Mapping the potential distribution of five species of Passiflora in Andean countries

Geographic location data for 383 accessions of five Passiflora species from five Andean countries (P. cumbalensis, P. mixta, P. tripartita var. mollissima, P. natistipula, and P. manicata) were linked to interpolated continental surfaces of monthly mean rainfall, monthly mean temperature, and monthly mean diurnal temperature range. This permitted us to identify the potential distribution of each species and document its climatic adaptation. Maps are presented showing regions where the climate is similar to that in areas where each species has been found, but from which no collections have yet been made, thus representing possible geographical gaps in collections. Some species showed evidence of intra-specific variation in their climatic adaptation. The study of Passiflora diversity in Andean countries continues and these maps based on passport data are expected to be useful tools for the planning of both ex situ and in situ conservation activities.     

An AFLP diversity study of the genus Passiflora focusing on subgenus Tacsonia

DNA variation was studied at the intra- andinterspecific levels within the genus Passiflora, with particular emphasis on the subgenusTacsonia and its relationship with the subgenusPassiflora. AFLP fingerprints were generated for35 accessions from 21 species, 14 of which belong to subgenusTacsonia, and four to subgenusPassiflora. The morphologically intermediateP. manicata (subgenusManicata) was also included, as wereP. trinervia (subgenusPsylanthus) and P.alnifolia (subgenus Decaloba). The two latter were used as outgroup species. Twoprimer combinations generated 34–80 scorable fragments pergenotype for a total of 260 fragments. Polymorphism analyses spannedthe levels from individual genotype to section. SubgenusTacsonia presented wide genetic variability atboth intra- and interspecific levels, particularly within wildspecies. The classification based on these markers generally agreeswell with current taxonomic definitions of common species, but lesswith definitions of sections. A geographical component was evident inthe intraspecific variation of P.mixta, P.tripartita var. mollissimaand P. tarminiana, withwider variation in Ecuador and Peru than in Colombia and Venezuela.These same three species, plus P.cumbalensis, formed adjacent clusters, showingcloser affinity with each other than with the other species ofsubgenus Tacsonia. As expected, P. manicata clustered at anintermediate position between subgenera Tacsoniaand Passiflora.     

Isozyme Variation in <Emphasis Type="Italic">Passiflora</Emphasis> Subgenus <Emphasis Type="Italic">Tacsonia</Emphasis>: Geographic and Interspecific Differentiation Among the Three Most Common Species

In a general study of banana passion fruit genetic resources, diversity was analyzed in the two main cultigens, P. tripartita var. mollissima and P. tarminiana, and their closest wild relative, P. mixta, scoring isozyme bands (IDH,PGM,ACP,PGD,DIA,andPRX) on288 plants from 31 accessions. Polymorphismandallelic richness, Nei diversity indices, and neighbor joining clustering showed that variation was poor in the cultigens in northern and central Colombia, while P. mixta appeared much more polymorphic. The populations of P. tripartita var. mollissima and P. mixta from southern Colombia and Ecuador show higher diversity values and are clearly differentiated from those of central and northern Colombia. This geographic component of variation is even stronger than the interspecific one, which suggests a close relation and a regular gene flow between these two species. In contrast, all the accessions of P. tarminiana constitute a clearly differentiated group, even if some introgression with P. tripartita var. mollissima is also suspected. The high variation observed in the southern region indicates the proximity of a center of diversity for banana passion fruit and collecting in Ecuador, Peru and Bolivia is recommended. The high diversity of P. mixta and the evidence of gene flow with P. tripartita var. mollissima constitute a favorable context for the implementation of in situ conservation strategies.     

Genetic relationships among cultivated types of Perilla frutescens and their weedy types in East Asia revealed by AFLP markers

AFLP markers were employed to detect genetic diversity in two cultivated Perilla frutescens (i.e. var. frutescens and var. crispa) and their weedy types and to assess their genetic relationships. Analysis of 60 Perilla accessions from China, Korea and Japan by seven AFLP primer combinations identified a total of 125 fragments, of which 80 (64%) were polymorphic at the species level. The phenotypic diversity meassured by Shannon's index of information for the cultivated type of var. frutescens, the weedy type of var. frutescens, the cultivated type of var. crispa and the weedy type of var. crispa were on average 1.07, 2.23, 1.24 and 1.75, respectively. The weedy types exhibited high within-type variation in spite of a small number of samples. In the neighbor joining tree, two major clusters were recognized: (1) cultivated type of var. frutescens, (2) weedy type of var. frutescens, and cultivated and weedy types of var. crispa. The cultivated types of var. frutescens and of var. crispa were sharply separated by AFLPs. However, there remained ambiguities in regard to the intraspecific relaltionships, due to the clustering of the weedy types which occured in each of the clusters of the cultivated types. Two cultivated types of P. frutescens and their weedy types should be taxonomically considered as a P. frutescens complex. The present AFLP data are consistent with the hypothesis that China is the original place of cultivation of var. frutescens and Korea is a secondary center of diffusion of var. frutescens.     

Characterisation of germplasm accessions of Napier grass (pennisetum purpureum and P. purpureum×P. glaucum Hybrids) and comparison with farm clones using RAPD

Fifty six germplasm accessions of the important East African fodder crop Napier grass, Pennisetum purpureum, and its hybrids with P. glaucum, were characterised using 67 random amplified polymorphic DNA (RAPD) fragments. No or very low intra-accession variation was found for 49 of the accessions examined, confirming field observations that this species is predominantly clonally propagated. Comparison of intra and inter-accession variation identified several groups of identical/similar accessions that could be targeted if the collection is to be rationalised, and also highlighted two misplantings of germplasm material during transfer to a field trial site. A neighbour joining dendrogram of Jaccard's similarity estimates, clearly separated 50 accessions of P. purpureum from three P. glaucum individuals, and placed six hybrid accessions in an intermediate position. These groupings were well supported by a nested AMOVA (P<0.001; 29.5% of total variance due to taxonomic delineation). The main group of P. purpureum individuals could be further differentiated into five sub-groups (designated East Africa, Southern Africa, USA1, USA2 and Miscellaneous, to reflect the majority membership of sub-groups) and examination of the within P. purpureum component of the nested AMOVA, found them to be significantly different (P<0.001; 18.8% of variance). Genetic diversity across all accessions was found to be fairly high (Shannon's diversity index 0.306) and thus the collection probably represents a wide genetic base for this species. In addition to germplasm accessions, 25 Kenyan farm clones were also analysed. A principal coordinate analysis found that all but one of the clones clustered with the main P. purpureum group of accessions, indicating that the majority are probably not interspecific hybrids. The origin and pedigree of clones is discussed based on genetic similarity amongst clones and to germplasm accessions.     

Taxonomic status and geographic provenance of germplasm accessions in the Solanum nigrum L. complex: AFLP data

Amplified Fragment Length Polymorphisms (AFLPs) were employed within the taxonomically difficult Solanum nigrum L. complex in order to characterize the genetic diversity present in a collection of the Gatersleben Genebank, to classify taxonomically unknown material, and to correlate the clustering of the examined accessions with their geographic origin. The results from AFLP analyses using two primer combinations on 44 entries from five species led to the detection of four major clusters, simultaneously uncovering significant differences in the levels of genetic diversity within or between species. S. americanumexhibited the highest infraspecific variation despite close geographic origins, simultaneously being placed in a clearly separated cluster in comparison to the other examined species of the complex. In addition, these other species showed even less interspecific variation than was found at the infraspecific level in S. americanum. In terms of taxonomy, the application of AFLPs helped in the classification of 13 black nightshade accessions formerly only listed as Solanum sp. This also was confirmed by morphological determination. Furthermore, one accession formerly classified as S. physalifolium var. nitidibaccatum i) clustered with AFLPs and ii) was identified morphologically as S. villosum. Contradictory classifications remain for two further entries from the same species, found within the S. nigrum cluster after AFLP analyses, while belonging to S. physalifolium var. nitidibaccatum according to herbarium specimen. Finally, as indicated by the information on provenance in geographically separated subclusters in S. americanum and partially in S. villosum, clues on the currently unknown origin of accessions from the genebank seem feasible by AFLP data.     

Genetic diversity and structure of Ethiopian,Yemen and Brazilian C<Emphasis Type="Italic">offea arabica</Emphasis> L. accessions using microsatellites markers

Genetic diversity among 115 coffee accessions from the Coffea Germplasm Collection of IAC was assessed using SSR markers. The germplasm represents 73 accessions of Coffea arabica derived from spontaneous and subspontaneous plants in Ethiopia and Eritrea, species center of origin and diversity, 13 commercial cultivars of C. arabica developed by the Breeding Program of IAC, 1 accession of C. arabica cv. ‘Geisha’, 13 accessions of C. arabica from Yemen, 5 accessions of C. eugenioides, 4 accessions of C. racemosa and 6 accessions of C. canephora. Genetic analysis was performed using average number of alleles per locus (A), proportion of polymorphic loci (P), Shannon’s genetic index (H′ and G′_ST) and clustering analysis. All evaluated species were distinguished by a cluster analysis based on Jaccard’s coefficient. Differentiation between the cultivated plants of C. arabica and accessions derived from spontaneous and subspontaneous plants was observed. Spontaneous and subspontaneous accessions from Ethiopia were separated according to the geographical origin: east and west of the Great Rift Valley. Cultivated plants showed a low genetic diversity with a division in two groups: accessions from Yemen (H′=0,028) and Brazilian commercial cultivars (H′=0,030). The results agreed with previously reported narrow genetic basis of cultivated plants of C. arabica and supported the hypotheses about domestication of the species. This study also showed a significant genetic diversity among accessions from Ethiopia and Eritrea present in the Germplasm Collection of IAC. This diversity is specially observed in accessions from Sidamo (H′=0,143), Kaffa (H′=0,142) and Illubabor (H′=0,147) indicating their importance as source of genetic variability for coffee breeding programs.     

Genetic relationships among cultivated and wild <Emphasis Type="Italic">Vigna angularis</Emphasis> (Willd.) Ohwi et Ohashi and relatives from Korea based on AFLP markers

Genetic variation and relationships among members of the azuki bean complex (Vigna angularis) including wild (V. angularis var. nipponensis), weedy, and cultivated types (V. angularis var. angularis), V. nakashimae, and rice bean (V. umbellata) from Korea were examined using the Amplified fragment length polymorphism (AFLP) method. AFLP analysis of 50 accessions revealed 333 (72.1%) polymorphic fragments out of 462 fragments amplified using seven primer combinations. The number of polymorphic fragments within each species was 70 in the azuki bean complex and 41 in V. nakashimae, but there was no polymorphism in rice bean. The number of shared fragments among species ranges from 142 between the azuki bean complex and V. nakashimae to 166 between the azuki bean complex and rice bean. Within the azuki bean complex, the range of shared bands was from 231 between cultivated and weedy types to 238 between cultivated and wild types. A dendrogram generated from Jaccard’s similarity matrix was divided into three groups, which correspond to V. nakashimae, azuki bean complex, and rice bean. The relationship between azuki bean and rice bean is closer than between azuki bean and V. nakashimae. Phenetic distances averaged 0.502 between the azuki bean complex and V. nakashimae and 0.467 between the azuki bean complex and rice bean. Within the azuki bean complex, the weedy type was more closely related to wild than cultivated types. But UPGMA dendrogram of the azuki bean complex reveals that each type is not clearly isolated. These results will help to understand genetic diversity and evolutionary dynamics of Vigna in Korea.     

Genetic diversity in Hordeum agriocrithon E. Åberg, six-rowed barley with brittle rachis, from Tibet

Twenty-two accessions of H. agriocrithon from Tibet were investigated for morphological and physiological characters, and genotypes combined alleles at the tightly linked Est1, Est2 and Est4 complex locus encoding esterase isozymes. H. agriocrithon was similar in plant type to Tibetan cultivated barley, but different from H. spontaneum. The accessions of H. agriocrithon were classified by their spike-awn types into vars. eu-agriocrithon, dawoense and paradoxon, with one exceptional accession of the awnless naked type similar to var. nuditonsum of cultivated barley. They were characterized by spring growth habit, susceptibility to Japanese race I of powdery mildew, and either of the same three esterase genotypes as those of cultivated barley from Tibet, Bhutan and Ladakh. The similarity suggested that the esterase complex locus on chromosome 3H is closely linked with some QTL for adaptation to Tibetan conditions. On the origin of H. agriocrithon, it might be concluded that natural hybridization between H. spontaneum and six-rowed barley occurred in northern parts of Afghanistan, Pakistan or India, and seeds of their segregants mixed into barley or wheat were brought up to Tibet, resulting six-rowed barley with brittle rachis.     

Description of Iranian Diploid Wheat Resources

Iran is one of the primary centers of diversity for wheat and its relatives. Wild wheats, in particular diploid species, are extensively distributed in various parts of Iran. Of these, the existence of two “A" genome donor species, i.e., T. baeoticum and T. monococcum, has already been reported in Iranian floras. However, the existence of the other important “A" genome donor, i.e., T. urartu, has not been clearly reported. In a germplasm collection survey in several regions of Iran, T. urartu was identified, collected, and described, and is reported here for the first time. In a detailed and extensive taxonomic program, the collected germplasms of the above three species were studied. Morphological characters and species-specific traits of the three species were evaluated and compared. Using the monographs by Gandilyan (1980) and Dorofeev et al. (1979) for the collected germplasms, 14 varieties were identified of T. boeoticum, 3 varieties of T. urartu, 2 forms of T. monococcum. Of these 5 varieties of T. baeoticum ssp. baeoticum (var. albinigrum, var. garniense, var. zuccarinii, var. baeoticum, var. pseudobaeoticum), 3 varieties of T. baeoticum ssp. thaoudar (var. abovjanii, var. albinigrescens, var. ebrahimzadehae, var. viridinigrireuteri) and 1 variety of T. monococcum (var. mansfeldii) are new to Iran. In addition, 1 variety of T. baeoticum ssp. baeoticum (var. khorramabadicum), 3 varieties of T. baeoticum ssp. thaoudar (var. ebrehimeadena var. taleghanicum, var. ilamicum) and 2 varieties of T. urartu (var. iranicum, var. sardashticum) are new to the wheat botany.     

Genetic diversity in Ethiopian hexaploid and tetraploid wheat germplasm assessed by microsatellite markers

The genetic diversity of a subset of the Ethiopian genebank collection maintained at the IPK Gatersleben was investigated applying 22 wheat microsatellites (WMS). The material consisted of 135 accessions belonging to the species T. aestivum L. (69 accessions), T. aethiopicum Jacubz. (54 accessions) and T. durum Desf. (12 accessions), obtained from different collection missions. In total 286 alleles were detected, ranging from 4 to 26 per WMS. For the three species T. aestivum, T. aethiopicum and T. durum on average 9.9, 7.9 and 7.9 alleles per locus, respectively, were observed. The average PIC values per locus were highly comparable for the three species analysed. Considering the genomes it was shown that the largest numbers of alleles per locus occurred in the B genome (18.4 alleles per locus) compared to A (10.1 alleles per locus) and D (8.2 alleles per locus) genomes. Genetic dissimilarity values between accessions were used to produce a dendrogram. All accessions could be distinguished, clustering in two large groups. Whereas T. aestivum formed a separate cluster, no clear discrimination between the two tetraploid species T. durum and T. aethiopicum was observed.     

Genetic variation within and among species of genus Arachis, section Rhizomatosae

The genus Arachis is endemic to South America and comprises 80 species, 69 of which have already been described and eleven not yet published. The genus includes the cultivated peanut (A. hypogaea) and several forage species, the most important ones being A. glabrata and A. pintoi. Accessions of section Rhizomatosae, including three tetraploid species 2n = 4x = 40 (A. glabrata, A. pseudovillosa and A. nitida nom. nud.) and one diploid species 2n = 2x = 20 (A. burkartii), were evaluated using RAPD markers to assay genetic variability within and among species. The ten random primers used yielded a total of 113 polymorphic bands. The data were scored as the presence or absence of each band in each sample. A distance matrix and dendrogram were obtained using Link's coefficient and the neighbor-joining method. Most accessions analyzed grouped into two major clusters: the first comprised most accessions of A. glabrata and accessions of A. nitida, and the second cluster comprised accessions of A. burkartii. Arachis pseudovillosa and a few accessions of A. glabrata and A. nitida were placed between these major clusters. The diploid and tetraploid species were grouped quite separately, suggesting that the tetraploids did not originate from the diploid species analyzed.     

Diversity among landraces of Indian snapmelon (<Emphasis Type="Italic">Cucumis melo</Emphasis> var. <Emphasis Type="Italic">momordica</Emphasis>)

Diversity among 36 snapmelon landraces, collected from 2 agro-ecological regions of India (9 agro-climatic sub-regions), was assayed using RAPD primers, morphological traits of plant habit and fruit, 2 yield-associated traits, pest and disease resistance and biochemical composition (TSS, ascorbic acid, titrable acidity). Typical differences among accessions were observed in plant and fruit characteristics and snapmelon germplasm with high titrable acidity and possessing resistance to downy mildew, Cucumber mosaic virus, Zucchini yellow mosaic virus, Papaya ringspot virus, Aphis gossypii and Meloidogyne incognita was noticed in the collection. RAPD based grouping analysis revealed that Indian snapmelon was rich in genetic variation and region and sub-region approach should be followed across India for acquisition of additional melon landraces. Accessions of var. agrestis and var. momordica clustered together and there was a separate cluster of the accessions of var. reticulatus. Comparative analysis of the genetic variability among Indian snapmelons and an array of previously characterized reference accessions of melon from Spain, Israel, Korea, Japan, Maldives, Iraq, Pakistan and India using SSRs showed that Indian snapmelon germplasm contained a high degree of unique genetic variability which was needed to be preserved to broaden the genetic base of melon germplasm available with the scientific community. N. P. S. Dhillon and Ranjana contributed equally to this work and are considered the first authors.     

Analysis of genetic diversity in Piper nigrum L. using RAPD markers

RAPD analysis was conducted in 22 cultivars of P. nigrum(black pepper) from South India and one accession each of P. longum and P. colubrinum. Twenty-four primers generated 372 RAPD markers of which 367 were polymorphic. Jaccard's similarity between pairs of accessions ranged between 0.11 and 0.66 with a mean of 0.38. Among P. nigrum cultivars, the similarity ranged between 0.20 and 0.66 and the mean was 0.42. The existence of wide genetic diversity as revealed in the present study is supported by earlier reports of extensive inter- and intrapopulation morphological variability in pepper cultivars from South India. UPGMA dendrogram and PCO plot revealed P. colubrinum to be most distant of the three species. Genetic proximity among P. nigrum cultivars could be related to their phenotypic similarities or geographical distribution. Greater divergence was observed among landraces than among advanced cultivars. Landraces grown in southern parts of coastal India and those grown in more northern parts were grouped in separate clusters of the dendrogram.     

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.     

Agricultural potential of Mediterranean grain and forage legumes: Key differences between and within Vicia species in terms of phenology, yield, and agronomy give insight into plant adaptation to semi-arid environments

In order to identify key adaptive traits which affect productivity in Mediterranean grain and forage legumes and simultaneously determine the agricultural potential of a wide range of Vicia species, germplasm collected from the wild throughout the eastern Mediterranean was grown under semi-arid conditions in Tel Hadya, Syria (313 mm growing season rainfall). These included species currently in use in Mediterranean agriculture, such as V. sativa L., as well as those more widely used in the past-such as V. ervilia L., but also a broad selection from Section Narbonensis (B. Fedtsch. ex Radzhi) Maxted, including V. narbonensis L, V. johannis Tamamsch., V. hyaeniscyamus Mout., V. serratifolia Jacq., and V. kalakhensis Khattab et al. V. faba, a near relative of the taxa in Section Narbonensis, was included as a domesticated control. Where applicable, a representative range of subspecies was used. Accessions were chosen from a wide range of habitats in terms of latitude (31.02–40.72 decimal^o), longitude (27.1–43.17 decimal^o), altitude (20–1510 m), rainfall (180–1700 mm/yr) and soil depth (5–50 cm) in order to maximise diversity within species. Agricultural potential was determined by measuring seed, hay and biological yield, as well as agronomic traits such as harvest index, standing crop height, and seed size. The comparative influence of phenology and key agronomic traits such as plant habit and seed size on productivity varied tremendously between species, depending on their reproductive strategies. In V. sativa and V. ervilia, the smaller seed species which rely on long vegetative phases and growing seasons to accumulate sufficient biomass to set seed, and in which there was comparatively little agronomic variation, phenology had a large impact on yield. In early emerging taxa such as V. ervilia and V. s. subsp. sativa, with built-in long vegetative phases and growing seasons, seed yield was negatively correlated with flower ing (r = –0.86 to –0.88), whereas the opposite was the case for later emerging taxa such as V. s. subsp. nigra (L.) Ehrh. (r = 0.95). Within V. narbonensis and relatives, the larger seeded Vicia species which rely on more conservative reproductive strategies where high seedling vigour associated with large seeds enables the species to enter reproductive phases relatively early, phenology had a much smaller impact on yield than did variation of key traits such as seed weight, plant habit and pod shattering. Among the undomesticated germplasm harvest indices ranged from 0.09–0.31, hay yields from 0.1–3.4 t/ha, seed yield from 0–2.0 t/ha, and dry matter at maturity from 1.6–6.5 t/ha. Sub-specific taxonomy was crucial in determining agronomic potential. V. narbonensis var. aegyptiaca Kornhuber ex Asch. et Schweinf. showed the most potential, combining an upright habit, large seeds (212 mg) and tendency to retain intact pods after maturity, with the highest yield, harvest index and crop height of all the wild Vicia species. V. sativa subsp. sativa, V. ervilia and V. narbonensis var. narbonensis were less productive, but still showed agricultural potential. The smaller seeded V. narbonensis, var. affinis, var. jordanica H. Schäf. and var. salmonea (Mout.) H. Schäf., and their close relatives V. johannis, V. hyaeniscyamus, V. serratifolia and V. kalakhensis have little to offer Mediterranean agriculture on the basis of poor agronomy.     

Genetic relationships among perennial and annual Cicer species growing in Turkey as revealed by allozymes

Allozyme polymorphisms were used to assess genetic variation and relationships among ten Cicer species (annuals and perennials) growing in Turkey. Using seven enzyme systems, 12 putative scorable loci were detected and surveyed for polymorphism in an accession collection including wild and cultivated forms. Variation was generally low within accessions and species, but common between species. Cluster analysis based on the pairwise genetic distance coefficients among accessions and species using UPGMA revealed two species clusters; one includes three perennials (C. montbretii, C. isauricum and C. anatolicum) and the other contains six annuals (C. pinnatifidum, C. bijugum, C. judaicum, C. echinospermum, C. reticulatum and C. arietinum) and one perennial species (C.incisum). Grouping obtained in allozyme analysis appears to be consistent with the classification these species into three sections. However, contrary to relationships obtained in previous studies, three perennial species from section Polycicer were relatively distant to the group containing annuals. One perennial species, C. incisum from section Chamaecicer, clustered with annuals showing a close similarity. The grouping of six annual species was consistent with the previous reports of relationships. The relationships deduced between perennials and annuals appear to shed light on the evolution of annual habit from perennial habit.