首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 952 毫秒
1.
Summary Karyotypic differences among n = 9 Brassica species, as well as the inheritance of some morphological characteristics, are reported. Annual habit, anthocyanin pigmentation in leaf and stem, enlarged stem, glossy foliage, dark green foliage, white flower and leaf pubescence were all expressed as dominant characteristics and in most cases were determined by one or two genes. 172 intra- and interspecific hybrids of the species belonging to the Brassica oleracea cytodeme were analyzed for fertility and meiotic chromosome behavior. B. alboglabra, B. bourgeaui, B. cretica spp. cretica, B. montana and B. oleracea produced fertile interspecific hybrids, indicating that geographical isolation is the only barrier to gene exchange. Interspecific hybrids generated from crosses of B. incana, B. insularis and B. rupestris to other n = 9 species were semi-sterile. This was shown to be associated with abnormal meiotic behavior. The former two species, when crossed, produced fully fertile hybrids. Therefore, three different karyotypes are identified among the n = 9 Brassica species. Frequent changes in the genome of the species belonging to the Brassica oleracea cytodeme could have led to the formation of accessory chromosomes present in certain accessions.  相似文献   

2.
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   

3.
Summary The 99 accessions of seven wild Lactuca species (L. serriola, L. saligna, L. virosa, L. viminea, L. perennis, L. tenerrima, L. tatarica) and Mycelis muralis (syn. L. muralis) were tested for natural infection of Erysiphe cichoracearum L. serriola accessions were highly susceptible. L. saligna showed highly variable levels of resistance. Other Lactuca species were mostly resistant or only moderately susceptible.  相似文献   

4.
About 90% of chickpea (Cicer arietinum L.) in the world is grown under rainfed conditions where drought is one of the major constraints limiting its productivity. Unlike the cultivated chickpea, wild Cicer species possesses sources of resistance to multiple stresses; we therefore evaluated perennial wild Cicer species for resistance to drought. C. anatolicum, C. microphyllum, C. montbretii, C. oxydon and C. songaricum were compared with special checks; C. echinospermum, C. pinnatifidum and C. reticulatum and five cultivated chickpeas. After the cultivated chickpeas were killed, accessions were evaluated using a 1–5 scale, where 1 = highly drought resistant (no visible drought effect and full recovery after three successive wiltings) and 5 = highly drought susceptible (leaves and branches dried out, no recovery at all). All accessions of perennial wild Cicer species were significantly superior to those annual wild species and the cultivated chickpeas including the best drought tolerant chickpea, ICC 4958 under drought conditions. Perennial wild Cicer species did not only recover after wilting and drying out above ground level, they also tolerated high temperatures up to 41.8°C. But, they do not cross with the cultivated chickpeas. C. anatolicum should be taken account in long term breeding programs because it has closer affinities to the first crossability group than the others.  相似文献   

5.
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   

6.
About 90% of chickpea (Cicer arietinum L.) in the world is grown under rainfed conditions where it is subjected to drought and heat stress. Unlike the cultivated chickpea, annual wild Cicer species possess sources of resistance to multiple stress; annual wild Cicer species were therefore evaluated for resistance to drought and heat stress. Eight annual wild Cicer species (Cicer bijugum, C. chorassanicum, C. cuneatum, C. echinospermum, C. judaicum, C. pinnatifidum, C. reticulatum, and C. yamashitae) were compared with special checks, the cvs ICC 4958 and FLIP 87-59C (drought resistant) and ICCV 96029 (very early double-podded). ILC 3279 and 8617 as drought susceptible checks were sown after every 10 test lines. Yield losses due to drought and heat stress in some accessions and susceptible checks (ILC 3279 and ILC 8617) reached 100%. Accessions were evaluated for drought and heat resistance on a 1 (free from drought and heat damage)−9 (100% plant killed from drought and heat) visual scale. Four accessions of C. reticulatum and one accession of C. pinnatifidum were found to be as resistant to drought and heat stress (up to 41.8°C) as the best checks. C. reticulatum should be taken account in short term breeding programs since it can be crossed with the cultivated chickpea.  相似文献   

7.
The study was aimed to select cold tolerant accessions of annual wild Cicer species in the highlands in the west Mediterranean area of Turkey. A total of 43 accessions of eight annual wild Cicer species was screened for cold tolerance and compared with the best cold tolerant cultivars, ILC 8262 and FLIP 93-53C. After the sensitive check, ILC 533, was killed, accessions were evaluated using a 1–9 scale. Three accessions of Cicer bijugum, 2 accessions of Cicer reticulatum and 2 accessions of Cicer echinospermum were highly cold tolerant, while 3 accessions of C. bijugum, 9 accessions of C. reticulatum, 2 accessions of C. echinospermum and 1 accession of Cicer pinnatifidum were cold tolerant. All accessions of Cicer judaicum were sensitive to cold. Whereas Cicer chorassanicum and Cicer cuneatum were killed, Cicer yamashitae was recorded as highly sensitive to cold. The cold tolerant accessions of annual wild Cicer species were superior to the best cultivar as far as hardiness is concerned.  相似文献   

8.
A renewed interest in glucosinolates (GSLs) as compounds with biocidal and anticarcinogenic activity demands evaluation of the available variability in germplasm collections. The objective of the present study was to evaluate a germplasm collection of the genus Brassica for total content and profile of seed GSLs. A total of 1708 entries from 20 Brassica species were nondestructively analysed by near-infrared reflectance spectroscopy. The total GSL content and the concentrations of sinigrin, progoitrin, gluconapin, glucoerucin, glucoiberin, and 4-hydroxyglucobrassicin were estimated by means of previously developed calibration equations. One hundred and fifty entries, having either high GSL content or potentially interesting GSL profiles, were selected and further analysed by high-performance liquid chromatography. The collection contained great variability for GSL content and profile. Very high GSL contents (>200 mol g-1) were measured in accessions of B. montana, B. nigra, and B. oleracea. The greatest intraspecific variability occurred in B. oleracea, where six contrasting GSL profiles were identified. The detected variability might be useful for the development of Brassica crops containing high GSL content and specific GSL profiles.  相似文献   

9.
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   

10.
Summary During the winters of 1990/91 and 1991/92, 181 accessions of Triticum dicoccon Schrank from the CIMMYT gene-bank were screened in the field for resistance to Russian wheat aphid, Diuraphis noxia (Kurdjumov). Accessions were sown in hill plots of 10 seeds and artificially infested with D. noxia at the two-leaf growth stage. Hills were visually assessed for damage at tillering, booting and heading. Entries differed significantly in their reaction to D. noxia, and severity of symptoms increased with time. Twenty four of the entries were highly resistant to the aphid. In winter 1991/92, 807 accessions of wild and cultivated wheats (26 species) and synthetic hexaploids were screened similarly for resistance to D. noxia. A large number of A-genome species were resistant, while few D-genome species were identified as resistant. These newly discovered sources of resistance can be used to expand the genetic base of resistance to D. noxia in both bread (T. aestivum L.) and durum wheats (T. turgidum L. convar. durum (Desf.) Mackey).  相似文献   

11.
Polyploidization has been viewed as a highly dynamic process and a major force in the evolution of higher plants, including many important crops. To better understand the genomic evolution of Brassica polyploids, we used the Brassica triangle, including three allopolyploids and three diploids, to study genomic evolution after the formation of polyploids. Based on the inter-simple sequence repeat (ISSR) analysis, the different degree of A, B or C genomic modifications were observed in the three Brassica allopolyploids. In B-contained allopolyploids, B genome always altered less than the other genome (A or C), showing that B genome was relatively conserved in the evolution of Brassica allopolyploids. ISSR data supported that a higher degree of ancestral genomic divergence gave rise to a greater frequency of genomic change of polyploids. The possible mechanisms for the genomic changes and the reason for the relatively conserved B genome were discussed.  相似文献   

12.
Oryza officinalis complex is the largest and the most complicated group in the genus Oryza L., consisting of about ten species with the B, C, BC, CD, and E genomes. Taxonomy and identification of the species, particularly those with the B, C and BC genomes, are difficult due to the similar morphology and overlapping distribution of some species. The difference in ploidy levels of some species adds more complexity. In the present study, we surveyed 64 accessions of rice germplasm in the O. officinalis complex using RFLP analysis of PCR-amplified Adh genes in addition to chromosome counting. The results confirmed that all O. rhizomatis accessions are diploids with the C genome, whereas all O. minuta accessions are tetraploids having the BC genome. However, both diploid and tetraploid forms were found for the accessions identified in the genebank as O. officinalis, O. punctata and O. eichingeri. The tetraploid form of O. officinalis with the BC genome is exclusively distributed in India and has been described as O. malampuzhaensis. The tetraploid form of O. punctata which has been called O. schweinfurthiana by some workers was found to be as widely distributed as its diploid form in Africa. It is noteworthy that two accessions that had been determined as tetraploid O. officinalis were actually belonging to a species with the CD genome (O. latifolia). Our results promote a better understanding of the genomic constitutions of many accessions in the O. officinalis complex and correct determination of the genebank material, which serves as an important basis of germplasm cataloguing for further research and utilization.  相似文献   

13.
Nuclear RFLPs were used to study the genetic relationships of 2 Portuguese coles, tronchuda cabbage and Galega kale, and 13 otherBrassica oleracea cultivars and 4 nine-chromosome wild brassicas. Cluster and principal coordinates analysis were conducted using RFLP data from 60 probe-enzyme combinations, detecting 277 polymorphic restriction fragments. The results showed that the accessions clustered in five groups: one with all theB. oleracea cultivars except kailan, and the four others isolated with kailan, wildB. oleracea, B. insularis andB. cretica, andB. montana, respectively. Kailan was separated from the other accessions ofB. oleracea cultivars and genetically close to the wildB. oleracea, that was clearly separated from the other nine-chromosome wild brassicas. In theB. oleracea cultivars 3 groupings were clearly individualized: i) including broccolis and cauliflower; ii) with a misture of kales and cabbages originally from Central-North Europe; iii) formed by Portuguese coles. These preliminary results suggest the existence of three major regions of domestication of B. oleracea in Europe: Italy, Central-North Europe and Portugal. Kailan or chinese kale seems to have evolved separately from the otherB. oleracea cultivars in Eastern Asia.  相似文献   

14.
The legume pod borer, Helicoverpa armigera (Hübn.), is one of the major constraints to chickpea production, and host plant resistance is an important component for the management of this pest. The levels of resistance in the cultivated chickpea are low to moderate, and therefore, we evaluated 17 accessions of perennial Cicer along with three cultivated chickpea genotypes for resistance to H. armigera. There was a significant reduction in both leaf feeding and larval weights when the larvae were fed on the leaves of Cicer microphyllum Benth. accessions ICC 17146, ICC 17236, ICC 17240, and ICC 17248. Relative resistance index based on leaf feeding, larval survival, and larval weight indicated that C. microphyllum accessions ICC 17146, ICC 17236, ICC 17234, ICC 17240, ICC 17243, and ICC 17248 were highly resistant to H. armigera. Under natural infestation, accessions belonging to C. microphyllum, C. canariense Santos Guerra et Lewis, and C. macracanthum M. Pop suffered a damage rating of <2.0 compared to 4.0 in C. judaicum Boiss. accession ICC 17148 (annual species) and 8.5–9.0 in the cultivated chickpeas (1 = <10% leaf area damaged, and, 9 = >80% leaf area damaged). There was considerable diversity in the accessions belonging to perennial wild species of chickpea, and these can be exploited to increase the levels and diversify the basis of resistance to H. armigera in the cultivated chickpea.  相似文献   

15.
Lentil anthracnose (Colletotrichum truncatum (Schwein.) Andrus et W.D. Moore is a potential threat in many lentil (Lens culinaris Medik.) production regions of North America. In the lentil germplasm maintained in Germany and North America, 16 lines were reported to have resistance to race Ct1, but none has resistance reported to race Ct0. The objective of this study was to examine accessions of wild Lens species for their resistance to races Ct1 and Ct0 of lentil anthracnose. Five hundred and seventy-four wild accessions of six species and control lines were screened in two replications under both field and greenhouse conditions using a 1–9 scoring scale (1, highly resistant; 2–3, resistant; 4–5, moderately resistant; 6–7, susceptible; and 8–9, highly susceptible). Indianhead and PI 320937 were resistant while Eston and Pardina were susceptible to race Ct1 as expected. However, none of the check lines were resistant to race Ct0. Among the six Lens wild species tested, accessions of Lens ervoides (Brign.) Grande had the highest level of resistance, 3–5 to race Ct1 and Ct0 followed by L. lamottei Czefr. in the field and greenhouse. Lens orientalis (Boiss.), L. odemensis L., L. nigricans (M. Bieb.) Godron and L. tomentosus L. were highly susceptible, 8–9 to race Ct0 in the greenhouse. The highest frequency of resistance, especially in L. ervoides (Brign.) Grande, was found in accessions originating from Syria and Turkey. The usefulness of these L. ervoides (Brign.) Grande accessions as sources of resistance to the more virulent race of anthracnose in a lentil breeding program is discussed.  相似文献   

16.
Summary An extensive crossing program including 10 wild taxa and 23 accessions representing 6 major cultivated forms and landraces of theBrassica oleracea group was carried out. Data for crossability, germination, viability, fertility inF 1 andF 2 were studied as well as the meiotic chromosomal pairing inF 1 hybrids in some combinations. The fertility of hybrids between all cultivated forms and wild populations ofB. oleracea was high and it was concluded that all, including the Chinese endemicalboglabra form, belong to the same biological species. Among the other species,B. macrocarpa, B. montana, andB. rupestris had the lowest andB. cretica the highest fertility values in crosses with cultivated forms. The crossing data do not give any further information as to the genetic differentiation ofB. oleracea during the course of domestication. Introgression between wild and cultivated forms has probably occurred frequently. All members of theB. oleracea cytodeme belong to the primary and secondary gene pools of the 18 chromosomic crops and are as such of great importance for breeding purposes.  相似文献   

17.
Perennial kale is a rare leafy vegetable and forage crop that is mainly vegetatively propagated and therefore expensive to conserve ex situ. A genebank collection of 47 perennial kales and 34 reference samples from the main Brassica oleracea crop types were characterized with seven microsatellite markers in order to verify potential redundancies and to obtain more insight in the position of perennial kales within B. oleracea. Based on the obtained results and on data from previous studies, the collection was reduced with 49% to 24 perennial kales. Considering this level of reduction, it was estimated that the investments made for the final verification by microsatellite analysis are returned after only 4-year time. A principal coordinate plot clearly separated the perennial kales from the other crop types of B. oleracea, except in one case. This deviating accession of vegetatively preserved perennial kale clustered closely together with the single seed-preserved accession of perennial kale included in the study. These two accessions occupied an intermediate position between the group of vegetatively propagated perennial kales and the group of seed-propagated Brassica accessions, suggesting a hybridization background with another B. oleracea crop type. The microsatellite study demonstrated a close genetic relationship among the investigated perennial kales and their unique position within B. oleracea.  相似文献   

18.
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.  相似文献   

19.
Summary Leaf miner (Liriomyza cicerina Rond.) causes considerable damage to chickpea (Cicer arietinum L.) in West Asia, North Africa and Southern Europe. Use of resistant cultivar is the economical method of control. Screening of over 7000 germplasm accessions did not result in identification of highly resistant accessions to this insect. Therefore, 200 accessions of eight wild Cicer species were evaluated in search of resistance to leaf miner between 1988 and 1991 at ICARDA, Syria. Accessions of Cicer species were screened under natural insect infestation in the field during spring (March–June), along with a susceptible-cum-indicator line. Two accessions of C. cuneatum (ILWC-40 and -187) and 10 accessions of C. judaicum (ILWC-44, -46, -56, -57, -58, -95, -103, -196, -206, and -207) were rated 2 on a 1–9 scale, where 1 = free from any damage and 9 = maximum damage. Another 18 lines of C. judaicum, four lines of C. pinnatidum and one line of C. reticulatum were rated 3 (resistant). Currently three species are incompatible in crossing with chickpea, but C. reticulatum is being used in breeding programme.Joint contribution from ICARDA and ICRISAT (Inter-national Crops Research Institute for the Semi-Arid Tropics), Patancheru P.O., AP 502 324, India.  相似文献   

20.
Summary Isozyme variation in 25 accessions of wild and cultivated Vigna unguiculata, 49 accessions of seven wild species belonging to section Vigna, and 11 accessions of V. vexillata (subgenus Plectrotropis) was scored at 17 putative loci to assess genetic relationships within and among species. The wild species selected for this study are among those which carry important agronomical traits useful in cowpea (V. unguiculata) breeding programs. Allelic frequencies were calculated and Nei's genetic distances were obtained. Low levels of intraspecific variation were observed for V. heterophylla, V. luteola and V. racemosa, whereas the other species showed a higher polymorphism. Vigna unguiculata possessed intraspecific genetic distances comparable to those previously found by other authors. Most of the isozyme variation was apportioned among species. Although V. luteola and V. marina had an interspecific genetic distance resembling the range observed at intraspecific level, all the other species showed very high interspecific distances. Vigna unguiculata was relatively closer genetically to V. vexillata than to the species belonging to section Vigna.Abbreviations AUS Australia - BDI Burundi - BRA Brazil - BWA Botswana - CAF Central African Republic - GHA Ghana - CMR Cameroon - COG Congo - RI Costa Rica - EGY Egypt - ETE Ethiopia - GAB Gabon - GRC Greece - ITA Italy - KEN Kenya - MOZ Mozambique - NER Niger - NGA Nigeria - PAN Panama - RWA Rwanda - TCD Chad - TZA Tanzania - ZAF South Africa - ZAR Zaire - ZMB Zambia  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号