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1.
Knowing pests and diseases that may cause injuries and are likely to affect plant health and quality is critical to minimizing
the gap between attainable yield and actual yield. In this paper, we highlight concepts and strategies aimed at controlling
major biotic constraints affecting wheat in intensive production systems and present emerging challenges, with a special attention
to the developing world. Disease epidemics result from the combination of inoculum, favorable environment, and host susceptibility.
Changes in cropping systems as a result of adoption of conservation agriculture may have serious implications. Necrotrophic
pathogens such as those responsible for tan spot or septorias are likely to emerge, and Fusarium head blight may increase. However, resistance breeding combined with rotations, timely sowing, and irrigation or even fungicide
utilization, if affordable, are part of integrated crop management practices that can minimize losses. In South Asia, the
effect of spot blotch, a devastating foliar disease caused by Cochliobolus sativus, can be minimized by reducing physiological stress through timely sowing and adequate use of fertilizers, which demonstrates
the complex relationships among crop physiology, disease resistance, and yield. Although some root rots that induce premature
death of tillers in cooler high-yielding humid environments can be important, the dryland crown rot (Fusarium spp.), common root rot (C. sativus), and the cereal nematode (Heterodera spp. and Pratylenchus spp.) should not be ignored. These are all known to be much more damaging under suboptimal moisture (rainfed or supplementary
irrigation), particularly where plant growth is stressed. Climate change is likely to modify the wheat disease spectrum in
some regions, and pathogens or pests considered unimportant today may turn out to be potential new threats in future. 相似文献
2.
Daniel A. Presello Juliana Iglesias Grisela Botta Lana M. Reid Gladys A. Lori Guillermo H. Eyhérabide 《Euphytica》2006,147(3):403-407
Sources of resistance to Fusarium spp. are needed to develop maize hybrids resistant to the accumulation of fungal mycotoxins in the grain. In a search for
resistant germplasm in 1999 and 2000, a set of Argentinian maize populations was evaluated in Ottawa, Canada, for resistance
to ear rots after inoculation with local isolates of Fusarium verticillioides and F. graminearum. Sixteen of these populations, varying in observed resistance levels, were re-evaluated in 2003 and 2004 in Pergamino, Argentina,
using local isolates of the same fungi. Conidial suspensions of each fungal species were inoculated into the silk channel
of primary ears. Disease severity was assessed after physiological maturity using a scale based on the percentage of visibly
infected kernels. Genotype effect was more important than genotype-by-fungal species or genotype-by-fungal species-by-environment
interaction effects. In addition, disease severity levels associated with each fungal species were positively correlated (P < 0.05) (r = 0.90, r = 0.81, r = 0.87 and r = 0.53, in Ottawa 1999 and 2000, and Pergamino 2003 and 2004, respectively). Populations ARZM 01107, ARZM 07138, ARZM 10041,
ARZM 13031, ARZM 16002 and Pora INTA exhibited the highest and most stable resistance to both species. Considering that disease
resistance exhibited low specificity to the environment and to the fungal species in evaluations conducted in a wide range
of environments and with fungal isolates collected from different hemispheres, the most resistant populations are potential
sources of genes for stable resistance to these Fusarium spp. 相似文献
3.
Summary Pathogenicity of 20 isolates of 12 Fusarium species recovered from triticale seed against seedlings of 14 varieties of winter cereals (triticale, wheat, and rye) was tested. The most pathogenic inoculum was a mixture of isolates (a composite isolate) of all the species. The following species were individually the most pathogenic: F. avenaceum, F. culmorum, F. sambucinum var. coeruleum, and F. graminearum. Winter triticale was more resistant to seedling blight than rye but more susceptible than wheat.Also reactions of 31 winter and 12 spring varieties of cereals to head inoculation with a composite isolate of 4 Fusarium spp. (F. avenaceum, F. culmorum, F. graminearum, and F. sambucinum var. coeruleum) was studied. In comparison to other cereals of similar type winter and spring wheat appeared to be the most susceptible while winter rye reaction was comparable to winter triticale. Spring and winter triticale varieties responded to head infection intermediately.There was no significant correlation between seedling and head reactions to infection with Fusarium spp. for winter rye and triticale. For winter wheat a negative trend was found. The above findings imply that screening of cereals at the seedling stage can not be used to predict the resistance to head blight. Nevertheless, resistance at the stage is highly desirable to prevent excessive damage of the crops due to the seedling blight incited by Fusarium spp.. 相似文献
4.
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
5.
Fusarium head blight (FHB), caused primarily by Fusarium graminearum (Schwabe), is an important wheat disease. In addition to head blight, F. graminearum also causes Fusarium seedling blight (FSB) and produces the mycotoxin deoxynivalenol (DON) in the grain. The objectives of
this study were: (1) to compare the relationship between resistance of wheat lines to F. graminearum in the seedlings and spikes and (2) to determine whether the quantitative trait loci (QTL) for FSB were the same as QTLs
for FHB resistance and DON level reported for the same population previously (Somers et al. 2003). There was no relationship between FSB infection and FHB index or DON content across the population. A single QTL on chromosome
5B that controlled FSB resistance was identified in the population; the marker WMC75 explained 13.8% of the phenotypic variation
for FSB. This value implies that there may be other QTL with minor effects present, but they were not detected in the analysis.
Such a QTL on chromosome 5B was not reported previously among the QTLs associated with FHB resistance and DON level in this
population. However, because of recombination, some lines in the present study have Fusarium resistance for both seedling
and head blight simultaneously. For example, DH line HC 450 had the highest level of resistance to FSB and FHB and was among
the ten lines with lowest DON content. This line is a good candidate to be used as a parent for future crosses in breeding
for Fusarium seedling resistance, together with breeding for head blight resistance. This approach may be effective in increasing overall
plant resistance to Fusarium. 相似文献
6.
Phytophthora sojae, an important yield limiting pathogen of soybean, causes seed, seedling, root, and stem rots. Losses caused by P. sojae can be controlled by both major gene and partial resistance. Early maturity group (MG) soybeans are an increasingly important
crop in northwestern Minnesota and eastern North Dakota. Early MG plant introductions (PIs) from the USDA Soybean Germplasm
Collection and early MG public and private cultivars were evaluated for resistance and partial resistance to P. sojae. Of the 113 PIs, PI438445, and PI438454 exhibited resistance to P. sojae races 4, 7, 17, and 28 indicating they may possess either Rps1c, Rps1k, previously unidentified or multiple resistance gene to Phytophthora sojae (Rps) genes. Because they exhibited partial resistance equal to or greater than the standard check cultivar Conrad, three early
MG soybean cultivars (MN0902, MN0302, and 91B53) were selected as standard checks to evaluate early MG PIs for partial resistance.
Sixty-nine PIs were evaluated for partial resistance to P. sojae races 7 and 25 using the inoculum layer method. Of this group of PIs, 22 had the same level of partial resistance as Conrad
to P. sojae race 7 while 19 had the same degree of partial resistance to race 25. Twelve PIs had same level of partial resistance as
Conrad to both P. sojae races 7 and 25. The PIs and cultivars identified in this study will be of great value in developing early MG soybean cultivars
suitable for planting in Canada and the northern United States. 相似文献
7.
Summary
Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases. 相似文献
8.
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
9.
Summary Twenty three accessions of nine Portuguese cabbage and kale land races from different geographic origins were tested at the seedling stage for resistance to several important brassica diseases. Resistance to downy mildew (Peronospora parasitica), expressed as necrosis of the cotyledon mesophyll, was found in all the accessions. Type A resistance to cabbage yellows (Fusarium oxysporum f. sp. conglutinans race 1) was present in most of the landraces. Resistance to clubroot (Plasmodiophora brassicae race 6) was found in one accession of the Portuguese tree kale. High resistance to blackleg (Leptosphaeria maculans) and white rust (Albuco candida) was not detected, although several accessions showed 20 to 30% of plants with intermediate expression of resistance. All Portuguese cole accessions were susceptible to blackrot (Xanthomonas campestris pv. campestris). 相似文献
10.
Summary Melon germplasm was screened for cucumber green mottle mosaic virus (CGMMV), powdery mildew (Sphaerotheca fuliginea), downy mildew (Pseudoperonospora cubensis) and Fusarium wilt (Fusarium oxysporum f. sp. melonis) resistance under artificial conditions except downy mildew for which screening was done under natural epiphytotic conditions. High level resistance to all the four diseases was not recorded in any of the collections tested. Nevertheless, ertheless, resistance to three diseases was located in three germplasm. Wild Cucumis species C. figarei exhibited absolute resistance to CGMMV and Fusarium wilt and high level resistance to downy mildew. Phoot or snapmelon (Cucumis melo var. momordica) — a non-dessert from of Indian origin—was highly resistant to downy mildew and resistant to CGMMV and medium resistant to Fusarium wilt. Iroquois was resistant to powdery mildew and medium resistant to downy mildew and CGMMV. 相似文献
11.
Assessment of Gossypium sturtianum and G. australe as potential sources of Fusarium wilt resistance to cotton 总被引：1，自引：0，他引：1
When challenged with Fusarium oxysporum f. sp. vasinfectum (Fov) from vegetative compatibility groups (VCGs) 01111 and 01112 in glasshouse tests, Gossypium australe Mueller and Gossypium sturtianum Willis accessions showed a variety of disease responses ranging from highly resistant to highly susceptible. Under high disease
pressure G. sturtianum accession Gos-5275 was significantly more resistant than the commercial G. hirsutum cultivars that are designated standards for Fusarium resistance by Australian cotton breeders. Under low disease pressure
G. sturtianum accession Gos-5250 was more susceptible than a highly susceptible commercial cultivar. A series of glasshouse tests was performed
at two locations (Indooroopilly, QLD. and Canberra, ACT), and under low and high disease pressure. In these tests, a hexaploid
cross (Gos-5271) generated from a Fusarium-resistant G. sturtianum (Gos-5275) and a Fusarium-susceptible G. hirsutum L. (CPI-138969) was significantly more resistant to Fusarium wilt than its G. hirsutum parent. Thus G. sturtianum, with a diploid genome and a range of responses to Fov challenge, has the potential to provide the basis for the elucidation of the genetic basis of resistance to Fusarium wilt
in cotton species. In addition, resistant accessions of G. sturtianum are identified as a potential source of Fusarium wilt resistance genes for cotton breeding. In the glasshouse tests used
to assess the resistance of various Gossypium accessions to Fusarium wilt disease, the scoring of vascular browning was found to give a more reliable indication of disease
severity than the scoring of foliar symptoms.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
12.
Christopher S. Cramer 《Euphytica》2000,115(3):159-166
Fusarium basal plate rot (FBR), caused by Fusarium oxysporum f. sp. cepae, is an important soil-borne disease of onions worldwide. The causal organism infects the basal stem plate of the bulb and
eventually kills the entire plant through degradation of the basal plate. F. o. f. sp.cepae infections in dormant bulbs during storage allow secondary infections to occur. The primary method of infection by F. o. f. sp. cepaeis through direct penetration of the basal stem plate. Infection can also occur through wounded tissue particularly roots
and basal portions of bulb scales. The most cost-effective methods of control are crop rotation and host plant resistance.
Current research suggests that a single gene, two genes, or multiple genes govern resistance to FBR. Breeding programs have
successfully used screening procedures to develop intermediate- and long-day, FBR-resistant cultivars.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
Oliver E. Manangkil Hien Thi Thu Vu Shinya Yoshida Naoki Mori Chiharu Nakamura 《Euphytica》2008,163(2):267-274
Submergence is a major stress causing yield losses particularly in the direct-seeded rice cultivation system and necessitates
the development of a simple, rapid and reliable bioassay for a large scale screening of rice germplasms with tolerance against
submergence stress. We developed two new bioassay methods that were based primarily on the seedling vigor evaluated by the
ability of fast shoot elongation under submerged conditions, and compared their effectiveness with two other available methods.
All four bioassay methods using cultivars of 7 indica and 6 japonica types revealed significant and consistent cultivar differences in seedling vigor under submergence and/or submergence tolerance.
Japonica cultivars were more vigorous than indica cultivars, with Nipponbare being the most vigorous. The simplest test tube method showed the highest correlations to all
other methods. Our results suggest that seedling vigor serves as a submergence avoidance mechanism and confers tolerance on
rice seedlings to flooding during early crop establishment. A possible relationship is discussed between seedling vigor based
on fast shoot elongation and submergence tolerance defined by recovery from submergence stress. 相似文献
14.
A. M. Torres B. Román C. M. Avila Z. Satovic D. Rubiales J. C. Sillero J. I. Cubero M. T. Moreno 《Euphytica》2006,147(1-2):67-80
Summary Faba beans are adversely affected by numerous fungal diseases leading to a steady reduction in the cultivated area in many
countries. Major diseases such as Ascochyta blight (Ascochyta fabae), rust (Uromyces viciae-fabae), chocolate spot (Botrytis fabae), downy mildew (Peornospora viciae) and foot rots (Fusarium spp.) are considered to be the major constraints to the crop. Importantly, broomrape (Orobanche crenata), a very aggressive parasitic angiosperm, is the most damaging and widespread enemy along the Mediterranean basin and Northern
Africa. Recent mapping studies have allowed the identification of genes and QTLs controlling resistance to some of these diseases.
In case of broomrape, 3 QTLs explained more than 70% of the phenotypic variance of the trait. Concerning Ascochyta, two QTLs
located in chromosomes 2 and 3 explained 45% of variation. A second population sharing the susceptible parental line also
revealed two QTLs, one of them likely sharing chromosomal location and jointly contributing with a similar percentage of the
total phenotypic variance. Finally, several RAPD markers linked to a gene determining hypersensitive resistance to race 1
of the rust fungus U. viciae-fabae have also been reported. The aim of this paper is to review the state of the art of gene technology for genetic improvement
of faba bean against several important biotic stresses. Special emphasis is given on the application of marker technology,
and Quantitative Trait Loci (QTL) analysis for Marker-Assisted Selection (MAS) in the species. Finally, the potential use
of genomic tools to facilitate breeding in the species is discussed. The combined approach should expedite the future development
of lines and cultivars with multiple disease resistance, one of the top priorities in faba bean research programs. 相似文献
15.
Devastating maize grain yield and quality losses are caused by Aspergillus flavus, Fusarium verticillioides and Stenocarpella maydis ear rots especially in tropical countries. Therefore, combining ability of tropical maize populations for ear rot severity
and ear rot-related traits was investigated. Ten full-sib progenies, comprising one resistant and one susceptible from each
of the five populations, were selected for mating in a 10 × 10 full diallel. The full-sib progeny crosses were evaluated across
two environments with two replications in Zambia. To determine resistance across three ear rots that occur together in Zambia,
the crosses were artificially inoculated with a mixture of Aspergillus flavus, Fusarium verticillioides and Stenocarpella maydis isolates. There were marked differences between environment main effects and their interaction with GCA and SCA effects were
highly significant, suggesting observation of genotype × environment interaction effects. Both additive and non-additive gene
effects were significant for ear rot severity. Highly significant reciprocal differences were also revealed, suggesting that
cytoplasmic gene effects and their interaction with nuclear genes were responsible in modifying resistance across the three
ear rot diseases in the full-sib progenies that were derived from the five tropical maize populations. 相似文献
16.
M. C. Luterbacher M. J. C. Asher W. Beyer G. Mandolino O. E. Scholten L. Frese E. Biancardi P. Stevanato W. Mechelke O. Slyvchenko 《Euphytica》2005,141(1-2):49-63
Between 580 and 700 accessions of related cultivated and wild species of the genus Beta were assessed for resistance to four soil-borne diseases of sugar beet: two seedling damping-off diseases caused by the fungi Aphanomyces cochlioides and Pythium ultimum and two diseases of more mature plants, Rhizoctonia root and crown rot, caused by the fungus R. solani, and Rhizomania, caused by Beet necrotic yellow vein virus (BNYVV), a furovirus transmitted by the plasmodiophorid Polymyxa betae. Analysis of resistance data (assessed on an international standardised 1–9 scale of Resistance Scores) indicated that the highest levels of resistance ({RS} 2) to A. cochlioides and P. ultimum were to be found amongst accessions of the more distantly related sections Corollinae (93% of accessions tested) and Procumbentes (10%), respectively; although useful levels could also be found in the more closely related, and sexually compatible, section Beta (1–6%). Resistance to Rhizoctonia was also found in section Beta (5–7%), depending on whether field or glasshouse tests were used, but there was little evidence of generally high levels of resistance to Rhizomania among accessions of this section. None of the accessions of sections Corollinae and Procumbentes exhibited any notable resistance to Rhizoctonia. However, all sections Procumbentes and some sections Corollinae (4%) accessions were highly resistant to Rhizomania. Individuals with high levels of resistance to Rhizomania were identified from within some section Beta and Corollinae accessions, in which there was evidence of segregation. 相似文献
17.
Bernard Tivoli Alain Baranger Carmen M. Avila Sabine Banniza Martin Barbetti Weidong Chen Jenny Davidson Kurt Lindeck Mohammed Kharrat Diego Rubiales Mohamed Sadiki Josefina C. Sillero Mark Sweetingham Fred J. Muehlbauer 《Euphytica》2006,147(1-2):223-253
Summary Necrotrophic pathogens of the cool season food legumes (pea, lentil, chickpea, faba bean and lupin) cause wide spread disease
and severe crop losses throughout the world. Environmental conditions play an important role in the development and spread
of these diseases. Form of inoculum, inoculum concentration and physiological plant growth stage all affect the degree of
infection and the amount of crop loss. Measures to control these diseases have relied on identification of resistant germplasm
and development of resistant varieties through screening in the field and in controlled environments. Procedures for screening
and scoring germplasm and breeding lines for resistance have lacked uniformity among the various programs worldwide. However,
this review highlights the most consistent screening and scoring procedures that are simple to use and provide reliable results.
Sources of resistance to the major necrotrophic fungi are summarized for each of the cool season food legumes. Marker-assisted
selection is underway for Ascochyta blight of pea, lentil and chickpea, and Phomopsis blight of lupin. Other measures such
as fungicidal control and cultural control are also reviewed. The emerging genomic information on the model legume, Medicago truncatula, which has various degrees of genetic synteny with the cool season food legumes, has promise for identification of closely
linked markers for resistance genes and possibly for eventual map-based cloning of resistance genes. Durable resistance to
the necrotrophic pathogens is a common goal of cool season food legume breeders. 相似文献
18.
Summary Calluses of spring and winter wheats (Triticum aestivum L.) were selected for Fusarium resistance in vitro, using the double-layer culture technique. Potato-dextrose agar medium in vials was inoculated with mycelia of Fusarium graminearum and F. culmorum. After one week, fungal cells were killed by autoclaving and the agar medium containing the thermostable toxic metabolites was overlayered with MS callus-growing medium. Later, wheat calluses were placed on the upper medium for 4–5 weeks, and from the surviving calluses plants were regenerated. R2 seedling populations from self-fertilized R1 plants of 4 varieties were tested for Fusarium resistance by artificial infections in the greenhouse, and 3% of the regenerated R2 plants have been found to be more resistant than the original cultivars. 相似文献
19.
J. L. Gonzalez-Hernandez P. K. Singh M. Mergoum T. B. Adhikari S. F. Kianian S. Simsek E. M. Elias 《Euphytica》2009,166(2):199-206
Stagonospora nodorum blotch (SNB) is an important foliar disease of durum wheat (Triticum turgidum var. durum) worldwide. The combined effects of SNB and tan spot, considered as components of the leaf spotting disease complex,
result in significant damage to wheat production in the northern Great Plains of North America. The main objective of this
study was the genetic analysis of resistance to SNB caused by Phaeosphaeria nodorum in tetraploid wheat, and its association with tan spot caused by Pyrenophora tritici-repentis race 2. The 133 recombinant inbred chromosome lines (RICL) developed from the cross LDN/LDN(Dic-5B) were evaluated for SNB
reaction at the seedling stage under greenhouse conditions. Molecular markers were used to map a quantitative trait locus
(QTL) on chromosome 5B, explaining 37.6% of the phenotypic variation in SNB reaction. The location of the QTL was 8.8 cM distal
to the tsn1 locus coding for resistance to P. tritici-repentis race 2. The presence of genes for resistance to both SNB and tan spot in close proximity in tetraploid wheat and the identification
of molecular markers linked to these genes or QTLs will be useful for incorporating resistance to these diseases in wheat
breeding programs. 相似文献
20.
Fusarium head blight (FHB), caused by Fusarium graminearum and Fusarium culmorum, is a devastating disease in cereals. This study was undertaken to estimate progeny means and variances in each of five winter triticale and winter wheat crosses using unselected F2−derived lines in F4 or F5 generation bulked at harvest of the previous generation. Fifty (triticale) and 95 (wheat) progeny per cross were inoculated in two (triticale) or three (wheat) field environments. FHB rating was assessed on a whole-plot basis. Mean disease severities of the parents ranged from 2.3 to 6.4 in triticale and from 3.1 to 6.5 in wheat on a 1-to-9 scale (1 = symptomless, 9 = 100% infected). The midparent values generally resembled the means of their derived progeny. Significant (P < 0.01) genotypic variance was detected within each cross, but genotype × environment interaction and error variances were also high for both crops. Medium to high entry-mean heritabilities (0.6–0.8) underline the feasibility of selecting F2-derived bulks on a plot basis in several environments. Phenotypic correlation of FHB resistance between generation F2:4 and F2:5 was r = 0.87 (P < 0.01) tested across 150 wheat bulks at two locations. Our estimates of selection gain are encouraging for breeders to improve FHB resistance in triticale and wheat by recurrent selection within adapted materials. 相似文献