Chinese Spring (CS) wheat (Triticum aestivum L.) is commonly used in genetic research including cytogenetic analysis, molecular mapping and germplasm development. Aneuploid lines of alien chromosomes in the CS background have been used in studies with diverse objectives. Thousands of genomic and complementary DNA sequences from expressed sequence tag (EST) libraries of biotic- and abiotic-stressed tissues are publicly available from CS. Gene expression analysis of salt-tolerant wheat lines, W4909 and W4910, compared with the CS common wheat background led to the discovery of several expressed sequences that were absent in the CS accession held in our laboratory. A survey of 20 CS accessions from 13 laboratories using the polymerase chain reaction with gene-specific primers for eight salt-responsive genes resulted in amplification success ranging from 15 to 100%. Amplified fragment length polymorphism analysis showed that 99% of the genetic variation was among the accessions while the remaining 1% was within the accessions. A neighbour-joining phylogram showed that four of the five CS accessions from the International Maize and Wheat Improvement Center (CIMMYT) grouped with the salt-tolerant wheat cultivar Yecora Rojo while the remaining 16 CS accessions had limited genetic differences. Thus, variation exists among these highly self-pollinating CS sources, suggesting that appropriate consideration should be taken when using CS accessions to conduct molecular and genetic analyses.

Sweet cherries can be grafted on a wide range of rootstocks belonging to Prunus avium, Prunus cerasus, Prunus mahaleb, Prunus angustifolia or hybrids of different Prunus species. Identification of Prunus rootstocks using morphological traits is almost impossible particularly during the dormant season. However, molecular analysis carried out on actively growing shoot tips, leaves or dormant buds provides good opportunity to reliably distinguish rootstocks. In this study, DNA was extracted from the leaves of a total of 184 sweet cherry rootstock candidates belonging to P. avium L., P. cerasus L., P. mahaleb L. and P. angustifolia L. previously selected from the north-western part of Turkey. The rootstock candidates were tested with ten simple sequence repeat (SSR) primers, developed for the Prunus genus. The primers successfully identified all rootstock candidates. The results showed that the number of alleles per locus ranged from 10 (UDAp-401, UCD-CH21 and CPSCT010) to 20 (UCD-CH31) with an average of 13.3 alleles per locus, indicating that the SSRs were highly informative. Unweighted Pair-Group Method with Arithmetic mean analysis demonstrated that P. avium accessions are closely related to P. cerasus. The reference rootstocks were clustered with their associated botanical species.

Nicaragua is located in the Mesoamerican diversity centre for common beans (Phaseolus vulgaris L.). Yet, there is insufficient knowledge of the molecular characteristics of most common bean landraces in Nicaragua. The objectives of the present study were to investigate the genetic diversity of common bean landraces and to identify promising sources of genetic variation for breeding purposes. Two cultivars and 40 landraces never studied before were selected from a collection based on the geographic origin, seed coloration and information provided by farmers. Fourteen microsatellite markers distributed in different linkage groups were analysed. The study revealed that there is a high genetic diversity (mean 8.9 alleles per locus). The populations showed structuring into three groups where seed weight had a strong relationship with population clustering. At least 20% of the populations hold promising allelic variation and potential for good market acceptance that could be maximized in breeding programmes. Additionally, four markers revealed a high correlation with seed length, width and weight, suggesting that marker-assisted selection for these yield-determinant traits could be straightforward. Nonetheless, more marker–trait associations should be addressed in order to enforce this practice.

International Institute of Tropical Agriculture maintains 2544 cassava accessions (Manihot esculenta Crantz) from 28 countries in its field bank. Being vegetatively propagated, this poses challenges in maintenance in terms of cost as well as in labour requirements. A core collection representing the range of phenotypic diversity present in the entire collection would enhance the conservation aspects and increase the potential for its exploitation in crop improvement programmes. The present study aimed to establish a core collection using 40 agro-morphological traits evaluated at two locations using a different number of accessions in each location. To meet the challenges generated by the types of variables and include maximum diversity in the core collection, a sequential strategy based on five major concepts was used: hierarchical multiple factor analysis allowing the mixture of variables of different kinds; three-way analysis that included the effect of genotype × environment interaction in the clustering process; linear discriminant function to assign all those individuals who were included in one location but not in the other to the groups that were generated from the common number of accessions evaluated in both locations; and D-allocation method to select samples from each cluster. The representativeness of the core subset to the entire collection was further estimated by comparing means and variances, range, and distances between accessions. The established cassava core collection consisted of 428 accessions that conserved 15% higher phenotypic diversity with no redundancies. The phenotypic diversity represented in this core collection will be a guide to users of cassava germplasm in their crop improvement programmes.

The genus Malacomeles (Decne.) G. N. Jones (Rosaceae subtribe Pyrinae) represents several fruit shrubs, which is mainly distributed in North and Central America, from southern USA to Honduras and Guatemala, although the main distribution of this genus is in Mexico. Five species of the genus Malacomeles have been reported to exist in Mexico. Malacomeles is widely distributed in several mountainous ranges in Mexico, although it is unknown where most of the diversity of the Malacomeles genus is located in the country. The aim of this biogeographic study was to determine the areas of highest diversity of the genus Malacomeles in Mexico based on species richness and diversity indices in order to identify the best regions of Mexico to collect germplasm. The results indicated that most of the diversity of the genus Malacomeles is concentrated in northeast Mexico, mainly in the biogeographic province of Sierra Madre Oriental. In this province, the highest values on three biodiversity indices were found. Thus, this area can be considered as the priority area to collect the germplasm of Malacomeles. M. denticulata is the predominant and the most interesting species in Mexico from the viewpoint of collecting plant genetic resources; this species is mainly distributed in the provinces of Trans-Mexican Volcanic Axis, Mexican Plateau and Sierra Madre del Sur, where secondary priority areas to collect germplasm are located.

Germination tests are performed on a routine basis to determine the viability of genebank accessions. The results determine which accessions have to be rejuvenated. The reliability of the germination test results used by the Centre for Genetic Resources, the Netherlands was determined by the retesting of 641 random samples anonymously, in the same year and by the same testing agency as the original tests. Results showed alarmingly low reliabilities, with error levels much higher than expected based on sampling effects. The result of a germination test of a random sample with a germination of 80% was shown to have a 95% confidence interval from 63 to 97%. The errors differed strongly over crops and testing years, and were larger for crop wild relatives than for crop species.

The pattern of inheritance of powdery mildew resistance expressed by two bread wheat (cultivar ‘Alcedo’)/Aegilops markgrafii introgression lines was explored using F2 populations bred from crosses made with the powdery mildew-susceptible cultivar ‘Kanzler’. Disease reaction was tested at both seedling and adult plant stages. Two resistance loci, designated QPm.ipk-1A and QPm.ipk-7A, were identified as mapping to the distal ends of chromosome arms 1AS and 7AL, respectively. Whereas QPm.ipk-1A was expressed throughout the plant's life, QPm.ipk-7A was only effective at the seedling stage. The map location of both resistance loci indicated that resistances originated from A. markgrafii. The possible genetic relationship of these disease-resistant genes to known Pm genes is discussed in the context of synteny.

A well-documented karyo-morphological analysis has been presented in one unexplored cultivar of Capsicum annuum L., collected from South Sikkim, India, to determine the chromosome number. This report confirms that the cultivar contains 2n = 48 chromosomes, which are not produced through self-duplication. More studies are required to determine its actual taxonomic position and genetic relationship with other cultivars and species. This cultivar of C. annuum provides a new, unexplored genetic resource with a high chromosome number.

In this paper, we describe variations among autochthonous olive cultivars from five different areas in Basilicata (Southern Italy) classified according to 33 chemical oil components and morphological traits. While all examined descriptors show no significant differences among cultivars, means and coefficients of variations have been highlighted. Principal component analysis has then been used to reduce the number of descriptors. Cultivars have been classified by cluster analysis into three groups. Following a discussion of cultivar group similarities, results suggest that an ‘a priori’ classification of cultivars according to growing area does not strictly correspond to phenotypic grouping. From the spatial distribution of cultivars, however, it has been possible to identify ‘superior’ genotypes in terms of olive oil composition.

The antimalarial drug artemisinin (ART) is commercially extracted from the medicinal plant Artemisia annua L. Here, we report the screening of 70 A. annua plants representing 14 diverse germplasm accessions sourced from around the world, and identify lines containing >2% ART. These extremely high-yielding individuals have been maintained as vegetative clones, and they represent promising germplasm resources for future A. annua breeding programmes.

This paper shows the results of the investigation on some ecological aspects and on the sanitary status of the wild Euroasiatic native grapevine (Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi) in Georgia (South Caucasus). This taxon is seriously endangered by human activities such as forest cleaning and setting fires. Moreover, invasive Vitaceae of the North American origin, imported after phylloxera (Daktulosphaira vitifoliae Fitch) when vineyards were being replanted, increase the risk to lose these spontaneous vines. The survey includes collection of data on the population structure, the plant sex ratio, the main botanical supporters of the vines and the associated flora, the presence of invasive vines of the North American origin and the incidence of phytophagous arthropods and pathogens. The phytosanitary study showed that monophagous eriophyid mites and exotic fungal diseases, such as downy (Plasmopara viticola (Berkeley and Curtis) Berlease and de Toni) and powdery mildews (Erysiphe necator –(Schweinitz) Burrill), cause symptoms on all the observed populations. The absence of symptoms caused by phylloxera, root-knot nematodes and root rot is remarkable. However, the level of detected injuries caused by these parasitic organisms does not seem to be a real problem for the survival of the populations.