Faba bean is cultivated worldwide and widely used in Mediterranean countries, Asia and Europe. However, only a few faba bean breeders are active in cultivar development. As a result, a limited number of varieties are available for growers. Plant genetic resources or germplasm are fundamental sources for plant breeding, and the assessment of the genetic diversity among germplasm accessions is useful to facilitate more efficient use of plant genetic resources. A mini-core collection of faba bean germplasm (178 landraces and four cultivars), from diverse geographic regions of Turkey, was assessed for agro-morphological performance and some quality traits. There were substantial variations for the investigated morphological and quality characteristics. The analysis of variance revealed that the differences among 182 accessions were significant for all the studied characters. Some accessions showed very good agronomic performance for some traits. Positive and negative correlations existed among different morphological and agronomic traits. Landraces have been classified into four different groups using a cluster analysis. These results suggest that an a priori classification of accessions according to the growing area does not strictly correspond to phenotypic grouping. From the spatial distribution of landraces, however, it has been possible to identify ‘superior’ accessions of some traits. These findings indicate a number of useful traits in the gene pools and a wide range of phenotypic variation that provides a good source of diversity for use in modern faba bean breeding programmes.

Knowledge about genetic diversity among Brassica napus cultivars developed for many growing regions and their possible use as potential inbred lines for hybrid seed production is limited. We studied the genetic diversity and relationships among B. napus accessions using Sequence Related Amplified Polymorphism (SRAP) markers, which preferentially amplify open reading frames. A total of 60 spring-type B. napus accessions were screened using 20 SRAP primers, which revealed 162 polymorphic fragments with an average of eight markers per primer combination. Genetic similarity estimates ranged from 40 to 100, which indicated sufficient diversity among the accessions. The majority of the accessions were uniquely identified by the markers with the exception of near-isogenic inbred lines. Cluster analysis displayed five major groups. The first major cluster comprised 23 accessions mostly of Australian origin, whereas the second cluster included 13 accessions mostly of Canadian origin. The accessions in the first and second clusters were identified as maintainers of cytoplasmic male sterility. The two restorer lines R-111 and R-101 along with their corresponding backcross progeny constituted the third cluster. Scandinavian cultivars made the fourth separate cluster. One cultivar Salam and its respective inbred line were the most divergent lines. Variations in the number of markers between open-pollinated cultivars and their respective selfed inbred lines were also observed. The clustering pattern mostly supported their respective pedigree and characteristic traits. Genetic diversity in genetically distinct groups in the tested maintainer and restorer lines can be exploited for hybrid development in B. napus.

Niger harbours a wealth of diversity of Africa's rice (Oryza glaberrima) and its related wild species. We therefore engaged in a collecting mission of rice species across growing regions and agrosystems in Niger. A total of 270 rice accessions were assembled, including 177 Asian rice (O. sativa) cultivars, 67 African rice landraces (O.glaberrima), 25 O. barthii and one O.longistaminata. We found most accessions (80.7%) along the Niger River and its tributary the Dallol Maouri. Many of the accessions, except those belonging to the wild O. barthii initially found around the Lake Chad region, were also collected along the Niger River. Drought, insects, birds, rice yellow mottle virus and bacterial blight were noted as major constraints on rice production. Accession naming by farmers was consistent within regions but seldom across regions. Based on the recorded agro-morphological traits, the germplasm was classified into three clusters: (1) O. longistaminata with floating African landraces and late-maturing floating Asian rice; (2) lowland O.barthii and African landraces; (3) a mixture of irrigated Asian rice with lowland accessions of both cultivated species. The phenotypic variability of the germplasm collection, as measured by the Shannon–Weaver diversity index, was relatively high (H′ = 0.69), with accessions in the irrigated agrosystem being less diverse than those in the traditional agrosystems. There was no significant difference in the magnitude of diversity between the main eco-geographical zones and between the clusters. However, some traits contributing the most to this diversity were different. This study suggested a substantial germplasm exchange between regions in Niger.

Pearl millet (Pennisetum glaucum (L.) R. Br.) is an important staple cereal cultivated in the arid and semi-arid tropics of Asia and Africa, regions severely affected by malnutrition. Knowledge about the extent of genetic variability and patterns of agro-morphological variation in local germplasm from a target region is an important prerequisite for efficient crop improvement. To assess the potential of Sudanese pearl millet landraces as sources of desirable traits for pearl millet improvement including biofortification, a total of 225 accessions were evaluated in Sudan at three locations for agro-morphological traits and at one location for grain mineral nutrient contents (Fe, Zn, Ca, P, K, Mg, Mn, S, Na, Cu and β-carotene). Genetic variation was highly significant, but relatively limited for some agro-morphological traits (62–78 d to flowering, 119–188 cm plant height and 16–34 cm panicle length), pointing to the potential usefulness of a targeted diversification for these traits. Self-pollinated grain micronutrient contents showed a wide variation: 19.7–86.4 mg/kg for Fe and 13.5–82.4 mg/kg for Zn. Significant and positive correlations among most of the nutritional traits were observed; therefore, enhancement of the concentrations of some nutrients will lead to the improvement of other related nutrients. No significant associations were observed between the nutritional and agro-morphological traits, indicating good prospects for simultaneous improvement of both trait categories. No clear patterns of geographic differentiation for specific traits were detected for the Sudanese pearl millet. Nutrient-rich accessions were identified and those with acceptable agro-morphological traits are encouraging materials for future pearl millet biofortification programmes in Sudan.

Despite Capsicum's importance in the Caribbean, comprehensive diversity studies of this species in the region are limited, especially regarding its morphological variation. This study evaluated 37 traits (seedling, vegetative and reproductive) in 201 accessions among four Capsicum species. Multivariate analyses revealed that (i) 54% of the quantitative (seedling and fruit) variation and (ii) 64% of the qualitative (floral and fruit) variation were explained by the first two components. The three main clusters identified did not immediately highlight geographic and species-specific separation. However, significance testing revealed some separation based on geographic subgroups and species assignment. Most Southern Caribbean accessions were considerably similar to each other (if not identical in some cases), thus providing opportunity to identify and remove duplicates from the collection. These Southern Caribbean accessions shared their greatest similarity with Upper Amazon accessions, and least similarity with Lower Amazon accessions, suggesting movement of material primarily from the Upper Amazon into the Southern Caribbean Basin. The dominant differentiating traits displayed in these Southern Caribbean accessions are probably due to strong active selection for certain morphotypes and not to founder effects. Upper and Lower Amazon accessions were largely well differentiated from each other, highlighting key underlying genetic differences between these two populations and possible ongoing barriers to germplasm exchange. Central American, Greater Antilles/Bahamas and Guiana Shield accessions shared similarities with both the Upper and Lower Amazon populations, hinting at probable introductions from both Amazon regions. Collectively, this provides essential baseline information on the morphological (and underlying genetic) relationships among these accessions to guide future characterisation and evaluation efforts on this collection.

Nagaland is one of the eight states in the north-eastern region of India, where a considerable diversity exists in cultivated rice. Recent exploration in this tribal-dominated state has resulted in a collection of 130 rice accessions growing under diverse agroecological conditions. The agromorphological characterization data of 124 rice landraces revealed a significant variability in plant architecture and grain morphological and quality traits. Multivariate analyses including principal component analysis (PCA) and cluster analysis were performed to assess the patterns of morphological variation. The PCA extracted 12 components, which explained 75.4% of the total variation for 38 quantitative and qualitative traits. The cluster analysis grouped 124 rice landraces into five clusters, and the number of landraces in each cluster ranged from 1 to 59. The correlations among the traits are discussed, which will be useful in considering traits for genetic improvement in grain yield and quality. The landraces have been conserved in the national genebank for further utilization.

Yellow endosperm maize can be used to reduce vitamin A deficiency among many pre-school children and women of reproductive age in sub-Saharan Africa. Assessment of the genetic diversity of tropical yellow endosperm maize inbred lines will have genetic gains in breeding design to develop lines with an enhanced level of provitamin A. We screened 122 tropical yellow endosperm maize inbred lines with 62 simple sequence repeat (SSR) markers and 51 SSR loci were polymorphic. We detected 190 alleles with an average of 3.72 alleles per locus, and polymorphic information content values among the inbred lines varied from 0.12 to 0.74 with an average of 0.43. Genetic distance (GD) values among all the pairs of the 122 inbred lines varied from 0.02 to 0.61 with an average of 0.41 for the SSR markers. The inbred lines exhibited a substantial level of genetic diversity. Genetic diversity was also evaluated using carotenoid data. The Euclidean GDs varied from 1.00 to 9.97 with an average of 3.81 for the carotenoid data. Cluster and principal coordinate analyses revealed clear separation of maize inbred lines into SSR-based groupings and carotenoid-based groupings. Cluster based on SSR markers were predominantly consistent with known pedigree data of the inbred lines. The correlation using Mantel's test between carotenoid-based GD estimates and SSR marker-based GD estimates gave a low r value ( − 0.06). The grouping of lines will facilitate the selection of parental lines for making crosses to develop new lines with enhanced provitamin A content.

In order to investigate further the interest of using the Chilean gene pool in potato breeding programmes, the genetic diversity and population structure of a collection of Solanum tuberosum L. genotypes including 350 worldwide varieties or breeders' lines (referred to as the modern group) and 30 Chiloé Island landraces were examined using simple sequence repeat markers. The close genetic proximity of the Chiloé Island landraces to the modern group was confirmed using several structure analysis methods: principal coordinate analysis; hierarchical clustering analysis; analysis of molecular variance; Bayesian model-based clustering analysis. The latter analysis, in particular, revealed no clear genetic structure between the modern group and the Chiloé Island landraces. The Chiloé Island germplasm appears to represent an interesting gene pool that could be exploited in potato breeding programmes using an association mapping approach.

Triggered by the need to develop inter-seasonal, multi-cut cereal forage crops, this study aimed at the exploitation of phenotypic variations among the rich pearl millet (Pennisetum glaucum L.) collections in Sudan for possible utilization in forage-type breeding programmes. A total of 100 pearl millet accessions were used in three field trials grown in rainy, winter and summer seasons (2008–2009) at the Gezira Research Station Farm and the Gezira University Experimental Farm. Wide diversity and highly significant differences in the total dry forage yield, days to harvest, plant height, number of tillers/plant and leaf/stem ratio were found among the accessions. At an 80% morphological similarity level, the 100 accessions of pearl millet were clustered into four main groups. In the rainy and winter seasons, 71 and 56% of the accessions produced forage yield of more than 5 t/ha, respectively. In contrast, 77% of the accessions produced less than 5 t/ha in the summer season. Among the top-ranking 25 accessions, two accessions (HSD 2190 and HSD 2236) were common in dry matter yield in the three seasons, whereas 11 accessions were identified in at least two seasons. The presence of such common accessions in more than one season is encouraging for growing pearl millet as a multi-cut crop for a longer period. These results indicated the possibility of the development of forage-suited varieties of pearl millet directly through further evaluation of those common accessions or indirectly through a crop breeding programme.

The genebank at ICRISAT, Patancheru, India conserves a total of 19,063 pearl millet landraces from latitudes ranging from 33.00° in the Southern Hemisphere (SH) to 34.37° in the Northern Hemisphere (NH). In the present study, the NH was found to be the major region for growing pearl millet landraces (80.5%). More landraces were found at lower latitudes ( < 20°) in both hemispheres than at higher latitudes. The latitude range of 10°–15° in the NH and 15°–20° in the SH were found to be important source regions for the prevalence of pearl millet, with 39.6% and 13.1% in the world collection of landraces, respectively. Landraces from lower-latitude regions on either side of the equator varied widely for all traits. Landraces from the 5°–10°N latitude region flowered late and grew tall in the rainy and post-rainy seasons and produced more tillers. Landraces from the 10°–15°N latitude region produced few tillers and had long and thick panicles with larger seeds. Long-bristled bird-resistant landraces were considerable at latitudes of 10°–15°S and 20°–25°S. The minimum temperature at the collection sites was found to be one of the important factors for determining the patterns of the prevalence of pearl millet across the latitudes. Late-maturing, tall and high-tillering landraces from lower-latitude regions were better sources for fodder production. Early-maturing landraces producing long and thick panicles with large seeds from mid-latitude regions (15°–20°) in both hemispheres were useful for developing high-yielding cultivars. Using the latitudinal patterns of diversity in pearl millet landraces, missions may be launched to explore high-diversity, under-collected and threatened areas for the collection of materials of interest at latitudes of 15°–20°.

Seeds of wild and cultivated species of Luffa were studied to determine the variability in morphological (seed size, colour, seed-coat surface and 100-seed weight) and biochemical (oil and protein) characteristics. A total of 80 accessions of three cultivated species (71 accessions) and three wild species (9 accessions) of Luffa under the present investigation from diverse regions (12 states of five regions) of India showed variations in seed size, colour, seed-coat surface, 100-seed weight, and seed protein and oil contents both within the accessions of the same species and between different species. Significant variability in seed morphological traits was observed. Both seed oil and soluble seed protein contents were highest in some accessions of the cultivated species (25–27% oil and 8–10% protein, respectively, on a fresh seed weight basis). Using the 2D scatter plot diagram derived from the principal components analysis, the morphological and biochemical traits of the 80 Luffa accessions classified the wild species into one cluster (cluster I) and the cultivated species into a second major cluster (cluster II). The present investigation on the correlation between seed morphology and biochemical traits in the cultivated and wild species of Luffa can help in identifying the genotypes of Luffa species with valuable traits for further exploring the potential of this valuable crop as a source of edible oil, food and fodder in edible seed types or as a source of industrial oil/biodiesel in non-edible seed types. The protein-rich seed could be further explored to be utilized in the fortification of food products for value addition.

Sesame (Sesamum indicum L.) is one of the oldest oil crops and is widely cultivated in Asia and Africa. The aim of this study was to assess the genetic diversity, phylogenetic relationships and population structure of 277 sesame core collection accessions collected from 15 countries in four different continents. A total of 158 alleles were detected among the sesame accessions, with the number varying from 3 to 25 alleles per locus and an average of 11.3. Polymorphism information content values ranged from 0.34 to 0.84, with an average of 0.568. These values indicated a high genetic diversity at 14 loci both among and within the populations. Of these, 44 genotype-specific alleles were identified in 12 of the 14 polymorphic simple sequence repeat markers. The core collection preserved a much higher level of genetic variation. Therefore, 10.1% was selected as the best sampling percentage from the whole collection when constructing the core collection. The 277 core collection accessions formed four robust clusters in the unweighted pair group method and the arithmetic averages (UPGMA) dendrogram, although the clustering did not indicate any clear division among the sesame accessions based on their geographical locations. Similar patterns were obtained using model-based structure analysis and country-based dendrograms, as some accessions situated geographically far apart were grouped together in the same cluster. The results of these analyses will increase our understanding of the genotype-specific alleles, genetic diversity and population structure of core collections, and the information can be used for the development of a future breeding strategy to improve sesame yield.

Several Desmodium species are adapted to the environment of Griffin, Georgia, USA. The determination of flavonoid concentrations, oil content and fatty acid compositions of 25 Desmodium accessions representing five species (D. discolor Vogel, D. incanum (G.Mey.) DC., D. intortum (Mill.) Urb., D. sandwicense E. Mey. and D. tortuosum (Sw.) DC.) would add value to the members of the genus Desmodium for possible use as livestock health supplements. In this study, the seeds of these 25 accessions were evaluated for flavonoid concentrations, oil content and fatty acid compositions using high-performance liquid chromatography, nuclear magnetic resonance and gas chromatography, respectively. Several accessions exhibited significantly greater values for all the traits than the controls. The Desmodium accessions produced significantly greater concentrations of quercetin and kaempferol than the best control accession (D. incanum, PI 477072). However, all the Desmodium accessions produced significantly greater concentrations of isorhamnetin and luteolin than the control accessions. All the Desmodium accessions had greater linoleic (18:2) and behenic (22:0) acid content than a couple of D. incanum control accessions in 2010 and 2011. Significant correlations were observed between several traits. The concentration of quercetin was significantly correlated with that of kaempferol (r2= 0.69***); however, the concentration of quercetin exhibited a significantly negative correlation (r2= − 0.41*) with that of isorhamnetin. Oil content was significantly correlated with palmitic acid (r2= 0.61**), stearic acid (r2= 0.81***), linolenic acid (r2= 0.58**) and lignoceric acid (r2= 0.80***) content. This information will assist breeders and other scientists in developing superior cultivars with optimum levels of flavonoid concentrations, oil content and fatty acid compositions for many of these Desmodium species.

The secret art of silk culture along with mulberry seeds is presumed to have spread from China to other parts of the world including India through the famous Silk Road. In this study, we investigated a set of 36 important mulberry genotypes (designated as ‘breeders’ collection’) of historical importance that have been frequently used in Indian crop improvement programmes over the last five decades. This study is the first to employ a large number of microsatellite markers (140 screened; 70 used for profiling) to elucidate the diversity, structure and breeding history of mulberry. The cluster and STRUCTURE analysis corroborated with the known genetic relationships and origin. The groupings by STRUCTURE (k= 4) confirm parallel breeding efforts undertaken in the eastern, southern and northern regions of the country. The cultivar ‘Mysore Local’ shares a common parent with ‘Berhampore Local’, and this supports the historical records of its introduction from eastern India to the Kingdom of Mysore by the erstwhile ruler Tippu Sultan. The popular variety ‘Kanva-2’ shared a common male parent with the Japanese variety ‘Kousen’, supporting the contribution of exotic progenitors in Indian cultivars. The findings of this study will be useful in formulating new strategies for mulberry improvement and reveals the historical events of the introduction and spread of cultivated mulberry in the Indian subcontinent.

Ziziphus mauritiana Lam. is an important fruit crop of the Thar Desert of India. About 330 accessions and cultivars collected from various parts of India are currently being maintained at a farm in the Central Institute for Arid Horticulture. Utilization of such a large collection of germplasm for breeding and crop improvement is difficult. Therefore, in the present study, using a heuristic approach based on phenotypic characters, we identified 52 accessions that represented a core collection, with a coverage of 100% and a coincidence rate of 98.1%. No significant difference was observed with respect to either the Shannon–Weaver or the Nei diversity index for qualitative traits, mean values and ranges for quantitative traits or clustering patterns between the core and whole collections. The core collection represents the entire range of diversity with minimum redundancy and should be useful for the conservation and utilization of Z. mauritiana germplasm.

A global survey was conducted among a wide range of stakeholders to gain insight into the state of on-farm management (OFM) as a strategy for enhancing the conservation and sustainable use of plant genetic resources for food and agriculture (PGRFA). The results show that OFM is not considered a priority in national PGRFA programmes (NPGRPs), and that OFM practitioners and their organizations are not always aware of, or involved in, NPGRPs. The survey also highlighted the lack of awareness, understanding and collaboration between OFM practitioners and the managers and policy-makers associated with NPGRPs. The outcome of the analysis supports a hypothesis that OFM is, to a large extent, supported by stakeholders who are not directly engaged in the conservation and use of PGRFA, and therefore not associated with NPGRPs. This should be taken into consideration when seeking to improve the performance and impact of national programmes, and their commitment to safeguard PGRFA and contribute to food security, poverty alleviation and sustainable agriculture.

The Drake Passage arises as a likely route for gene flow into Antarctica, as it is the shortest path between this continent and the rest of the world. Despite this, long-distance dispersion into Antarctica could be particularly complex for terrestrial biota. To compare the levels of genetic diversity between Antarctic and South American populations of the Antarctic pearlwort, Colobanthus quitensis, we conducted the first estimation of genetic diversity in this species using amplified fragment length polymorphism. Four populations across the Drake Passage were selected and their genetic composition was characterized. Differences among the levels of genetic diversity were found between the populations analysed as well as between their allelic identities. However, interestingly, their spatial distribution across the Drake Passage suggests a north-to-south gradient of increasing genetic diversity.

Genetic diversity and structure plays a key role in the selection of parents for crosses in plant breeding programmes. The aim of the present study was to analyse the genetic diversity and structure of Eritrean bread wheat accessions. We analysed 284 wheat accessions from Eritrea using 30 simple sequence repeat markers. A total of 539 alleles were detected. The allele number per locus ranged from 2 to 21, with a mean allele number of 9.2. The average genetic diversity index was 0.66, with values ranging from 0.01 to 0.89. Comparing the three genomes of wheat, the B genome had the highest genetic diversity (0.66) and the D genome the lowest diversity (0.61). A STRUCTURE analysis based on the Bayesian model-based cluster analysis followed by a graphical representation of the distances by non-parametric multidimensional scaling revealed a distinct partition of the Eritrean wheat accessions into two major groups. This is the first report of the genetic diversity and structure of Eritrean bread wheat.

In India, the registration and protection of new and notified/extant plant varieties are based on the criteria of distinctness, uniformity and stability (DUS) of morphological characteristics. However, these morphological traits have not been helpful in resolving closely related genotypes. The molecular markers can very well support the DUS testing in such cases. Therefore, in the present study, 20 accessions of bottle gourd were fingerprinted using 20 simple sequence repeat (SSR) primers. Of these, ten primers exhibited polymorphic profiles, while nine exhibited monomorphic patterns and one revealed a null allele. The number of alleles ranged from 2 to 4 with an average of 2.6 alleles per locus. Unique DNA profiles of all the accessions could be created using a set of five polymorphic primers. Therefore, SSR markers used in the present study could precisely distinguish all the 20 accessions from each other, and these SSR markers can be further used to differentiate the future genotypes from the existing ones. The dendrogram depicting the genetic relationships as revealed by NTSYS-pc 2.02 and the tree diagram generated using the DARwin 5.0 program classified the accessions into two main clusters. There is no strong association between the clustering pattern and geographical origin of these accessions. This SSR marker-based diversity would facilitate the implementation of marker-assisted breeding schemes for efficient introduction of the desired traits into bottle gourd.