Characterization of high-molecular-weight (HMW) glutenins is an important criterion for identifying genotypes with good bread-making quality. In synthetic hexaploids (SHs), the D-genome encodes several allelic variants of HMW glutenins that require proper identification prior to their utilization for bread wheat (BW) improvement. In this study, SHs with promising agronomic features were characterized for HMW glutenin composition. Seven different allelic variants were observed at the Glu-Dt1 locus, three of which (1Dx1.5+1Dy10, 1Dx1.5+1Dy12.2 and 1Dx2.1+1Dy10) have not been previously reported in existing BW germplasm. The results also showed a variety of D-genome-encoded subunits along with superior glutenin alleles in the B-genome (1Bx7+1By8, 1Bx6+1By8 and 1Bx13+1By16). About 63% of these SHs encoded favourable allelic variants of HMW glutenins, which make them a good choice for improvement in wheat bread making. Glu-Dt1 encoded favourable allelic variants (1Dx5+1Dy10 and 1Dx1.5+1Dy10) that are frequently observed in SHs can be easily incorporated into BW through recombination breeding.

The objective of this study was to investigate the effect of one cycle of seed regeneration on the conservation of genetic diversity in five Italian ryegrass landraces (Lolium multiflorum Lam.). Regeneration took place outdoors, in a sheltered site surrounded by tall Galician wheat, 20 m from the nearest source of alien pollen. A balanced mixture of seed (the same weight of seed per plant) was made from 90–100 plants harvested within each population. The conservation of allele frequencies was assessed by starch gel electrophoresis. Five enzyme systems from 78–153 plants per population were examined on slices of a single histidine–citrate starch gel. Each regenerated population differed from its original landrace in at least one of the five loci. The mean heterozygosity per locus was 0.45 for original and regenerated populations, and the mean number of alleles per locus was 3.7 and 3.6 for original and regenerated populations, respectively. There was no loss of common alleles (frequency >0.05) in the five regenerated populations compared with the original populations. Only three rare alleles (frequency < 0.05) were lost (e.g. alleles phosphoglucose isomerase (PGI)-2a, PGI-2c* and shikimate dehydrogenase (SDH)-1d in Padrón, Pravia and Luarca, respectively). No regeneration effect (P>0.05) was observed in the six agromorphological characters. However, a significant landrace effect was observed (P < 0.05) in the five agromorphological traits and the regenerated landraces deviated from the original landraces in 20% of direct comparisons. The results suggest that the method of regeneration used was not very suitable for maintaining the genetic integrity of the original landraces.

Cryopreservation using an aluminium cryo-plate was successfully applied to in vitro-grown strawberry (Fragaria × ananassa Duch.) shoot tips. The shoots were cold-hardened at 5°C for 3 weeks with an 8-h photoperiod. The shoot tips (1.5–2.0 mm × 0.5–1.0 mm) were dissected from the shoot and pre-cultured at 5°C for 2 d on Murashige and Skoog medium containing 2 M glycerol and 0.3 M sucrose. The pre-cultured shoot tips were placed on the aluminium cryo-plate containing ten wells embedded in alginate gel. Osmoprotection was performed by immersing the cryo-plates in a loading solution (2 M glycerol and 0.8 M sucrose) for 30 min at 25°C. Dehydration was performed by immersing the cryo-plates in plant vitrification solution 2 for 50 min at 25°C. Then, the cryo-plate with shoot tips was transferred into an uncapped cryotube that was held on a cryo-cane and directly immersed into liquid nitrogen (LN). After storage in LN, shoot tips attached to the cryo-plate were directly immersed into 2 ml of a 1 M sucrose solution for regeneration. Using this procedure, the average regrowth level of vitrified shoot tips of 15 strawberry cultivars reached 81%. This new method has many advantages and will facilitate the cryostorage of strawberry germplasm.

Biotechnological techniques comprise useful tools for the conservation of endangered plant genetic resources. In the present work, polymorphism and usefulness of amplified fragment length polymorphism (AFLP) markers in assessing the genetic diversity in populations of Billbergia zebrina were investigated in nodular cultures and adult plants of the species. AFLP markers revealed moderate-to-high genetic diversity based on the estimations of Nei's gene diversity (mean He = 0.28), Shannon index of diversity (mean HS = 0.48) and the number of polymorphic fragments (mean of 56.17 polymorphic fragments over six primer pairs). In comparison to published studies of population genetics performed in other bromeliad species, the present study suggests that natural populations of B. zebrina likely maintain high levels of genetic diversity, an important feature towards conservation of plant genetic resources. The results obtained reveal that AFLP markers comprise a powerful tool in order to assess the levels of genetic diversity in natural populations of this endangered species. Integrating AFLP markers with in vitro propagation techniques is understood as an adequate strategy for conservation programmes of this species.

Global food security could be imperilled by the combined pressures from the effects of continually evolving climatic conditions, demographics and other socio-economic factors, the demands of the livestock, bioenergy and fibre industries for food-based substrates, the static or decreasing availability of natural resources for agriculture and the impracticality of increased use of economically and environmentally costly agricultural inputs. The optimal harnessing of plant genetic resources for food and agriculture (PGRFA) in manners that translate their repertoire of hidden potentials into significantly enhanced crop productivities has been severally identified as crucial to achieving the required considerably significant increases in food production. The scope of the problems and the plausible means for addressing them compel the devising of novel and more efficient ways for deploying PGRFA in need-based crop improvement programmes. We posit a continuum approach to the management of PGRFA which links seamlessly the effective conservation and access to PGRFA through their use in developing superior and resilient crop varieties to the provision of their high-quality seeds and planting materials to the growers. To achieve the mainstreaming of this paradigm, we propose the institutionalization of overarching national PGRFA strategies that prescribe result-oriented action plans spanning above three components of the management of PGRFA for a country's priority crops. We also describe the strategy as a means for identifying and assigning responsibilities to critical stakeholders and providing for the governance of all aspects of PGRFA activities over specific time frames. Steps to developing and adopting a national PGRFA strategy are also suggested.

The present study was undertaken to examine the population structure of the Solanum pimpinellifolium collection maintained by AVRDC – The World Vegetable Center – and to construct a core set of this collection. Out of the entire collection of 322 accessions, a diverse subset of 190 accessions was chosen representing 14 countries of origin. Data on 32 qualitative and 22 quantitative phenotypic traits (IPGRI–AVRDC descriptor traits) and 48 simple sequence repeat markers evenly distributed over the genome were used to develop the core set. A total of 377 alleles were detected with 7.85 alleles per locus, on average. Of these, 52 alleles at 28 loci were extremely rare-frequency alleles. The 190 accessions clustered into two main populations and an admixture group. Population I (PopI) included 99 accessions, 93 of which originated from Peru. Population II (PopII) contained 49 accessions, the majority of which originated from Ecuador and Mexico. The remaining 42 accessions were classified as admixture group. The two main populations were further subdivided into five subgroups. Values of Fst among the five sub-populations were significant (average pairwise Fst of 0.296), suggesting a real difference between these populations. A clear differentiation was observed among and within populations based on geography. Peruvian accessions were genetically more diverse than accessions originating in Ecuador and Mexico. Within the Peruvian group, a gradual increase in genetic diversity was observed from southern to northern Peru. The constructed core collection consists of 75 accessions representing 23.4% of AVRDC's entire S. pimpinellifolium collection and 39.5% of the subset used in this study. It is a well-balanced core with a good representation of the different populations (31 accessions from PopI, 22 from PopII and 22 from the Admixture group) and geographic origins (40 accessions from Peru, 17 from Ecuador, 14 from Mexico and four from other countries).

The stagnation of sorghum grain yields worldwide and utilization of inbred lines by public and private organizations (multinational seed companies) warrant the understanding of genetic diversity present in inbred lines. The objectives of this study were (1) to compare morphological and molecular diversity analysis and (2) to identify heterotic pools from the genotypes evaluated. Sixty-five rainy-season elite lines were evaluated during the 2006 and 2007 rainy seasons, and 15 post-rainy-season genotypes in the 2003 and 2004 post-rainy seasons for their distinctiveness, uniformity and stability at the Directorate of Sorghum Research, Hyderabad, India. Ninety-three genotypes (ten rainy-season B lines, 13 rainy-season R lines, 36 rainy-season varieties, seven rainy-season hybrids, ten forage varieties and 17 post-rainy-season genotypes) were evaluated using 48 simple sequence repeat (SSR) markers that are uniformly distributed over the sorghum genome. From the 93 genotypes analysed, 310 alleles were observed, with an average of 6.5 alleles per locus. A high level of polymorphism (mean 97%) was detected. A significant positive correlation (r = 0.463; P = 0.001) between genetic similarities and morphological similarities was obtained. Unlike previous reports, both methods clearly distinguished B lines, R lines, rainy-season varieties, post-rainy-season varieties and forage varieties. Forage and post-rainy-season varieties present a higher diversity of 60%. This could be because the post-rainy-season varieties are developed from local landraces and forage genotypes from crosses such as Sorghum bicolor × Sudan grass. Herein, we further discuss the grouping of elite genotypes into different heterotic pools.

The ICRISAT genebank, Patancheru, India holds 22,211 pearl millet germplasm accessions from 50 countries, including 19,063 landraces. Among these, 15,904 landraces that were geo-referenced are either thermo-sensitive (52.5%), or photoperiod-sensitive (45.6%), or insensitive to both temperature and photoperiod (2%). Latitude ranges of 10–15°N with 39.6% and 15–20°S with 13.1% of total accessions are the important regions for pearl millet germplasm. A study on climate data of the germplasm collection sites revealed that most accessions from latitudes ranging from 10 to 20° on both sides of the equator were highly sensitive to longer photoperiod (>12.5 h) and/or lower temperature ( < 12°C). Accessions that originated in locations at higher latitudes (>20–35°) on both the hemispheres exhibited low sensitivity to both photoperiod and low temperature, as they were exposed to such climates during their evolution. The accessions that are insensitive to both photoperiod and temperature were few but they originated from locations spread across all latitudes, although the highest numbers were from mid-latitudes (15–20°) in both hemispheres. As germplasm accessions are sensitive to climatic variables such as temperature and photoperiod, recording of location-specific geo-reference data while collecting the germplasm, which can help to elucidate the sensitivity of accessions to temperature and photoperiod, is emphasized. Critical evaluation of photoperiod-sensitive accessions that are late flowering for forage production and the photoperiod-insensitive early-maturing accessions for grain production, multiple cropping and development of parental lines with synchronized flowering for the development of hybrids is suggested.

The purpose of the study was to support the selection process of the most valuable currant and gooseberry accessions cultivated in Northern Europe, in order to establish a decentralized core collection and, following the selection, to ensure sufficient genetic diversity in the selected collection. Molecular analyses of the material from nine project partners were run at seven different laboratories. The results were first analysed for each partner separately, and then combined to ensure sufficient genetic diversity in the core collection.

Red bean, also known as azuki bean [Vigna angularis (Willd.) Ohwi & Ohashi], belongs to a group of legumes (family Fabaceae). The name azuki is a transliteration of the native Japanese name from the Chinese word Shōzu, which means small bean. In Korea, it is known as pat. In total, 178 red bean accessions were taken to analyse the genetic diversity, population structure and gene flow using 39 polymorphic simple sequence repeat markers. A total of 431 alleles were detected, with an average of 11 alleles per locus, among the 178 tested red bean accessions. Forty-six specific alleles were identified with 20 loci. Locus CEDG090 had the highest number (n = 22) of alleles, whereas only two alleles were observed at loci CEDG144 and CEDC018. The proportion of different alleles for microsatellite loci was analysed using a microsatellite toolkit. In locus CEDG029, one allele was shared in all the three groups of varieties and species, and three alleles were shared between the wild ancestors and cultivated varieties, while in locus CEDG090, one allele was shared in all the three groups and 12 alleles were shared between the wild ancestors and cultivated varieties. Our findings describe the genetic relationships and population structure of the red bean in Korea and will be useful for designing effective breeding programmes and broadening the genetic base of commercial varieties. Moreover, the results demonstrate substantial gene flow from the red bean to nearby wild relatives in a given region.

The Southern Andes, especially the inter-Andean valleys of south Bolivia, is thought to be a probable point of domestication within the primary centre of diversity for Andean common beans (Phaseolus vulgaris L.). The national Phaseolus germplasm collection of Bolivia is maintained by the Pairumani Foundation and consists of 449 accessions where most of the accessions are of common bean but some are of related cultivated and wild species. The goal of this study was to determine the genetic diversity of this collection by sampling 174 accessions of P. vulgaris and an outgroup of eight Phaseolus augusti, two Phaseolus lunatus and one Phaseolus coccineus genotype. The genetic diversity and population structure were estimated using 29 microsatellite markers. High levels of polymorphism were found, with a total of 311 alleles identified and an average of 10.7 alleles per marker. Correspondence analysis and an unweighted pair group method with arithmetic mean-based dendrogram distinguished P. vulgaris from the other species of Phaseolus. Common bean accessions were separated into two groups: the first one including Andean controls and most accessions from high altitudes with morphological characteristics and growth habits typical of this gene pool; the second one including Mesoamerican controls and accessions from low altitudes. Inside the Andean gene pool, the wild accessions were diverse and separated from the weedy and cultivated accessions. Low geographical distances between collection sites (up to 100 km) were shown to be related to low genetic distances. These results are important for the conservation of common beans in the Southern Andes.