JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Applied Ecology. Summary 1. Changes in the seed bank, seedling emergence and plant density of the most common grass species, and all legume species, were monitored in a grassland in north Syria from October 1986 to May 1989. 2. The seed bank was greatest in May-June, following pasture maturity, then declined to its minimum in March-April. Losses of seeds during summer were mainly due to sheep grazing, while losses in winter and spring were mainly due to germination, although some seeds were eaten by soil fauna and some seeds died. The seed bank, particularly of the small-seeded species (Trifolium tomentosum and T. campestre) was greater under the high stocking rate than under the low stocking rate. 3. There was little seed carry-over of grasses from season to season (Avena spp. 5%, Heteranthelium piliferum 1%, Bromus spp. 0%), but seed carry-over was greater in legumes (Trifolium stellatum 27%, T. campestre 35%, and T. tomentosum 38%). Most seedlings emerged in the autumn, but emergence continued throughout the growing season. Plant density within each year reached a peak in January, declining as spring approached. 4. The ecological and agricultural importance of seed banks in native Mediterranean grasslands is discussed.

No abstract

Background A thorough verification of the ability of genomic selection (GS) to predict estimated breeding values for pea ( Pisum sativum L.) grain yield is pending. Prediction for different environments (inter-environment prediction) has key importance when breeding for target environments featuring high genotype × environment interaction (GEI). The interest of GS would increase if it could display acceptable prediction accuracies in different environments also for germplasm that was not used in model training (inter-population prediction). Results Some 306 genotypes belonging to three connected RIL populations derived from paired crosses between elite cultivars were genotyped through genotyping-by-sequencing and phenotyped for grain yield, onset of flowering, lodging susceptibility, seed weight and winter plant survival in three autumn-sown environments of northern or central Italy. The large GEI for grain yield and its pattern (implying larger variation across years than sites mainly due to year-to-year variability for low winter temperatures) encouraged the breeding for wide adaptation. Wider within-population than between-population variation was observed for nearly all traits, supporting GS application to many lines of relatively few elite RIL populations. Bayesian Lasso without structure imputation and 1% maximum genotype missing rate (including 6058 polymorphic SNP markers) was selected for GS modelling after assessing different GS models and data configurations. On average, inter-environment predictive ability using intra-population predictions reached 0.30 for yield, 0.65 for onset of flowering, 0.64 for seed weight, and 0.28 for lodging susceptibility. Using inter-population instead of intra-population predictions reduced the inter-environment predictive ability to 0.19 for grain yield, 0.40 for onset of flowering, 0.28 for seed weight, and 0.22 for lodging susceptibility. A comparison of GS vs phenotypic selection (PS) based on predicted genetic gains per unit time for same selection costs suggested greater efficiency of GS for all traits under various selection scenarios. For yield, the advantage in predicted efficiency of GS over PS was at least 80% using intra-population predictions and 20% using inter-population predictions. A genome-wide association study confirmed the highly polygenic control of most traits. Conclusions Genome-enabled predictions can increase the efficiency of pea line selection for wide adaptation to Italian environments relative to phenotypic selection. Electronic supplementary material The online version of this article (10.1186/s12864-019-5920-x) contains supplementary material, which is available to authorized users.

Three rates of phosphate (0, 25, and 60 kg/ha P 2 O 5 ) were applied to phosphorus-deficient native grassland at Tel Hadya, in northern Syria, and biomass productivity, botanical composition and number of legume seeds in the soil were monitored for five seasons (1984/85-1988/89). The experiment was grazed at low (0-8 sheep/ha per year) and high (1-7 sheep/ha per year) stocking rates from the second to the fourth seasons of the experiment; in the fifth season, the low and high stocking rates were increased to 11 and 2-3 sheep/ha per year, respectively. The experimental site was typical of native grassland within the cereal zone of west Asia, where cropping is not possible because of shallow, stony soils and steep slopes.The results showed that annual applications of phosphorus, even as low as 25 kg P 2 O 6 /ha, alleviated the deficiency in soil P and resulted in improved pasture production, even in dry years. Legume production showed the greatest response to P, increasing by 0-3-3 times the production of the control treatments. By the fifth season, legume seed mass had increased threefold and number of seeds sixfold in the P-treated plots, compared with the first season, while in the control plots there was little change. Rain-use efficiency on the P-treated plots was more than double that of the controls by the fourth and fifth seasons.Practical application of the results depends on whether (i) legumes are as frequent in native grasslands, as a whole, as they are at Tel Hadya, (ii) the P deficiency observed at Tel Hadya is widespread, and (iii) grazing of communally owned grasslands can be controlled. It is suggested that all three criteria will often be fulfilled and, therefore, that grassland productivity in west Asia could be substantially increased. Furthermore, the results suggest that above-ground cover and soil organic matter will also increase after P application, both of which will help to reduce soil erosion and thereby increase the sustainability of livestock production in west Asia.

In the last 50 years, intensive farming systems have been boosted by modern agricultural techniques and newly bred cultivars. The massive use of few and related cultivars has dramatically reduced the apple genetic diversity of local varieties, confined to marginal areas. In Central Italy a limited spread of intensive fruit orchards has made it possible to preserve much of the local genetic diversity, but at the same time the coexistence of both modern and ancient varieties has generated some confusion. The characterization and clarification of possible synonyms, homonyms, and/or labeling errors in old local genetic resources is an issue in the conservation and management of living collections. 175 accessions provided by 10 apple collections, mainly local varieties, some of unknown origin, and well-known modern and ancient varieties, were studied by using 19 SSRs, analyzed by STRUCTURE, Ward’s clustering and parentage analysis. We were able to identify 25 duplicates, 9 synonyms, and 9 homonyms. As many as 37 unknown accession were assigned to well known local or commercial varieties. Polyploids made up 20%. Some markers were found to be significantly correlated with morphological traits and the loci associated with the fruit over color were related to QTLs for resistance to biotic stresses, aroma compounds, stiffness, and acidity. In conclusion the gene pool of Central Italy seems to be rather consistent and highly differentiated compared with other European studies (FST = 0.147). The importance of safeguarding this diversity and the impact on the management of the germplasm living collection is discussed.

Native Bituminaria bituminosa (L.) Stirt. accessions from central and southern Italy were evaluated for chemical composition to assess their nutritional value as forages. The germplasm was evaluated subjectively ex situ for intensity of 'oil' smell and analysed for fibre fraction, crude protein and water-soluble carbohydrate contents as well as furanocoumarin (psoralen and angelicin) concentration. Total phenolics and their antioxidant activity were also evaluated. The quality parameters indicated this species as a good forage source, showing nutritive values similar to those of other wild legume species. Psoralen and angelicin contents ranged from 2.8 to 5.4 and from 2.3 to 4.7 mg g −1 dry weight respectively, while total phenolic concentrations were between 11.2 and 13.5 mg g −1 dry weight. Correlations among forage quality parameters, chemical components and climatic features at sites of origin were also assessed.

Pear is one of the oldest fruit tree crops and the third most important temperate fruit species. Its domestication took place independently in the Far East (China) and in the Caucasus region. While the origin of Eastern Asian cultivars is clear, that of European cultivars is still in doubt. Italy has a wealth of local varieties and genetic resources safeguarded by several public and private collections to face the erosion caused by the introduction of improved varieties in specialized orchards. The objectives of the present study were: (i) to characterize the existing germplasm through nuclear (SSR) and (ii) to clarify the genetic divergence between local and cultivated populations through chloroplast DNA (cpDNA) markers in order to provide insights into phylogenetic relationships of Pyrus spp. For this reason, 95 entries from five different germplasm collections, including nine European, Mediterranean and Eastern Asian species, were analyzed, and the intergenic accD-psaI sequences were compared to the worldwide distributed dataset encompassing a total of 298 sequences from 26 different Pyrus species. The nine nuclear SSRs were able to identify a total of 179 alleles, with a loci polymorphism P = 0.89. Most of the variation (97%) was found within groups. Five accessions from different sources were confirmed to be the same. Eight out of 20 accessions of unknown origin were identified, and six synonyms were detected. Locus NH030a was found to be monomorphic in all the cultivated accessions and in reference species interfertile with P. communis, leading to hypothesize selection pressures for adaptation to cultivation. The cpDNA sequences of the 95 accessions were represented by 14 haplotypes, six of which (derived from P. communis, P. cossonii and P. ussuriensis) are recorded here for the first time and may suggest the ancient origin of some local varieties. The network analysis of the 298 cpDNA sequences allowed two different haplogroups, Eastern and Western Eurasia, to be defined, supporting recent views of a clear division between Occidental and Oriental species. By combining the results from nuclear and uniparental markers, it was possible to better define many unknown accessions.

SUMMARYMeasurements were made of the recovery and germination rates of seed of eight species of annual medic (Medicago spp.) and three of clover (Trifolium spp.) after ingestion by sheep. Recovery of medic seed was measured as the number of seeds collected from faeces after feeding, in addition to a basal diet, either (i) 200 g of pods at a single meal, or (ii) a quantity of pods estimated to contain 30000 seeds at a single meal or (iii) 200 g of pods daily for 21 days. Only the first method was applied to the clovers.There were large differences (P < 0·001) in seed recovery between species, from < 2% to nearly 20% in medics, and up to 59% in T. campestre, which has low single-seed mass. Although there was a curvilinear decrease in seed recovery as single-seed mass increased (r2 = 0·80), the high recovery of M. rotata, a fairly large-seeded species, suggests that there are important differences between species, irrespective of seed size.When 200 g of medic pods was offered to sheep at a single meal, mean seed recovery was slightly lower than when 200 g of medic pods was offered daily for 21 days. Seed recovery of medics was much higher (P < 0·001) when 30000 seeds were offered at one meal.Germination rate before ingestion was 1·9–6·5% (P < 0·001) for hard-seeded medics and 2·7–9·7% (P < 0·001) for clovers with low single-seed mass; passage through the digestive tract increased (P < 0·001) germination rate in both medics and clovers.