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.     

Genetic diversity of the D-genome in <Emphasis Type="Italic">T. aestivum</Emphasis> and <Emphasis Type="Italic">Aegilops</Emphasis> species using SSR markers

Simple sequence repeats (SSRs), highly dispersed nucleotide sequences in genomes, were used for germplasm analysis and estimation of the genetic relationship of the D-genome among 52 accessions of T. aestivum (AABBDD), Ae. tauschii (D^tD^t), Ae. cylindrica (CCD^cD^c) and Ae. crassa (MMD^cr1D^cr1), collected from 13 different sites in Iran. A set of 21 microsatellite primers, from various locations on the seven D-genome chromosomes, revealed a high level of polymorphism. A total of 273 alleles were detected across all four species and the number of alleles per each microsatellite marker varied from 3 to 27. The highest genetic diversity occurred in Ae. tauschii followed by Ae. crassa, and the genetic distance was the smallest between Ae. tauschii and Ae. cylindrica. Data obtained in this study supports the view that genetic variability in the D-genome of hexaploid wheat is less than in Ae. tauschii. The highest number of unique alleles was observed within Ae. crassa accessions, indicating this species as a great potential source of novel genes for bread wheat improvement. Knowledge of genetic diversity in Aegilops species provides different levels of information which is important in the management of germplasm resources.     

Genetic diversity among <Emphasis Type="Italic">Jatropha</Emphasis> species as revealed by RAPD markers

The genus Jatropha is native of tropical America with more than 200 species that are widely distributed in tropics with a promise for use as an oil crop for biodiesel. This investigation was carried out to assess the genetic diversity of 12 Jatropha species based on random amplified polymorphic DNA markers. From 26 random primers used, 18 primers gave reproducible amplification banding patterns of 112 polymorphic bands out of 134 bands scored accounting for 80.2% polymorphism across the genotypes. Three primers viz., OPA 4, OPF 11, and OPD 14 generated 100% polymorphic patterns. The polymorphic information content was highest for the primer OPD 14 (0.50) followed by the primers OPF 11 and OPAD 11 (0.48). Jaccard’s coefficient of similarity varied from 0.00 to 0.85, indicative of high level of genetic variation among the genotypes studied. UPGMA cluster analysis indicated three distinct clusters, one comprising all accessions of J. curcas L., while second included six species viz., J. ramanadensis Ramam., J. gossypiifolia L., J. podagrica Hook., J. tanjorensis J. L. Ellis et Saroja J. villosa Wight and J. integerrima Jacq. J. glandulifera Roxb. remained distinct and formed third cluster indicating its higher genetic distinctness from other species. The overall grouping pattern of clustering corresponds well with principal component analysis confirming patterns of genetic diversity observed among the species. The result provides valid guidelines for collection, conservation and characterization of Jatropha genetic resources.     

Genetic Diversity of the Greater Yam (<Emphasis Type="Italic">Dioscorea alata</Emphasis> L.) and Relatedness to <Emphasis Type="Italic">D. nummularia</Emphasis> Lam. and <Emphasis Type="Italic">D. transversa</Emphasis> Br. as Revealed with AFLP Markers

Amplified fragment length polymorphism markers were used to assess the genetic relatedness between Dioscorea alata and nine other edible Dioscorea. These species include D. abyssinica Hoch., D. bulbifera L., D. cayenensis-rotundata Lamk. et Poir., D. esculenta Burk., D. nummularia Lam., D. pentaphylla L., D. persimilis Prain. et Burk., D. transversa Br. and D. trifida L. Four successive studies were conducted with emphasis on the genetic relationship within D. alata and among species of the Enantiophyllum section from Vanuatu. Study 1 was carried out to select a set of polymorphic primer pairs using 11 combinations and eight species belonging to five distinct sections. The four most polymorphic primer pairs were used in study 2 among six species of the Enantiophyllum section. Study 3 focussed mainly on the genetic relationship among 83 accessions of D. alata, mostly from Vanuatu (78 acc.) but also from Benin, Guadeloupe, New Caledonia and Vietnam. The ploidy level of 53 accessions was determined and results indicated the presence of tetraploid, hexaploid and octoploid cultivars. Study 4, included 35 accessions of D. alata, D. nummularia and D. transversa and was conducted using two primer pairs to verify the taxonomical identity of the cultivars `langlang', `maro' and `netsar' from Vanuatu. The overall results indicated that each accession can be fingerprinted uniquely with AFLP. D. alata is an heterogeneous species which shares a common genetic background with D. nummularia and `langlang', `maro' and `netsar'. UPGMA cluster analysis revealed the existence of three major groups of genotypes within D. alata, each assembling accessions from distant geographical origins and different ploidy levels. The analysis also revealed that `langlang', `maro' and `netsar' clustered together with the cultivar `wael' (D. transversa) from New Caledonia. Results are discussed in the paper.     

Analysis of genetic diversity and relationships of wild <Emphasis Type="Italic">Guizotia</Emphasis> species from Ethiopia using ISSR markers

Genetic relationships and diversity of 45 Guizotia populations each consisting of ten individuals and belonging to five taxa of the genus Guizotia were analyzed using Inter Simple Sequence Repeat (ISSR) markers. Five ISSR primers generated a total of 145 scorable bands across the 450 individuals used for the study. The percent polymorphic loci for the taxa ranged from 68.2 (G. arborescens) to 88% (G. scabra ssp. schimperi), with G. scabra ssp. scabra, G. zavattarii and G. villosa following G. scabra ssp. schimperi in this order with respect to the abundance of percent polymorphic loci. The Shannon-Weaver diversity indices (H′), for the five taxa also followed a similar pattern, with G. scabra ssp. schimperi exhibiting the highest H′ (0.7373) and G. arborescens the least (0.5791), while H′ for G. scabra ssp. scabra, G. villosa and G. zavattarii were 0.7313, 0.6620 and 0.6564, respectively. The least genetic distance (0.1188) was observed between G. scabra ssp. schimperi and G.villosa, revealing closer genetic relationships of the two species with each other than with the others, and the highest genetic distance (0.2740) was observed between G. scabra ssp. schimperi and G. zavattarii. The unweighted pair group method using the arithmetic average clustering of the five taxa using the standard genetic distances produced two clusters, with G. scabra ssp. schimperi and G. villosa occurring in one cluster and G. scabra ssp. scabra, G. arborescens and G. zavattarii together in the other cluster. The study reveals that G. scabra ssp. schimperi is more closely related to G. villosa than to G. scabra ssp. scabra.     

Characterization of fertile amphidiploid between <Emphasis Type="Italic">Raphanus sativus</Emphasis> and <Emphasis Type="Italic">Brassica alboglabra</Emphasis> and the crossability with <Emphasis Type="Italic">Brassica</Emphasis> species

A fertile amphidiploid × Brassicoraphanus (RRCC, 2n = 36) between Raphanus sativus cv. HQ-04 (2n = 18, RR) and Brassica alboglabra Bailey (2n = 18, CC) was synthesized and successive selections for seed fertility were made from F₄ to F₁₀. F₁₀ plants exhibited good fertility with 14.9 seeds per siliqua and 32.3 g seeds per plant. Cytological observation revealed that frequent secondary pairing occurred among 3 chromosome pairs in pollen mother cells of plants (F₄) with lower fertility, but not of plants with high fertility (F₁₀). GISH analysis indicated that these F₁₀ plants included the expected 18 chromosomes from R. sativus and B. alboglabra, respectively, but they lost approximately 27.6% R. sativus and 35.6% B. alboglabra AFLP (amplified fragment length polymorphism) bands. The crossability of the Raphanobrassica with R. sativus and 5 Brassica species (13 cultivars) were investigated. Seeds or F₁ seedlings were easy to be produced from crosses × Brassicoraphanus × R. sativus, and B. napus, B. juncea and B. carinata × Brassicoraphanus. Fewer seeds or seedlings were obtained from crosses × Brassicoraphanus × B. napus, B. juncea and B. carinata. However, few seeds were harvested in the reciprocals of × Brassicoraphanus with B. rapa and B. oleracea. The possible cause of fertility improvements and the potential of the present × Brassicoraphanus for breeding were discussed.     

Genetic diversity of HMW glutenin subunits in diploid,tetraploid and hexaploid <Emphasis Type="Italic">Triticum</Emphasis> species

The genetic variations of high-molecular-weight (HMW) glutenin subunits in 1051 accessions of 13 Triticum subspecies were investigated using sodium dodecyl sulfate polyacrylamide-gel electrophoresis. A total of 37 alleles were detected, resulting in 117 different allele combinations, among which 20, 68 and 29 combinations were observed in diploid, tetraploid and hexaploid wheats, respectively. Abundance and frequency of allele and combinations in tetraploid wheats were higher than these in hexaploid wheats. Allele Glu-A1c was the most frequent subunit at Glu-A1 locus in tetraploid and hexaploid wheats. Consequently, the results also suggested that the higher variations occurred at Glu-B1 locus compared to Glu-A1 and Glu-D1. Therefore, carthlicum wheat possessing the allele 1Ay could be presumed a special evolutional approach distinguished from other tetraploid species. Furthermore, this provides a convenient approach of induction of the 1Ay to common wheat through direct cross with carthlicum wheat. Alleles Glu-B1c and Glu-B1i generally absent in tetraploid wheats were also found in tetraploid wheats. Our results implied that tetraploid and hexaploid wheats were distinguished in dendrogram, whereas carthlicum and spelta wheats and however displayed the unique performance. In addition, founder effect, no-randomness of diploidization, mutation and artificial selection could cause allele distribution of HMW-GS in Triticum. All alleles of HMW-GS in Triticum could be further utilized through hybrid in the quality improvement of common wheat.     

<Emphasis Type="Italic">Rhizobium</Emphasis>,<Emphasis Type="Italic"> Bradyrhizobium</Emphasis> and<Emphasis Type="Italic"> Agrobacterium</Emphasis> strains isolated from cultivated legumes

The present study was conducted to isolate and characterize rhizobial strains from root nodules of cultivated legumes, i.e. chickpea, mungbean, pea and siratro. Preliminary characterization of these isolates was done on the basis of plant infectivity test, acetylene reduction assay, C-source utilization, phosphate solubilization, phytohormones and polysaccharide production. The plant infectivity test and acetylene reduction assay showed effective root nodule formation by all the isolates on their respective hosts, except for chickpea isolate Ca-18 that failed to infect its original host. All strains showed homology to a typical Rhizobium strain on the basis of growth pattern, C-source utilization and polysaccharide production. The strain Ca-18 was characterized by its phosphate solubilization and indole acetic acid (IAA) production. The genetic relationship of the six rhizobial strains was carried out by random amplified polymorphic DNA (RAPD) including a reference strain of Bradyrhizobium japonicum TAL-102. Analysis conducted with 60 primers discriminated between the strains of Rhizobium and Bradyrhizobium in two different clusters. One of the primers, OPB-5, yielded a unique RAPD pattern for the six strains and well discriminated the non-nodulating chickpea isolate Ca-18 from all the other nodulating rhizobial strains. Isolate Ca-18 showed the least homology of 15% and 18% with Rhizobium and Bradyrhizobium, respectively, and was probably not a (Brady)rhizobium strain. Partial 16S rRNA gene sequence analysis for MN-S, TAL-102 and Ca-18 strains showed 97% homology between MN-S and TAL-102 strains, supporting the view that they were strains of B. japonicum species. The non-infective isolate Ca-18 was 67% different from the other two strains and probably was an Agrobacterium strain.     

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.     

Morphological and molecular diversity analysis among the Indian clones of <Emphasis Type="Italic">Sesuvium portulacastrum</Emphasis> L.

Sesuvium portulacastrum L. (seapurslane) is a halophyte used as pioneer species in sand dune fixation and stabilization of saline soil. Studies on the morphological and molecular diversity were carried out for the 14 clones of Sesuvium collected from the different coastal regions of India. Significant differences were observed for morphological traits viz., length, width, diameter and area of leaf, internodal distance and stem diameter for different clones when compared with the clone from Gujarat state (GJ1). A UPGMA dendrogram for morphological traits based on the Pearson’s similarity coefficient clustered the clones into three groups considering 80% polymorphism as criteria. Molecular diversity among the clones was studied using Randomly Amplified Polymorphic DNA (RAPD), Internal Transcribed Spacer (ITS) and markers specific to Ac homologous region. Of the total 749 RAPD loci amplified with 70 random primers, 294 were polymorphic with 39.25% diversity. A phylogenetic tree constructed with UPGMA and SHAN, grouped the clones into three major clades based on RAPD data. The molecular diversity studied with ITS and markers specific to Ac homologous region revealed 37.50% and 66.66% polymorphism and clustered the clones into three and four clades, respectively. The genetic diversity analysis revealed wide variations among the S. portulacastrum clones, reflecting a high level of diversity within the species which might be due to anthropogenic impact and geographic environmental conditions. Further, the various clones from the different eco-geographic coastal localities might have originated from native places of wild abundance. To the best of our knowledge, this is the first attempt to evaluate both morphological and genetic diversity among the Sesuvium clones collected from the distant habitats of the coastal regions of the India.     

Genetic Characterization of Brazilian Annual <Emphasis Type="Italic">Arachis</Emphasis> Species from Sections <Emphasis Type="Italic">Arachis</Emphasis> and <Emphasis Type="Italic">Heteranthae</Emphasis> using RAPD Markers

The genus Arachis is divided into nine taxonomic sections. Section Arachis is composed of annual and perennial species, while section Heteranthae has only annual species. The objective of this study was to investigate the genetic relationships among 15 Brazilian annual accessions from Arachis and Heteranthae using RAPD markers. Twenty-seven primers were tested, of which nine produced unique fingerprintings for all the accessions studied. A total of 88 polymorphic fragments were scored and the number of fragments per primer varied from 6 to 17 with a mean of 9.8. Two specific markers were identified for species with 2n = 18 chromosomes. The phenogram derived from the RAPD data corroborated the morphological classification. The bootstrap analysis divided the genotypes into two significant clusters. The first cluster contained all the section Arachis species, and the accessions within it were grouped based upon the presence or absence of the ‘A’ pair and the number of chromosomes. The second cluster grouped all accessions belonging to section Heteranthae.     

Salt tolerance in <Emphasis Type="Italic">Zea mays</Emphasis> (L). following inoculation with <Emphasis Type="Italic">Rhizobium</Emphasis> and <Emphasis Type="Italic">Pseudomonas</Emphasis>

This study aimed to investigate the effect of inoculation with plant growth-promoting Rhizobium and Pseudomonas species on NaCl-affected maize. Two cultivars of maize (cv. Agaiti 2002 and cv. Av 4001) selected on the basis of their yield potential were grown in pots outdoors under natural conditions during July. Microorganisms were applied at seedling stage and salt stress was induced 21 days after sowing and maintained up to 50% flowering after 120 days of stress. The salt treatment caused a detrimental effect on growth and development of plants. Co-inoculation resulted in some positive adaptative responses of maize plants under salinity. The salt tolerance from inoculation was generally mediated by decreases in electrolyte leakage and in osmotic potential, an increase in osmoregulant (proline) production, maintenance of relative water content of leaves, and selective uptake of K ions. Generally, the microbial strain acted synergistically. However, under unstressed conditions, Rhizobium was more effective than Pseudomonas but under salt stress the favorable effect was observed even if some exceptions were also observed. The maize cv. Agaiti 2002 appeared to be more responsive to inoculation and was relatively less tolerant to salt compared to that of cv. Av 4001.     

Genetic diversity of a <Emphasis Type="Italic">Coffea</Emphasis> Germplasm Collection assessed by RAPD markers

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.     

A new mycorrhizal helper bacterium, <Emphasis Type="Italic">Ralstonia</Emphasis> species,in the ectomycorrhizal symbiosis between <Emphasis Type="Italic">Pinus thunbergii</Emphasis> and <Emphasis Type="Italic">Suillus granulatus</Emphasis>

In a Robinia-pseudoacacia-dominated coastal forest in Tottori prefecture Japan, the growth and survival of Pinus thunbergii seedlings and the natural regeneration of P. thunbergii was disturbed by R. pseudoacacia. In order to improve the growth of P. thunbergii seedling in the Tottori sand dune, we tried to find a mycorrhiza helper bacteria (MHB) from P. thunbergii mycorrhizosphere in a Tottori sand dune. Two MHB, Ralstonia sp. and Bacillus subtilis, were selected from the nine bacterial species isolated from the mycorrhizosphere of P. thunbergii. The bacterial effect on the ectomycorrhizal fungus Suillus granulatus was investigated by confrontation assay and a microcosm experiment. The confrontation assay showed that Ralstonia sp. promoted the hyphal growth of S. granulatus. Moreover, the S. granulatus–P. thunbergii symbiosis was significantly stimulated by Ralstonia sp. and B. subtilis. Ralstonia sp. and B. subtilis were regarded as MHB associated with P. thunbergii. This is the first report of Ralstonia sp. as an MHB.     

AFLP and RFLP linkage map in <Emphasis Type="Italic">Coix</Emphasis>

Coix is a genus in the grass family placed in the tribe Maydeae. It is closely related to maize and is also used as a crop plant. Since many valuable traits have been identified recently in Coix, it is considered to be a valuable genetic resource, particularly for maize improvement. In this study, a Coix genetic linkage map was constructed using an F2 population of 131 individuals. Eighty AFLP and 10 RFLP markers were mapped, covering a total length of 1339.5 cM with an average interval of 14.88 cM. The map consisted of 10 linkage groups, were consistent with the chromosome numbers observed cytogenetically. Both AFLP and RFLP markers were used first for genetic analysis in Coix. AFLP markers were generated by two restriction enzyme combinations, EcoRI/MseI and PstI/MseI. A total of 1349 bands were amplified, of which 140 were polymorphic. The polymorphism detection efficiency of the two enzyme combinations was compared, and utility of AFLP markers to construct the linkage map was discussed. Ten RFLP markers detected by three different probes were distributed on eight different linkage groups. The results provide a foundation to map and isolate important genes in Coix, and to investigate its genomic architecture, possible origins, and relationship with maize at the DNA level.     

On evolutionary pathways of <Emphasis Type="Italic">Avena</Emphasis> species

This article presents literary review and results analysis of evaluation of representative set of oat accessions of all Avena L. species. Results of complex study of major morphological characters and utilization of the karyotype structure data confirmed by the results of RAPD and avenin spectrum analysis are presented. Relationships of genomes of different Avena species at each ploidy level are discussed. Two genomes form the base of all Avena species, namely the A and C genomes. Results of the evaluation of several characteristics of the oat species and their geographical distribution are analysed. Probable evolutionary pathway of Avena species are suggested. Most likely the centres of origin of genus Avena L. are determined.     

Evaluation and utilization of <Emphasis Type="Italic">Aegilops</Emphasis> and wild <Emphasis Type="Italic">Triticum</Emphasis> species for enhancing iron and zinc content in wheat

Grains of 80 accessions of nine species of wild Triticum and Aegilops along with 15 semi-dwarf cultivars of bread and durum wheat grown over 2 years at Indian Institute of Technology, Roorkee, were analyzed for grain iron and zinc content. The bread and durum cultivars had very low content and little variability for both of these micronutrients. The related non-progenitor wild species with S, U and M genomes showed up to 3–4 folds higher iron and zinc content in their grains as compared to bread and durum wheat. For confirmation, two Ae. kotschyi Boiss. accessions were analyzed after ashing and were found to have more than 30% higher grain ash content than the wheat cultivars containing more than 75% higher iron and 60% higher zinc than that of wheat. There were highly significant differences for iron and zinc contents among various cultivars and wild relatives over both the years with very high broad sense heritability. There was a significantly high positive correlation between flag leaf iron and grain iron (r = 0.82) and flag leaf zinc and grain zinc (r = 0.92) content of the selected donors suggesting that the leaf analysis could be used for early selection for high iron and zinc content. ‘Chinese Spring’ (Ph ^I ) was used for inducing homoeologous chromosome pairing between Aegilops and wheat genomes and transferring these useful traits from the wild species to the elite wheat cultivars. A majority of the interspecific hybrids had higher leaf iron and zinc content than their wheat parents and equivalent or higher content than their Aegilops parents suggesting that the parental Aegilops donors possess a more efficient system for uptake and translocation of the micronutrients which could ultimately be utilized for wheat grain biofortification. Partially fertile to sterile BC₁ derivatives with variable chromosomes of Aegilops species had also higher leaf iron and zinc content confirming the possibility of transfer of required variability. Some of the fertile BC₁F₃ and BC₂F₂ derivatives had as high grain ash and grain ash iron and zinc content as that of the donor Aegilops parent. Further work on backcrossing, selfing, selection of fertile derivatives, leaf and grain analyses for iron and zinc for developing biofortified bread and durum wheat cultivars is in progress. Nidhi Rawat, Vijay K. Tiwari, and Neelam Singh have contributed equally to the work.     

AFLP-based genetic diversity assessment among Chinese vegetable mustards (<Emphasis Type="Italic">Brassica juncea</Emphasis> (L.) Czern.)

Amplified fragment length polymorphism (AFLP) analysis was used to evaluate the genetic relationships and diversities of Chinese vegetable mustards. Fourteen pairs of primers generated a total of 366 scorable fragments among 16 accessions of Brassica juncea studied, of which 296 bands were polymorphic with an average of 21.1% polymorphic bands per primer combination. Genetic similarities were obtained using Nei and Li similarity coefficients, and a dendrogram of the 16 accessions was made by UPGMA clustering method. The Nei and Li Similarity coefficient value ranged from 0.63 to 0.88. This result indicated that the 16 accessions of B. juncea possessed high level genetic variations. The cluster analysis showed that the vegetable mustards could be grouped into two main groups and some minor rami, which was partially in accordance with the traditional classification that based on different edible organs of vegetable mustards. The incongruity between morphological and molecular classification might be attributed to the high selection pressure during domestication of Chinese vegetable mustards, producing some accessions with similar genetic backgrounds evolving into abundant morphological variations. The great diversification among Chinese vegetable mustards not only provides an excellent object for molecular evolution research of B. juncea but also is of great value for widening the genetic basis of breeding programs and breeding materials selection. Besides, our study also indicates that AFLP are informative and can provide significant insights for genetic diversity research in B. juncea.     

Diversity analysis of Central Asia and Caucasian lentil (<Emphasis Type="Italic">Lens</Emphasis><Emphasis Type="Italic">culinaris</Emphasis> Medik.) germplasm using SSR fingerprinting

Diversity analysis was performed among 39 cultivated lentil (Lens culinaris Medik.) accessions of Central Asia and Caucasian origin using five highly polymorphic microsatellite markers. A total of 33 alleles determined ranging from 3 to 8 per locus. Estimated gene diversity value for 33 loci was 0.66. Genetic similarity indices among 39 accessions ranged from 0.24 to 1.0. Cluster analysis using the unweighted pair group method with arithmetic mean method classified accessions into six major groups at 0.5 similarity coefficient. More than half accessions from Tajikistan formed large cluster. On the other hand, a few accessions from each country showed unique genotypes. Overall, most of the accessions, except ones with closely related origin, were distinguished by the present high quality DNA fingerprinting. This molecular diversity information gives important basis for conservation strategy in gene bank and exotic germplasm introduction in breeding programs in Central Asia and Caucasian countries.