The Triticeae tribe (Poaceae) includes several important cereal crops, cultivated forages, annual and perennial grass weeds and ecologically diverse native North American grasses. Elymus L. is the largest and most complex genus in the Triticeae tribe with approximately 150 polyploid perennial grass species occurring worldwide. The genomic constitutions of approximately 40% of the Elymus species are unknown. Molecular markers are needed to facilitate genetic analysis of diversity and functional traits in these species. We have developed simple sequence repeat (SSR) markers for use in Elymus based on Elymus expressed sequence tag sequences. To test the polymorphic content and transferability of these SSRs, 100 SSR primer pairs were tested on 84 plants representing seven North American Elymus, Pseudoroegneria and Pascopyrum species. The number of bands produced from each of the SSRs ranged from 1 to 11 with an average of 4.3 bands/SSR. A subset of the 23 most polymorphic SSRs produced 142 bands, an average of 6.2 bands/SSR. Binary data from the 100 SSRs successfully separated all individuals into their respective accessions in a neighbour-joining phylogram with a 100% confidence interval. Analysis of molecular variance showed that 29.9% of the total variation was within and 70.1% was among the accessions. These SSRs will be a useful tool for investigating genetic diversity, genome constitutions and molecular mapping in Elymus and other Triticeae grasses.

For maintaining food security and livelihood, farmers in marginal areas of production environments make use of high levels of crop genetic diversity. The exchange of seed and varieties among villagers, and also the relative isolation of local varieties in their production environments, contributes to the continued existence of locally adapted genotypes. In Tigray, one of the major barley-growing regions of Ethiopia, local varieties and local seed systems are dominant. The annual barley seed requirement is met with seed produced, saved and exchanged by farmers. In order to understand the flows of seed and varieties within and between villages, a study was conducted using a survey to gather information from 130 respondents in seven villages. Seed network analysis was used as an analytical tool to assess flows of seed and varieties and to identify farmers who play different roles in the seed system. Within the major seed exchange network, nodal or connector farmers linked seed subnetworks. The flow within villages was much more dominant than beyond. Rare varieties appeared to be sourced from farms that maintain a broad variety portfolio. Varieties seemed to disseminate informally across farms, in their target environments, following participatory varietal selection. The methodology of social seed network analysis proved to be a powerful tool for monitoring seed and variety flows. Furthermore, it identified farmers as critical partners in the conservation and on-farm management of plant genetic resources, recognized the role of plant breeders in participatory varietal selection and that of seed experts, engaged in strengthening local seed supply and in disseminating quality seed of superior varieties.

Inter simple sequence repeat markers were used to assess the genetic diversity and population genetic structure in 12 populations of Nothapodytes nimmoniana from Western Ghats of India. A total of 16 selected primers produced 103 discernible bands, with 76 (73.7%) being polymorphic. The Nei's gene diversity (h) ranged from 0.1166 to 0.2124, with an average of 0.1518 at the population level and 0.2965 at the species level indicating high genetic diversity. The Shannon's index (I) was estimated to be 0.2189 within populations (range 0.1703–0.2947) and 0.4352 at the species level. The analysis of molecular variance showed that the genetic variation was found mainly within populations (73%), but variance among populations was only 27% and its value, ΦPT = 0.271, P < 0.001, implied that high genetic differentiation among populations. In addition, Nei's differentiation coefficient (GST) was found to be high (0.4882) and the gene flow (Nm) was low (0.5242), confirming the high population genetic differentiation. The unweighted pair-group method using arithmetic average clustering elicited similar results. Based on this, we propose conservation strategy for this plant species.

Cowpea, an indigenous crop to sub-Saharan Africa, is found mainly in the dry savanna regions along with cereals such as millets and sorghum. Cowpea is grown primarily for human consumption of the grains, which are rich in protein, carbohydrates and contain some minerals. The development and deployment of cowpea varieties with higher nutritional value will be of immense benefit to consumers. As a first step in the enhancement of mineral content in cowpea grains, several germplasm lines (1541) of different origins and obtained from the genetic resources unit at IITA were sown in the experimental field in Minjibir, Kano State, Nigeria. The grains were analysed for protein and nine mineral contents. However, in this study, we shall report data on crude protein, Fe, Zn, Ca, Mg, K and P. The data generated from the chemical analysis were subjected to the ‘mixture of normal distributions’ clustering method, which distributed the cowpea lines into nine groups. Groups G7 and G9 contained 174 genotypes and these were characterized by high mineral concentrations. The mean nutritional content values for group G9 were 24.7% for protein, and 58.9, 41.5, 1107, 2132, 15,282 and 5664 mg/kg for Fe, Zn, Ca, Mg, K and P, respectively. On the other hand, the 363 lines making up groups G2, G3 and G6 showed low amounts of nutrients in their grains. Some of the lines in G7 and G9 would be good as parents to use in breeding programmes that aimed at developing nutrient-dense cowpea varieties.

Knowledge of the genetic diversity of germplasm of breeding material is invaluable in crop improvement programmes. Frequently, qualitative and quantitative data are used separately to assess genetic diversity of crop genotypes. While assessing diversity based on qualitative and quantitative traits separately, there may occur a problem when the degree of correspondence between the clusters formed does not agree with each other. This study compares five different procedures of clustering based on the criterion of weighted average of observed proportion of misclassification in black gram genotypes using qualitative, quantitative traits and mixture data. The INDOMIX- and PRINQUAL-based clustering procedures, i.e. INDOMIX and PRINQUAL methods in conjunction with the k-means clustering procedure, show better performance compared with other clustering procedures, followed by clustering based on either quantitative or qualitative data alone. The use of the INDOMIX- and PRINQUAL-based procedures can help breeders in capturing the variation present in both qualitative and quantitative trait data simultaneously and solving the problem of ambiguity over the degree of correspondence between clustering based on either qualitative or quantitative traits alone.

A useful biological interpretation of diploid heterozygotes is in terms of the dose of the common allele (0, 1 or 2 copies). We have developed a PERL script that converts FASTA files into coded spreadsheets suitable for principal component analysis. In combination with R and R Commander, two- and three-dimensional plots can be generated for visualizing genetic relationships. Such plots are useful for characterizing plant genetic resources. This method nicely illustrated the spectrum of genetic diversity in tomato landraces and the varieties categorized according to human-mediated dispersal.

Zingiber barbatum Wall. (family Zingiberaceae), is an underutilized medicinal plant and commonly known as ‘Meik tha-lin’ in Myanmar where it is used in the indigenous system of medicine. In the present study, 19 accessions of Z. barbatum from five provinces in Myanmar have been utilized to characterize and assess genetic diversity. Twenty-nine morphological characters were noted, including growth habit, leaf, pseudo-stem and rhizome characters. Fifteen primer sets of P450-based analogue (PBA) markers were used to reveal molecular characteristics. Of the 29 morphological characters, 22 showed a high degree of variation within wild ginger accessions, whereas 20 of these characters contributed significantly to morphological variation. Eleven amplified primer sets gave a total of 175 bands and exhibited 92.15% polymorphism across Z. barbatum accessions. Based on morphological characters and PBA markers, 19 accessions can be divided into two morphotype groups with comparatively higher genetic diversity. This information can be applied in future crop improvement, proper conservation and better use of this underutilized medicinal species.

Faba bean (Vicia faba L.) was used as the rootstock for lentil scions to test the feasibility of using in vivo inter-generic grafting techniques as a substitute for root induction and as a tool in lentil genetic improvement. An accession of each of the six wild Lens species was used as the scion in grafts to faba bean breeding line FB50-9 rootstock. Successful grafts were obtained for all species with survival of grafts to seed maturity between 70.7 and 87.7% except for Lens orientalis PI 72735 with 55.3% survival. Days to flower remained the same after grafting, except for scions of L. nigricans PI 72560 and L. orientalis PI 72735 which had a lag phase of 9 and 7 d, respectively. For all six wild species, seed diameter and seed weight were not significantly different between non-grafted controls and scions grafted onto faba bean rootstocks. This simple approach opens the possibility of using in vivo grafting techniques to rescue inter-specific hybrids of lentil. The technique has potential as a useful tool in lentil breeding, as a means of improving seed multiplication rate of rare genetic resources of wild lentil and as a way to reduce the costs of germplasm multiplication of wild lentil species.

Based on the distribution, molecular similarity and use of Morinda citrifolia L., and occurrence of a wild Morinda species, Southeast Asia and Micronesia have been suggested to be the places where noni originated. The present article discusses the indices used by Vavilov and subsequent authorities on the origin of crop plants to argue that South Asia (Southeast India) has a greater probability of being the centre of domestication/origin for noni than Southeast Asia or Micronesia. The basic reasoning is that economically important plant cannot originate without richness in biodiversity and ingenuity of local people. India with rich floristic diversity, one of the centres of origin of crop plants with a natural distribution of Morinda species, including M. citrifolia L. and its immediate ancestors, has the oldest reference of occurrence, use and cultivation (Vedic literature); therefore, it appears to be the more probable centre of noni's origin. The ancient history of the expansion of Indian culture, religion and trade to Southeast Asian countries corroborate the possible role of Indians in the introduction of noni or knowledge regarding its value to Southeast Asia, from which it was carried to Micronesia and Polynesia, which provided a more favourable environmental niche for perpetuation and use.

Mineral concentration levels in cultivated vegetables have received very little concern in the context of biodiversity despite the fact that most vegetables have a rich micronutrient composition. Swiss chard is an important salad crop which is high yielding and rich in minerals, vitamins and phenolic compounds. It is also extremely easy to grow. However, there is a lack of information on the genetic variability of mineral concentration of Swiss chard. Mineral composition diversity of 54 genetically diverse Swiss chard accessions, representative of all Turkish Swiss chard genetic resources, was investigated using multivariate analysis. These traits are useful in evaluating germplasm diversity in the nutritional concentration context and for use in further breeding programmes which will focus on improving mineral concentrations in Swiss chard cultivars. The results displayed significant differences among accessions and remarkably high nutrient contents. The data gathered were analyzed using principal components (PCs) and cluster analysis and revealed five major groupings. The data also observed 74.39% of total variation. The first three PCs accounted for 49.86% of the total variation in the population. Present values provided great variability among accessions and the results demonstrate that it is possible to identify genetic differentiation among Swiss chard accession for some nutritional elements. The genetic resources that exist indicate that potentially important accessions could be used as a gene source due to their high levels of K, Ca, Cu and Zn in breeding programmes.