity was higher in accessions conserved as sublines. The genetic differentiation between ''Kyprerounda'' accessions and the different clustering of landrace accessions conserved under the same name signifies that passport data is not a reliable method to eliminate duplicates in genebanks. Phenotypic evaluation revealed the existence of genetic diversity for all the traits, however, for most of them the highest percentage of variance was explained by the environmental effect. In most cases, number of seeds per m2 was significantly correlated with grain yield and the correlations were stronger in the low yielding environments. Number of seeds per spike was the trait consistently related with number of seeds per m2. Trait offs between yield components were recorded. Varieties had different yield formation strategies. The two highest yielding varieties had the highest number of fertile tillers per m2 combined with high number of seeds per spike or high kernel weight. The differences between varieties for plasticity were significant for yellow pigment content, protein content, gluten index, growing degree days to heading, thousand kernel weight and plant height. In some cases, significant correlations were found between plasticities and between plasticities and the traits per se. Statistically significant differences between varieties were observed for Spectral Vegetation Indices derived by Unmanned Aerial Vehicle imagery. Grain yield was significantly correlated with SVIs, when recorded at early reproductive stages. Both positive and negative correlations were observed indicating that the environmental conditions during grain filling can affect the sign of the correlations. The predictive ability of SVIs was affected by plant phenology. Correlations of grain yield with SVIs were stronger as the correlations of SVIs with heading were weaker or not significant. These findings highlight the potential use of SVIs derived by UAV imagery for durum wheat phenotyping at low yielding Mediterranean conditions.Complete

Assessment of vegetation indices derived by UAV imagery for durum wheat phenotyping under a water limited and heat stressed Mediterranean environment

There is growing interest for using Spectral Vegetation Indices (SVI) derived by Unmanned Aerial Vehicle (UAV) imagery as a fast and cost-efficient tool for plant phenotyping. The development of such tools is of paramount importance to continue progress through plant breeding, especially in the Mediterranean basin, where climate change is expected to further increase yield uncertainty. In the present study, Normalized Difference Vegetation Index (NDVI), Simple Ratio (SR) and Green Normalized Difference Vegetation Index (GNDVI) derived from UAV imagery were calculated for two consecutive years in a set of twenty durum wheat varieties grown under a water limited and heat stressed environment. Statistically significant differences between genotypes were observed for SVIs. GNDVI explained more variability than NDVI and SR, when recorded at booting. GNDVI was significantly correlated with grain yield when recorded at booting and anthesis during the 1st and 2nd year, respectively, while NDVI was correlated to grain yield when recorded at booting, but only for the 1st year. These results suggest that GNDVI has a better discriminating efficiency and can be a better predictor of yield when recorded at early reproductive stages. The predictive ability of SVIs was affected by plant phenology. Correlations of grain yield with SVIs were stronger as the correlations of SVIs with heading were weaker or not significant. NDVIs recorded at the experimental site were significantly correlated with grain yield of the same set of genotypes grown in other environments. Both positive and negative correlations were observed indicating that the environmental conditions during grain filling can affect the sign of the correlations. These findings highlight the potential use of SVIs derived by UAV imagery for durum wheat phenotyping under low yielding Mediterranean conditions

Genetic variability in landraces populations and the risk to lose genetic variation. The example of landrace 'Kyperounda' and its implications for ex situ conservation

Genetic characterization enhances the development of rational conservation strategies and the utilization of germplasm to plant breeding programs. In the present study, 19 microsatellite markers were employed to evaluate the genetic diversity and the genetic affiliations across 20 Cypriot durum wheat (Triticum turgidum L. subsp. durum) landraces, 13 landraces from the broader Mediterranean basin and 22 modern varieties. Cluster analysis depicted a clear separation among modern varieties and landraces, regardless of their origin. Landraces presented the highest genetic variation (average discriminating power of 0.89) and a high number of private alleles (131) was detected; underlying the unique genetic mark-up of this genepool. AMOVA revealed that the highest variability was detected within the landraces originating from Cyprus and landraces from the broader Mediterranean basin. The Cypriot landrace 'Kyperounda' was selected for further evaluation of its' intra-genetic variation and it was determined that genetic diversity was higher in accessions conserved as sublines (He 0.643-0.731) than bulks (He 0.384-0.469). Bayesian analysis revealed substantial admixture within 'Kyperounda' accessions, depicted also by Principal Coordinate Analysis. The findings of the current manuscript emphasize that high intra-genetic diversity is retained when landraces are conserved as sublines in ex situ collections, while landraces that are conserved as bulks have a higher risk of bottleneck. Hence, a more exhausting diversity evaluation is needed in order to fully utilize landraces in breeding schemes and to prevent the loss of genetic variation

Investigating Stability Parameters for Agronomic and Quality Traits of Durum Wheat Grown under Mediterranean Conditions

Durum wheat in the Mediterranean grows under rainfed conditions, where unpredictable climatic conditions result in substantial variation in grain yield and quality. Climate change intensifies Genotype × Environment interactions and urges breeders to escalate their efforts to breed cultivars combining high performance and stability. The current study aimed to appraise the relations between twelve stability parameters derived by different statistical models for yield, yield-related and quality traits of durum wheat grown under Mediterranean conditions. Stability parameters were estimated in two experiments of twenty and sixteen cultivars, respectively. The parameters were categorized into three groups. Group A included Additive Main Effect and Multiplicative Interaction (AMMI)-derived parameters (ASV and AWAI), Wrickle’s ecovalence (Wi), Shukla’s stability variance (σ2), and the nonparametric parameters Si(1) and Si(2). Group B included regression parameters (bi, Bi_A), Coefficient of Variance (CV), and Superiority measure (Pi). Group C encompassed deviation from regression parameters (s2di-DJi) when the heterogeneity of the slope was significant. Correlations between stability parameters for different traits and the between stability parameters and the traits per se were modest. Stability parameters of Group B had higher repeatability for grain yield. The results of the present study contribute to the adjustment of durum wheat breeding strategies

Investigating Stability Parameters for Agronomic and Quality Traits of Durum Wheat Grown under Mediterranean Conditions

Durum wheat in the Mediterranean grows under rainfed conditions, where unpredictable climatic conditions result in substantial variation in grain yield and quality. Climate change intensifies Genotype × Environment interactions and urges breeders to escalate their efforts to breed cultivars combining high performance and stability. The current study aimed to appraise the relations between twelve stability parameters derived by different statistical models for yield, yield-related and quality traits of durum wheat grown under Mediterranean conditions. Stability parameters were estimated in two experiments of twenty and sixteen cultivars, respectively. The parameters were categorized into three groups. Group A included Additive Main Effect and Multiplicative Interaction (AMMI)-derived parameters (ASV and AWAI), Wrickle’s ecovalence (Wi), Shukla’s stability variance (σ2), and the nonparametric parameters Si(1) and Si(2). Group B included regression parameters (bi, Bi_A), Coefficient of Variance (CV), and Superiority measure (Pi). Group C encompassed deviation from regression parameters (s2di-DJi) when the heterogeneity of the slope was significant. Correlations between stability parameters for different traits and the between stability parameters and the traits per se were modest. Stability parameters of Group B had higher repeatability for grain yield. The results of the present study contribute to the adjustment of durum wheat breeding strategies

Genetic diversity of Avena ventricosa populations along an ecogeographical transect in Cyprus is correlated to environmental variables

Avena ventricosa Balansa ex Coss. is considered the C-genome donor of the cultivated hexaploid oat and is a `priority' species for conservation, since it has limited geographic distribution and the only recorded populations in Europe are present in Cyprus. The current study attempts to characterize the genetic structure and fragmentation of the species via the application of genotypic markers. It was revealed that the genetic variety was mainly allocated among the populations collected, since clustering obtained was according to the geographic origin of the samples and the habitat. Species distribution modeling showed that the most important climatic variable defining A. ventricosa distribution is the mean diurnal temperature. Furthermore, significant association of the genetic structure to environmental variables was detected; overall, a negative association to precipitation was confirmed, while significant correlations of genetic structure and the temperature at the time of anthesis and germination were established. The safeguarding of this valuable genetic resource is discussed