Rhizoctonia cerealis, the causal agent of sharp eyespot on wheat, was not considered to be an important pathogen for many years. Recently, the disease has become endemic in many countries except for South America. The disease has created a new threat to world wheat production because the damage of wheat sharp eyespot has become increasingly severe. In this paper, previous studies on this pathogen, including the disease geographical distribution, pathogen identification, life cycle, symptoms, favourable environmental conditions, effects on wheat yield and control strategy, are reviewed. Such information will be helpful in management of sharp eyespot.

To develop an effective biocontrol strategy for management of Fusarium head blight on wheat caused by Fusarium graminearum, the bacterial biocontrol agent Pcho10 was selected from more than 1,476 wheat-head-associated bacterial strains according to its antagonistic activity in vitro. This strain was subsequently characterized as Pseudomonas chlororaphis subsp. aurantiaca based on 16S ribosomal DNA sequence analysis, assays of the BIOLOG microbial identification system, and unique pigment production. The major antifungal metabolite produced by Pcho10 was further identified as phenazine-1-carboxamide (PCN) on the basis of nuclear magnetic resonance data. The core PCN biosynthesis gene cluster in Pcho10 was cloned and sequenced. PCN showed strong inhibitory activity against F. graminearum conidial germination, mycelial growth, and deoxynivalenol production. Tests both under growth chamber conditions and in field trials showed that Pcho10 well colonized on the wheat head and effectively controlled the disease caused by F. graminearum. Results of this study indicate that P. chlororaphis subsp. aurantiaca Pcho10 has high potential to be developed as a biocontrol agent against F. graminearum. To our knowledge, this is the first report of the use of P. chlororaphis for the management of Fusarium head blight.

Two hundred and forty isolates of Botrytis cinerea were collected during the early summer of 2012 and 2013 from strawberry greenhouses in 10 locations in Hubei Province and examined for sensitivity to five fungicides, most of which were commonly used to control this fungus. High frequency of resistance to carbendazim (Car, 63.63%) and cyprodinil (Cyp, 42.42%) was detected. Boscalid-resistant (BosR) isolates were detected for the first time in China, whereas no fludioxonil-resistant isolates were identified. Dual resistance to carbendazim and diethofencarb (Die) was also detected. There were six phenotypes of resistance profile (i.e., CarRDieSBosSCypS, CarRDieRBosSCypS, CarRDieSBosSCypR, CarRDieSBosRCypS, CarRDieRBosSCypR, and CarRDieSBosRCypR). CarRDieSBosSCypS and CarRDieSBosSCypR were the most common phenotypes, occurring at eight and seven locations, respectively. After 10 successive transfers on fungicide-free potato dextrose agar, tested resistant isolates retained levels of resistance similar to or comparative with the initial generation, indicating the stability of these resistances. Fitness evaluations based on investigation of mycelial growth, osmotic sensitivity, sporulation in vitro and in vivo, and virulence revealed the uncompromising fitness in resistant isolates, except that decreased virulence was observed in BosR isolates. The molecular basis of carbendazim, diethofencarb, and boscalid resistance was investigated. Results showed that all 13 sequenced carbendazim-resistant isolates harbored the mutation E198V or E198A in the β-tubulin gene and the five isolates with dual resistance to carbendazim and diethofencarb showed the mutation E198K in the same gene. BosR isolates possessed the H272R mutation in succinate dehydrogenase subunit B gene. The results achieved in this study challenge the current management strategies for B. cinerea, which largely depend on applications of these fungicides.

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Car(R) populations of G. zeae develop rapidly under the selection pressure of carbendazim. Real-time PCR assays detecting the resistance frequencies in populations of perithecia would provide useful information for FHB control and management of resistance.

Gray mold, caused by Botrytis cinerea, is one of the most destructive diseases of strawberry in China. For resistance monitoring, 198 B. cinerea isolates were collected from strawberry greenhouses at 10 locations in Hubei Province. The isolates were screened for resistance to fungicides procymidone and zoxamide. In mycelium growth assays for procymidone, the mean values of effective concentration at which mycelium growth is inhibited by 50% (EC 50) for sensitive (Pro S) and resistant (Pro R) isolates were 0.25 μg/mL and 2.21 μg/mL, respectively. The frequency of Pro R isolates was 14%, and the highest frequency (48%) was observed in Yichang. Positive cross-resistance was detected for Pro R isolates to other dicarboximide fungicides, but not to phenylpyrroles. Comparative analysis of fitness parameters revealed increased osmotic sensitivity of Pro R isolates compared to Pro S ones. Sequence analysis of the dicarboximide target gene BcOs1 revealed that Pro R isolates carried either a single point mutation at codon 365 (I365S) or a pair of point mutations (Q369P and N373S). The mean EC 50 values for zoxamide sensitive (Zox S) and resistant (Zox R) isolates were 0.31 μg/mL and 7.76 μg/mL, respectively. Only six (3%) isolates from three locations were found to be resistant to zoxamide. All Zox R isolates were found resistant to carbendazim. Fitness parameters did not show significant difference between Zox R and Zox S isolates. Sequence analysis of the beta-tubulin gene in resistant isolates revealed four previously reported point mutations (E198A, E198K, F200Y and T351I). The mutation T351I was detected only in the isolates possessing E198K point mutation. Mutation F200Y was detected in a highly resistant isolate. Results of this study will be helpful for the management of fungicide resistance in B. cinerea.

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This study was implemented to assess the mechanism by which Moringa oleifera leaf extract (MOLE) improves the quality and prolongs shelf-life of the broilers’ breast meat. Ninety Cobb chicks were randomly allocated to 3 groups. A control group received the standard diet, whereas the other two groups received diets containing MOLE at the doses of 250 and 500 mg/kg for 21 days. Inclusion of MOLE in broilers diet significantly reduced the detrimental changes in the overall sensory attribute scores, characteristic color and odor, and the loss of breast muscle elasticity during storage. Furthermore, it significantly reduced concentrations of thiobarbituric acid, total volatile nitrogen, non-esterified fatty acids, and peroxide, during storage compared to the control samples. No effect on the concentrations of heavy metals, such as copper, cadmium, and lead, was observed. Decomposition of samples was delayed as indicated by lower pH values and higher sensory scores at 4 and 6 days of storage in the MOLE groups. Reduced contamination with E. coli and Salmonella species indicated an antibacterial effect of MOLE. Finally, the present study highlights that MOLE supplementation may play a role in improving quality and shelf-life of the chilled breast meat in broilers.