1,720,989 research outputs found
Triterpenoid glycosides from the leaves of two cultivars of Medicago polymorpha
No full textThe saponin composition of leaves from the Medicago polymorpha cultivars 'Santiago' and 'Anglona' belonging to the botanical varieties brevispina and vulgaris, respectively, was investigated by a combination of chromatographic, spectroscopic, and spectrometric techniques. Several compounds were detected and quantitated by HPLC analysis using the external standard method. Twelve triterpene saponins (1-12) were purified by reverse-phase chromatography and their structures elucidated by spectroscopic (1D and 2D NMR, ESI-MS/MS) and chemical methods. They were identified as glycosides of echinocystic acid, hederagenin, caulophyllogenin, bayogenin, and soyasapogenol B. Two of them (2, 10) were previously reported in M. polymorpha; five of them (4, 6, 7, 9, 12) were already identified in other Medicago species; and three of them (1, 8, 11) were found in other plant genera. The two saponins identified as 3-O-alpha-L-arabinopyranosyl-28-O-[beta-D-glucopyranosyl(1 -> 6)beta-D-glucopyranoside] echinocystic acid (3) and 3-O-alpha-L-arabinopyranosyl-28-O-beta-D-glucopyranoside echinocystic acid (5) are newly identified natural compounds. The presence of echinocystic acid is reported here for the first time in the genus Medicago. Saponins from the cultivar 'Anglona' were characterized by a higher amount of echinocystic acid glycosydes, whereas saponins from the cultivar 'Santiago' were characterized by a higher amount of hederagenin glycosydes
Farmer-participatory vs. conventional market-oriented breeding of inbred crops using phenotypic and genome-enabled approaches: A pea case study
No full textParticipatory plant breeding (PPB) has gained increasing importance in developing countries, but its value for market-oriented breeding programmes of countries with developed agriculture that are committed to pure line selection (as needed to comply with DUS requirements) is unknown. This study aimed to compare PPB vs. conventional plant breeding of pea (Pisum sativum L.) targeted to organic systems of Italy, exploring phenotypic and genome-enabled selection approaches. Priority values assigned on a 0–5 scale to 14 traits by 18 farmers from Northern and Central Italy and six breeders were used to define weights of farmer and breeder selection indexes. Farmers and breeders attributed outmost importance to a visual acceptability score assigned a few weeks before crop maturity on a 1–9 scale, followed in importance by grain yield and tolerance to lodging. However, breeders and farmers differed (P < 0.05) for trait importance in a few cases. Five phenotypic selection criteria (farmer selection index; breeder selection index; average of farmer and breeder selection indexes; grain yield; farmer acceptability score) were applied onto 306 lines evaluated in two researcher-managed experiments of Northern and Central Italy under organic crop management, selecting overall nine lines per criterion that were tested in four organically-managed environments of the same regions and one conventionally-managed site. The farmer selection index exhibited greater selection efficiency (+23% based on yield gains over elite commercial cultivars under organic farming) and farmer's acceptability of selected material than the breeder selection index. Breeding values based on the farmer selection index or the farmer acceptability score exhibited greater correlation with grain yields in independent environments than those from breeder selection criteria. Compared with grain yield-based selection, selection for the farmer acceptability score performed comparably in terms of yield gains, and somewhat better according to correlations of its breeding values with line grain yields in independent environments. The accuracy of genome-enabled predictions issued by a Bayesian Lasso model with 3443 SNP markers generated by genotyping-by-sequencing, estimated by averaging cross-environment correlations between predicted and observed values over two locations, was very high for the farmer acceptability score (rAc = 0.77), and high for grain yield (rAc = 0.59). Genomic selection for the farmer acceptability score ranked first in a preliminary comparison of eight genome-enabled or phenotypic selection criteria based on correlations of breeding values with grain yields in independent environments, suggesting its adoption for preliminary screening of genotype sets that are too numerous for field-based evaluation
Lucerne cultivar adaptation to Italian geographic areas is affected crucially by the selection environment and encourages the breeding for specific adaptation
No full textPlant breeding programmes frequently face the dilemma whether to breed for wide or specific adaptation. This is especially true for forage crop breeding, whose genetic resources may largely include landraces that are adapted to specific growing conditions. This study aimed to (1) investigate the extent and pattern of genotype × location (GL) interaction for biomass yield of recent lucerne cultivars across organically-managed sites of Northern and Central Italy and its relationship with cultivar selection environments, (2) provide an empirical assessment of yield gains derived from specific-adaptation and wide-adaptation breeding strategies, and (3) identify top-performing cultivars for different geographic regions. Cultivar adaptive responses, modelled by additive main effects and multiplicative interaction analysis, displayed wide GL interaction of cross-over type across test sites that reflected remarkably the geographic area and/or the growing conditions (particularly for extent of summer drought) of their selection environment. GL interaction patterns suggested three putative subregions to breed for specific adaptation, namely, Northern Italy north of the Po river, Northern Italy south of the Po river, and Central Italy. Growing specifically-adapted cultivars provided an estimated average advantage of 12.9% across subregions relative to the best-performing widely-adapted cultivar. Yield gains of recent top-performing material over an historical, widely-adapted cultivar indicated that selection for specific adaptation would provide 3.2-fold greater yield gain averaged across subregions, and 3.4-fold greater yield gain over the target region when weighting yield gains on the putative proportion of the target region of each subregion, compared with selection for wide adaptation
Morpho-physiological and adaptive variation of Italian germplasm of sulla (Hedysarum coronarium L.)
No full textSulla 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
Effect of three volatile compounds from lucerne flowers on their attractiveness towards pollinators
No full textIndagini sull’impiego di Apoidei solitari per l’impollinazione controllata di leguminose foraggere
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effects of plant architecture and drought stress level on lucerne forage quality
No full textBreeding for enhanced quality in lucerne (Medicago sativa) frequently involves selection for higher leaf-to-stem ratio, multifoliolate leaves or short-internode stems. Three populations selected for such alternative morphologies and a reference cultivar were evaluated for forage yield, leaf-to-stem ratio and protein and fibre concentrations in leaves, stems and whole plants. Four managed environments were obtained by combining two stress levels (moderate or nil) with two sowing times. The population selected for high leaf-to-stem ratio, as well as the short-internode population, had highest leaf-to-stem ratio (1.27) across six harvests in two non-stress environments. The latter population had higher stem protein (12.9%) and lower stem neutral-detergent fibre (NDF) concentration (58.7%) than other populations. The multifoliolate population had intermediate quality, showing low expression of the multifoliolate trait (14.0% across four environments), particularly under stress (10.5%). The autumn-sown, fully irrigated environment had, on average, highest dry-matter yield (4.19 t haâ1) and lowest leaf-to-stem ratio (0.74). Drought-stressed environments had lower plant NDF (â12.3% on average) and leaf protein (â9.7%), and higher stem protein (+8.6%) than fully irrigated environments. The results suggested that environmental effects might have greater impact on quality than genetic effects, even for a population set including material selected for quality-driven morphology
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