Response of Contrasting Cocksfoot Varieties to Summer Moisture Availability in a Mediterranean Environment

The responsiveness to water availability in summer and the effect of summer drought were assessed in a Mediterranean environment on both temperate and Mediterranean cocksfoot (Dactylis glomerata L.) materials. Three consecutive evaluation phases were contemplated: i) under rainfed conditions from autumn to spring; ii) under contrasting moisture conditions in the following summer; and iii) under rainfed conditions in the subsequent autumn-spring season to assess the effect of the previous summer treatments. The ability to become summer dormant under conducive conditions, such as in Mediterranean germplasm, proved a plant pre-requisite for survival under drought. All the “summer-active”, temperate varieties did not survive drought stress. Mediterranean materials showed a facultative dormancy behaviour in that they responded to moisture availability in summer. There was evidence that selection for such responsiveness was effective, as shown by a variety selected from Mediterranean germplasm also considering this criterion. Forcing summer growth by preventing dormancy had little detrimental effect on subsequent autumn recovery of Mediterranean improved varieties but more evidence is required on this aspect

Broadening and exploiting the genetic base of white lupin

White lupin is a European crop with a long history of domestication and high potential interest for high-protein food or feedstuff. This report aims to summarize the research steps that were undertaken to (i) verify the extent of genetic diversity exploited by modern breeding, (ii) identify elite bitter-seed landraces and sweet-seed germplasm aimed to broaden the genetic base for European breeding, (iii) assess the genetic variation for tolerance to key abiotic stresses in the germplasm of the novel genetic base, and (iv) verify the potential of genomic models based on genotyping-bysequencing (GBS) SNP data to select simultaneously and cost-efficiently for some complex traits. Molecular diversity patterns of 83 landraces from nine major historical cropping regions and 15 commercial varieties confirmed that modern plant breeding exploited only a modest part of the crop genetic variation. Germplasm evaluation experiments for adaptation to severe drought or calcareous soil revealed substantial genetic variation (Annicchiarico and Thami-Alami, 2012; Annicchiarico et al., 2018), which, along with other information, was exploited to identify four elite landraces and four elite, sweet-seed lines that acted as parents of a broadly-based population. Some 144 sweet-seed lines extracted from this population were evaluated for grain yield under severe drought in a managed environment of Italy and for adaptation to moderately calcareous soil in a spring-sown environment of the Netherlands and an autumn-sown environment of Greece. We report on the observed line variation for these traits, and on the construction of genomic selection models and their ability to predict the line adaptation to drought or lime soil based on cross validations. Genome-enabled models may be used also to select for tolerance to anthracnose and the sweet-seed trait

Floral advertisement scent in a changing plant-pollinators market

Plant-pollinator systems may be considered as biological markets in which pollinators choose between different flowers that advertise their nectar/pollen rewards. Although expected to play a major role in structuring plant-pollinator interactions, community-wide patterns of flower scent signals remain largely unexplored. Here we show for the first time that scent advertisement is higher in plant species that bloom early in the flowering period when pollinators are scarce relative to flowers than in species blooming later in the season when there is a surplus of pollinators relative to flowers. We also show that less abundant flowering species that may compete with dominant species for pollinator visitation early in the flowering period emit much higher proportions of the generalist attractant β-ocimene. Overall, we provide a first community-wide description of the key role of seasonal dynamics of plant-specific flower scent emissions, and reveal the coexistence of contrasting plant signaling strategies in a plant-pollinator market

Genetic resources and selection methods for drought and salinity resistance in durum wheat

SIGLEAvailable from British Library Document Supply Centre- DSC:DX179827 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Contribution of some agronomic traits to durum wheat performance in a dry Mediterranean region of Northern Syria

The study assessed the possible role of some agronomic traits in an integrated breeding approach to select durum wheats for a dry Mediterranean region in Northern Syria. Sixty-three entries of various origins, previously tested for adaptation to the target region, were grown at 2 locations during 2 seasons sharply contrasting for rainfall amount and distribution, and definable on the whole as "favorable" and "unfavorable" for the crop in the area. While heading and maturity time and kernel number/spike always correlated with grain yield, other traits correlated either in the wetter or in the drier season. The capability of each trait to identify materials with high and stable yield across the contrasting seasons was assessed by discriminant analysis. Early heading and high kernel number/spike were consistent features of these materials. However, the contribution of these traits to genotype discrimination proved rather limited when combined with grain yield information. Multivariate comparison among the best genotypes showed that similar yield responses could be attained by genotypes with very differing architectures of favorable traits.Contribution de quelques caractères agronomiques au rendement du blé dur dans une région méditerranéenne sèche du Nord de la Syrie. L'étude a examiné le rôle potentiel que quelques caractères agronomiques peuvent jouer dans la sélection de blés durs pour une région méditerranéenne du Nord de la Syrie. Soixante-trois génotypes d'origines différentes, dont l'adaptation à la région donnée avait déjà été vérifiée, ont été comparés en 2 localités pendant 2 saisons très contrastées quant à leur niveau et distribution de précipitation et pouvant être définies dans l'ensemble comme «favorable» et «défavorable» pour la culture dans la région. Précocité d'épiaison et nombre de grains par épi ont toujours été corrélés avec le rendement, tandis que d'autres caractères ont été corrélés au rendement soit dans le cas de l'année humide, soit dans le cas de l'année sèche. La capacité des caractères à identifier les génotypes à rendement haut et stable au cours des 2 années a été établie par analyse discriminante. Ces génotypes ont toujours été caractérisés par un certain niveau de précocité et par un nombre élevé de grains par épi. Cependant, la contribution de ces caractères à la discrimination des génotypes s'est révélée plutôt limitée lorsque leur information a été combinée à celle donnée par le rendement. La comparaison multivariée parmi les meilleurs génotypes a montré que des performances similaires peuvent être atteintes par des génotypes avec des combinaisons très variées de caractères favorables

Morpho-physiological and adaptive variation of Italian germplasm of sulla (Hedysarum coronarium L.)

Sulla is a biennial forage legume native to the central-western Mediterranean Basin and has increasing interest for regions with Mediterranean-climate. The Italian germplasm is a reservoir of variation for important agronomic traits. This study aimed to support breeding programs by investigating patterns of agronomic, adaptive and morpho-physiological variation among ecotypes collected from the three main Italian regions of species cultivation: central Italy, and the two islands of Sicily and Sardinia. Forage yield and morpho-physiological traits were evaluated at a site with Mediterranean climate in Sicily. Forage yield and cold tolerance in a cold-prone site of northern Italy were also assessed, to locate useful germplasm for widening crop resilience and climatic adaptability. Collection regions, and ecotypes within regions, differed for total forage yield and final plant survival, but their responses were subjected to interactions with test location. Specific adaptation dominated the adaptive responses of ecotypes and elite commercial varieties. Ecotype adaptation to cold winter was associated with latitude and, more specifically, the extent of cold stress in collecting sites. The ecotype collection region had a bearing also on morpho-physiological characteristics. A few ecotypes from central Italy performed outstandingly with respect to elite varieties, displaying wide adaptation across cold-prone and drought-prone environments