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991.
M. I. Tajul Takayuki Motoyama Akikazu Hatanaka M. Sariah Hiroyuki Osada 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(1):91-100
Four green-odour compounds—trans-2-hexenal, cis-3-hexenol, n-hexanal, and cis-3-hexenal—were applied (0.85 μg ml−1 as vapour) to rice plants in laboratory conditions to observe their biological activity against the phytopathogenic fungus
Maganporthe oryzae, which causes rice blast disease worldwide. Two compounds, trans-2-hexenal and cis-3-hexenal, showed remarkable disease suppression efficacy (99.7% and 100% suppression, respectively), while n-hexanal had moderate (86.5%) and cis-3-hexenol had weak (20.8%) disease-suppressing effects. Pre-application and post-application of trans-2-hexenal or cis-3-hexenal had slight effects on blast incidence, suggesting that these compounds had direct effects to suppress M. oryzae infection. In fact, trans-2-hexenal and cis-3-hexenal exhibited a growth suppression effect on M. oryzae. Interestingly, these two compounds inhibited appressorium formation at lower concentrations than the growth suppression.
Studies on the hypersensitive response (HR)-like reaction and plant β-1,3-glucanase activity in rice plant confirmed that
induced resistance was not the major factor involved in the disease suppression mechanism. Results of this study conclusively
showed that trans-2-hexenal and cis-3-hexenal possess potent inhibitory activities against the growth and the appressorium formation of M. oryzae and could be used as antifungal agents to significantly reduce M. oryzae infections in rice. 相似文献
992.
Michel Almaguer Teresa Irene Rojas Francisco Javier Rodríguez-Rajo María Jesús Aira 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(2):473-482
This study characterised the airborne mycobiota of a rice plantation in Bauta (Havana, Cuba), with a view to improving crop
quality. Culturable airborne fungi were sampled between March 2007 and February 2008 using a volumetric method (SAS Super
100) with potato dextrose agar as culture medium. The total fungal count was 51,425 cfu/m3. The 39 filamentous genera identified included several major rice pathogens (Bipolaris, Curvularia, Alternaria, Pyricularia, Cercospora and Fusarium) as well as potentially mycotoxigenic species of Fusarium, Penicillium and Aspergillus. Analysis of the influence of weather-related factors on spore counts revealed that total counts and Penicillium counts correlated positively with daily relative humidity, mean temperature and dew point. 相似文献
993.
Nalini Mallikarjuna Deepak R. Jadhav Kanaka Reddy Fatema Husain Kumkum Das 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(1):17-21
Cultivated groundnut is susceptible to late leaf spot (LLS) caused by Phaeoisariopsis personata [(Berk. & M.A. Curtis) Aex] and resistance is low to moderate in the primary gene pool of groundnut. Closely related wild
species in the secondary gene pool are highly resistant to the disease. All the closely related Arachis species are diploid and cultivated groundnut is a tetraploid. Utilization of diploid Arachis species to transfer LLS resistance is time consuming and cumbersome. New sources of Arachis hypogaea (also called synthetic groundnut) were developed at ICRISAT. These are tetraploids and the present investigation has shown
that they are resistant to LLS. 相似文献
994.
Sameh Boukef Bruce A. McDonald Amor Yahyaoui Salah Rezgui Patrick C. Brunner 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(1):111-122
The occurrence of fungicide resistance in Mycosphaerella graminicola populations from Tunisia was investigated by examining mutations known to be associated with strobilurin and azole resistance.
Few mutations associated with fungicide resistance were detected. No evidence for strobilurin resistance was found among 357
Tunisian isolates and only two among 80 sequenced isolates carried mutations associated with azole resistance. A network analysis
suggested that these mutations emerged independently from mutations found in previously described European populations. The
population genetic structure of M. graminicola in Tunisia was analyzed using variation at 11 microsatellite loci. Populations in Tunisia were characterized by high gene
and genotype diversity. All populations were in gametic equilibrium and mating type proportions did not deviate from the 1:1
ratio expected under random mating, consistent with regular cycles of sexual reproduction. In combination with a high degree
of gene flow among sampling sites, M. graminicola must be considered a pathogens with high evolutionary potential. Thus, control strategies against Septoria blotch in Tunisia
should be optimized to reduce the emergence and spread of resistant isolates. 相似文献
995.
Hyun Cheol Soh Ae Ran Park Sangkyu Park Kyoungwhan Back Jae Bok Yoon Hyo Guen Park Young Soon Kim 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(1):37-48
To elucidate the functional roles of PR10 genes from two pepper species during plant-pathogen interactions, PR10 genes were isolated from fungal-resistant (Capsicum baccatum var. PBC80) and fungal-susceptible (C. annuum var. Yeoju) pepper fruits infected with anthracnose fungus (Colletotrichum acutatum). Despite strong nucleotide sequence identity, there were significant differences in the patterns of gene expression and
protein accumulation between the genes from the two host species. Induced expression of the PR10 mRNA in PBC80 (bacPR10) was highly maintained from 24 h after infection (HAI) rather than that in Yeoju (annPR10). These mRNA expression patterns were correlated with the level of respective protein that was detected as two or three
bands in each species. Substantial induction of bacPR10 proteins was confirmed by 2D-gel analysis followed by immunoblotting. Immunolocalization study showed that deposition
of bacPR10 was exclusively observed in the pericarp of PBC80 fruits after fungal infection, suggesting functional significance
in defence. Additionally, in vitro analysis of the enzymatic properties of PR10 proteins revealed that recombinant bacPR10 had higher ribonucleolytic activity
and exhibited less sensitivity to proteinase treatment than did annPR10. Taken together, these results support the idea that
relative abundance and prolonged longevity of bacPR10 in PBC80 fruits may contribute to their increased resistance in response
to the anthracnose fungus, as compared with Yeoju fruit. 相似文献
996.
Biological control of postharvest diseases of fruit 总被引:1,自引:0,他引:1
Carla Alexandra Nunes 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(1):181-196
Postharvest decay in harvested fruit causes considerable economical losses. Fungicides are the primary means to control these
losses. Public concern in food safety and environmental issues and the increase of pathogen resistant populations have enhanced
the interest in developing alternative methods to fungicides to control postharvest fruit decay. During the last two decades
a huge information and advances concerning the selection of antagonists, mode of action, different approaches to enhance biocontrol
activity, formulation and production have been achieved, and some biofungicides are already in the market. It is likely that
several more products will enter the market in the near future, as the result of the biological control research programs
worldwide. Nonetheless, it is necessary to continue finding new potential microorganisms, better understanding the mode of
action, and pathogen, antagonist and host interactions, to increase the potential of biocontrol helping to become a real alternative
to synthetic postharvest fungicides. This article presents an overview of postharvest biological control approaches and explores
new research possibilities to improve biocontrol activity. 相似文献
997.
998.
Ploidy manipulations and interspecific crosses have allowed considerable genetic progress in Musa breeding, but estimation
of genetic parameters for parental selection remains a major challenge. This study aimed to determine the components of genetic
variance and the relative contribution of genetic effects to phenotypic variation of yield and phenological traits in secondary
triploid hybrids from tetraploid–diploid crosses. The hybrids were evaluated in two consecutive growth cycles on a tropical
forest site. Non-genetic effects accounted for a large fraction of the variation observed for most traits, except bunch weight.
Partitioning of genetic variance into additive and dominance components confirmed the predominant role of additive genetic
effects on the expression of bunch weight, fruit filling time, fruit length, plant height, and number of leaves while primarily
non-additive effects accounted for suckering behavior and fruit circumference. Maternal general combining ability (GCA) effects
accounted for the additive genetic variation in plant height and number of leaves, suggesting that selection for these traits
should be carried out in tetraploid clones. Conversely, paternal GCA effects were the primary causes of genetic variation
for fruit filling time, bunch weight, and fruit length, suggesting that these characters should be selected for in diploid
clones. Specific combining ability (SCA) effects were observed for all traits, except fruit filling time, suggesting that
additional genetic gain could be achieved through recombinative heterosis for these traits. 相似文献
999.
Zhenchang Liang Min Sang Benhong Wu Aihong Ma Shengjian Zhao Gan-Yuan Zhong Shaohua Li 《Euphytica》2012,186(2):343-356
Variation patterns and inheritance of anthocyanin content in the ripe berries of a tetraploid × diploid table grape cross population were investigated in two successive years. The population segregated for three different ploid levels: dipolids, triploids, and tetraploids. A total of 28 different anthocyanins were detected and quantified in the progeny population. Transgressive segregation for the total anthocyanin content was observed in all the three ploid progeny populations. The total anthocyanin content increased as the ploid level increased. The broad sense heritabilities (H2) of the total anthocyanin content were all relatively high, ranging from 0.53 to 0.98, 0.57 to 0.97 and 0.43 to 0.94 in the diploid, triploid and tetraploid population, respectively. Our results suggested that the total anthocyanin content followed an additive inheritance model in this polyploid segregation population. We also observed that the relative contribution of individual anthocyanins to the total anthocyanin content varied significantly among different ploid populations, suggesting that genetic background has important impact on the accumulation of the individual anthocyanin compounds. These results will help develop better breeding strategies in a polyploid table grape breeding program for improving the content of anthocyanins, an important class of polyphenolics possessing antioxidant activities and many other health-related benefits. 相似文献
1000.
Varietal seed mixtures tend to increase and stabilize crop yields, yet their application is sparse. Large-scale cultivation of variety mixtures may require a better understanding of how inter-varietal interactions and their interaction with the environment may influence the grain yield of variety mixtures relative to their component varieties. For this purpose, six variety mixtures of spring barley and 14 component varieties were grown in each of 17 trial environments. A total of 28 observed and a priori plant characteristics, including grain yield, disease severity and weed competitiveness, were derived for each component variety in each trial. The relationship between inter-varietal diversity of each characteristic and the mixing effect on grain yield was analysed. Additionally, various types of yield stability were estimated and compared among mixtures and component varieties. One mixture out-yielded all of its component varieties in almost half of the trial environments. Inter-varietal diversity in grain yield potential correlated significantly with mixing effect, as did straw length diversity when weighted with weed pressure. The grain yields of most mixtures were more stable across environments than their component varieties when accounting also for the general response to environmental productivity. Hence, most mixtures adapted slightly better to environmental productivity and were less sensitive to environmental stress than their component varieties. We conclude that the efficacy of variety mixtures may be enhanced by mixing relatively high-yielding varieties differing in responsiveness to environmental productivity. 相似文献