Diversity and genetic resources of wild <Emphasis Type="Italic">Vigna</Emphasis> species in India

Diversity in morphological characters of 206 accessions of 14 wild Vigna species from India was assessed. Of these, 12 species belonged to Asian Vigna in the subgenus Ceratotropis and two were V. vexillata and V. pilosa belonging to subgenus Plectotropis and Dolichovigna, respectively. Data on 71 morphological traits, both qualitative and quantitative, were recorded. Data on 45 qualitative and quantitative traits exhibiting higher variation were subjected to multivariate analysis for establishing species relationships and assessing the pattern of intraspecific variation. Of the three easily distinguishable groups in the subgenus Ceratotropis, all the species in mungo-radiata group, except V. khandalensis, viz. V. radiata var. sublobata, V. radiata var. setulosa, V. mungo var. silvestris and V. hainiana showed greater homology in vegetative morphology and growth habit. The species, however, differed in other plant, flower, pod and seed characteristics. Within species variation was higher in V. mungo var. silvestris populations and three distinct clusters could be identified in multivariate analysis. V. umbellata showed more similarity to V. dalzelliana than V. bourneae and V. minima in the angularis-umbellata (azuki bean) group. Within species variations was higher in V. umbellata than other species in the group. In the aconitifolia-trilobata (mothbean), V. trilobata populations, were more diverse than V. aconitifolia. The cultigens of the conspecific wild species were more robust in growth, with large vegetative parts and often of erect growth with three- to five-fold increase in seed size and seed weight, except V. aconitifolia, which has still retained the wild type morphology to a greater extent. More intensive collection, characterisation and conservation of species diversity and intraspecific variations, particularly of the close wild relatives of Asian Vigna with valuable characters such as resistance to biotic/abiotic stresses, more number of pod bearing clusters per plant etc. assumes great priority in crop improvement programmes.     

Isozyme relationships between cultivated artichoke and the wild relatives

Summary The genetic affinities between the cultivated artichoke Cynara cardunculus L. var. scolym (L.) Fiori [= C. scolymus L.] and its wild relatives were assessed by tests of 20 enzyme systems (28 loci). Six representative cultivars and the following wild taxa were examined: (i) wild cardoon C.cardunculus L. var. sylvestris (Lamk) Fiori, (ii) C. syriaca Boiss., (iii) C. cornigera (Lindley) [=C. sibthorpiana Boiss.], (iv) C. algarbiensis Cosson, (v) C. baetica (Spreng.) Pau [=C. alba Boiss.], and (vi) C. humilis L. Twenty one out of the 28 loci tested were polymorphic (mainly between species). The genetic identity between the cultivars and the wild cardoon forms ranged from 0.92 to 0.96; while that between these two taxa and the five other wild Cynara species ranged between 0.67 and 0.79. This implicates wild C. cardunculus in the wild ancestry of the cultivated artichoke.     

Isozyme analysis of genetic diversity in wild Sicilian populations of Brassica sect. Brassica in view of genetic resources management

In Sicily and in the small surrounding islands the section Brassica of the genus Brassica comprises five species, B. insularis Moris, B. incana Ten., B. macrocarpa Guss., B. rupestris Raf. and B. villosa Biv. These taxa represent a genetic resource as relatives of kale crops but some populations are endangered or threatened, thus isozyme analyses were performed to assess the genetic diversity degree at population and species levels in order to assist the design of conservation management programs.Eleven loci from five enzyme systems (aconitase, leucine aminopeptidase, 6-phosphogluconate dehydrogenase, phosphoglucoisomerase phosphoglucomutase) were analyzed in sixteen natural population (fifteen from Sicily, one from Calabria). Mean within-population genetic diversity was moderate (P = 41%, A = 1.54, H = 0.16). In some cases a great number of heterozygous individuals were detected, in other cases fixation index (F) deviated significantly from Hardy-Weinberg genotypic expectations.A total of 37 alleles was recognized, six of which resulted exclusive to single populations. The among-population component of the total genetic diversity (Gst mean values) for each species was 0.30–0.37, indicating genetic differentiation among populations.Among B. villosa and B. rupestris populations genetic distance values resulted rather low and they resulted high with B. incana and B. macrocarpa populations.The results are discussed with regard to the distribution of the genetic diversity level and the genetic resources management.     

Analyses of the seed protein contents on the cultivated and wild buckwheat <Emphasis Type="Italic">Fagopyrum esculentum</Emphasis> resources

The seed protein contents of 179 accessions belonging to ten species of genus Fagopyrum were determined by means of the Kjeldahl method. The results indicated that there are significant differences of seed protein content among different accessions within the same species. The average protein content of F. esculentum is 12.94%, ranging from 8.81–18.71%, and the protein content of Sibano is the highest, up to 18.71%, Gantian 1 the lowest with 8.81%. The average protein content of tartary buckwheat is 12.17%, with the range from 7.82–18.94%, and the protein content of cultivated tartary buckwheat Qianku 2 is the highest (18.59%), and that of Ganku 1 (7.82%) the lowest. Moreover, there are significant differences of seed protein content among different buckwheat species and between the different buckwheat types (between common buckwheat and tartary buckwheat, between the diploid and the tetraploid, between the cultivated and the wild, and between the big-achene group and the small-achene group). The average seed protein content of F. giganteum is the highest in all tested species, up to 17.81% with the range of 13.91–21.27%, and that of F. callianthum the lowest, only 8.31%. This study was financed by the Natural Science Foundation of China (30270852, 30471116), Program for New Century Excellent Talents in University (NCET-2004-0913), Guizhou Key International Cooperation Project (Qianke Hewai G Zi 2005#400108), Guizhou Oversea Talent Project (Qianren Xiangmu Zizhu Hetong 2004#02), and Key Project of Students in Guizhou Normal University (GNU-SP-2005-SJXY-A01)     

Genetic diversity of wild banana (<Emphasis Type="Italic">Musa balbisiana</Emphasis> Colla) in China as revealed by AFLP markers

Wild banana Musa balbisiana Colla is one of the progenitors of cultivated bananas and plantains. It is native to Southeast Asia and the western Pacific. South China represents the northern limit of its distribution range. The genetic diversity of Musa balbisiana was assessed by the amplified fragment length polymorphism (AFLP) fingerprinting in 15 populations of China. Four primer pairs produced 199 discernible loci. High levels of genetic diversity were detected, with P = 78.5%, H _E = 0.241, and H _pop = 0.3684 at population level, and P = 100%, H _T = 0.3362 and H _sp = 0.5048 at species level. Significant genetic differentiation among populations was detected based on Hickory’s analysis (27.6%), Shannon’s diversity index (27.0%) and AMOVA (27.1%). The AFLP results are discussed and compared with data obtained by microsatellites method. The estimates of genetic diversity and differentiation between each pair of populations computed with microsatellites and AFLP markers were not significantly correlated. Conservation strategies for Musa balbisiana in China are proposed.     

Using SSR markers to determine the population genetic structure of wild apricot (<Emphasis Type="Italic">Prunus armeniaca</Emphasis> L.) in the Ily Valley of West China

Genetic structure of three wild populations (Xinyuan, Gongliu and Daxigou) of apricot in the Ily Valley, Xinjiang Uygur Autonomous Region of China, was investigated with microsatellite (simple sequence repeat, SSR) markers. The higher polymorphism and greater transportability of these markers between Prunus species proved SSR markers were much efficient for conducting genetic diversity studies in wild apricot. Nei's gene diversity (He) and Shannon's index of diversity (I) were 0.287 and 0.458, respectively. This indicated that the wild apricot in the Ily Valley still maintained a relatively high level of diversity. The Gst of 0.137 and Fst of 0.164 revealed that genetic variation mainly resided among individuals within populations (83.6–86.3%). Population differentiation could also be found according to the distribution of SSR alleles between the populations. Mantel test showed the genetic distance between populations was significantly correlated to the geographical distance. The modest amount of gene flow (2.684) would reduce the disjunction between wild apricots. The long-distance dispersal of pollen by insects was probably the main way of gene flow between populations. Based on the study of population genetic structure, an effective conservation strategy of the species was discussed.     

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.     

Realizing value of genetic resources of <Emphasis Type="Italic">Allium</Emphasis> in India

The genetic resources of Allium in India are potential source of genes for widening the crop genetic base. Despite their high economic value, limited number of germplasm accessions of wild species have been collected and conserved mainly due to difficult access to areas of occurrence. The present work mainly highlights information on species diversity distribution and utilization of wild Allium species to assess the value of Indian germplasm and prioritization for future collection and conservation programmes.     

AFLP analysis of diploid species in the genus Vigna subgenus Ceratotropis

A representative set of germplasm of genusVigna subgenus Ceratotropis specieswas used to analyze genetic diversity using amplified fragment lengthpolymorphism (AFLP) methodology. The germplasm was selected based onmorphological diversity and geographic origin and includes 18 out of the 21species in the subgenus Ceratotropis. Genetic diversitywithin and between taxa was measured using information generated by AFLP bandpolymorphism from which Jaccard's similarity coefficient and nucleotidediversity were estimated. The data were also used to generate phenograms tovisualize relationships among analyzed accessions. All species in sectionsCeratotropis and Aconitifoliae arewell separated. However, most of the species in sectionAngulares show a high level of similarity suggesting a lowlevel of genetic differentiation. In section Angulares onespecies, V. trinervia, is welldifferentiated from the other species and represents a separate evolutionarybranch between section Ceratotropis and other species insection Angulares. The relationships between the newlydescribed species V. aridicola,V. exilis, V.nepalensis and V.tenuicaulis and other species in the subgenusCeratotropis are described for the first time based on AFLPdata.     

Identification of artichoke SSR markers: molecular variation and patterns of diversity in genetically cohesive taxa and wild allies

A set of 24 microsatellite markers was identified in the artichoke genome, using various approaches. A genomic library allowed the development of 14 SSR markers, whereas the other 10 were obtained from gene intron/UTR regions or from other species. Allelic variation was scored in C. cardunculus (artichoke, cultivated cardoon, and wild cardoon) samples, and in other wild Cynara allies. For the 23 polymorphic loci, a total of 165 alleles were scored, 135 of which in the artichoke primary genepool, and the remaining ones in the other Cynara species. Some allele combinations were able to identify artichoke varietal types, and some alleles were unique to specific groups. This makes these markers potentially useful in product traceability and in contributing to the saturation of genetic maps. The percentage of shared alleles between C. cardunculus taxonomic groups, and Nei’s genetic distances indicated that wild cardoons from the Eastern Mediterranean were more closely related to artichoke and less to cultivated cardoon in comparison to wild cardoons from the Western Mediterranean, and the genetic distance between the two wild cardoon genepools was rather high. The UPGMA dendrogram based on Nei’s genetic distances revealed that artichokes formed a fairly defined cluster, whereas Eastern wild cardoons occupied another branch, and Western wild cardoons were clustered together with cultivated cardoons. The transferability of microsatellite markers to other Cynara wild species was quite good. Sequencing alleles at three loci showed that, apart from microsatellite length variation, point mutations and insertion/deletions were quite abundant especially when comparing C. cardunculus to the other Cynara species. In the sequenced regions, some SNPs were identified which distinguished artichoke on one side, and cultivated and wild cardoon on the other, while other SNPs were apportioned according to the geographic distribution of Cynara wild species.     

Genetic relationships among Arachis hypogaea L. (AABB) and diploid Arachis species with AA and BB genomes

The cultivated peanut (Arachis hypogaea L.) is an allotetraploid, with two types of genomes, classified as AA and BB, according to cytogenetic characters. Similar genomes to those of A. hypogaea are found in the wild diploid species of section Arachis, which is one of the nine Arachis sections. The wild species have resistances to pests and diseases that affect the cultivated peanut and are a potential source of genes to increase the resistance levels in peanut. The aim of this study was to analyze the genetic variability within AA and BB genome species and to evaluate how they are related to each other and to A. hypogaea, using RAPD markers. Eighty-seven polymorphic bands amplified by ten 10-mer primers were analyzed. The species were divided into two major groups, and the AA and the BB genome species were, in general, separated from each other. The results showed that high variation is available within species that have genomes similar to the AA and the BB genomes of A. hypogaea.     

Sources of resistance to cyst nematode in cultivated and wild Cicer species

Summary Among the nematodes infesting chickpea (Cicer arietinum L.) plants in Syria, cyst nematode (Heterodera ciceri Vovlas, Greco et Di Vito) is the most important. It is uneconomical to grow chickpea in fields infested with cyst nematode and to control this nematode with nematicide. Therefore, investigations were conducted at ICARDA, Syria from 1987 to 1991 to identify sources of resistance to cyst nematode in 7258 lines of C. arietinum and 102 lines of eight annual Cicer species including C. bijugum K.R. Rech. (13 lines), C. chorassanicum (Bge) M. Pop. (3 lines), C. cuneatum Hochst. ex Rich. (3 lines), C. echinospermum P.H. Davis (8 lines), C. judaicum Boiss. (18 lines), C. pinnatifidum Jaub. & Sp. (18 lines), C. reticulatum Ladiz. (36 lines), and C. yamashitae Kitamura (3 lines). All lines were grown in a greenhouse at 15–25°C in pots containing soil infested with 20 eggs of the nematode g^-1 soil. Nematode infestation was evaluated on a 0 to 5 scale based on number of females and cysts on roots. Resistance was found in one line of C. bijugum, six lines of C. pinnatifidum, and one line of C. reticulatum. No lines of C. arietinum, C. chorassanicum, C. cuneatum, C. echinospermum, C. judaicum, or C. yamashitae was resistant to cyst nematode. Plants with resistance have been recovered in the F₃ generation from crosses between the cultigen and C. reticulatum, indicating the possibility of transfer of gene(s) for resistance to cyst nematode from wild to cultivated Cicer species.Joint contribution from Istituto di Nematologia Agraria, ICARDA and ICRISAT (International Crops Research Institute for the Semi-Arid Tropics), Patancheru P.O., A.P. 502 324, India.     

Geographical distribution of wild <Emphasis Type="Italic">Daucus</Emphasis> species in the natural grasslands of the Argentinian pampas

Three wild carrot species have been reported in the argentinian flora: Daucus montanus Humb. et Bonpl. ex Schult., D. montevidensis Link ex Sprengel and D. pusillus Michx. There is a discrepancy among authors about the distinctive morphological traits of the last two species; thus, it is difficult to ascertain if they are truly two distinct taxa. Based on the available literature and in the search of a paradigmatic site, four collection trips were carried out in 2004 and 2005 in Buenos Aires and Southern Entre Ríos provinces. Populations were sampled at 30 sites, and local environmental parameters and associated plant species were recorded. Morphological observations and chromosome counts were carried out on 10 plants/population. Three morphological phenotypes were distinguished: one in 18 populations, all with 2n = 2x = 18, and two in the remaining 12, with 2n = 2x = 22 or aneusomaty (2n = 2x = 20, 22). Populations of the first phenotype were assigned to wild D. carota and the rest, tentatively, to D. pusillus (D. montevidensis?), till further evaluations are carried out in test sites to verify this tentative conclusion.     

The extent of embryo and endosperm growth following interspecific hybridization between Cicer arietinum L. and related annual wild species

In vivo interspecific pollinations were performed and immature seed development investigated by histological methods in order to study crossability barrier(s) in Cicer L. species wide hybridization. Seven of the eight wild annual Cicer species, belonging to the secondary and tertiary gene pools, were used in reciprocal crosses with the cultivated chickpea. It was confirmed that the zygote was formed in all interspecific crosses. The embryos showed continued and retarded growth at different rate in various crosses, but eventually aborted at an early pro-embryo stage in all crosses except C. arietinum L. ×C. echinospermum Dav. Reciprocal cross differences were observed in early embryo growth rate and could have implications in obtaining hybrids. This study further emphasizes the necessity for developing appropriate and efficient in vitro procedures for rescuing immature globular hybrid pro-embryos, which will make the wild Cicer gene resources amenable to chickpea improvement.     

A Preliminary Comparative Evaluation of Genetic Diversity between Chinese and Japanese Wild Soybean (<Emphasis Type="Italic">Glycine soja</Emphasis>) Germplasm Pools using SSR markers

The wild soybean, an annual self-pollinating plant, is the progenitor of soybeans and is extensively distributed in the Far East of Russia, the Korea peninsula, China and Japan. Geographically, Japan is surrounded by sea and insulated from China. We preliminarily evaluate whether the Japanese and Chinese wild soybean germplasm pools are genetically differentiated from each other using SSR markers. The results showed that the two pools have great genetic differentiation. Some loci presented obvious differences in mean genetic divergence (G_ST) value between the two pools. The G_ST among the geographic regions in China was higher than that in Japan. The average within-geographic region gene diversity values (H_S) in the two pools were completely identical and thus the genetic difference between the two pools was mostly attributed to the relatively high level of between-geographic region gene diversity (D_ST) in China. We suggest that Japanese and Chinese wild soybeans should be comparatively independently evolving in phylogeny.     

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 resource conservation of the endemic genus Argyranthemum Sch. Bip. (Asteraceae: Anthemideae) in the Macaronesian Islands

Germplasm from one or more populations of each taxon of the Macaronesian endemic genus Argyranthemum Sch. Bip. (Asteraceae: Anthemideae) was collected in the Canary Islands, Madeira, the Selvagens Islands and the Desertas Islands. A total of 253 germplasm samples was collected and they are conserved ex situ at the seed bank of Centro de Investigación y Tecnología Agraria de Canarias (Tenerife, Canary Islands, Spain). Duplicates are held at the germplasm bank of Escuela Técnica Superior de Ingenieros Agrónomos (Madrid, Spain). A preliminary account of the ecogeography of the genus based on field observation is provided. In situ conservation strategies are discussed, particularly with regard to the occurrence of hybridization within Argyranthemum.Abbreviations IUCN international Union for Conservation of Nature - CITA Centro de Investigación y Tecnología Agraria de Canarias - ETSIA Escuela Técnica Superior de Ingenieros Agrónomos, Madrid     

Potential of wild species for genetic enhancement of some semi-arid food crops

Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.