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1.
Mitotic analysis of sticky chromosomes in aluminum tolerant and susceptible wheat lines grown in soils of differing aluminum saturation 总被引：3，自引：0，他引：3
Plant resistance is currently the most effective and environmentally safe method to control plant parasitic nematodes (PPNs).
Resistance genes generally act against sedentary PPNs by inducing a hypersensitive reaction that prevents the parasite installation
and/or reproduction. However, the recent emergence of virulent biotypes able to overcome the plant resistance genes may constitute
a severe limitation to this control strategy. In selection experiments conducted under controled environment, the genetic
variation, specificity and inheritance of nematode virulence have been demonstrated. Moreover, the occurrence of gene-for-gene
interactions has been shown in a few cases. Moleculars markers have been extensively used to investigate the genetic variability
of PPNs, but so far, the genomic polymorphisms observed are largely independent of virulence. Such data suggest that, within
a species, virulent isolates do not share a common origin, but are probably the result of independent mutational events. To
understand the molecular mechanisms responsible for virulence in PPNs, several strategies have been developed, in relation
with their mode of reproduction (parthenogenesis versus amphimixis). As an example, recent results obtained in our laboratory on the root-knot nematodes Meloidogyne spp. are presented. On a more general point of view, factors that may induce stable genome variability in PPNs, e.g. Transposition
of mobile elements and chromosomal rearrangements (leading to polyploidy, aneuploidy, etc) will also be considered. Advances in knowledge in these areas should have important consequences for the management and
durability of natural resistance genes, and for the engineering of new forms of resistance.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
2.
Genetic variation and response to selection for resistance to root-knot nematodes in oil radish (Raphanus sativus ssp. oleiferus) 总被引：1，自引：0，他引：1
Based on a preliminary screening of a collection of cruciferous crops, such as oilseed rape (Brassica napus L. ssp. oleifera Metzg.), oil radish (Raphanus sativus L. ssp. oleiferus DC.), and yellow mustard (Sinapis alba L.), some plants within the oil radish varieties showed resistance to the root-knot nematodes Meloidogyne hapla Chitwood and M. incognita (Kofoid & White) Chitwood. Resistance tests of S1 progeny of these selected genotypes revealed a quantitative nature of resistance to M. hapla. Only a few resistant individuals were found, but a significant effect of selection was observed. In contrast, the progenies of plants resistant to M. incognita showed a very low number of egg masses, suggesting that this resistance may be conferred by dominant major gene(s). The results indicate that resistance of oil radish to root-knot nematodes may be effective and may thus provide new possibilities for the management of M. hapla and M. incognita. 相似文献
3.
W. Erskine M. Tufail A. Russell M. C. Tyagi M. M. Rahman M. C. Saxena 《Euphytica》1993,73(1-2):127-135
Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed. 相似文献
4.
A germplasm collection of 39 eggplant Solanum melongena genotypes and one accession of S. torvum was evaluated for resistance to the root-knot nematode (Meloidogyne javanica) by using controlled greenhouse tests. Different degrees of resistance to the disease caused by this nematode species were observed among the genotypes tested. Complete resistance (no nematode egg mass formation up to 7 weeks after inoculation) was detected in one accession belonging to domesticated S. melongena species. Good levels of incomplete resistance were also observed in some commercial eggplant genotypes. This is apparently the first report of a source of complete resistance to M. javanica within the S. melongena gene pool and our finding could greatly facilitate the incorporation of this trait into commercial eggplant cultivars. S. torvum, previously described as resistant to several root-knot nematode species (including M. javanica, M. arenaria, and M. incognita) was also confirmed as a source of resistance to this Brazilian population of M. javanica. Therefore, S. torvum can be considered as one of the most promising sources of broad-spectrum resistance genes against root-knot nematodes. Broad-spectrum resistance is of paramount importance for breeding programmes focused on the development of cultivars for tropical and subtropical areas of the world where multiple infestation of soils with distinct Meloidogyne species is a very common feature. 相似文献
5.
Development of commercially available host-plant resistance to Meloidogyne spp. is essential to sugarbeet (Beta vulgaris L.) root-knot nematode resistance breeding. Reactions of seedlings from resistant crosses and hybrid derivatives were evaluated
against juvenile (J2) inoculations in the greenhouse. The noncultivated sea beet [B. vulgaris ssp. maritime (L.) Arcang] source of resistance is effective against the four economically important root-knot nematodes, i.e., M. incognita Races 1, 2 and 4 (Race 3 not tested), M. Javanica, M. arenaria Races 1 and 2, and M. hapla. In monoxenic culture, M. arenaria inoculations resulted in the most galling, and M. hapla, the least. Species combinations induced higher rates of infection. Different races of the same Meloidogyne species caused similar galling. Preliminary inoculation studies indicated that resistance was also effective to M. Chitwoodi and M. fallax. The trait of resistance to multiple Meloidogyne species may be valuable in developing sugarbeet, and possibly transgenic lines of other crops, resistant to root-knot nematode.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
马铃薯不同品种(系)和稻、薯轮作模式对根结线虫病的防治效果 总被引：2，自引：0，他引：2
根结线虫病是马铃薯连作减产的主要原因之一。为研究根结线虫病的农艺防治措施,本文开展了品种抗性评价、稻、薯轮作和土壤淹水下的线虫消减动态研究。抗性评价试验表明, 18个品种(系)中没有筛选到同时抗南方根结线虫和爪哇根结线虫的材料,品系1002-1和品种丽薯6号相对抗性较好,青薯9号和合作88相对敏感。马铃薯根结线虫发病土壤中可同时检测到卵、幼虫和成虫等不同形态。水旱轮作试验表明,经一茬水稻栽培可使土壤中根结线虫虫态完全消失,再种植马铃薯也不再发生根结线虫病,且马铃薯有效产量显著提高,青薯9号、合作88和丽薯6号的单株有效产量较对照分别提高50.5%、43.7%和26.0%,差异均极显著, 1002-1单株有效产量与对照差异不显著。由此可见,稻、薯轮作根结线虫防治效果明显。为进一步探索水旱轮作的防治机制,观察了土壤淹水进程中各种虫态消减动态。结果表明,在淹水过程中,根结线虫的卵、幼虫和成虫不同虫态此消彼长,要淹水60 d以上,土壤中才检测不到所有形态虫体。水早轮作中水稻生长期淹水时间足够长,满足防治线虫的淹水条件。因此结合抗病品种选用进行稻、薯轮作是防治马铃薯根结线虫病既绿色环保又可持续有效的方法。 相似文献
7.
The aim of this study was to obtain information on the response of cassava(Manihot esculenta Crantz) to root-knot nematode infestation. To achieve this aim, a novel in vitro dual root/nematode culture method was used, where root cultures of several cassava cultivars were inoculated with axenic
Meloidogyne javanica eggs. Following an incubation period,cassava roots were stained, weighed and dissected to determine the number of galls produced
on the roots, as well as the number of mature females embedded in the galls. The number of eggs and larvae produced during
this time were also determined. Results indicated that the modified in vitro nematode culture medium used was suitable for
most root cultures of cassava cultivars. It was found that some cassava cultivars were highly susceptible to root-knot nematode
infestation, with some cultivars showing very high numbers of galls and up to 50 mature females inside each gall. Some cassava
cultivars screened, however, showed low numbers of galls and mature females, even though the presence of larvae was high.
Some of these cultivars formed callus-like structures instead of galls, and this may be a resistance mechanism. This method
may be useful as a screening tool, to determine the response and resistance or susceptibility of cassava cultivars to root-knot
nematode infestation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Chickpea (Cicer arietinum L.) production has remained static for the past two decades. One major limiting factor has been susceptibility of cultivars to several biotic and abiotic stresses that adversely affect yield. In recent years, cultivars resistant to Ascochyta blight (Ascochyta rabiei [Pass.] Lab.), Fusarium wilt (Fusarium oxysporum f. sp. ciceris), and cold have been bred and released in many countries. Some progress has been made in breeding for resistance to drought, insects, and cyst nematode, but not for viruses, heat, and salinity. Two or more stresses are of equal importance in most chickpea growing areas. Therefore, future efforts should be directed toward the development of cultivars with multiple-stress resistance. Proper understanding of important stresses in different countries and the genetics of resistance should lead to more systematic approaches to resistance breeding. Wild Cicer species hold promise and deserve attention in resistance breeding. 相似文献
9.
10.
不同浓度臭氧水防治根结线虫效果的研究 总被引：3，自引：2，他引：3
为了确定臭氧水防治根结线虫的效果及适宜浓度,为根结线虫的防治提供理论依据。以不同浓度臭氧水0 mg/L、1.0 mg/L、1.5 mg/L、2.0 mg/L分别在生姜、西瓜、番茄不同生长期进行连续灌溉,于生姜收获期、西瓜膨大期、番茄拔园时进行根部根结数测定及根际土壤中线虫数量调查。结果表明：与臭氧水浓度0 mg/L相比,1.0 mg/L、1.5 mg/L处理生姜根结数量及根际土壤线虫数量降低59.1%、93.3%及57.8%、88.3%;西瓜根结数量及根际土壤线虫数量降低66.9%、91.1%及60.9%、89.1%;番茄根结数量及根际土壤线虫数量降低70.0%、93.8%及73.6%、92.2%。臭氧水浓度为2.0 mg/L防治根结线虫效果与1.5 mg/L差异不显著。综合考虑,灌溉水中臭氧浓度为1.5 mg/L防治根结线虫效果较理想。 相似文献
11.
健康与根结线虫病烟田根际土壤微生物群落对比分析 总被引：1，自引：0，他引：1
为了研究烟草根结线虫病与根际土壤微生物群落的关系,通过高通量测序研究了健康烟田和根结线虫病发病烟田根际土壤的微生物多样性、组成结构和功能变化。结果表明：健康烟田根际土壤微生物群落的Alpha多样性与发病烟田差异不显著,Beta多样性分析表明健康烟田样本与发病烟田样本分布基本一致。健康烟田与根结线虫发病烟田根际土壤细菌与真菌微生物群落在门水平上组成相似,但物种丰度存在差异,酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)、担子菌门(Basidiomycota)和壶菌门(Chytridiomycota)在健康烟田中占优势,而变形菌门(Proteobacteria)、芽单胞菌门(Gemmatimonadetes)、子囊菌门(Ascomycoda)、球囊菌门(Mortierellomycota)在发病烟田中占优势。在属水平上,根际土壤细菌与真菌微生物群落组成也基本一致,但健康烟田与根结线虫发病烟田微生物物种丰度存在显著差异,Cylidrocapon、镰刀菌属(Fusarium)等致病菌在发病烟田中占显著优势。种水平上,健康烟田中的Actinoallomurus spadix和分枝节杆菌(Arhrobacter ramosus)与发病烟田组存在显著差异。通过根际土壤微生物功能预测分析发现,发病和健康烟田土壤真菌、细菌功能组成相似,但发病烟田样本功能丰度大于健康烟田。因此,烟草根结线虫病的发生与根际土壤微生物群落的组成和多样性无直接关系,而是可能与物种丰度及样本功能丰度密切相关。研究结果可为通过调控根际微生物群落结构来防治烟草根结线虫病提供理论依据。 相似文献
12.
J. B. Hartman D. Vuylsteke P. R. Speijer F. Ssango D. L. Coyne D. De Waele 《Euphytica》2010,172(1):139-148
Crop growth and damage parameters (plant growth and yield, root damage and nematode population densities), believed to be
associated with resistance of Musa genotypes to nematodes under field conditions, were evaluated in a field trial of 24 Musa genotypes inoculated at planting with a combination of Radopholus similis and Helicotylenchus multicinctus with the objective to identify parameters with strong association with nematode resistance and high heritability. Correlation
and path analysis of the association between plant growth, yield, root damage and nematode population densities showed a strong
negative association between percentage dead roots, percentage root necrosis, R. similis and H. multicinctus population densities and yield. The strongest negative association was observed between percentage dead roots and yield.
Broad-sense genotype heritability estimates demonstrated that heritability estimates for percentage dead roots, number of
large lesions and nematode population density were most affected by inoculation with nematodes. These results indicate therefore
that effective selection for nematode resistance under field conditions could be obtained by using an index, that includes
percentage dead roots, the number of large lesions, and nematode population density. 相似文献
13.
Summary Allohexaploid (2n = 108) F2 and F3 interspecific hybrids ofHibiscus cannabinus × H. sabdariffa were intermediate in their resistance to the cotton root-knot nematode (Meloidogyne incognita acrita
Chitwood 1949) between their moderately resistant, tetraploid parent, roselle (Hibiscus sabdariffa L.) and their susceptible, diploid parent, kenaf (H. cannabinus L.). Whether or not this resistance, as measured by the amount of root galling, is sufficient to be of practical importance is not known at present. However, results were encouraging enough to suggest further testing of the hybrids for agronomic potential, stability, fertility, and response to root-knot, and other parasitic nematodes that attack this potentially important paper-pulp crop.Cooperative investigations of the Crops Research Division, Agricultural Research Service, US Department of Agriculture, and the Texas Agricultural Experiment Station. 相似文献
14.
Root‐knot nematodes, Meloidogyne spp., cause severe damage on solanaceous crops, including tomato and pepper. The objective of this study was to test whether nematodes virulent against the tomato Mi resistance gene were able to overcome the Me1 and Me3 resistance genes from pepper. For that purpose, a collection of 22 Meloidogyne arenaria, Meloidogyne incognita and Meloidogyne javanica isolates, avirulent or virulent against the Mi gene, was assembled. The reproduction of each isolate was evaluated on both susceptible and resistant tomato and pepper genotypes in a growth chamber. The Me1 resistance gene controlled all the avirulent and Mi‐virulent nematodes tested, and therefore appears promising for pepper breeding. In contrast, one M. arenaria and two M. incognita virulent isolates were shown to overcome the pepper Me3 resistance gene. These results encourage the testing of a large number of Meloidogyne isolates to evaluate the plant‐nematode interaction, which could have important consequences for the use and management of resistance genes in the field with respect to specificity and durability of the resistance. 相似文献
15.
Bananas cultivated for export all belong to Cavendish cultivars and are all recognized as very susceptible to nematodes, particularly
to the burrowing nematode Radopholus similis and the lesion nematode Pratylenchus coffeae. Even if there have been many changes in the management of banana nematodes in large commercial banana plantations, chemical
control still remains most often the last resort method to manage the nematodes, although the number of registered products
is definitely declining. Therefore, nematode control though genetic improvement is gaining new interest worldwide. In this
study, 55 banana accessions mostly diploids from the Musa acuminata genome group (AA) but including some triploid accessions (AAA), some diploids of the Musa balbisiana genome group (BB) and some interspecific hybrids (AAB, AB) were evaluated for resistance to four nematode species R. similis, P. coffeae, Meloidogyne incognita and M. arenaria. These experiments were conducted in a growth chamber under controlled conditions. All banana accessions were susceptible
to nematode species, although many different levels of susceptibility were detected. This study confirmed the good resistance
status to R. similis of some cultivars from the Pisang jari buaya and Pisang batuau subgroups and the partial resistance of 17 diploid accessions
significantly different from the susceptible reference cv. Grande Naine. This study also showed that 12 diploid accessions
exhibited a partial resistance to P. coffeae, including some usual or potential genitors belonging to the wild diploids subspecies burmannica (cvs. Long Tavoy 1 and 2) and burmannicoides (cv. Calcutta 4). No source of resistance to Meloidogyne spp. was found. These screening results, combining for the first time four nematode species, are discussed within the scope
of banana breeding in order to produce parental diploid lines with single or combined nematode resistances and further develop
triploids that can substitute existing susceptible commercial cultivars. 相似文献
16.
The economic importance and current progress made in studies of the host-parasite relationship and identification of sources of resistance and breeding strategies of some important biotic diseases of pea are reviewed in this paper. The root rot complex caused by Rhizoctonia solani, Fusarium solani, Aphanomyces euteiches, Pythium ultimum and Fusarium oxysporum f. sp. pisi, race 1 and 2 has been reported from all commercial pea growing areas of the world. Adequate sources of resistance have been identified and there has been impressive success in the control of the Fusarium wilt pathogen following the introduction of wilt-resistant cultivars. Leaf and stem diseases of pea caused by the Ascochyta complex, Peronospora viciae and Erysiphe pisi are prevalent in most temperate pea growing regions of the world. Several sources of resistance are available, some of which are surprisingly durable. The biochemical genetic parameters of phenolic content used for assaying resistance to Erysiphe pisi offers an alternative method of evaluating breeding material. Wild relatives of pea (Pisum fulvum and P. humile) are valuable additional sources of genetic variation and provide good sources of resistance to pests and diseases. In temperate rainfed pea growing areas of southern Australia, pea seed yield is more closely related to dry matter production than harvest index. Tall and leafy cultivars proved more productive than afila types. 相似文献
17.
António A. Monteiro Paula S. Coelho Kiril Bahcevandziev Luísa Valério 《Euphytica》2005,143(1-2):85-92
Parasitic nematodes damage white clover (Trifolium repens) roots, negatively impacting forage yield and persistence. No single gene resistance to nematodes has been identified in white clover. Trifolium semipilosum (2n = 2x = 16) genotypes exhibiting either complete resistance or susceptibility to infection by the clover root-knot nematode (CRKN), Meloidogyne trifoliophila, were identified. F1 progeny (n = 92) of a pair-cross between ‘TsR’, a plant heterozygous for the resistance phenotype and ‘TsS’, a plant homozygous for the susceptible phenotype, were challenged with infective CRKN juveniles and evaluated subsequently for root galling. Segregation analysis indicated the resistance phenotype may be conferred by a single dominant allele at a locus (designated TRKR, Trifolium Root-knot Resistance) subject to segregation distortion. TsR, TsS, and bulked resistant and bulked susceptible F1 progeny (n = 12/bulk) were screened using T. repens microsatellite (SSR) markers. Three SSRs revealed polymorphism in TsR and the resistant bulk, of which prs090 and prs247 map to loci on T. repens linkage group D2. Progeny were genotyped with these three SSRs and 23 additional SSRs from T. repens groups D1 and D2. Linkage analysis in both TsR and TsS demonstrated macro-synteny between T. repens group D homoeologues and the T. semipilosum linkage group (designated DTs) containing the TRKR locus. Significant segregation distortion was detected in TsR, and recombination in the central region of the T. semipilosum linkage group was suppressed relative to T. repens in both parents. These data demonstrate the opportunities and challenges for comparative mapping in Trifolium and characterisation of loci conferring resistance to plant-parasitic nematodes. 相似文献
18.
Summary In two experiments, using different testing methods, the number of newly formed cysts was determined on nine potato genotypes with resistance from various sources. Ten potato cyst nematode (PCN) populations were used in these experiments. Rank correlation between numbers of cysts over potato genotype-PCN population combinations for both experiments was high (rs = 0.90). Dendrograms for PCN populations and potato genotypes were constructed, based on a simultaneous hierarchical clustering procedure for potato genotype-PCN population interaction terms. Several virulence groups could be identified within Globodera rostochiensis as well as within G. pallida. Host genotypes, derived from the same sources of resistance, were clustered in different resistance groups. 相似文献
19.
Ascochyta blight is a devastating disease of chickpea. Breeders have been trying to introduce resistance from wild Cicer into cultivated chickpea, however, the effort is hampered by the frequent genetic drag of undesirable traits. Therefore,
this study was aimed to identify potential markers linked to plant growth habit, ascochyta blight resistance and days to flowering
for marker-assisted breeding. An interspecific F2 population between chickpea and C. reticulatum was constructed to develop a genetic linkage map. F2 plants were cloned through stem cuttings for replicated assessment of ascochyta blight resistance. A closely linked marker
(TA34) on linkage group (LG) 3 was identified for plant growth habit explaining 95.2% of the variation. Three quantitative
trait loci (QTLs) explaining approximately 49% of the phenotypic variation were found for ascochyta blight resistance on LG
3 and LG 4. Flowering time was controlled by two QTLs on LG3 explaining 90.2% of the variation. Ascochyta blight resistance
was negatively correlated with flowering time (r = −0.22, P < 0.001) but not correlated with plant growth habit. 相似文献
20.
摘要： 通过对根结线虫不同病害程度的设施蔬菜根围土壤中丛枝菌根真菌资源的取样调查,结果表明：发生根结线虫病害的土壤中AM真菌孢子数量较少,共鉴定出4属7种,其中,无梗囊霉属(Acaulospora)l 种,球囊霉属(Glomus)4种,多样囊霉属(Diversispora)1 种,类球囊霉属(Paraglomus）1 种,球囊霉属和多样孢囊霉属为设施蔬菜根围土壤中丛枝菌根真菌的优势属,沾屑多样孢囊霉D. spurcum、幼套球囊霉G. etunicatum、摩西球囊霉G. mosseae是此土壤中的优势种。这对于筛选抗根结线虫病害的优良菌种及其在设施生产中的应用具有非常重要意义。 相似文献