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1.
Lectin fromGlycine max L. was extracted and purified by affinity chromatography using asialofetuin-linked porous amino-activated silica beads. The
concentration-dependent effect of lectin was studied on freshly laid eggs (0–8 h old) of the melon flyBactrocera cucurbitae (Coquillett); lectin failed to influence egg hatching. However, treating second instar larvae (64–72 h old) with increasing
concentrations of lectin significantly reduced the development period, number of pupae and number of emergingB. cucurbitae, and was negatively correlated with the increase in the lectin concentration. The LC50 value, 54μg ml−1, was calculated on the basis of adult emergence. Treatment of the larvae (64–72 h old) with the LC50 concentration resulted in a decrease in pupal weight. The activity of three hydrolase enzymes (esterases, acid and alkaline
phosphatases), one oxidoreductase (catalase) and one group transfer enzyme (glutathione S-transferase) was assayed in second
instar larvae at the LC50 concentration of lectin after exposure for 24, 48 and 72 h. The activity of esterases increased significantly (P<0.01) at the three exposure intervals, whereas the activities of the three other hydrolyses and the transferases were significantly
suppressed (P<0.01).
http://www.phytoparasitica.org posting Sept. 13, 2006. 相似文献
2.
J. B. Malaquias F. S. Ramalho F. S. Fernandes J. V. S. Souza T. L. Azeredo 《Phytoparasitica》2009,37(3):241-248
The effects of photoperiod on nymphal development, growth and adult size in Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) were studied. Predators were collected in cotton fields in Patos (7°S, 37°W), Paraíba
State, Brazil. A randomized block experimental design was used, with treatments consisting of photoperiods of 10L:14D, 11L:13D,
12L:12D, 13L:11D, 14L:10D, 15L:9D and 16L:8D (LD, in h), at a constant temperature of 28 ± 1°C and relative air humidity of
70 ± 10%. Treatments were distributed in four replications, with each experimental unit composed of 40 nymphs. The development
period for each instar of P. nigrispinus varied according to the photoperiod exposure. Regardless of the photophase (PhP), the 5th instar nymphs exhibited the longest
development period, except for the 15-h PhP, in which the development period of 2nd instar nymphs (4.13 days) was as long
as that of the 5th instar nymphs (4.23 days). In the 1st, 3rd and 5th instars of P. nigrispinus, the development period was inversely proportional to the increase in light period in which the nymphs developed, for the
PhP intervals of 10–14 h, 12–14 h, and 12–15 h, respectively. Predators exposed to a 14-h PhP developed a wider pronotum than
those exposed to extreme PhP’s (of 10 h, 11 h and 16 h). Conditions from 14 h to 15 h of light resulted in higher daily growth
rates in P. nigrispinus than those obtained with the other PhP’s tested. P. nigrispinus females exhibited faster daily growth rates than did males. 相似文献
3.
Laboratory evaluation of the insect growth regulator lufenuron againstHelicoverpa armigera on cotton
An insect growth regulator (IGR), lufenuron (Match 5EC), was tested for its toxicity toHelicoverpa armigera on cotton. Potency of the IGR against the larval stage of the pest was demonstrated with respect to larval instars; the LC90 values of 1st, 2nd, 3rd, 4th and 5th instar larvae were 5.63, 7.89, 8.03, 11.39 and 14.76 mg a.i.l
−1, respectively. However, different larval instars did not differ significantly with respect to LC50 and LC10. IGR-treated larvae had swollen heads and were significantly smaller (1.5–2.3 mm) than the untreated control (2.9 mm). Larval
weight was significantly reduced from 190 mg in the control to 50–70 mg in the lufenuron treatment. IGR treatment in the larval
stage significantly affected both pupal length and pupal weight. Pupal duration of the test insect was significantly extended
by IGR treatment. Pupal deformities, including an inability to shed the last larval skin and formation of larval-pupal intermediates,
occurred following treatment. A significant reduction in adult emergence was recorded. In addition, abnormalities in the form
of development of cavities in the forewings of adult were evident. A significant decline in fecundity was noted in the studies.
http://www.phytoparasitica.org posting Feb. 3, 2003. 相似文献
4.
Kishor Bhandari Pankaj Sood Pawan K. Mehta Amit Choudhary Chandra S. Prabhakar 《Phytoparasitica》2009,37(4):317-322
A granulosis virus strain infecting Pieris brassicae (PbGV) was isolated from the dry temperate region of northwestern Himalayas as a potential microbial agent for its management.
The effect of different botanicals (having insecticidal action against P. brassicae) on the bioefficacy of PbGV was evaluated under laboratory conditions using leaf disc bioassays on cabbage for improving
the insecticidal performance of the PbGV. The synergistic action of different botanical extracts was evident in terms of reduction
in LC50 values against different botanical extracts. Among different extracts, petroleum-ether extract of neem seed kernel (NSK)
when combined with PbGV resulted in maximum reduction of LC50 value (4.39 × 102 occlusion bodies [OBs] ml−1) followed by methanolic extract (7.38 × 102 OBs ml−1) and aqueous extract (9.36 × 103 OBs ml−1) as compared with PbGV alone (1.85 × 104 OBs ml−1) for 2nd instar larvae of the test insect. These trends were found analogous in cases of 3rd and 4th instars of P. brassicae with different solvent extracts of NSK. The other botanicals evaluated, viz., Eupatorium and Artemesia, also resulted in reduction of LC50 values for 2nd, 3rd and 4th instars as compared with PbGV alone when different extracts were combined with virus for bioassays.
The studies suggest that the PbGV in combination with botanical pesticides could be more useful as a bio-pesticide against
cabbage butterfly (P. brassicae) in IPM programs. 相似文献
5.
Kazutaka Kido Rie Adachi Masaru Hasegawa Kazutaka Yano Yasufumi Hikichi Shigeharu Takeuchi Tae Atsuchi Yuichi Takikawa 《Journal of General Plant Pathology》2008,74(4):302-312
An internal fruit rot with a malodor was found in netted melons (Cucumis melo L.) in commercial greenhouses in Kochi Prefecture, Japan, in 1998, despite their healthy appearance and lack of water-soaking
or brown spots on the surface. A yellow bacterium was consistently isolated from the affected fruits. To confirm the pathogenicity
of eight representative isolates of the yellow bacterium, we stub-inoculated ovaries (immature-fruits) 5–7 days after artificial
pollination, with a pin smeared with bacteria. After the melon fruits had grown for 60 more days, an internal fruit rot resembling
the natural infection appeared, and the inoculated bacterium was reisolated. The melon isolates had properties identical with
Pantoea ananatis, such as gram-negative staining, facultative anaerobic growth, indole production, phenylalanine deaminase absence, and acid
production from melibiose, sorbitol, glycerol, and inositol. Phylogenetic analysis based on 16S rDNA sequences showed that
the melon bacterium positioned closely with known P. ananatis strains. The melon bacterium had indole acetic acid (IAA) biosynthesis genes (iaaM and iaaH) and a cytokinin biosynthesis gene (etz). The bacterium could be distinguished from the other ‘Pantoea’ group strains by rep-PCR genomic fingerprinting. From these results, the causal agent of internal fruit rot was identified
as a strain of P.ananatis [Serrano in (Philipp J Sci 36:271–305, 1928); Mergaert et al. in (Int J Syst Bacteriol 43:162–173, 1993)].
The nucleotide sequence data reported are available in the DDBJ database under accessions AB297969, AB373739, AB373740, AB373741,
AB373742, AB373743 and AB373744. 相似文献
6.
The comparative toxicity of two non-steroidal ecdysteroid agonists, RH-2485 and RH-5992 (tebufenozide), on development stages,
fecundity and egg viability of a susceptible laboratory strain and a pyrethroid-resistant field strain ofSpodoptera littoralis (Boisduval) was evaluated. Taking the LC50s as the criterion, RH-2485 was 3–7-fold more potent than RH-5992 against the susceptible and 7–14-fold more against the field
strain. The LC50 of RH-2485 in the 1st and 6th instars of the susceptible strain was 0.32 and 0.57 mg a.i./l, respectively. The field strain showed a mild cross-resistance of about threefold to both compounds in 1st instars and to
a lesser extent in 6th instars. A considerable increase in fecundity (~3-fold) and no effect on egg viability was observed
when 6th instars were fed on cotton leaves treated with 0.25 mg a.i./l RH-2485 (~LC40). Our results indicate that both compounds are potentially potent insecticides for controllingS. littoralis larvae, being 10-60-fold more potent than a previous ecdysteroid agonist, RH-5849. 相似文献
7.
Kazutaka Kido Masaru Hasegawa Hiroyuki Matsumoto Masaki Kobayashi Yuichi Takikawa 《Journal of General Plant Pathology》2010,76(3):208-218
Ninety-six strains of Pantoea ananatis were isolated from 14 plant species including melon, rice, tea and other crops of economic importance. They were classified
into three groups (group I, II, III) based on a welsh onion stabbing assay, tobacco infiltration test, and polymerase chain
reaction to detect indole acetic acid (IAA) biosynthesis genes (iaaM and iaaH) and a cytokinin biosynthesis gene (etz). Group Ι strains were characterized as causing significant blight symptom on welsh onion and inducing a hypersensitive response
(HR)-like reaction on tobacco leaves after 36–48 h and encompassed 20 isolates from foxtail millet, hydrangea, pineapple,
river water and rice. These 20 isolates did not possess iaaM, iaaH, or etz genes. Group II, consisting of 34 melon isolates, harbored iaaM,
iaaH and etz genes, but did not cause either blight on welsh onion or HR-like reaction on tobacco. Group III strains did not have the
iaaM, iaaH, and etz genes, nor did they cause any reaction on welsh onion or tobacco. The 42 strains in group III were isolated from bamboo grass,
Chinese silver grass, citrus, dogwood, melon, mugwort, silk tree, sweet corn, tea and welsh onion. Representative strains
of the three groups were tested for pathogenicity on melon and rice. Group Ι strains caused palea browning on rice but not
internal fruit rot on melon. On the contrary, group II strains did not cause disease on rice but caused internal fruit rot
on melon. Group III strains were not pathogenic on rice or melon. These results suggested that the host range of P. ananatis may be predicted by the reactions of welsh onion and tobacco and detection of iaaM, iaaH and etz genes. These tools may serve as rapid tests to identify the pathogenicity groups of P. ananatis. 相似文献
8.
Laboratory experiments were conducted to evaluate the prey stage preference and the daily consumption of each stage of the
coccinellid predatorStethorus punctillum Weise (Coleoptera: Coccinellidae) feeding on the two-spotted spider miteTetranychus urticae (Koch) (Acari: Tetranychidae). Groups of different life stages of the prey were offered (eggs, larvae, nymphs and adults).
The prey preference varied with the stage ofS. punctillum. First larval instars had no significant preference among theT. urticae stages offered. Second larval instars consumed significantly more spider mite larvae in comparison with nymphs. In contrast,
third larval instars indicated a strong preference for mite eggs. Significantly fewerT. urticae larvae were consumed by the fourth larval instars ofS. punctillum, in comparison with the three other mite stages. Finally, adult predators consumed significantly more mite eggs than the
other stages offered. This preferential trend was similar for all adults tested, whether during the pre-oviposition or the
oviposition period.
http://www.phytoparasitica.org posting Feb. 17, 2004. 相似文献
10.
Mulberry twigs were inserted into the soil as bait to detect Rosellinia necatrix at an early stage of tree infection in the orchard. R. necatrix was frequently trapped on twigs near the trunk base at soil depths of 6–20 cm within 10–20 days in May–July, suggesting that
the incubation period was dependent on soil temperature. Subsequently, we inserted twig in the soil around healthy-looking
trees in naturally infested orchards. R. necatrix was trapped from 80.0% of Japanese pear and 75.0% of apple trees that later proved to be infected. This bait twig method
facilitated quicker diagnosis of white root rot on Japanese pear and apple at early stages of infection and can be used to
detect recurrence of the fungus after fungicide treatment. 相似文献
11.
实蝇类昆虫种类很多,其中地中海实蝇Ceratitis capitata、橘小实蝇Bactrocera dorsalis、瓜实蝇B. cucurbitae等严重为害多类果蔬,造成巨大经济损失,是国际重要检疫性或入侵性害虫。目前,杀虫剂仍然是防治实蝇类害虫的重要手段,但是多种实蝇因已经产生抗药性而导致防治困难。在昆虫抗药性产生与发展中,解毒代谢家族基因起着十分重要的作用。本文综述了实蝇科重要经济性昆虫包括橘小实蝇、瓜实蝇、油橄榄果实蝇B. oleae、昆士兰果实蝇B. tryoni、辣椒果实蝇B. latifrons、桃果实蝇B. zonata、木瓜果实蝇B. papayae、杨桃果实蝇B. carambolae、柑橘大实蝇B. minax、地中海实蝇、苹绕实蝇Rhagoletis pomonella、雪果绕实蝇R. zephyria和泽兰始实蝇Procecidochares utilis等的细胞色素P450酶、酯酶、谷胱甘肽S转移酶、ABC转运蛋白这4类解毒代谢基因方面的研究进展,为全面深入了解研究实蝇科昆虫应对有毒有害物质的生理和遗传机制以及研发实蝇类害虫化学防治新策略、新技术等提供参... 相似文献
12.
In a 2-year field study, the effects of four heating regimes established by varying temperature or duration of heating on
efficiency of on-farm wastes as soil amendments in controlling Fusarium oxysporum f.sp. cumini (Foc) causing wilt on cumin (Cuminum cyminum L.), were ascertained. Significant improvement in reduction of Foc propagules was achieved with the increase in duration and amount of heat. In 2000, mild heating under shade (heat level 4),
31.8–65.9% reduction in Foc propagules was estimated in all the amendments at 0–30 cm soil depth, which improved by 75.7–86.5% in the treatment where
Foc-infested soil brought from the laboratory was exposed to direct heat (heat level 3) and amendments and irrigation were applied.
Foc propagules were reduced by 76.6–88.3% when infested soil was exposed continuously to dry heat for 56 days (heat level 2),
improving efficiency of amendments by 0.9–13.5% compared with heat level 3. After 56 days of exposure to dry heat, elevating
the temperature by mulching amended soil with a transparent polyethylene film (50 μm thick) for 20 days (heat level 1) augmented
reduction by 80.2–95.5%. In the second season, combining 0.04% of onion, Verbisina encelioides or mustard oil-cake with mustard residues (0.18%) improved the reduction in Foc propagules at all heat levels even at the lower soil depth. Maximum reduction (94.9–100%) in Foc propagules at heat levels 1 to 3 was achieved when residues of Verbisina were supplemented with those of mustard. These results suggest a new approach to improve the control of Foc by combining prolonged heating with on-farm wastes such as Verbisina residues and one summer irrigation. 相似文献
13.
Diafenthiuron (CGA 106 ’630), a thiourea, was sprayed prior to a 48-h infestation by adult females of the sweetpotato whiteflyBemisia tabaci Gennadius, on cotton seedlings under greenhouse conditions; it subsequently suppressed strongly progeny formation of the
whitefly, resulting in approximately 50% progeny formation relative to control at 5 mg a.i./l. When the different development
stages were separately sprayed directly, the larval stage was the most susceptible, resulting in 50% and 90% mortality of
2nd instars at concentrations of 6.5 and 49.2 mg a.i./l, whereas the LC50 values of adults and pupae were 23 and 45 mg a.i./l,
respectively. A mild (30–35%) reduction of egg hatch was obtained at a range of 5–125 mg a.i./l. Thus the potency of diafenthiuron
against various stages was in the order larvae > adults > pupae > eggs. Diafenthiuron exhibited a low vapor phase toxicity
and had no translaminar effect when tested on first instars ofB. tabaci. The high potency of diafenthiuron against whiteflies described herein, against aphids and mites, as stated in the literature,
and against some lepidopterous pests, render this compound an important insect control agent for pests of cotton and other
crops. 相似文献
14.
Charmi Shailesh Patel Janardan J. Jani Vipulkumar B. Parekh Vijay B. Darji Piyush R. Vaishnav 《Phytoparasitica》2009,37(5):407-413
India has a rich biodiversity of microbes. Soil is the major source for isolation of entomopathogens, after the infected insects
themselves. Four isolates of Helicoverpa armigera nuclear polyhedrosis virus (HearNPV) were obtained from the samples collected one each from Anand, Surat and Junagadh of
Gujarat and Patancheru of Andhra Pradesh. All the HearNPV isolates appeared as clear, irregular six-sided objects with rounded
edges, phase-bright under phase contrast. Junagadh, Surat, Patancheru and Anand isolates gave 27.47–42.80%, 36.83–51.32%,
26.05–43.76% and 42.99–54.85% mortality, respectively, when the percent mortality was pooled over period. The least number
of HearNPV polyhedral inclusion bodies (PIBs) (5.1 × 107) of the Anand isolate were required to kill 50% of the H. armigera population within 120 h. The Anand isolate was fastest (90.30 h), followed by Surat (120.26 h), Junagadh (139.53 h) and Patancheru
(143.10 h) in killing 50% of the H. armigera population at a dose of 109 PIBs ml−1. RAPD analysis of all 15 arbitrary oligonucleotide primers generated 353 scorable bands with 201 loci. A total of 181 polymorphic
bands were obtained, ranging in size from 141 to 1,873 base pairs. The percentage of polymorphic loci was 90.19%. The mean
polymorphism information content (PIC) value for 15 primers was found to be 0.99. The similarity coefficient values based
on 15 RAPD markers ranged from 0.235 to 0.407. The four isolates were grouped into two clusters: one cluster consisted of
Junagadh and Anand and the second cluster consisted of Surat and Patancheru. 相似文献
15.
Masahiro Shishido Kyoko Sato Nanako Yoshida Rie Tsukui Toshiyuki Usami 《Journal of General Plant Pathology》2010,76(1):21-30
We developed polymerase chain reaction (PCR) assays to detect and quantify Phomopsis sclerotioides, the causal agent of black root rot of cucurbits. We used internal transcribed spacers 1 and 2 of the ribosomal DNA (rDNA)
from representative isolates to search for target sequences. Primer pairs were selected after testing against 40 fungal isolates
including 13 Ph. sclerotioides isolates, 9 Phomopsis isolates other than Ph. sclerotioides, and 18 soilborne fungi that were either pathogenic or nonpathogenic to cucurbits. Conventional PCR assays with the primer
pair of CPs-1 (forward) and CPs-2 (reverse) produced target DNA amplicons from all Ph. sclerotioides isolates but none of the other isolates tested. From soil and root samples collected from fields naturally infested with
black root rot of cucumber and melon, the CPs-1/CPs-2 primer pair successfully amplified target DNA fragments in conventional
PCR assays. Moreover, we applied the CPs-1/CPs-2 primer pair in a real-time PCR assay with SYBR Green I, and PCR-amplified
products were successfully quantified by reference to a standard curve generated by adding known amounts of target DNA. Target
Ph. sclerotioides DNA fragments were similarly detected in artificially inoculated roots of cucumber, melon, pumpkin, and watermelon, but quantities
of Ph. sclerotioides DNA in their hypocotyls of the hosts varied as follows: melon ≥ cucumber ≥ watermelon > pumpkin. These results suggest that
Ph. sclerotioides infection is not species-specific but the rate of infection may differ among host species. 相似文献
16.
R. B. Silva J. C. Zanuncio J. E. Serrão E. R. Lima M. L. C. Figueiredo I. Cruz 《Phytoparasitica》2009,37(2):115-123
The ladybug Eriopis connexa (Germar) (Coleoptera: Coccinellidae) is an important natural enemy of various pests. The potential of rearing it on 17 different
diets was evaluated. The percentage of E. connexa adults was higher when its larvae received only eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) after freezing for 1 day (92.5%) or combined in artificial diets with honey and water (82.5%
to 100.0%). The viability from larvae to adult was 72.5% with eggs of A. kuehniella (after 1 day’s freezing) plus an artificial diet based on pet food. No adults of E. connexa were obtained with artificial diets as a stand-alone food source. The duration of the larval period to adult of this predator
was longer, but with low viability, with only A. kuehniella eggs (after 6 months’ freezing) or with eggs + artificial diets. Eggs of A. kuehniella (after 1 day’s freezing) supplied separately or along with artificial diets were more appropriate to rear E. connexa and both diets can be used for mass rearing of this natural enemy. 相似文献
17.
Dry fungal biomass ofPenicillium chrysogenum (dry mycelium), a waste product of the pharmaceutical industry, was extracted with water and applied to the roots of melon
plants before or after inoculation withFusarium oxysporum f.sp.melonis (Font). Seedlings (4–6 days after emergence) treated with either acidic dry mycelium extract (DME) or neutralized dry mycelium extract
(NDME) were protected against challenge infection withFom. A single drench with 2–5% DME applied 12–72 h before inoculation provided significant control of the disease compared with
water-drenched, challenged seedlings. No protection was seen in plants treated 0–6 h before inoculation or 0–48 h after inoculation.
Neither DME nor NDME (0.5–5%) had any effect on fungal growthin vitro, which implied that disease controlin vivo was mediated by induced resistance. The resistance induced by DME protected melon plants not only against race 1,2, but also
against the three other races of the pathogen, indicating a race-non-specific resistance againstFom. Both DME and NDME significantly increased peroxidase activity and free L-proline content in seedlings 12 h and 48 h after
soil drench, respectively. Resistance to Fusarium wilt was significantly associated with elevated levels of peroxidase activity
but not with free L-proline content. Thus, peroxidase might be involved in the defense mechanisms activated by DME or NDME.
http://www.phytoparasitica.org posting Aug. 31, 2001. 相似文献
18.
Entomopathogenic nematodes (EPNs) from the genus Steinernema (Steinernematidae) are used for biological control of insect pests. The infective stages of these nematodes are intolerant
of extreme environmental conditions. Genetic improvement has been suggested as an approach for improving their ability to
overcome these limitations. In this study, we bred a heterogeneous population of the EPN Steinernema feltiae Filipjev for desiccation tolerance (both rapid and slow) and enhanced host-seeking ability. We selected for tolerance of
rapid desiccation by exposing infective juveniles (IJs) to ambient conditions (22–25°C; 50–65% r.h.) for 100 min. A survival
rate of 80–90% was reached after ten selection cycles. To select for tolerance of slow desiccation, we exposed IJs to 97%
r.h. for 72 h, followed by further exposure to 85% r.h. for an additional 72 h. A high survival rate (>85%) was obtained after
20 selection cycles. We selected for enhanced downward dispersal by forcing IJs to move through a sand column to reach larvae
of last-instar Galleria mellonella placed at the bottom of the column. After 25 selection cycles, the majority (>75%) of these nematodes were found at the layer
close to the insects. No reduction in fitness was detected in the selected populations. Nevertheless, the nematode population
selected for enhanced downward dispersal displayed significantly higher infectivity than the foundation population. The population
selected for slow desiccation was more tolerant of heat stress than the foundation population. These findings establish the
basis for improvement of this nematode for use as a biological control agent under field conditions. 相似文献
19.
Rita M. De Miccolis Angelini Wassim Habib Caterina Rotolo Stefania Pollastro Francesco Faretra 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(2):185-199
Resistance to the fungicide boscalid in laboratory mutants of Botryotinia fuckeliana (Botrytis cinerea) was investigated. The baseline sensitivity to boscalid was evaluated in terms of colony growth (EC50 = 0.3–3 μg ml−1; MIC = 10–30 μg ml−1) and conidial germination (EC50 = 0.03–0.1 μg ml−1; MIC = 1–3 μg ml−1) tests. Mutants were selected in vitro from wild-type strains of the fungus on a fungicide-amended medium containing acetate as a carbon source. Mutants showed
two different levels of resistance to boscalid, distinguishable through the conidial germination tests: low (EC50 ∼ 0.3 μg ml−1, ranging from 0.03 to 1 μg ml−1; MIC > 100 μg ml−1) and high (EC50 > 100 μg ml−1) resistance. Analysis of meiotic progeny from crosses between resistant mutants and sensitive reference strains showed that
resistant phenotypes were due to mutations in single major gene(s) inherited in a Mendelian fashion, and linked with both
the Daf1 and Mbc1 genes, responsible for resistance to dicarboximide and benzimidazole fungicides, respectively. Gene sequence analysis of
the four sub-units of the boscalid-target protein, the succinate dehydrogenase enzyme, revealed that single or double point
mutations in the highly conserved regions of the iron-sulphur protein (Ip) gene were associated with resistance. Mutations
resulted in proline to leucine or phenylalanine replacements at position 225 (P225L or P225F) in high resistant mutants, and
in a histidine to tyrosine replacement at position 272 (H272Y) in low resistant mutants. Sequences of the flavoprotein and
the two transmembrane sub-units of succinate dehydrogenase were never affected. 相似文献
20.
T. Miedaner C. Bolduan A. E. Melchinger 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(1):113-123
Fusarium graminearum and F. verticillioides are among the most important pathogens causing ear rot of maize in Central Europe. Our objectives were to (1) compare eight
isolates of each species on two susceptible inbred lines for their variation in ear rot rating and mycotoxin production across
3 years, and (2) analyse two susceptible and three resistant inbred lines for potential isolate x line interactions across
2 years by silk-channel inoculation. Ear rot rating, zearalenone (ZEA) and deoxynivalenol (DON) concentrations were evaluated
for all F. graminearum isolates. In addition, nivalenol (NIV) concentrations were analysed for two NIV producers. Fumonisin (FUM) concentrations
were measured for all F. verticillioides isolates. Mean ear rot severity was highest for DON producers of F. graminearum (62.9% of the ear covered by mycelium), followed by NIV producers of the same species (24.2%) and lowest for F. verticillioides isolates (9.8%). For the latter species, ear rot severities differed highly among years (2006: 24%, 2007: 3%, 2008: 7%). Mycotoxin concentrations among isolates showed
a broad range (DON: 100–284 mg kg−1, NIV: 15–38 mg kg−1, ZEA: 1.1–49.5 mg kg−1, FUM: 14.5–57.5 mg kg−1). Genotypic variances were significant for isolates and inbred lines in all traits and for both species. Isolate x line interactions
were significant only for ear rot rating (P < 0.01) and DON concentration (P < 0.05) of the F. graminearum isolates, but no rank reversals occurred. Most isolates were capable of differentiating the susceptible from the resistant
lines for ear rot severity. For resistance screening, a sufficiently aggressive isolate should be used to warrant maximal
differentiation among inbred lines. With respect to F. verticillioides infections, high FUM concentrations were found in grains from ears with minimal disease symptoms. 相似文献