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Tuberose [Agave amica (Medik.) Thiede & Govaerts] is a tropical bulb grown commercially for its sweet-scented flowers and highly valued essential oil. In this study, the floral morphologies of 18 tuberose genotypes were studied to understand their diversity and compatibility (for selfing and crossing) so that prerequisites for parental selection can be established. The genotypes—all of which had single florets—varied significantly in terms of floret length, floret diameter, tepal thickness, number of tepals, and stamen length. The flowers opened in the evening, and anther dehiscence occurred within 20–30 min of anthesis. The styles showed three distinct morphological types in terms of the relative positions of the stigma and the upper or lower ends of the stamen, as follows: L-morph, for long styles, if the stigma was located above the upper end of the stamen; S-morph, for short styles, if the stigma was below the lower end of the stamen; and I-morph, for style of intermediate length, if the stigma was positioned somewhere in between the upper and lower ends of the stamen. Stigma receptivity increased gradually, whereas pollen viability declined slowly from the 1st to the 4th day of anthesis. Self-compatibility, self-incompatibility, and sterility were confirmed via autogamy, geitonogamy, and controlled pollination. In ‘Arka Prajwal’, the pollen tube entered the ovule 24 h after pollination and the female gametophyte developed up to 5 days after pollination. However, the embryo sac began to degenerate from the 7th day of pollination and the pods were shed, which confirmed the sterility of the ovule. This comprehensive study of floral morphology is expected to provide useful insights for breeding tuberoses of superior flower quality and improved yield of the essential oil.

Temporal and spatial changes of sorghum landrace diversity and related factors in five farming communities in north Shewa and south Welo, between 1992/1993 and 2000/2001, were studied in order to ascertain the stability of a range of factors that support the maintenance of the crop genetic diversity. The same farmers were interviewed and the same sorghum fields were surveyed both times. Over the 8-year period: the total area planted to sorghum decreased drastically in all five farming communities and a large percentage of the farmers in the communities (Hayk, 69%; Borkena, 68%; Epheson,  51%; Merewa Adere, 72%; and Bati, 54%) decreased the field size planted to sorghum, because of population growth, land redistribution policy, seasonal changes, and stagger cropping followed by interspecies crop displacement; landrace richness increased significantly in Merewa and Borkena, but decreased significantly in Bati, Epheson and Hayk; and farmers’ selection criteria, the reasons for growing specific landraces, increased significantly (10 in 1992/1993 vs. 22 in 2000/2001). Significant differences in field size distribution occur among the five farming communities. In 2000/2001, 22 “generalist” landraces (grown widely across three or more communities), and 46 “specialist” landraces (niche specific, restricted to certain microhabitats in one or two communities) were found. Landrace gains and losses from the farms surveyed in individual communities over the period are demonstrated.

Ancient germplasm represents a reservoir of traits and genes that might maintain large the genetic diversity of a species, like pear, and help breeders to cope with climatic changes and the evolving demand of the market. This paper reports the analysis of 170 pear accessions profiled at 12 simple sequence repeat (SSR) markers. The collection was replicated in three different locations and the identification of matching profiles of duplicated genotypes reduced the dataset to 118 genotypes. Of these, 32 (27.1%) were shown to be triploid by flow cytometry, a result that was confirmed by the occurrence of triallelic profiles at molecular markers and the large leaf size. The geographic location of original plants explained very little molecular variance (2%), that was instead very high among genotypes (98%). This evidence confirms the extensive exchange of plant material among the different geographic areas of the region as well as with neighbouring countries as reported in historical documents. The analysis of synonymy revealed 38 duplicated genotypes and reduced the dataset to 80 unique genotypes, of which 12 were triploid (15.0%). The molecular metrics analysed on 70 unique diploid genotypes, including two commercial cultivars, ‘Abate Fétél’ and ‘Conference’ added as controls, revealed that the observed heterozygosity over all loci (Ho) was 0.742 (range 0.471–0.937 for individual loci), while the expected heterozygosity or gene diversity was 0.808 (range 0.534–0.912). The polymorphic information content was 0.784 on average (range 0.501–0.906 for individual loci). The probability of identity (PID) calculated for individual loci and unrelated genotypes ranged from 0.014 for the most discriminating locus, Ch01d09, to 0.250 for the least discriminating one, Ch04e03. The PID product over all loci was 2.50e−16 for unrelated genotypes and 4.86e−06 for full sibs. The analysis of data is integrated with a discussion on the use of SSR markers in pear genotyping and the origin and the frequency of triploids compared with data from the literature. Finally, a discussion on the resemblance of several groups of cultivars to those of the pomological treatises is included.

Genetic diversity and relationships within and among nine species of Coffea, one species of Psilanthus and the Piatã hybrid from the Coffee Germplasm Collection of Instituto Agronômico de Campinas (IAC), Brazil were assessed using RAPD markers. Genetic diversity and relationships were evaluated by proportion of polymorphic loci (P), Shannon’s genetic index (H′ and G′ST) and clustering analysis. The overall RAPD variation among all accessions was mostly partitioned between rather than within species. However, C. canephora and C. liberica showed a high genetic diversity within the species ( $${\underline{\hbox{H}'}} $$ sp = 0.414 and $${\underline{\hbox{H}'}} $$ sp = 0.380, respectively) and this was highly structured (high $${\underline{\hbox{G}'}} $$ ST). Genetic diversity from C. congensis and C. arabica was also structured, but with lower levels of genetic diversity ( $${\underline{\hbox{H}'}} $$ sp = 0.218 and $${\underline{\hbox{H}'}} $$ sp = 0.126, respectively). The results were consistent with agronomic and molecular studies and demonstrated that the IAC Coffea Collection is representative of the phylogenetic structure observed in the genera. This study devises sampling strategies for coffee germplasm collections and provides genetic diversity parameters for future comparisons among them.

The present study evaluated the population structure and genetic diversity using inter simple sequence repeat (ISSR) markers in 18 natural populations belonging to three species of Eplingiella (E. cuniloides, E. fruticosa and E. brightoniae), found growing naturally in the semiarid region of Northeast Brazil. Samples of 265 plants were analyzed using nine primer combinations, which generated 131 informative bands. Eplingiella spp. populations showed moderate genetic diversity (percentage of polymorphic bands, PPB = 75.6–96.9%, Nei's genetic diversity He = 0.31–0.39, Shannon's information index I = 0.33–0.48). Molecular variance analysis revealed that within populations, variations contributed more (74%) to the genetic diversity than between population variations (26%), with percentage of the genetic differentiation coefficient (GST = 0.29). The mean value of FST was 0.175, demonstrating good differentiation between populations. The analysis of the structure by the Bayesian method revealed the formation of two groups (K = 2), with many migrant individuals and a high level of miscegenation. The hierarchical cluster dendrogram grouped the 18 populations into two major clusters, with good support for the main clades (100%). According to principal component analysis, the two main principal components explained 21.06% of the total variation. The ISSR markers used were effective in identifying the variability of natural populations of Eplingiella spp., and population structure demonstrated recent diversification of species. The results shed more light on the genetic variation and evolutionary dynamics of Eplingiella, helping to formulate effective breeding strategies.

At the beginning of the 20th Century Italy was one of the most important producers of lentil in the Mediterranean basin. Presently, this pulse is mainly cultivated in marginal areas of Central and Southern Italy and in some small islands. As a result of the reduced attention devoted to lentil, several autochthonous populations have disappeared together with the traditions related to their cultivation. Moreover, how long the cultivation of those still grown today will continue is unpredictable. Governmental and local associations have a time window for anticipating a possible epoch when to grow these landraces will be no longer profitable. In the last decades the Germplasm Institute of the National Research Council (Bari, Italy) and the Institut für Pflanzengenetik und Kulturpflanzenforschung (Gatersleben, Germany) have collected 63 lentil populations in Italy, presently stored ex situ. The evaluation of this collection has shown the existence of an appreciable morphological, agronomic and genetic diversity that could foster future breeding programmes. It is concluded that there is an urgent need to promote the survival of lentil populations in situ, since this will further support the adaptation and evolution of autochthonous genotypes in their original environments.

Farmers use and conserve a large variety of tree species. In Meru, a tree census on 35 farms covering 60 ha was conducted. This study included farmer interviews and biological measurements, with about 63,000 trees and 297 species being recorded. This paper discusses tree densities per species and germplasm sources for trees and species. The low densities and limited influx of germplasm from outside the farming community for some species, may result in an increased vulnerability to inbreeding and genetic erosion. This paper aims to provide some baseline data for understanding genetic resource management in agroforestry systems. It also provides suggestions for interventions to lower the vulnerability for species in Meru. Farmers need to have increased access to germplasm to diversify their farms in terms of species evenness, by substituting trees of more common species with trees of rarer species, or by increasing trees of rarer species.

Caragana korshinskyi Kom. is a long-lived shrub species indigenous to northwestern China, and important in vegetation rehabilitation of widely degraded and degrading semiarid and arid regions because of its high ecological and economic values. Information at molecular level on its genetic diversity, however, is not available. Accordingly, the extent and distribution for genetic diversity and population structure in 11 populations of C. korshinskyi were assessed using polyacrylamide gel electrophoresis for seven enzymes including aminopeptidase, aspartate aminotransferase, glucose-6-phosphate dehydrogenase, malate dehydrogenase, phosphoglucoisomerase, phosphogluconate dehydrogenase, and peroxidase. The seven-enzyme systems produced 11 loci encompassing 19 alleles demonstrating high genetic variation at both species and population levels. A considerable excess of heterozygotes relative to Hardy–Weinberg expectations was detected at the both levels as well. GST ranged from 0.0074 for AMP-1 to 0.4646 for PGD with a mean of 0.1517, indicating that approximately 84.8% of the total allozyme variation occurred within populations. An indirect estimate of the number of migrants per generation indicated that gene flow was high among populations of the species.