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1.
Forty-two accessions of Arachis duranensis, a wild groundnut species that has been reported as a source of resistance to several groundnut diseases, were studied for 30 quantitative traits including total protein content, oil content, and reaction to groundnut rust. Protein profiles were also investigated for variation at the molecular level. Principal component analysis was applied to 28 traits that showed significant variation. Of these, only five characters, namely, height of the main stem, length of apical leaflet on the main stem, length of isthmus between pods, width of seed, and reaction to groundnut rust, accounted for more than 61.4% of the total variation. Protein profiles of these accessions were broadly similar, except some accessions which differed in few bands. The importance of these variations in strategies for germplasm collection and breeding is discussed.Submitted as Journal Article No. 1507 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru P.O. 502 324 A.P. India.  相似文献   

2.
Some Arachis species are widely used as commercial plants, e.g. the groundnut A. hypogaea, an important source of good quality protein and oil, and A. pintoi and A. glabrata, that are utilized as forage species. Germplasm of most Arachis species is available in germplasm banks. However, little it is known about the genetic attributes of this germplasm, and mainly about its genetic variability, which is very important for its maintenance. In the present study RAPDs were used to assay the genetic variation within and among 48 accessions of five sections of the genus Arachis and to establish the genetic relationships among these accessions. Ten of 34 primers tested were selected for DNA amplification reactions since they yielded the largest numbers of polymorphic loci. A dendrogram was constructed based on data from the 10 primers selected. Eighty RAPD polymorphic bands were analyzed among the accessions studied. The relationships among species based on RAPDs were similar to those previously reported based on morphological, cytological and crossability data; demonstrating that RAPDs can be used to determine the genetic relationships among species of the different sections of the genus Arachis. In general, wide variation was found among accessions and low variation was found within the accessions that had two or more plants analyzed. However, higher polymorphism was found in the section Trierectoides and in one accession of A. major, indicating that generalizations should be avoided and each species should be analyzed in order to establish collection and maintenance strategies.  相似文献   

3.
Summary 27 accessions ofVicia benghalensis from different geographical origins constitute the pool on which the present study was performed. Genetic variation among the samples was biochemically and cytologically evaluated: seed storage protein profiles and C-banded karyotypes were analysed from single individuals of each accession. SDS-PAGE has shown the possibility to divide the samples into two groups, each characterized by specific protein profiles. The two patterns were indicated as A and B. From individual seed electrophoresis it was ascertained that samples possessing the pattern A showed a low level of individual variation, while those possessing the pattern B were highly polymorphic, thus suggesting differences in the allogamic rate. The cytological analysis demonstrated the presence of two groups of accessions, one being much richer in heterochromatin as evidenced by C-banding (H+) than the other (H-). The analysis of biochemical and karyological data showed a constant association between pattern A and karyotype H− and between pattern B and karyotype H+. On the basis of these results it is proposed to considerV. benghalensis as a highly heteromorphic species, in which two groups may be identified.  相似文献   

4.
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.  相似文献   

5.
Total seed storage protein of 9 accessions of cultivated C. cajan and 10 wild Cajanus species was reported and compared by sodium dodecyl sulphate polyacrylamide gel electrophoresis. A considerable variation was detected among the protein profiles of different accessions of C. cajan while those of wild species were very specific and distinctly different from each other. Relative similarities between various taxa were estimated by Jaccard's similarity index and cluster analysis was performed to produce a UPGMA dendrogram. The clustering of 10 wild species and C. cajan more or less agrees with their sectional classification and available data based on morphological characteristics, crossability, genome pairing in hybrids and nuclear RFLPs. The species closest to C. cajan is C. cajanifolia although the accessions of C. cajan also share some bands present in the profiles of C. scarabaeoides, C. goensis, C. lineatus, C. acutifolius and C. volubilis. This points towards polyphyletic origin of the cultigen which has been discussed in this paper.  相似文献   

6.
SDS PAGE of endosperm proteins and␣RAPD profiles from different accessions of Himalayan buckwheat were studied to determine their genetic variation and phylogenetic relationships. Comparisons based on Jaccard’s coefficient and UPGMA clustering revealed interrelationships broadly in conformity with conventional treatments. Cluster analysis of the endosperm protein profiles of the selected accessions revealed three broad clusters. A moderate level of intraspecific variability was detected in the endosperm protein profile of different accessions of Fagopyrum esculentum, Moench. Three subgroups were detected in cluster 1. Subgroup 1 included varieties designated as Local, Kamroo local, OC-2 and␣VL-7 which were collected from VPKAS, Almora. Local, Kamroo local and OC-2 showed a similarity coefficient of 1.0 inspite of their being identified as different accessions. VL-7 emerged out separately from the rest of the three accessions. Accessions having winged grains and those having striations on the seed coat formed a 2nd and 3rd subgroup, respectively. IC-13145 which been identified as “F. himalianum”, showed 100%␣similarity in endosperm protein profile with IC-13376 (F. esculentum) and 85–90% similarity which other accessions of F. esculentum. Our results indicate that “F. himalianum” belongs to the esculentum group and should not be regarded as a different species. Cluster 2 included all the accessions of F. tataricum (L.) Gaertn. with Sangla 1, 2, 3, 5, 6, 7 and IC-412863 showing 100% similarity. F. cymosum emerged as a separate group distinct from both esculentum and tataricum. Accessions of F. tataricum and F. cymosum did not show significant intraspecific variation in the SDS PAGE profile of endosperm proteins. Out of the 20 primers used, 3 generated robust, easily interpretable amplified products. While a 1490 bp and a 300 bp RAPD was detected only in F. tataricum, a 1154 bp RAPD was detected in all accessions of F. tataricum except in Shimla B-1. This variety is early maturing and has high seed yields.  相似文献   

7.
Many tropical forage grasses and legumes grow well in acid soils, adapting to excess aluminum (Al) and phosphorus (P) starvation stresses by using mechanisms that are still unclear. To determine these mechanisms, responses to Al toxicity and P starvation in three tropical forages were studied: two grasses, Brachiaria hybrid cv. ‘Mulato’ (B. ruziziensis clone 44-06 × B. brizantha cv. ‘Marandú’) and Andropogon gayanus, and one legume, Arachis pintoi. The tropical grasses tolerated high levels of Al toxicity and P starvation, with the Brachiaria hybrid maintaining very low levels of Al concentration in shoots. 27Al Nuclear Magnetic Resonance spectroscopy (NMR) analysis revealed that, in the Brachiaria hybrid, Al makes complexes with some ligands such as organic-acid anions in the root symplast. The forages probably adapted to P starvation through high P-use efficiency. These experiments provide the first direct evidence we know of that organic acid anions within root tissue help detoxify Al in non-accumulator species such as the Brachiaria hybrid.  相似文献   

8.
Seven short‐fallow plant species were evaluated for their aboveground biomass production, nutrient accumulation, and weed suppression potential in Nkolbisson, Cameroon. The fallow species included Arachis pintoi, Vigna radiata, Desmodium intortum, Centrosema pubescens, Indigofera hirsutus, Indigofera spicata, and Pueraria phaseoloides. The experimental design was a randomized complete block with four replications and seven treatments (fallow species). Twelve months after planting, highly significant differences (p < 0.01) were observed among fallow species for phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) concentrations, respectively, in plant tissue. Similarly, highly significant differences (p = 0.0013) occurred among fallow species for aboveground biomass production, which ranged between 3.12 t ha?1 (I. spicata) and 9.16 t ha?1 (A. pintoi). Potassium only showed highly significant differences among plant species for nutrient accumulation (p = 0.0001). However, A. pintoi, C. pubescens, I. hirsutus, and P. phaseoloides yielded substantial amounts of recycled N (>100 kg ha?1 year?1) that can benefit the subsequent crop. For small‐scale producers, these species are likely to supply adequate nitrogen for cereal crops. A total of 26 weed species belonging to 15 botanical families were encountered in the various plots. Weed dry weight differed significantly (p = 0.02) among the fallow plots and ranged from 0.12 t ha?1 (in P. phaseoloides plots) to 2.32 t ha?1 (in A. pintoi plots). Results of this study suggest that there are a wide range of plant species that could be used in improved fallow technologies aimed at improving nutrient‐degraded soils and suppressing weeds.  相似文献   

9.
Summary The use of random amplified DNA fragments as genetic markers in Coffea was investigated. Arbitrary oligonucleotides were used as primers to amplify genomic DNA of different coffee accessions representing major Coffea species by polymerase chain reaction. Intraspecific variation was easily detected in C. canephora and C. liberica whereas the primers assayed failed to reveal polymorphism between C. arabica accessions. Extensive interspecific variation was observed. Genetic relationships between Coffea species are deduced from the degrees of similarity in amplified product profiles. Random amplified DNA markers appeared to be of high value for characterization, analysis and utilization of coffee genetic resources.  相似文献   

10.
Information on genetic diversity and genetic relationships among genotypes of Brassica carinata is currently limited. The objectives of this study were to evaluate patterns and levels of genetic diversity in B. carinata based on amplified fragment length polymorphisms (AFLP) as compared with Brassica juncea and Brassica nigra, and to evaluate agronomic and seed quality data for plants grown in the field in western Canada. A total of 296 AFLP bands were generated from four primer pair combinations and scored for presence/absence in 66, 20 and 7 accessions of B. carinata, B. juncea and B. nigra, respectively. B. carinata was less genetically diverse than the other two species. Differences in diversity were evident in the proportion of polymorphic loci within each species: 23, 35 and 50% for B. carinata, B. nigra and B. juncea, respectively. Pair-wise similarity measures based on the Jaccard coefficient were highest among accessions of B. carinata and showed the narrowest range: 0.911 (0.810–0.981) compared to B. nigra: 0.569 (0.438–0.660) and B. juncea: 0.715 (0.345–0.951). AFLP-based genetic distance information can be used by plant breeders to select diverse genotypes. AFLPs are also useful for fingerprinting cultivars and two primer pair combinations were sufficient to uniquely identify all the accessions of B. carinata. More variation among accessions was identified in the agronomic trial than had previously been described in studies of B. carinata in western Canada, but the data were too limited to draw conclusions regarding specific accessions. Overall, the findings were in agreement with other published work describing the favourable agronomic potential of this species.  相似文献   

11.
Asian cotton (Gossypium arboreum L.) was once widely cultivated in China. It has also been a valuable source of genetic variation in modern cotton improvement. In this study, the genetic diversity of selected G. arboreum accessions collected from different regions of China was evaluated by microsatellite (simple sequence repeats, SSRs) analysis. Of the 358 microsatellite markers analyzed, 74 primer pairs detected 165 polymorphic DNA fragments among 39 G. arboreum accessions examined. Twelve accessions could be fingerprinted with one or more SSR markers. With the exception of two accessions, DaZiJie and DaZiMian, genetic similarity coefficients among all accessions ranged from 0.58 to 0.87 suggesting high level of genetic variation in the G. arboreum collections. The UPGMA dendrogram constructed from genetic similarity coefficients revealed positive correlation between cluster groupings and geographic distances. In addition, comparison of the microsatellite amplification profiles of the diploid G. arboreum and tetraploid Gossypium hirsutum L. found that size distribution of amplified products in G. arboreum was dispersive and that of G. hirsutum was relatively concentrated. The information on the genetic diversity and SSR fingerprinting from this study is useful for developing mapping populations for constructing diploid cotton genetic linkage map and tagging economically important traits.Diqiu Liu, Xiaoping Guo: These two authors contributed equally to this work.  相似文献   

12.
Sequence variation of nuclear internal transcribed spacer regions of ribosomal DNA (ITS1, 5.8S rRNA and ITS2) from Chinese vegetable mustards (AB-genome) and its putative parents Brassica rapa (the A-genome) and Brassica nigra (the B-genome) were used to investigate the molecular phylogeny and the probable evolutional pattern of this amphidiploid species that uniquely formed in China. Totally, 16 accessions of Chinese vegetable mustard those covering nearly all the diverse variations were included in this study, and together with three accessions of B. rapa and one accession of B. nigra. The results disclosed two strongly supported clades, one containing four accessions of vegetable mustard which have closer relationship with B-genome species “B.nigra” lineage and the other containing 12 accessions of B. juncea and three A-genome accessions. This classification was in disagreement with the evidence from chloroplast DNA, mitochondrial DNA, nuclear DNA restriction fragment length polymorphism (RFLP), which suggested that B. juncea was closely related to the A-genome type. For the incongruence, we speculated that the B. juncea crops derived from Chinese have evolved through different recombined events of the diploid morphutypes and evolved unidirectional concerted evolution. The traditional phenotypic classification of B. juncea was not wholly supported by ITS results, and hence the phylogenetic relationships among these subspecies need to be reconsidered on molecular level.  相似文献   

13.
When planning optimal conservation strategies for wild and cultivated types of a plant species, a number of influencing biological and environmental factors should be considered from the outset. In the present study Brassica rapa was used to illustrate this: to develop Scandinavian conservation strategies for wild and cultivated B. rapa, DNA-marker analysis was performed on 15 cultivated and 17 wild accessions of B. rapa plus 8 accessions of the cross compatible B. napus. The B. rapa cultivars were bred in Sweden and Finland in 1944–1997 and the wild B. rapa material was collected from Denmark, Sweden and United Kingdom. The B. napus accessions were bred within the last 20 years in the Scandinavian countries. Results were based on scoring of 131 polymorphic ISSR markers in the total plant material. A Bayesian Markov chain Monte Carlo (MCMC) approach implemented in NewHybrids demonstrated a clear distinction of B. rapa and B. napus individuals except for three individuals that seemed to be backcrosses. The backcrossed hybrids descended from two Swedish populations, one wild and one escaped. The overall pattern of genetic variation and structure in B. rapa showed that cultivated and wild B. rapa accessions formed two almost separated clusters. Geographical origin and breeding history of cultivars were reflected in these genetic relationships. In addition, wild populations from Denmark and Sweden seemed to be closely related, except for a Swedish population, which seemingly was an escaped cultivar. The study point to that many processes, e.g. spontaneous introgression, naturalisation, breeding and agricultural practise affected the genetic structure of wild and cultivated B. rapa populations.  相似文献   

14.
The genetic diversity of 58 wild and weedy populations representing taxa within the V. sativa aggregate from the former USSR, 4 cultivars of V. sativa, 2 accessions of V. cordata and 3 accessions of V. macrocarpa from Mediterranean countries were analysed using randomly amplified DNA fragments (RAPDs) and seed protein electrophoresis (SDS-PAGE). Interspecific variation between taxa in the V. sativa aggregate could readily be detected using both techniques. RAPDs and seed protein patterns were found to be an effective means of identifying accessions that cannot be identified clearly by morphological criteria alone. RAPD and seed protein analysis revealed a clear relationship between observed genetic variation of populations and their geographical distribution. Populations from each region had their own gene pools. Geographical variation was detected in V. segetalis. The degree of genetic divergence between local populations was usually related to proximity. In several locations where wild and weedy populations of different V. sativa agg. taxa grow sympatrically, intermediate forms could be detected at the DNA and protein levels. Both RAPD and seed protein analysis support the view that the V. sativa aggregate consists of 8 taxa warranting recognition at the species level. Several species in this aggregate are evolving intra-specific groups which can readily be detected at the molecular level.  相似文献   

15.
Genetic variation within the U.S. cucumber collection (Cucumis sativus var. sativus L. and var. hardwickii (Royle) Alef.) was assessed by examing the variation at 21 polymorphic isozyme loci and comparing the results of this investigation with a similar previous analysis of 14 loci. About 29% (15 of 51) of the enzyme systems examined in an initial survey were polymorphic. Seven loci (Ak-2, Ak-3, Fdp-1, Fdp-2, Mpi-1, Pep-gl and Skdh) which were not previously used to estimate genetic diversity, were assessed. On average, 1.4 loci were polymorphic per enzyme system and 2.2 alleles were present per polymorphic locus. The frequency of polymorphisms was relatively low for Fdp-1(2) (0.01), Mpi-1(1) (0.03), and Skdh(1) (0.02). Principal component and cluster analyses of allelic variation at polymorphic loci separated a diverse array of 757 cucumber accessions from the U.S. National Plant Germplasm Systesm's (NPGS) collection into distinct groups by country (45 nations examined). All accessions of C. s. var. sativus were isozymically distinct from C. s. var. hardwickii, which were themselves dissimilar from each other. Data suggest that C. s. var. hardwickii is not a feral derivative of extant C. s. var. sativus populations. The allelic profile of C. s. var. sativus accessions originating from Burma, Thailand, Indonesia, Hong Kong, Zimbabwe and Ethiopia were distinct from the other accessions examined. Allelic fixation has occurred at Pgd-2 in accessions from Burma, and at Ak-2 in accessions from Zimbabwe and Ethiopia. Some of the countries examined that were in close geographic proximity (e.g., Thailand, Indonesia and Hong Kong) contained accessions with similar isozyme profiles. Accessions are fixed for certain alleles [e.g., Gr(1) (100%), Fdp-1(1) (100%) and Mpi-2(2) (50%) for accessions from Thailand, Indonesia and Hong Kong]. Grouping countries by continent or sub-continent (i.e., North and South American, China, Eastern Europe, Western Europe) and by numbers of accessions examined (i.e., India/Burma, Iran, Japan, Turkey, and remaining accessions) was used to identify accessions with unique allozymic profiles [PIs 209064 (USA), 257486 (China), 188749 (Egypt), 285607 (Poland), 369717 (Yugoslavia), 357844 (Poland), 255936 (Netherlands), 183127 (India), 200818 (Burma), 200815 (Burma), 137836 (Iran), 227013 (Iran), 227235 (Iran), 451976 (Japan), 181752 (Syria), 181874 (Syria), 169383 (Turkey), 171613 (Turkey)].  相似文献   

16.
Forty-four accessions of cultivated peanut (Arachis hypogaea L.) representing sixbotanical varieties of two subspecies along with three accessions ofthe wild relative A. monticola Krapov et Rigoni were evaluated for their genetic relationships using theAFLP marker technology. Fifteen AFLP primer pairs (EcoRI/MseI) generated 28distinct polymorphic markers that were employed to develop uniqueprofiles of all accessions and to construct a phenogram. The resultsshowed that the botanical varieties aequatoriana and peruviana werecloser to subspecies hypogaea than subspeciesfastigiata Waldr. to which they belong, and the wildA. monticola was notdistinct from the cultivated A.hypogaea. Although the extent of geneticdiversity in peanut is low compared to many other crops, our studiesshow that by employing the AFLP approach, sufficient DNA variationcan be detected in the cultivated peanut germplasm to conductevolutionary studies.  相似文献   

17.
Thirty eight accessions of brown mustard (Brassica juncea (L.) Czern. and Coss.) were screened after two weeks growth in solution culture containing 120 mol m‐3 NaCl. Considerable variation for salt tolerance was observed in this set of germplasm, since some accessions showed relatively vigorous growth in saline medium.

In order to determine the consistency of degree of salt tolerance at different growth stages of crop life cycle two salt tolerant accessions, P‐15 and KS‐51 and two salt sensitive 85362 and 85605 were tested at the adult stage in 0(control), 100 and 200 mol m‐3 NaCl. Both the tolerant accessions produced significantly greater fresh and dry biomass and had considerably higher seed yield than those of the salt sensitive accessions. Analysis of different ions in the leaves showed that salt tolerant accessions contained greater amounts of Na+, K+ and Ca2+ than the salt sensitive accessions, although they did not differ significantly for leaf Cl‐. Only one salt tolerant accession P‐15 had greater leaf K/Na ratio and K+ versus Na+ selectivity compared with the tolerant KS‐51 and the two salt sensitive accessions.

From this study it was established that there is a considerable variation for salt tolerance in B.juncea which can be exploited by selection and breeding for improvement of its salt tolerance. Since the degree of salt tolerance in B.juncea does not change at different growth stages of the crop life cycle, selection for salt tolerance at the initial growth stages could provide individuals that would be tolerant at all other growth stages. Accumulation of Na+, K+ and Ca2+ in the leaves are important components of salt tolerance in B.juncea.  相似文献   

18.
Starch was extracted and cleaned from 99 accessions of 20 species of Aegilops and also from 200 accessions of hexaploid wheat. Amylose content was determined by iodine staining and absorbance at 535 and 620 nm. Particle‐size distribution was determined by laser scattering. The amylose content of the Aegilops accessions did not exceed the extremes found in domesticated wheat. Aegilops species, on the whole, had a lower content of small particles than the hexaploid wheats. There was no correlation between amylose content and particle‐size distribution. Some species of Aegilops may be useful sources of low‐starch B‐type granules for hexaploid wheat, if the trait can be transferred, but they are unlikely to contribute to further variation in amylose content.  相似文献   

19.
The tetraploid relatives (subspecies) of commercial durum wheat (Triticum turgidum L. subsp. turgidum conv. durum (Desf.) MacKey) offer a source of economically useful genes for the genetic improvement of durum cultivars. Thirty‐two accessions, representing five different subspecies: var. durum (13 accessions), polonicum (7), persicum (3), turanicum (5), and turgidum (4) were grown at Tamworth, Australia, in 1997 and 1999. These accessions were compared with three durum cultivars: Wollaroi and Kamilaroi (in both years) and Yallaroi (in 1998 only). In this study, the glutenin subunit composition and molecular weight distribution, together with starch properties of these accessions, were studied. A much wider range in both the glutenin subunit composition and the starch RVA paste viscosities and gelatinization profiles were found in the accessions compared with the cultivated durum wheats. Most of the accessions had lower gluten strength and the presence of poor quality LMW alleles, and low proportions of unextractable polymeric protein could explain this. For starch, RVA peak viscosity correlated strongly with cooking loss of pasta, the only significant correlation between starch properties and measured aspects of pasta quality.  相似文献   

20.
Gliadin composition has been analysed in 403 accessions of spelt wheat (Triticum aestivum ssp. spelta); 61 different patterns were found for the -gliadins, 44 for the -gliadins, 19 for the -gliadins and 15 for the -gliadins. A subset of 333 accessions belonging to fifty populations from Asturias, North of Spain, showed high levels of genetic variation (A = 3.89, P = 0.88, Ne = 3.35 and He = 0.553), indicating that 82.5% of the genetic variation was within populations, and only 18.5% among populations. Thirty-five of these populations presented more of five accessions, in this new subset the values of genetic variation were higher that those of fifty populations (A = 4.49, P = 0.91, Ne = 3.80 and He = 0.595). The genetic variation within populations was 59.7% of the total, and 40.3% among populations, which could be associated to fixation effects of some alleles by genetic drift.  相似文献   

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