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1.
Seedlings of 213 accessions representing 9, 14, and 10 Israeli natural populations of the wild Lactuca serriola, L. saligna, and L. aculeata, respectively, were initially screened for their resistance to a pathotype CAVIII isolate of Bremia lactucae. All 60 L. serriola accessions were susceptible while all 83 accessions of L. saligna were resistant. Out of the 69 L. aculeata accessions, 36 (52.2 %) were resistant. From those resistant accessions, 56 L. saligna and 23 L. aculeata accessions were then tested at the seedling stage for their reaction against five highly virulent isolates originating from California and representing the two current major pathotypes and a novel type of B. lactucae; true leaves of adult plants were also tested with two out of these five isolates. Our study supports previous observations that L. saligna is highly resistant to B. lactucae. However, our results provide additional evidence that L. saligna may not be an absolutely non-host plant for B. lactucae at least at a seedling stage, which is in agreement with other recent data for this species. Sixteen (69.6 %) out of the 23 L. aculeata accessions expressed resistance against all isolates tested, even in seedling stage as well as in true leaves of adult plants. This study is probably the first report of detailed screening of resistance to some B. lactucae isolates in natural populations of L. aculeata. These patterns of resistance reactions show that L. aculeata, a species within the primary lettuce gene pool, should be considered as an attractive source of germplasm for resistance breeding of cultivated lettuce (L. sativa).  相似文献   

2.
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.  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.
Summary Patterns of achene proteins of L. sativa cultivars are mutually compared and compared with L. saligna, L. serriola and L. virosa. L. virosa and L. saligna are easy to identify and are characterized by typical banding patterns. L. sativa and L. serriola share the same banding pattern. They differ clearly from L. saligna and L. virosa. L. sativa and L. serriola are closely related (in terms of similarity), they form a common genepool and L. serriola is involved in the domestication process of L. sativa. Cultivar identification was not possible with the SDS-PAGE method.  相似文献   

5.
Expeditions were conducted in the Czech Republic, Germany, the Netherlands and United Kingdom in 2001 (partly 1998) to study Lactuca serriola L. (prickly lettuce, compass plant) geographic distribution, ecology, habitat characteristics and occurrence of diseases and pests on this species. During these missions the seed material of L. serriola L. was collected in an east–west transect of these four countries. The European transect where seeds were collected and field observations were made represents a relatively large area between 2°34′50′′ W–17°32′46′′ E and 47°40′42′′–54°04′19′′ N. The seed material was used for regeneration, inclusion in the national genetic resources collections of individual countries and for research purposes in follow-up studies. During the missions, 50 locations with occurrence of L. serriola L. were visited (16 in Czech Republic and Germany, 10 in UK and 8 in the Netherlands). Individual seed lots of sixteen different plants were collected at each location (L. serriola L. population). Thus, in total 800 seed samples were collected. In Czech Republic and Germany L. serriola L. f. serriola dominated in all observed populations, in the Netherlands both f. serriola and f. integrifolia occurred in pure or mixed stands, whereas in the United Kingdom L. serriola L. f. integrifolia (S.F. Gray) S.D. Prince et R.N. Carter was dominant. L. serriola L. was recorded at various altitudes (−4 to 410 m), different habitats (ditches, along roads, fields and field margins, ruderal places, pavements and parking sites, fallow fields), individual populations varied substantially in size (20 to >1000 plants), area covered (25–10,000 m2), and the structure and character of associated plant communities. Natural infections by downy mildew (Bremia lactucae Regel) and powdery mildew (Golovinomyces cichoracearum (DC.) V.P. Gelyuta) were observed in some populations. B. lactucae Regel was recorded only in Czech Republic, G. cichoracearum (DC.) V.P. Gelyuta was more common in continental Europe. General and specific aspects of L. serriola L. geographic distribution and ecology are discussed.  相似文献   

6.
The wild lettuce, Lactuca aculeata Boiss. et Ky., is closely related and fully interfertile with cultivated lettuce, Lactuca sativa L. Altogether, 155 accessions of this wild species, which is rare conserved within the world’s germplasm collections, were collected from 12 localities throughout northeastern Israel. Ten of these localities represent different sites across the Golan Heights, while two, high-density populations were suprisingly found at the Hula Plain (first report of this species in this region). Lactuca aculeata was recorded at various elevations (222–968 m a.s.l.) and habitats. The taxonomic status of 30 L. aculeata accessions was morphologically validated during ex situ seed regeneration of 31 random accessions representing all 12 localities. Characterization of 12 traits showed that the Israeli populations of L. aculeata do not exhibit broad morphological variability, but more great levels of variation were obtained for developmental traits. Relatively little variability was observed in the morphology of cauline leaves or in the distribution of anthocyanin pigmentation in bracteae. In two cases, L. aculeata plants lacked trichomes in the inflorescence, a typical feature in the majority of plants. These unique collections of wild lettuce may carry novel sources of genetic variation for a wide range of traits and, thus, should be of interest for careful evaluation and exploitation in lettuce breeding.  相似文献   

7.
During 2002, 2004, 2006 and 2008, trips were undertaken in the United States and Canada by members of the Department of Botany, Palacky University in Olomouc (Czech Republic) to record distributions and sample the diversity of wild and weedy Lactuca species. In that period, 16 states in the USA (Arizona, California, Colorado, Idaho, Iowa, Minnesota, Montana, Nevada, New York, North Carolina, Oregon, South Dakota, Utah, Washington, Wisconsin, Wyoming) and two provinces in Canada (Ontario, Quebec) were visited. Seven wild and weedy Lactuca species (L. serriola, L. saligna, L. virosa, L. canadensis, L. biennis, L. floridana, L. ludoviciana), an interspecific hybrid (L. canadensis?×?L. ludoviciana), and an undetermined Lactuca species were recorded, and 343 seed samples were collected from 200 locations. The largest number of wild Lactuca species that we observed was recorded in Iowa, and the largest number of samples was collected in California. The most common habitats of weedy species (L. serriola, L. saligna and L. virosa) were along transport corridors, such as roadsides, road ditches, parking sites and petrol stations, grassy slopes and ruderal places. The most frequent species was L. serriola, an Old World introduction, which we observed in all states and provinces visited, except for New York, and in broad range of elevations (up to 2,358?m a.s.l.). Lactuca saligna was recorded only one time in Salinas, California. Lactuca virosa was found repeatedly in Washington State along the road to the Mt. St. Helens and in Redwoods, California. Native North American taxa (L. canadensis, L. floridana, L. ludoviciana) were recorded only in Iowa. Lactuca biennis was found only in Canada in the southern part of Quebec. Records of diseases and pests showed only occasional occurrences of downy mildew (Bremia lactucae) and powdery mildew (Golovinomyces cichoracearum). Most plant-disease findings were made in Canada. Results of these efforts enrich our knowledge of the distribution, ecogeography and ecobiology of Lactuca species occurring spontaneously in North America. Seed collections (accessions) will be conserved in the working collection of the genebank at Palacky University to support future research in ecogeography, ecobiology, resistance and genetic polymorphisms, and to enrich of germplasm diversity available for lettuce breeding.  相似文献   

8.
Twenty four barley lines derived from the F 7generation of crosses between two winter barley cultivars and different accessions of Hordeum spontaneum Koch collected in Israel were tested against a set of ten European and five Israeli powdery mildew cultures, possessing virulence genes which completely match the spectrum of known mildew resistance genes. The comparison of reaction patterns justified the conclusion that new genes for resistance have been conferred from H. spontaneum which also differ from genes previously identified in other wild barley accessions from Israel. Participation in the expression of the resistance reaction of one of the two barley cultivars used in the development of the lines is well documented in some cases. The majority of the lines was found to be highly resistant against all or almost all European isolates, while various kinds of reactions were observed against the Israeli cultures. The effective transfer of novel mildew resistance from H. spontaneum into winter barley confirms similar results with spring barley, indicating natural wild barley populations in Israel as a significant gene pool for yet unexploited mildew resistance in barley.  相似文献   

9.
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   

10.
Genetic micro-differentiation was studied in wild barley at the Neve Yaar microsite, Israel, an area of 3182 m2, which includes a mosaic of sun-rock, sun-soil, shade-rock, and shade-soil microniches. Fifty-six genotypes were tested for ecological-genetic microniche correlates. Analysis of 75 RAPD loci revealed a significantly higher polymorphism and gene diversity (P 0.05 = 0.920; He = 0.411) on the more stressful sun-rock microniche, compared to the least stressful shade-soil microniche (P 0.05 = 0.653; He = 0.188). Fifty-six (74.7%) out of the 75 loci varied significantly in allele frequencies. On the average, of the 75 loci, 75.7% of the total genetic diversity exists within the four microniches, while 24.3% exists between the microniches. The highest genetic distance was between shade-soil and sun-rock (D = 0.220), which confirmed their sharp microecological contrasts. Gametic phase disequilibria (LD) differed significantly between sunny and shady microniches. The levels of correct classification of individual genotypes into their respective microniche, based on the presence/absence of bands of the 2, 3, 4, 5, and 7 best differentiating loci, obtained by stepwise discriminant analysis, were 79, 84, 89, 95, and 100%, respectively. We conclude that ecological contrasts at the Neve Yaar microsite cause molecular diversifying selection (presumably at both coding and noncoding genomic regions of wild barley) overriding gene flow.  相似文献   

11.
Exploitation of wild gene pool for breeding is a common practice in an increasing number of cultivated plants. The cultivated lentil could not attain the substantial improvement in the yield potential due to loss of genes for higher productivity and lack of resistance against biotic and abiotic stresses. The absence of evaluation data of wild lentils for characters of economic importance, besides biotic and abiotic stresses, is one of the constraints in their use in lentil breeding programme. In the present study, 70 wild accessions from four wild Lens subsp./sp. (L. culinaris subsp. orientalis, L. odomensis, L. ervoides and L. nigricans) along with 3 checks (Precoz, PL-406 and PL-639) were evaluated for phenological and agro-morphological characters, for their reaction to three fungal diseases (wilt, powdery mildew and rust) and screened for tolerance to moisture stress. The wild accessions showed higher performance for branches/plant as compared to cultivated genotypes. Similarly, a few accessions of L. culinaris subsp. orientalis were earlier to flower and had higher seeds and seed yield/plant as compared to cultivated lentil. However, some were comparable with cultivated genotypes for flowers/peduncle, peduncle length and plant height. The mean performance for flowers per peduncle, leaflets per leaf, plant height, seeds and seed yield per plant increased, while decreased for days to flowering and maturity, and branches per plant during the evolution of cultivated lentil from the wild Lens taxa. Of Lens taxa, L. nigricans had the maximum resistant accessions for biotic and tolerance to abiotic stresses. The valuable variation existing among wild accessions can be exploited following introgression with cultivated lentils. It will help in the flow of useful genes from wild to cultivated lentil for generating wide spectrum of variability and its subsequent use in genetic restructuring of lentil.  相似文献   

12.
13.
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   

14.
One hundred and twenty-one of 123 previously detected new sources of wild barley (Hordeum vulgare ssp. spontaneum) resistant to powdery mildew (Blumeria graminis f. sp. hordei), and originating from Mediterranean area, and 20 standards were tested at the seedling stage for reaction to 38 selected Israeli powdery mildew isolates. The obtained resistance spectrum (a set of resistant and susceptible reactions) of each accession was divided into triplets and converted to octal numbers. This concentrates information on the resistance phenotype of each accession and makes their comparison much easier. One hundred and thirty-four different resistance spectra were determined. No compatible reaction was found in standards possessing genes mlo and Mlhb2 and in the accession PI 466634. The results demonstrate large diversity in new resistance sources, their distinction from the sources described till now as well as diversity in powdery mildew resistance of wild barley in the Mediterranean area. The results facilitate more effective further studies of such a large set of new resistance sources, and contribute to speeding up their use in barley breeding.  相似文献   

15.
In order to formulate appropriate strategies for the conservation and utilization of the wild mulberry genetic resources available in India, a study was undertaken with 20 mulberry genotypes from the four different species. Seventeen intersimple sequence repeat primers were used to generate a total of 114 markers, of which 98 (85.96%) were polymorphic. Seven unique bands for Morus serrata Roxb. and one for both M. serrata Roxb. and Morus macroura Miq. were identified, of which one fragment has been sequenced and deposited in the EMBL-GeneBank (AJ-585512). The genetic dissimilarity coefficients varied from 0.078 to 0.530 among these genotypes and from 0.168 to 0.465 among the species. The dendrograms realized from these markers clustered the genotypes into three groups. The outermost group was M. serrata Roxb., which was followed by the group of M. macroura Miq. and the innermost group contained genotypes of Morus indica L. and Morus alba L. This intermixing of genotypes of M. indica and M. alba supports the view that M. indica is merely a synonym of M. alba. Distribution of the genotypes on a two-dimensional figure upon multidimensional scaling with ALSCAL program, further, confirmed the genetic divergence between the cultivated and wild mulberry groups. On the basis of the results a few potential wild mulberry genotypes were identified for its conservation and utilization in breeding programs to confer the stress tolerance to the cultivated varieties of mulberry.  相似文献   

16.
It is surmised that domestication has reduced geneticvariability in the common bean (Phaseolusvulgaris L.). However, little is known about leaf anatomy responses to water stress in wild or domesticated forms ofP. vulgaris. In this study,anatomical variation was evaluated in watered and water stressed plants of wild and domesticated genotypes of P.vulgaris from Mexico, growing under greenhouse conditions. Five terminal leaflets of completely expanded leaves wereused to evaluate leaf area (LA) and theirmiddle-regions to evaluate leaf thickness (LT), and various anatomical features. Domesticated genotypes showed bigger LAthan that of the wild ones; there was an effect due to the origin of materials, LA being bigger in genotypes from warm and humid lands that those from dry and temperate ones. No differences were detected in LT among materials; however, in domesticated plants the palisadeparenchyma predominated over the spongy one, contrasting with thewild genotypes. Under drought conditions, stomatal abortion was observed in wild and domesticated genotypes, especially on theabaxial surface. We conclude that, in fact, there are contrasting differences in leaf anatomy among wild and domesticated forms of Mexican Phaseolus vulgaris. Results suggest that domestication not only favours the enlargement of the LA, but also an increase in palisade parenchyma, suggesting a divergence toward assimilation in domesticated forms, in contrast with a better internal gas diffusion in wild forms. Domestication seems to have accentuated stomatal abortion as means of a transpirational control mechanism to counteract the effects of drought.  相似文献   

17.
林仁亨  黄海涛  李焕秀  姜建业  蒋伟  唐懿 《土壤》2018,50(4):732-737
为了探讨银杏外种皮对生菜的化感作用,采用盆栽方法,分别设置5个外种皮施用量(0、15、30、60、90 g/盆)处理,研究银杏外种皮对生菜生长、抗氧化酶系统、渗透调节物质含量以及光合参数的影响。结果表明:随着银杏外种皮施用量的增加,生菜的主根长和地上部鲜重呈先上升后下降的趋势,而株高和茎粗则不断下降,在施用量为90 g/盆时生菜的各生长指标均达到最低值;生菜的光合色素含量随银杏外种皮施用量的增加呈下降趋势,各处理不同光合色素含量与对照相比均显著下降;生菜超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性、游离脯氨酸含量及可溶性蛋白含量随银杏外种皮施用量的增加均先上升后下降,但丙二醛(MDA)含量并未显著增加;生菜净光合速率Pn、胞间CO_2浓度Ci和蒸腾速率Tr随银杏外种皮施用量的增加呈先上升后下降的趋势,气孔导度Gs则不断下降。综上所述,银杏外种皮对生菜产生了明显的化感作用,对生菜的生长、生理和光合指标总体呈抑制作用,并且随着施用量的增加,抑制作用不断加强。  相似文献   

18.
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   

19.
Cultivated Solanum tuberosum L. subsp. andigena is well known as a rich source of valuable traits for potato breeding, especially for resistance to diseases and pests. The golden potato cyst nematode, Globodera rostochiensis Woll., is considered to be one of todays most serious hindrances to potato production in Europe and North America. Thus, the breeding of new cultivars that have resistance to PCN is of great importance. The USPG (USA) and VIR (Russian) potato genebanks, as well as others, maintain many samples of primitive cultivated and wild potato species originating from Latin America. Many of these samples are assumed to be genetically duplicated because the material in both genebanks came from the same original source. A joint investigation of new genotypes of subsp. andigena forms resistant to potato cyst nematode (PCN) was carried out on samples of subsp. andigena at VIR with reputed duplicate samples at USPG. After careful screening, 14 samples which possessed resistance to PCN were identified. A high level of this resistance was transmitted to sexual progeny at a high frequency for all of the selections. Eleven of the accessions found to be resistant have reputed duplicates in USPG that were not previously known to be resistant. Thus, this research not only broadens the choice of parents available for resistance breeding, but identifies model materials for future research to test the parity of PCN resistance among reputed duplicate samples in the two genebanks.  相似文献   

20.
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   

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