Variation among Spanish faba beans cultivars: taxonomic and evolutionary implications

Summary Univariate and multivariate analysis were used to examine phenotypic variability within a Spanish faba bean germplasm collection maintained at the Centro de Investigación y Desarrollo Agrario, Córdoba, Spain.The analysis of 158 Spanish faba bean accessions and 12 quantitative traits indicated highly significant differences among botanical groups for 8 characters and among geographic regions for 10 characters. An east to west clinal pattern of variation for some characters was detected.In order to identify the main characters which account for the major variation, the same collection was subjected to principal component analysis for 12 quantitative traits. Reproductive and plant height characters appeared to be the major sources of diversity.To determine the importance of both geographic and botanical variation among the Spanish cultivars, discriminant analysis was applied. According to these analyses, plant height, height of the lowest pod-bearing node, pod length and 100 seed weight, were important traits discriminating among different geographic regions. The main character discriminating among botanical groups was the 100 seed weight.Our results fit in a pattern in which both agroecological and anthropological causes could have played a role in the observed variation. This analysis can help plant breeders in choosing the most favorable accessions in plant breeding.     

Collecting spanish populations of the genusAegilops L.

Summary Several expeditions were made to the greater part of Peninsular Spain and the Balearic Islands, in order to collect samples from populations ofAegilops spp. The result has been the compilation of a collection reflecting both the presence and the distribution of the genus in Spain. The localisation and collection of two populations ofAe. cylindrica is particularly noteworthy.Ae. ovata is found all over the Peninsula except in the north and northwest of the country. It extends also to the Balearic Islands, which lie within the same biogeographical region.Ae. triuncialis also has a widespread distribution though smaller than that ofAe. ovata. In the Balearic Islands it is found only in Mallorca. All other species were found in more localised areas.Ae. neglecta was found in regions of W and SW Spain with the limits of its distribution bordering those ofAe. biuncialis, which is found in central Spain and in the South.     

Collection of Lupinus angustifolius L. Germplasm and Characterisation of Morphological and Molecular Diversity

Lupinus angustifolius L. is a Mediterranean species, domesticated in the 20th century, representing an important grain legume crop in Australia and other countries. This work is focused on the collection of wild germplasm and on the characterisation of morphological and molecular diversity of germplasm accessions. It reports the collection of 81 wild L. angustifolius accessions from the South and Centre of Portugal, available at the ‘Instituto Superior de Agronomia Gene Bank’, with subsequent morphological and molecular characterisation of a selection of these and other accessions. A multivariate analysis of morphological traits on 88 L. angustifolius accessions (including 59 wild Portuguese accessions, 15 cultivars and 14 breeding lines) showed a cline of variation on wild germplasm, with plants from Southern Portugal characterised by earlier flowering, higher vegetative development and larger seeds. AFLP and ISSR molecular markers grouped modern cultivars as sub-clusters within the wider diversity of wild germplasm, revealing the narrow pool of genetic diversity on which domesticated accessions are based. The importance of preserving, characterising and using wild genetic resources for L. angustifolius crop improvement is outlined by the results obtained.     

Host-plant resistance to Pseudomonas solanacearum in tomato germplasm

Seedlings of two hundred and thirty-three accessions of the tomato collection maintained at the Centro Agronómico Tropical de Investigación y Enseñanza, Turrialba, Costa Rica (CATIE) and 7 cultivars used as controls were evaluated for host-plant resistance to 4 virulent strains of Pseudomonas solanacearum representing race 1 biovars 1 and 3. In general, biovar 3 strains wilted seedlings faster than biovar 1 strains but, after 20 days post-inoculation, no significant differences were noted in susceptible control ratings. Significant differences for disease index were noted, but no line with complete resistance was found. For the USA biovar 1 strain UW-25, only 5 accessions, CATIE 17331, 17334, 17349, 17739, 17740, and 2 of the control cultivars, Hawaii 7998 and UC-82B showed some degree of resistance. Conversely, both the frequency and the degree of resistance were high for Costa Rican biovar 1 strain UW-256. For biovar 3, the Costa Rican strain UW-255 was more virulent than the Peruvian strain UW-130. Eight CATIE accessions, 5539, 17331, 17333, 17334, 17345, 17349, 17742, and MIP-CH1, were as resistant as the resistant control Hawaii 7998 to 3 strains and accession 17740 was as resistant as Hawaii 7998 to all 4 strains.Journal Paper No. J-16011 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project 3123.     

Selecting in situ conservation sites for grape genetic resources in the USA

Previously, there has not been any in situ conservation sites for crop germplasm within the United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Plant Germplasm System (NPGS). Using morphologic and molecular (SSR markers) techniques, we assessed the genetic variation present in populations of rock grape (Vitis rupestris Scheele), a native American grape species, throughout its range. We identified seven in situ conservation sites for rock grape using a strategy based on morphologic and molecular data, taxonomic information, population size and integrity, and landholder commitment. In collaboration with federal and state landholding agencies, we have established the first NPGS in situ conservation sites for American wild relatives of a crop.     

Genetic diversity in the Chamaecytisus proliferus complex (Fabaceae: Genisteae) in the Canary Islands in relation to in situ conservation

Summary Electrophoresis was carried out for six isozyme systems on 175 accessions of the seven morphological forms of Chamaecytisus proliferus (L. fil.) Link (Fabaceae: Genisteae) from the Canary Islands. Previous studies have shown that there is clear differentiation into morphological and ecological forms. The underlying genetic variation as visualised by studying isozymes does not reflect this. While substantial genetic diversity can be identified, this was found to be as much within as between morphological forms. This genetic diversity was found to decrease from east to west, and reflects the pattern of variation remaining after colonisation of the individual islands, which is assumed to have progressed in the same direction. Subsequently, adaptive radiation has given rise to the overlying morphological variation as exhibited in the seven morphological forms.In terms of in situ conservation, overall genetic diversity can be easily conserved in the abundant populations occurring in the east of the archipelago, while more attention is required for conservation of the much rarer morphological forms found in the west, despite their relative lack of isozyme diversity.Abbreviations ACO aconitase - ADH alcohol dehydrogenase - IDH Asocitrate dehydrogenase - MDH malate dehydrogenase - PGD 6-phosphogluconate dehydrogenase - PGM phosphoglucomutase - CA cluster analysis - PCA principal component analysis     

Rice Diversity Collection,Conservation and Management in Northeastern India

Rice is the principal crop of northeastern region of India, where a considerable range of diversity exists. The germplasm collection has also unfold the occurrence of large number of rice landraces in the region. Between 1985 and 2002, a total 2639 accessions of rice germplasms including their wild relatives have been collected. Most of these germplasm material have been conserved in the National Gene Bank, New Delhi following their necessary characterization and evaluation. With the establishment of the Regional Gene Bank Module with medium-term storage facilities (6–7°C with 40–45% relative humidity) at Barapani, Meghalaya, the rice germplasm conservation (ex situ) have been initiated in the region.     

Collection and Characterization of Citrus indica Tanaka and C. macroptera Montr.: Wild Endangered Species of Northeastern India

Citrus indica and C. macroptera are the wild endangered species of Citrus occurring in northeastern India. Surveys were undertaken in this region for ascertaining distribution, studying variability and for collection of germplasm of these two species. C. indica, an endemic species of this region, was collected from the Citrus Gene Sanctuary located in buffer zone of Nokrek Biosphere Reserve in the Garo hills of Meghalaya. In addition, a putative natural hybrid of C. indica and C. limon was collected for the first time from the south Garo hills. C. macroptera had much wider distribution and was collected from Mizoram and Meghalaya states. In Jantia hills of Meghalaya, natural populations of this species are in a highly threatened state. The two species were unevenly distributed all over the explored territory. Morphological characterization of leaves, fruits and seeds indicated the presence of sizable variability within collected accessions of these two Citrus species. Indigenous technical knowledge gathered on the use and socio-economic importance indicated commercial potential for these two species in northeastern India. However, lack of cultivation of these species and clearing of forest cover at an alarming rate has led to an urgent need to adopt complementary conservation strategies to safeguard these species and to ensure their availability for future utilization. A major emphasis on developing methods for their propagation, multiplication and regeneration in in situ and ex situ conditions is required.     

Strong negative effect of alien herbivores on endemic legumes of the Canary pine forest

We studied the effects of herbivores on populations of four endemic legume species in pine forests in Caldera de Taburiente National Park on La Palma, Canary Islands. Seeds of these species were sown in control and herbivore-exclusion plots. Over the subsequent 4-years period, we assessed the effects of herbivores by counting the number of individual plants that emerged and by following their growth. We assessed growth over time using three plant-size categories. For these four species, we conclude that the presence of herbivores, including barbary sheep (Ammotraguslervia), goat (Caprahircus) and European rabbit (Oryctolaguscuniculus), exerts a strong negative effect on plant establishment. We suggest that the paucity of understory plant species in the pine forests of the Canary Islands may be strongly correlated with the presence of introduced herbivores in this region. We propose urgent conservation measures, such as large fenced areas, control activities and the most effective measure, eradication.     

Analysis of the geographic distribution and relationships among Peruvian wild species of <Emphasis Type="Italic">Arracacia</Emphasis>

Relationships between Arracacia species were studied according to 28 morphological discriminant characters, in 90 accessions: 83 Arracacia (Arracacia elata, A. incisa and A. xanthorrhiza), and seven accessions of Neonelsonia acuminata, which has been confused with A. elata. The geographic distribution of the Arracacia species was determined from the passport data of the 90 accessions. A. elata was clearly differentiated from N. acuminata according to morphological characteristics. The species A. incisa was more closely related to A. xanthorrhiza. Within A. xanthorrhiza two forms, monocarpic, and polycarpic, were identified. The distribution of wild Arracacia species in Peru is characterized by two main ecological zones: (1) a dry zone, like the western Yunga and western and inter-Andean valleys of the Quechua region (with seasonal rain from November to March), where the species A. incisa and A. xanthorrhiza are present, and (2) a humid zone, like the Eastern Quechua where A. elata is adapted. These informations could be useful to establish strategies for in situ and ex situ conservation and management of germplasm.     

Conservation strategies and management guidelines for wild Prunus genetic resources in Andalusia, Spain

Six species of the genus Prunus occur inAndalusia. Matters regarding their ecology, ethnobotanical aspectsand conservation are discussed, as well as knowledge about thegermplasm of those species with greater economic importance and theirdegree of conservation, namely: P.avium, P.mahaleb and P.insititia. Various conservation measures areproposed for wild germplasm and for the germplasm of local varieties:a) conservation efforts should target the best populations,except in the case of P.avium and P.insititia, where every individual should beaddressed, including both wild and local cultivars; b) theDehesa del Camarate (Sierra Nevada) is proposed as an areafor in situ germplasm conservation; c) theawareness of the importance of Prunus germplasmshould be increased among forest workers, environmental managers andthe public; d) some silvicultural techniques are proposed, suchas mixed Prunus patches, hedge treatment,Z-tree selection at the early stages and the protection ofroot suckers; e) improved, selected P.avium and P.mahaleb germplasm should be used at highlyproductive sites since these two species can be cultivated as highvalue timber trees; f) some Prunus speciescan also provide profitable NTFPs in the region. Details regardingdifferent collection areas are covered. Finally, some topics arerecommended for scientific research. Three tables and a distributionmap of Prunus species in Andalusia areincluded.     

Germinability of <Emphasis Type="Italic">Vicia sativa</Emphasis> L. seeds After 10 Years of Storage in a Base Collection

The germinability of the Vicia sativa L. seed samples in the base collection at the Centro de Recursos Fitogenéticos (Spain) was controlled in 1986 and 1996. The mean germination of the collection, assessed by One-Sample T Test, was higher than 85%, suggesting its viability was properly maintained along the period. However, changes in germination along the same period assessed by Paired-Samples T Test showed a slight decrease in its global germinability. More data on the viability of stored seeds worldwide – including communication of unpublished data – are needed. Viability assays should be performed according to standard, internationally coordinated protocols and statistical analysis, within an adequate documentation system that assures the integrity of accession information.     

Phenotypic diversity for qualitative and phenologic characters in germplasm collections of tef (Eragrostis tef)

A total of 3600 entries of tef [Eragrostis tef (Zucc.) Trotter] germplasm collections representing 36 populations from six regions of Ethiopia were evaluated for phenotypic diversity in six qualitative and phenologic characters. High values of Shannon–Weaver diversity index ( ) were recorded for most characters in each population. Monomorphism was high for anther color (purple) and panicle form (loose). Larger variances for were obtained among regions than among populations within a region from hierarchical analysis of variance. Significant (P<0.05) to highly significant (P<0.01) t-values were observed among values of some regions for seed color, panicle form and days to maturity. A substantial level of variance (P<0.05) was obtained for populations within altitudinal zones only for days to maturity. Altitudinal zones exhibited similar levels of diversity across characters for these collections. Generally, considerable variations important for tef improvement work have been observed and regions with highest diversity for some traits have been suggested for future in situ or ex situ germplasm conservation works. Although similar mean diversity indices were obtained among regions, they were non overlapping.     

Analysis of the contribution of Mesoamerican and Andean gene pools to European common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) germplasm and strategies to establish a core collection

Common bean (Phaseolus vulgaris L.) was introduced in Europe from both Mesoamerican and Andean centres of origin. In this study, a collection including 544 accessions from all European regions showed that the Andean phaseolin types ‘T’ (45.6%) and ‘C’ (30.7%) prevailed over the Mesoamerican ones ‘S’ (23.7%), and accessions with cuboid seed shape (34.9%), maroon coat darker colour seed (44.3%), uniform seed colour (69.6%) were the most frequent. European accessions with phaseolin ‘S’ showed a significantly larger average seed size compared to those from America in the same phaseolin class while those presenting ‘T’ and ‘C’ phaseolin did not. This suggests that, during crop expansion in Europe, sampling or selection favoured the large-seeded races within the Mesoamerican ‘S’ gene pool or, possibly, introgression from Andean germplasm did occur. A core collection was developed using sampling approaches based on the information available in the genebank databases and on phaseolin patterns. Four sampling strategies were used: simple random sampling, and three random-stratified samplings, by logarithm of frequency of accessions by country, by European region, and by phaseolin pattern, respectively. Two sampling strategies resulted in core collections significantly different for phaseolin electrophoretic patterns from the whole collection. Stratification by phaseolin patterns increased the frequency of ‘S’ types (‘C’ type = 33%, ‘T’ type = 5.7% and ‘S’ type = 31.3%). The core collections were validated using seven seed characters, and no significant difference was observed in all strategies. This first developed European bean core collection will help to assess the contribution of the two American gene pools to the European germplasm and their relative importance for breeding purposes.     

Use of GIS for Optimizing a Collecting Mission for a Rare Wild Pepper (<Emphasis Type="Italic">Capsicum flexuosum</Emphasis> Sendtn.) in Paraguay

This paper presents an effective method for prioritizing areas within a country for acquisition of germplasm of a crop gene pool for ex situ conservation. The method was applied to the rare wild pepper species, Capsicum flexuosum Sendtn., in south-east Paraguay. A model to prioritize areas for collecting germplasm was constructed by combining (1) a prediction of the species' geographic distribution based on the climate at previous collection points, (2) the distribution of forest margins (the species' natural habitat) and (3) areas accessible by road. The model was then tested in the field by visiting 20 sites having both high and low predicted probability of occurrence of C. flexuosum. Six new populations were found, representing a significant improvement over two previous collecting missions for the species in the same region, undertaken without the use of GIS targeting. Using the most optimistic analysis of model performance, C. flexuosum was found at five out of seven points predicted to harbour the species and not found at four of five points predicted not to harbour the species. The model was then improved by the use of higher resolution climate surfaces. It is recommended that future explorers use more recent and higher resolution satellite images to locate suitable habitats. The method is replicable for different species in different geographic regions and is offered as a means of optimizing efficiency in financially constrained, national plant genetic resources programs.     

Observations on the geographic distribution, ecology and conservation status of several Phaseolus bean species in Costa Rica

Interest in bean genetic resources of Central America has resumed because of disease pressures (e.g., web blight, BGMV) and limitations of current bean varieties. As most of the diversity in landraces has been explored, focus is now on the exploration of wild forms of the primary gene pool and wild species of the secondary gene pool. A germplasm collection was carried out in the field and resulted in the collection of 29 wild populations for six Phaseolus species; it complemented field work done in 1987. Nine more populations were found for P. costaricensis, 10 for wild P. lunatus, one for P. oligospermus, one for P. tuerckheimii, four for wild P. vulgaris and four for P. xanthotrichus. Ninety-three herbarium voucher specimens were collected for 19 populations of the six species (deposited at CR). These results confirm the presence of wild P. vulgaris on both slopes of the central valley of Costa Rica, namely in the life zones bh-MB and bmh-P, and of P. costaricensis in the life zone bmh-MB. These life zones of limited range in Costa Rica have been heavily modified, thus fully justifying the germplasm collection for ex situ conservation. For both species the range of distribution in Costa Rica has been almost completely sampled. The life characteristics of each species that are relevant for their conservation in situ are briefly reviewed. Distribution ranges of each wild bean species are compared with the present extension of national parks, protected areas and fauna/flora sanctuaries, and suggestions for expanding such protected areas are made.     

Genetic Diversity in Accessions of Wild Rice Oryza granulata from South and Southeast Asia

Oryza granulata, an upland wild rice species, represents an unique germplasm for possessing abilities of tolerance to shade and drought, immune to bacterial blight and resistance to brown planthopper. Although low degree of genetic variability has been revealed within its populations, little genetic information at the species level is available in determining rational conservation strategies. Here we used dominant DNA marker random amplified polymorphism DNA (RAPD) to assess the genetic variability among 23 accessions of O. granulata that collected from main distribution areas worldwide. Twenty decamer primers generated a total of 243 bands, with 83.5% of them (203 bands) being polymorphic. Calculation of Shannon index of diversity revealed an average value of 0.42 ± 0.25, indicating that O. granulata maintains a relatively high degree of genetic diversity on the species level. Analysis of genetic dissimilarity (GD) showed that genetic differentiation occurred among studied accessions, which supports the feasibility of current ex situ conservation strategies. We also suggested that information based on population studies, which could be achieved by international co-operation, is needed to conserve this widespread germplasm more effectively.