The effectiveness of evaluating wild species: searching for sources of resistance to bruchid beetles in the genus Vigna subgenus Ceratotropis

A species level germplasm collection representing 76% of known taxa in the genus Vigna subgenus Ceratotropis was evaluated for resistance to two species of bruchid beetles, Callosobruchus chinensis and C. maculatus. Seven taxa consisting of 29 accessions were found to be resistant to C. chinensis and 4 taxa consisting of 24 accessions were found to be resistant to C. maculatus. This compared with no resistant accessions being found in several hundred landrace accessions of mungbean, V. radiata var. radiata, in the same subgenus. Sometimes resistance was found in all accessions of a particular taxon, such as complete resistance to both C. chinensis and C. macualtus in V. umbellata. Other taxa showed intra taxon variation for resistance such as V. reflexo-pilosa andV. minima. The levels and patterns of resistance among taxa were diverse. The results suggest that various factors cause resistance to bruchid in the subgenus Ceratotropis. While the number of eggs laid on seeds generally reflected seed size, one small seeded cultivar of V. mungo var. mungo, black gram, had an unusually high number of eggs laid per seed. No correlation was found between seed size and levels of resistance. The species level germplasm collection, which reflects the core collection concept in trying to maximize genetic diversity in a limited number of accessions, has enabled a large number of potentially useful sources of resistance to bruchid beetles to be found efficiently. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic diversity and relationships among Lablab purpureus genotypes evaluated using RAPD as markers

Summary Genetic variation in 40 accessions of Lablab purpureus was evaluated using random amplified polymorphic DNA as markers. A high level of genetic variation in this species was detected but this was mainly restricted to the difference between cultivated and wild forms. Of the cultivated genotypes, genetic variation among Asian collections was significantly higher than that among African collections. The three most divergent cultivated genotypes were all from Asia. Four of the five wild accessions, two from Zimbabwe and the other two from Zambia, were closely related. The other one, CPI 31113 collected from Uganda, was highly divergent. The two commercial forage varieties used in Australia, Rongai from Kenya and Highworth from India, were not very different.     

Genetic diversity in mung bean germplasm revealed by RAPD markers

Knowledge of the genetic relationships among landraces is useful to gene bank managers because it permits a better organization of the crop's gene pool management, more efficient sampling of the available germplasm resources and better access to useful genetic variation for breeders. Genetic diversity of 19 landraces of the cultivated mung bean, Vigna radiate, and three weedy and wild relatives including Vigna mungo, Vigna luteola and Vigna radiate var. sublobata, was investigated at the DNA level with the random amplified polymorphic DNA (RAPD) procedure. Sixty random decamer primers were employed in amplification reactions; 28 of these were informative and yielded 246 bands, of which 229 were polymorphic with a mean of 8.2 bands per primer. A genetic distance matrix based on Nei and Li coefficient was converted to a dendrogram and a two-dimensional plot using multidimensional scaling (MDS). The accessions studied were separated into three main clusters, which included V. radiate landraces, V. mungo and V. luteola, respectively. The variation of this cluster supports the view that the genetic distance of V. mungo and V. luteola varies considerably from the accession VO2955 (V. radiata). The multidimensional scaling plot confirmed that V. mungo, V. luteola and most of the accessions of V. radiata formed distinct clusters with no overlap, and two mung bean accessions (PI177493 and VO4134–1 from Turkey and India, respectively) were genetically distant from other V. radiata landraces. V. radiata and V. mungo are positioned in separate botanical species and V. radiata var. sublobata is classified within other V. radiata landraces. Based on the limited range of accessions tested, the approach holds promise for the classification of mung bean germplasm, identification of mung bean landraces and applications of molecular markers to mung bean breeding.     

Proteinase inhibitor polymorphism in the genus Vigna subgenus Ceratotropis and its biosystematic implications

The diversity of components for fourproteinase inhibitors found in species ofthe genus Vigna subgenus Ceratotropis are described. Trypsin,chymotrypsin, subtilisin and cysteineproteinase inhibitors were analyzedby isoelectric focusing followed by thegelatin replica method. Of these proteinaseinhibitors, trypsin inhibitors showedmost polymorphism both within and betweenspecies. Many trypsin inhibitor componentswere also active to chymotrypsin. Severalaccessions had very low levels or absenceof some inhibitors, such as very low levelsof trypsin inhibitor in two accessions ofthe V. tenuicaulis and absence ofchymotrypsin inhibitors in V.grandiflora and V. subramaniana.Proteinase inhibitor polymorphism broadlyagreed with the taxonomic system for thesubgenus Ceratotropis. Based oninhibitor variation species analyzed couldbe divided into three groups whichcorresponding to sections Aconitifoliae, Angulares and Ceratotropis. Some species have verylittle variation in trypsin inhibitorsdespite wide distribution, such as, V.radiata and V. reflexo-pilosa.Accessions of other species showedconsiderable intraspecific variation fortrypsin inhibitors, such as, V.grandiflora, V. aconitifolia andV. stipulacea. Proteinase inhibitorpolymorphism provides an indication of thespecies that may have contributed a genometo the tetraploid species, V. reflexo-pilosa.     

Random amplified polymorphic DNA (RAPD) variation in Fagopyrum tataricum Gaertn. accessions from China and the Himalayan region

The diversity among 52 landraces and cultivars of tartary buckwheat (Fagopyrum tataricum Gaertn.) and one accession of its wild ancestor, F. tataricum ssp. potanini Batalin, from diverse geographic origins was examined using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) markers. Eighteen primers produced a total of 240 fragments, of which 153 (63.75%) were monomorphic and 87 (36.25%) polymorphic bands. UPGMA-based pairwise Jaccard’s coefficient of similarity was used to deduce the relationships among 53 genetically diverse accessions. The similarity between cultivated tartary buckwheat accessions ranged from 0.61 to 1.00. Four distinct clusters were formed which corresponded well with the geographic distribution of the tartary buckwheat. Nepalese accessions showed maximum diversity followed by Chinese accessions. Tartary buckwheat accessions from the Himalayan region of northwestern India revealed a narrow gene pool. The wild buckwheat accession did not group with any of the three cultivated tartary buckwheat groups, and formed its own single-entry group. Genetic similarity (0.59) of Chinese buckwheat accessions with the wild ancestor reaffirmed that cultivated tartary buckwheat originated in the Yunnan province of northwestern China. Consistent with some earlier reports, our study demonstrated the usefulness of the RAPD technique for the characterization of plant genetic resources and assessment of diversity between species. This revised version was published online in August 2006 with corrections to the Cover Date.     

Diversity in selected wild and cultivated species of pigeonpea using RFLP of mtDNA

Diversity in 28 accessions representing 12 species of the genus, Cajanus arranged in 6 sections including 5 accessions of the cultivated species, C. cajan, and 4 species of the genus Rhyncosia available in the germplasm collection at ICRISAT was assessed using RFLP with maize mtDNA probes. Cluster analysis of the Southern blot hybridization data with 3 restriction enzymes – 3 probe combinations placed the genus Rhyncosia in a major group well separated from all the species belonging to the genus Cajanus. Within the genus Cajanus, the 4 accessions of C. platycarpus belonging to section Rhynchosoides formed a separate group in contrast to those in other sections of pigeonpea. In the section, Cajanus all the 5 accessions of C. cajan were grouped together and C. cajanifolius belonging to the same section was in a subgroup by itself closer to the main group. The four accessions of C. scarabaeoides, were together and the other species belonging to section Cantharospermum were in different subgroups. The intra-specific variation was seen even within accessions of certain pigeonpea wild species such as C. scarabaeoides, C. platycarpus, C. acutifolius, and even the cultivated species of C. cajan. This study suggests that RFLP of mtDNA can be used for the diversity analysis of pigeonpea and it gives some indications on the maternal lineage among the species. The variations in the mitochondrial DNA hybridization patterns also suggest the extensive rearrangement of the organelle genome among the Cajanus species. This revised version was published online in July 2006 with corrections to the Cover Date.     

Inheritance of seed resistance to bruchids in cultivated mungbean (Vigna radiata, L. Wilczek)

Bruchid beetles or seed weevils are the most devastating stored pests of grain legumes causing considerable loss to mungbean (Vigna radiata (L.) Wilczek). Breeding for bruchid resistance is a major goal in mungbean improvement. Few sources of resistance in cultivated genepool were identified and characterized, however, there has been no study on the genetic control of the resistance. In this study, we investigated the inheritance of seed resistance to Callosobruchus chinensis (L.) and C. maculatus (F.) in two landrace mungbean accessions, V2709BG and V2802BG. The F₁, F₂ and BC generations were developed from crosses between the resistant and susceptible accessions and evaluated for resistance to the insects. It was found that resistance to bruchids in seeds is controlled by maternal plant genotype. All F₁ plants derived from both direct and reciprocal crosses exhibited resistance to the bruchids. Segregation pattern of reaction to the beetles in the F₂ and backcross populations showed that the resistance is controlled by a major gene, with resistance is dominant at varying degrees of expressivity. Although the presence of modifiers was also observed. The gene is likely the same locus in both V2709BG and V2802BG. The resistant gene is considered very useful in breeding for seed resistance to bruchids in mungbean.     

Genetic relationship of Mediterranean mandarins (Citrus deliciosa Tenore) using RAPD markers

Summary Random amplified polymorphic DNA (RAPD) analysis was carried out to evaluate polymorphism and genetic similarity between 39 Mediterranean mandarin genotypes. One hundred eleven amplification products were identified using 21 random primers. An average of 2.2 RAPD markers was obtained for each primer, corresponding to 42% of the amplification products. Genotype-specific RAPD markers were also found, mainly in known hybrids. UPGMA cluster analysis revealed the low level of genetic variation between accessions of Mediterranean mandarins, whereas their hybrids with other Citrus species showed greater genetic dissimilarity. Twenty accessions yielded very similar patterns, suggesting either that they could be a single clone, or that the technique was not able to detect genomic variation. However, for the other specimens genetic polymorphism can easily be detected by RAPD, although the genetic variation between accessions was quite low. The large number of hybrids and the low polymorphism between accessions support the hypothesis that Mediterranean mandarins are all true hybrid of Common mandarins (Citrus reticulata Blanco).     

Evaluation of genetic variation in Lachenalia bulbifera (Hyacinthaceae) using RAPDs

RAPD (randomly amplified polymorphic DNA) analyses were carried out on 21 accessions of Lachenalia bulbifera (Cyrillo) Engl. Five pre-selected primers produced an average of 88% polymorphisms. Fifteen of the 21 accessions could be identified using the five primers. In a pairwise comparison genetic distance values ranging from 0.11 to 1.08 were obtained. These values reveal a high amount of variation within the species. The genetic distance values within the tetraploid and hexaploid groups on the south coast were low, but values were high between the groups on the south coast and those on the west coast. A dendogram was constructed from the RAPD banding profiles, using UPGM cluster analysis. The dendogram clusters certain accessions together. These clusters are supported by their geographical locality and chromosome data. The hexaploid group, tetraploid group and octoploid group on the south coast are respectively clustered together. It is concluded that RAPDs can be used to assess the genetic variation at an intra-specific level in Lachenalia. This revised version was published online in July 2006 with corrections to the Cover Date.     

Inter and intra-species Inter Simple Sequence Repeat (ISSR) variations in the genus Cicer

Intra and inter-species ISSR variation and use of ISSR markers in determination of genetic relationship were investigated in an accession collection representing twoperennial and six annual Cicerspecies. Screening of Ciceraccessions with SSR primers revealed highly reproducible amplicon profiles with relatively high multiplex ratios. Many of the primers generated amplicon profiles with which not only the differences among species can readily be identified, but also polymorphisms within species could be detected more efficiently. PCR products at 150 gel positions detected using six SSR primers in Cicer accessions were treated as dominant DNA markers and utilized to compute the distances among accessions and species. Cluster analysis of accessions and species revealed groupings that corroborate our previous studies of relationships based on allozyme and AFLP analysis. Consistent with the AFLP analysis carried out in the same accession collection, ISSR-based groupings indicated that perennial C. incisumis genetically close to the annuals of the second crossability group (C. pinnatifidum,C. bijugum, C. judaicum) while C. reticulatum is the closest wild species to the cultivated chickpea. ISSR-based variation estimates were relatively higher when compared to previous estimates computed from RAPD and AFLP data. Technically, ISSR analysis combines the PCR-based targeting of microsatellite-associated polymorphisms with no prior sequence requirement and stringent PCR conditions. Similarly, when compared to AFLP analysis, it is less technically demanding allowing to survey polymorphic loci in the genome. Thus, ISSR-PCR technology is a reliable, fast, and cost-effective marker system that can be used to study genetic variation and genetic relationships in the genusCicer. This revised version was published online in July 2006 with corrections to the Cover Date.     

Molecular diversity and genome-wide linkage disequilibrium patterns in a worldwide collection of <Emphasis Type="Italic">Oryza sativa</Emphasis> and its wild relatives

Genetic diversity analysis within a species is vital for understanding evolutionary processes at the population and genomic levels. We report a detailed study of molecular diversity, polymorphism and linkage disequilibrium in three groups of rice (Oryza) germplasm accessions based on 176 SSR markers. The first group included 65 rice (O. sativa L.) accessions introduced from seven countries, including five regions of China. The second group included 58 US rice varieties released in the past 25 years. The third group consisted of 54 accessions of rice wild relatives represented by ten different species. The number of alleles per SSR marker ranged from 4 to 32 with a mean of 16 alleles and the polymorphism information content values ranged from 0.43 to 0.91 with a mean of 0.70. The variation in SSR alleles was a significant contribution to the genetic discrimination of the 177 accessions within the three Oryza groups. Analysis of molecular variance identified deviation from Hardy–Weinberg equilibrium. Principal coordinates analysis clearly separated the accessions into their respective three groups. Neighbor-joining phylogenetic cluster reflects the ordination of each accession. Linkage disequilibrium (D′) averaged 0.75 in wild Oryza spp., and about 0.5 in both US and international O. sativa accessions. Our results showed that LD among adjacent loci in both O. sativa and Oryza spp. accessions is strong enough to be detecting marker-trait association via genome-wide scans.     

New sources of major gene resistance in Lactuca to Bremia lactucae

Summary A total of 1789 accessions of several lettuce collections was screened to find new major gene resistance to the downy mildew fungus Bremia lactucae Regel. The accessions belonged to the species Lactuca sativa (N=1288), L. serriola (N=399), L. saligna (N=52) and L. virosa (N=50). A total of 20 races of B. lactucae were used, 14 of which were NL-races, isolated from cultivated lettuce in the Netherlands. The other six races were isolated from wild L. serriola in Czechoslovakia. The accessions were initially screened with two races: NL1 and NL3. Accessions with resistance to one or both of these races were tested with the other races. Phenotypes with new resistance were found in accessions of all four Lactuca species. Of L. sativa, four accessions were found with resistance phenotypes that could not be explained by combinations of known major genes. Many accessions of L. serriola had resistance phenotypes that indicated the presence of unknown resistance genes. All interactions between accessions of L. saligna and races of B. lactucae were incompatible in leaf disc tests, except for four accessions, which showed some sporulation with race NL6. Several accessions of L. virosa were resistant to all races used. Other accessions of L. virosa gave a race-specific interaction with B. lactucae.     

Assessment of genetic relatedness of the genera Ananas and Pseudananas confirmed by RAPD markers

Genetic relationships among 18 accessions, including 16 of Ananas and two of Pseudananas, were investigated using RAPD molecular markers. The procedure for DNA extraction was adapted from the method of Dellaporta et al. (1983) where an incubation in proteinase K and a purification step were included. From the total of 148 markers scored,132 (89.2%) were polymorphic. The similarity matrix was used for cluster analysis. The phenogram developed from the RAPD bands showed that for most of the cases, the accessions within a species grouped together. Nevertheless, a moderate infraspecific genetic variation was observed. For example, DNA data grouped all A. comosus accessions with a mean similarity coefficient of 0.85. Comparable results were obtained with all other species investigated. The highest genetic divergence was found withinA. lucidus where the mean similarity coefficient among accessions was0.75. A similar level of genetic polymorphism was observed among species,therefore, a definition about which species were involved in the constitution of A. comosus genotypes was not possible. These results agree with the breeders standpoint suggesting that all Ananas species belong to the primary gene pool of pineapple. This revised version was published online in July 2006 with corrections to the Cover Date.     

Population genetic structure of the clonal plant Zingiber zerumbet (L.) Smith (Zingiberaceae), a wild relative of cultivated ginger, and its response to Pythium aphanidermatum

Zingiber zerumbet (L) Smith, a wild clonal species related to the cultivated ginger (Zingiber officinale Roscoe), is a potential resistance donor for soft rot disease in ginger caused by Pythium aphanidermatum (Edson) Fitzp. In this study we evaluated the genetic diversity and P. aphanidermatum resistance of 74 Z. zerumbet accessions belonging to 15 populations from eight districts in Kerala state, India. The disease index (DI) of the accessions varied from 0% to 72.24% and the accessions could be separated into six frequency classes according to their DI values. More than 65% of the accessions had a DI < 20%. Eight accessions were found to be immune to the infection. The relative frequency of resistant accessions was higher in the central and northern regions of Kerala. Amplified fragment length polymorphism (AFLP) analysis of Z. zerumbet accessions using five primer combinations yielded 215 bands in total, of which 175 (81.4%) were polymorphic. Nei’s genetic diversity (h) of 0.2738 and Shannon information index (I) of 0.4012 revealed a high genetic diversity in Z. zerumbet unexpected for a clonal species. In the UPGMA dendrogram, accessions were clustered mostly according to their geographical origin and no clear correspondence was observed between the clustering pattern of accessions and their responses to Pythium aphanidermatum. The study revealed high genetic diversity and variability for pathogen resistance among Z. zerumbet accessions and confirmed the value of Z. zerumbet as a potential donor for soft rot resistance for the genetic improvement of ginger.     

Geographical differentiation and diallel analysis of seed dormancy in barley

Seed dormancy is one of the most important parameters affecting the malting process and pre-harvest sprouting in barley (Hordeum vulgare L.). Variation of seed dormancy in 4365 cultivated and 177 wild barley (ssp. spontaneum) accessions derived from different regions of the world was investigated in Okayama University, Kurashiki, Japan. Seed dormancy of each accession was estimated from their germination percentages at 0, 5, 10 and 15 weeks post-harvest after-ripening periods. All of the wild barley accessions showed less than 10% germination at 0 week after-ripening period. Level of seed dormancy in 4365 cultivated barley accessions showed a clear geographical differentiation. Seventy seven percent of Ethiopian accessions showed high germination percentages, while 86% of Japanese, Turkish and North African accessions showed low germination percentages at 0 week after-ripening period. A half diallel cross using eleven barley accessions with different level of dormancy revealed that seed dormancy was predominately controlled by additive gene effects. These results suggest that large genetic diversity for seed dormancy in barley is explained as different levels of additive accumulation of genetic factors. Barley varieties showing appropriate dormancy could be developed by crossing among barley germplasm accessions used in the present study.     

Heredity of seventeen isozyme loci in cassava (Manihot esculenta Crantz)

Summary Starch gel electrophoresis was used to assess isozyme polymorphism in two Manihot species. Crude extracts were obtained from leaves and pollen. Ten enzymes were examined for their polymorphism in a germplasm collection of 365 cultivated plus 109 wild accessions, mainly from Africa. The inheritance of these enzymes was examined using 13 intra and interspecific progenies. Seventeen polymorphic loci were found for the ten enzyme systems, with 59 alleles. All the markers showed disomic heredity and three linkage groups were identified.     

Characterization of flowering time and SSR marker analysis of spring and winter type Brassica napus L. germplasm

Flowering dates and life forms of all available Brassica napus accessions conserved at the North Central Regional Plant Introduction Station (NCRPIS) were characterized, and a survey of molecular variation was conducted by using simple sequence repeats (SSR) in order to support better management of accessions with diverse life forms. To characterize flowering phenology, 598 B. napus accessions from the NCRPIS collection were planted in Iowa and Kansas field sites together with a current commercial cultivar and observed for days to flowering (first, 50% and 100% flowering) in 2003. Days from planting to 50% flowering ranged from 34 to 83 in Iowa and from 53 to 89 in Kansas. The mean accumulated growing degree days (GDD) to 50% flowering were 1,997 in Iowa, and 2,106 in Kansas. Between locations, the correlation in flowering time (r = 0.42) and the correlation in computed GDD (r = 0.40) were both significant. Differences in flowering-time rank were observed for several accessions. Accessions that failed to flower in Iowa in a single growing season comprised 28.5% of the accessions; of the flowering accessions, 100% plant flowering was not always achieved. Accessions were grouped according to flowering time. A stratified sample of 50 accessions was selected from these groups, including 10 non-flowering and 40 flowering accessions of diverse geographic origins and phenological variation. The flowering time observed in the sampled accessions when grown in the greenhouse were found to be significantly correlated to the flowering time observed in the field locations in Iowa (r = 0.79) and Kansas (r = 0.49). Thirty SSR markers, selected across 18 Brassica linkage groups from BrassicaDB, and 3 derived from Brassica expressed sequence tags (ESTs) were scored in the stratified sample. An average of three bands per SSR primer pair was observed. Associations of SSR marker fragments with the life forms were determined. Analysis of molecular variation by using cluster analysis and ordination resulted in recognizable, distinct groups of annual and biennial life-form types, which may have direct applications for planning and management of future seed regenerations. Mention of commercial brand names in this paper does not constitute an endorsement of any product by the U.S. Department of Agriculture or cooperating agencies.     

Identifying lettuce species (Lactuca subsect. Lactuca, Asteraceae): A practical application of flow cytometry

The wild lettuce species L. serriola, L. saligna, and L. virosa are important genitors in lettuce (L. sativa) breeding. Identifying these wild species can be problematic because in some cases they look very similar. Flow cytometry was tested for its reliability and general applicability as a tool to distinguish them. Three series of tests were conducted: (1) Tests with three accessions of L. sativa and one accession of each of the wild species, repeated three times throughout the year. In each repeat, the mean relative DNA amount of L. serriola was significantly higher than that of L. saligna, but significantly lower than that of L. virosa. The mean relative DNA amount of L. sativa did not differ from that of L. serriola.(2) Tests with each wild species represented by 10 accessions. Significant differences between the accessions within each species demonstrated the presence of intraspecific variation. Notwithstanding this intraspecific variation, the relative DNA amounts of all accessions of L. serriola were significantly higher than that of all L. saligna accessions, and significantly lower than that of all L. virosa accessions. Therefore, all accessions could be assigned to the appropriate species on the basis of their DNA amounts. (3) Tests with single plants from 10 accessions of each of the wild species. These test revealed that individual plants of L. serriola, L. saligna, and L. virosa can be reliably identified with flow cytometry, when aL. serriola sample of established identity is used as internal reference. This revised version was published online in July 2006 with corrections to the Cover Date.     

PCR-RFLP analysis of the whole chloroplast DNA from three cultivated species of cotton (Gossypium L.)

Variations of the chloroplast DNA (cpDNA) from three of the four cultivated species of cotton (Malvaceae); Gossypium barbadense L., Gossypium hirsutum L., Gossypium arboreum L. and its synonym Gossypium nanking Meyen., were analyzed. Using specific set of primers, the whole circular cpDNAs from the four test species were amplified. These were subsequently digested with the use of seven restriction enzymes. The amplified fragments of the whole cpDNAs of the diploid cultivated cotton G. arboreum and its synonym G. nanking did not show any differences. However, the allotetraploid cultivated cottons G. barbadense and G. hirsutum, showed some fragment length differences directly visible after amplification and two types of restriction fragment length polymorphism (RFLP), the first appeared as slightly lengthened bands and the other as gain or loss of a restriction site. The results also showed that the chloroplast genomes of the allotetraploid cultivated cottons are highly similar to the diploid cultivated cottons tested in terms of length and digestion patterns. The detected amplified length differences, RFLPs and the restriction sites can be considered as species specific markers for the allotetraploid cultivated cottons, which could be a useful tool for future studies of the cpDNA of the genus Gossypium L.     

Ribosomal DNA repeat unit polymorphism and heritability in peanut (Arachis hypogaea L.) accessions and related wild species

Repeat unit length and restriction site variation in ribosomal RNA geneclusters (rDNA) was surveyed in 77 Arachis accessions, includingsamples from 39 accessions of cultivated Arachis hypogaea(2n=4x=40), 36 accessions representing 15 related tetraploid and diploidwild species, and two synthetic amphidiploids. Total genomic DNA wasdigested with five restriction enzymes, and probed with three heterologousribosomal clones of wheat and broad bean. Four rDNA repeat unit lengthclasses were recognized in the Arachis species. Restriction site analysisshowed that some SacI, BamHI and TaqI cleavage sites in rDNA unit werehighly conserved. With few exceptions, the variable BamHI and EcoRV siteswere able to differentiate the taxonomic sections and species, respectively.Arachis hypogaea and A. duranensis accessions produced fourrDNA length classes. Among these, three were identical with those of otherArachis species. A SacI restriction site (s) from probe (Ver6-5) cangenerally distinguish the two subspecies A. hypogaea ssp. hypogaea and A. hypogaea ssp. fastigiata. Forty nine per centof bands were polymorphic across the A. hypogaea accessionsanalysed. This study does not support A. batizocoi to be a progenitorof A. hypogaea. For the gene array, the contribution from eachparental genome can be detected in the two synthetic amphidiploids.