In areas with less favourable conditions for agriculture, informal seed systems permit gene flow through pollen to play a crucial role in the development of new varieties. An important factor with great impact on cross-pollination is the plant breeding system, but so far this is little studied within the context of low-input farming systems. This research studied the chances of cross-pollination within and between rice fields in The Gambia. Size and time of flowering were measured for 28 rice fields in one village. The level of mixture was measured in 90 seed lots of rice collected from four villages. Based on the results, we suggest that in general cross-pollination between different rice genotypes occurs more often within fields than between fields. No clear relationship was found between the level of within-field mixture and socio-economic status of farmers. Some comparison was made with millet, which allowed the identification of various factors influencing pollen flow between different genotypes. Effective pollen flow (between genotypes) is a function of a number of factors, such as the rate of cross-pollination of a crop, number of off-types within fields, variety distinctiveness, farmer expert knowledge, length and reliability of the rainy season, growth duration of different varieties, availability of fields, pest pressure and number of varieties grown per field or per farmer. We hypothesize that a low cross-pollination rate is more favourable for the development of new varieties in farmer fields than a high cross-pollination rate.

Anatolia (Asia Minor) is considered to be the cradle of viticulture, but wild grape accessions from this region have not been subjected to any genetic analysis. We present the first genetic characterization of wild grapes (Vitis vinifera subsp. sylvestris) from this region. Using 15 nuclear microsatellites, we genotyped 84 wild grape accessions collected from three Anatolian locations. The unweighted pair group method with arithmetic mean analysis revealed four genetic clusters that partially separated Anatolian wild grape populations. In general, accessions from geographically closer locations showed higher genetic similarities than those from more distant locations. In some cases, accessions from one population showed close genetic relationships to accessions from a different population. The genetic diversity between natural populations from both ends of the Mediterranean basin has shown higher genetic diversity in the Anatolian Peninsula than peripheral populations, suggesting that this area could be one centre of diversity of the species. The genetic relationship between wild and cultivated grapevine from Anatolian Peninsula indicated a clear separation between them. However, we cannot discarded a local genetic contribution. Overall, this study reveals useful information for management and potential utilization of Anatolian wild grape germplasm.

Guava (Psidium guajava) and araçá (Psidium spp.) plants are important for the Brazilian economy, as their fruit is both accepted by the consumers, and makes a beneficial contribution to the human diet thanks to their content in vitamin C, carotenoids and phenolic compounds. Here, we report the content in the fruit of free ascorbic acid, lycopene, β-carotene, flavonoids and phenolic compounds, and the total antioxidant activity present in a collection of guava and araçá accessions curated at the Embrapa Semiarido germplasm bank. Guava fruits with a red-coloured pulp flesh contained a significant amount of carotenoids, especially lycopene, and a high concentration of phenolic compounds. These compounds were largely responsible for the antioxidant activity of the araçá accessions. Among the guava accessions, phenolic compounds were also responsible for the antioxidant activity. High levels of free ascorbic acid were present in most accessions. In both guava and araçá, there is substantial potential to develop cultivars with a good level of consumer acceptability.

This study discusses some of the important aspects of laws/regulations formulated for the protection of plant varieties in Union for the Protection of New Varieties of Plants (UPOV) member states, European Community countries and India. The study also provides an insight into some of the unique features of Indian sui generis system for the protection of plant varieties. During this study, the registration of crop notified in India and in some selected UPOV member countries has been examined. Since India is not an UPOV member state, the system of plant variety protection (PVP) is independent of international scenario but aims for similar standards. The study provides useful information in order to analyse the implementation of PVP laws in UPOV member states and India. Some important features were selected for carrying out a comparative analysis. These include Intellectual Property Rights protection (patent/breeder's right), types of varieties protected, methods of testing, criteria for protection, duration of protection, exemptions (researcher/farmer's exemption), infringement and penalty and compulsory license.

Mango (Mangifera indica L.) is an important fruit crop with a long cultivation history in Myanmar. This study evaluated the genetic variation within two economically important traditional varieties, ‘Yin Kwe’ and ‘Sein Ta Lone’, and the relationship between genetic variation and propagation practices. Genetic variation was estimated by genotyping 94 individuals with 12 single sequence repeat markers. ‘Yin Kwe’ (n = 53) showed higher levels of observed heterozygosity (Ho = 0.59) and average genetic distance among individuals (Da = 0.29) than did ‘Sein Ta Lone’ (n = 41; Ho = 0.45; Da = 0.09). The differences between the two varieties at the DNA level were significant (Fst = 0.44). The broader genetic background in ‘Yin Kwe’ compared with ‘Sein Ta Lone’ was also demonstrated by neighbour-joining and principal coordinates analyses. Differences in variety uses and propagation practices were determined by interviewing local specialists in Lower Myanmar (southern Myanmar). ‘Yin Kwe’ was often used as a rootstock for ‘Sein Ta Lone’. Clonal propagation by grafting was observed frequently for ‘Sein Ta Lone’ but never for ‘Yin Kwe’. The differences in genetic variation between these two varieties might have been caused by the propagation practices for each variety, which result from their respective uses.

This study reviews the various conservation strategies applied to the four redwood species, namely coast redwood (Sequoia sempervirens), Sierra redwood or giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides) and South American redwood or alerce (Fitzroya cupressoides), which are endemic in the USA, China and South America, respectively. All four redwood genera belong to the family Cupressaceae; they are monospecific, share a number of common phenotypic traits, including red wood, and are threatened in their native ranges due to human activity and a changing climate. Therefore, the management objective should be to conserve representative populations of the native species with as much genetic diversity as possible for their future survival. Those representative populations exhibiting relatively high levels of genetic diversity should be selected for germplasm preservation and monitored during the conservation phase by using molecular markers. In situ and ex situ strategies for the preservation of germplasm of the redwoods are discussed in this study. A holistic in situ gene conservation strategy calls for the regeneration of a large number of diverse redwood genotypes that exhibit adequate levels of neutral and adaptive genetic variability, by generative and vegetative methods for their preservation and maintenance in their endemic locations. At the same time, it would be desirable to conserve the redwoods in new ex situ reserves, away from their endemic locations with similar as well as different environmental conditions for testing their growth and survival capacities. In addition, other ex situ strategies involving biotechnological approaches for preservation of seeds, tissues, pollen and DNA in genebanks should also be fully exploited in the face of global climate change.

Dwarfing genes play an important role in improving yield and adaptability of wheat cultivars in most production environments. Understanding the allelic distribution at dwarfing loci is very important for any wheat-breeding programmes. In this study, we reported the allelic constitution at microsatellite locus Xgwm261 and the two major height-reducing genes Rht-B1 and Rht-D1 among a set of 56 bread wheat cultivars and nine landraces, based on diagnostic polymerase chain reaction assays. With respect to Rht-B1, 37% of the accessions carried the dwarfing allele Rht-B1b, while at Rht-D1, only one accession carried the dwarfing allele Rht-D1b. The allelic state at Rht8 was assayed indirectly by genotyping for the linked microsatellite locus Xgwm261. About 26% of the accessions carried the 192 bp allele (linked with Rht8 gene in some cases), whereas 35 and 12% genotypes carried 165 and 174 bp allele at the microsatellite locus Xgwm261. Cultivars released from 1980 onwards increasingly carried either Rht-B1b or Rht8. This information should allow for a more rational use of this collection for the purpose of wheat improvement in Turkey.

The International Cocoa Genebank, Trinidad, is the largest field genebank collection of cacao (Theobroma cacao L.) in the public domain and the correct identity of each tree is crucial for germplasm movement, evaluation and phenotypic characterization. Nine microsatellite loci were used to assess the identity of 1477 trees from 486 cacao accessions representing approximately 16.9% of the trees and 29.2% of the accessions within the genebank. Heterogeneous plots (plots containing more than one genotype group) averaged 25.1% in The International Cocoa Genebank, Trinidad, with maximal admixture (32.6%) being recorded in Field 5B. The error rate did not differ significantly among different fields. Mislabeling error could be affected by accession grouping with an average error rate of 27.4% for accession groups in the genebank. Synonymous accessions were estimated to account for 14.4% of the field genebank. The results of the present study provide essential information for the management and utilization of the germplasm collection. Single-tree genotyping of every tree in this collection is strongly recommended.

Triticum urartu, the A-genome donor of tetraploid and hexaploid wheats, is a potential source of novel alleles for crop improvement. A fertile amphiploid between T. urartu (2n = 2x = 14; AuAu) and durum wheat cv ‘Yavaros’ (Triticum turgidum ssp. durum; 2n = 4x = 28, AABB) was obtained as a first step to making the genetic variability of the wild ancestor available to durum wheat breeding. The amphiploid was backcrossed with ‘Yavaros’ and the offspring from this cross was selfed. A plant from this progeny (founder line) with 28 chromosomes and active x and y subunits of the Glu-A1 locus of T. urartu was selfed, which resulted in the obtaining of 98 pre-introgression lines (pre-ILs). In this work, a set of 78 wheat chromosome-specific microsatellite markers (simple sequence repeats, SSR), uniformly distributed over the A genome, was used for marker-assisted selection of T. urartu in a durum wheat background. A total of 57 SSRs allowed a clear discrimination between T. urartu and ‘Yavaros’. This set of markers was further used for characterizing the pre-ILs, identifying and defining the T. urartu introgressed regions. The applicability of these markers is discussed.

Amplified fragment length polymorphism analysis was employed to investigate the population structure of 32 Iranian Silybum marianum populations along with two commercial varieties. A total of 415 polymorphic marker loci were produced by 27 primer combinations with an average of 15.37 markers per combination. Polymorphic information content ranged from 0.24 to 0.44 with an average of 0.35 per primer combination, and marker index was in the range of 2.56–9.50 with an average of 5.37. The average Nei's genetic diversity (HE) and Shannon's diversity index (I) were 0.201 and 0.296, respectively. The coefficient of differentiation among populations (GST) was 0.44, indicating that 44% of the total molecular diversity resulted from differences between populations. We identified three major groups based on cluster analysis and principal coordinate analysis, which were mostly in concordance with the geographical grouping of the populations. The molecular diversity estimate could be useful for selecting appropriate populations to improve S. marianum through conventional and molecular breeding.

Rocket (Eruca spp. and Diplotaxis spp.) is widely cultivated as a green vegetable in Mediterranean countries, Europe, United States and Brazil, but few rocket cultivars are available and limited variety selection has taken place. Plant genetic resources and germplasm are fundamental sources for plant breeding, and the assessment of the genetic diversity among germplasm accessions is useful to facilitate the more efficient use of plant genetic resources. The objective of this study was to characterize phenotypic diversity and relationships among genotypes of Eruca and Diplotaxis originating from 11 countries across three regions (Europe, Africa and Asia). Principal component analyses explained over 85% of total variation for 51 qualitative and quantitative agromorphological traits. Cluster analyses divided the accessions into five major clusters according to plant traits, siliqua properties and geographical origin of genotype with a few exceptions. These findings indicate a number of useful traits in the gene pool and a wide range of phenotypic variation that provides a good source of diversity for use in modern Eruca breeding programmes.

Ginger (Zingiber officinale Rosc.), originated in the Indo-Malayan region, is now widely distributed across the tropics of Asia, Africa, America and Australia. It was domesticated in India and China, which represent the centre of origin of the species. Cultivated ginger though sterile, exhibits variations in rhizome and vegetative characters. The crop is gaining importance as a curative agent for a variety of ailments. Yield and quality traits (such as essential oil, fibre and oleoresin contents) along with volatile and non-volatile constituents are important determinants of the commodity's end product. Cultivar diversity for yield and morphological features is well known in ginger with few primitive types having excellent quality. However, the common name(s) of ginger cultivars are confusing and have resulted in geographical bias in its ex situ conservation. Most of the molecular/biochemical marker studies reported in ginger show low levels of polymorphism in contrast to plentiful phenotypic variability recorded in the species. The large influence of environmental factors on the content of key compounds, lack of seed set and confusion of the common names are the leading constraints to further varietal improvement of ginger. As tailor-made ginger varieties assume future significance these aspects will have relevance.

Given the increasing importance of data quality for the ex situ conservation and utilization of plant genetic resources (PGR), an indicator was created that quantifies the level of completeness of passport data. This passport data completeness index (PDCI) uses the presence or absence of data points in the documentation of a genebank accession, taking into account the presence or value of other data points. For example, a wild accession should have a well-defined collection site but no variety name. Any type of accession, wild, landrace, breeding material or modern variety, can attain a maximal score of ten for this index. The applicability of this index was tested on the complete contents of EURISCO, the European catalogue of ex situ maintained PGR containing over one million records. Analysis of the PDCI of the material in EURISCO provided valuable insight in the data quality of European collections. The PDCI can be used to identify datasets that might need additional attention and improvement or datasets that need more careful interpretation than others.