Authors:Ça?la Tükel, Pinar Şanlibaba, Banu Özden, M. Akçelik, and M. Akçelik
98 Lactococcus lactis strains were isolated from traditional fermented milk products in Turkey tested against 60 lactococcal lytic phages to determine their resistance levels. While 82 L. lactis strains were sensitive against lactic phages at different levels, 16 L. lactis strains showed resistance to all phages tested. Types of phage resistance among 16 L. lactis strains were identified as phage adsorption inhibition in eight strains, restriction/modification in six strains and abortive infection (heat sensitive phage resistance) in two strains, using three broad-spectrum phages Fpll 98-32, Fpld 67-42 and Fpld 67-44.
Authors:Sobiya Shafique, Shazia Shafique, and Aqeel Ahmad
indirectly the chili yield in Pakistan. Mal-cultural practice is one of those major reasons of yield loss [ 4 ]. Phytophthora root rot is another fungal infection of chilies which is very common in Pakistan. It also affects the chili price in international
Authors:Cosme Alvarado-Esquivel, Luis Francisco Sánchez-Anguiano, Alejandra Mendoza-Larios, Jesús Hernández-Tinoco, José Francisco Pérez-Ochoa, Elizabeth Irasema Antuna-Salcido, Elizabeth Rábago-Sánchez, and Oliver Liesenfeld
, Davis PH : Toxoplasma on the brain: understanding host-pathogen interactions in chronic CNS infection . J Parasitol Res 2012 , ( 2012 )
Field experiments were carried out with soybean [
(L.) Merrill] on a Haplic Chernozem soil. Eleven treatment combinations were applied with increasing rates of fertilizers in three replicates. At full maturity the dry weight production, total biomass production, root weight, yield, shoot NPK concentration and severity of
infection were determined. The highest degree of
infection was found in the lowest NPK treatment, while the lowest rate of disease was observed for the highest NPK combination. By increasing the NK supply, the degree of infection decreased. At the same fertilizer rates, significantly lower infection was observed at higher phosphorus levels. The dry weight production, total biomass production of the shoots, pod weight and nitrogen concentration of the shoots were negatively correlated with the rate and severity of infection, which was positively correlated with the concentration of phosphorus. No correlation was found between root weight and infection or between potassium concentration and infection.
Authors:A. Bittsánszky, V. Rai Ravishankar, and G. Oros
Okra seedlings tolerated soil-borne Rhizoctonia infection in strain dependent manner. No connection was revealed between pathogenicity of strains and their origin or taxonomic position. However, the okra proved to be susceptible to strains highly pathogenic to other host plants as well. R. zeae, a species new to European flora, was as aggressive to okra as the most potent R. solani strains. The effect of Rhizoctonia infection was more prominent on mass accumulation in hypocotyls than in cotyledons. The protein content and glutathione S-transferase activity increased in parallel with the evolution of disease syndrome. Metalaxyl, an acetanilide type systemic antioomycete fungicide induced glutathione S-transferase activity in cotyledons with 24 hours a phase, and this induction was more outstanding in symptomless seedlings grown in Rhizoctonia infested soil. It might be concluded, that the stress response of plants in tolerant host/parasite pair takes effect at higher level than in susceptible relationships.
As an economically important insect pest, the adults of the grey corn weevil, Tanymecus dilaticollis (Coleoptera: Curculionidae) were investigated for presence of pathogens. In 2009 and 2011, 1069 specimens were collected from maize and sunflower crops in 6 localities in Northern Bulgaria and studied in the laboratory. As a result of this study infections caused by a septate gregarine and Beauveria bassiana were established. In 2009, the prevalence of gregarine was 29.8% and of the fungi was 26.8%. Protozoan diseases were not found in the populations of T. dilaticollis investigated in 2011 but the weevils killed by mycosis were 52.55%±7.04 from all 901 analysed adults of the grey corn weevil. Morphometrical data about the gregarine found in the weevils were presented. Some isolates of B. bassiana were obtained in pure cultures. Occurrence of pathogens in T. dilaticollis populations was discussed with the view to their role as natural regulators of pest population density. The gregarine parasite is reported for first time for T. dilaticollis.
Authors:B. R. Bakheit, A. A. El-Shiemy, F. S. Sedek, and A. A. Ismail
The present study was carried out during the three successive growing seasons of 1996, 1997 and 1998 to estimate the additive, dominance and epistatic components of genetic variation for the yield, yield components and wilt infection by using ninety triple test cross families and their parents, F1 and F2 in four sesame crosses. A randomized complete block design with three replications was used. The results indicated that mean squares of the genetic analysis of variance and the overall epistatic gene effects for the crosses showed highly significant differences for all studied characters. The [i] type (additive × additive) was considered as a major component of the overall epistatic effects for 1000-seed weight in the TTC3 cross, wilt infection percentage in TTC3 and TTC4, number of capsules/plant in TTC1, TTC2 and TTC4 and seed yield/plant in all crosses. The ratio of (H/D)1 for all crosses confirms the presence of partial dominance for all studied traits. The direction of dominance was positive and significant for wilt infection in TTC4, oil percentage in TTC1 and TTC4, number of capsules/plant and 1000-seed weight in TTC2 and seed yield/plant in all four crosses. The results also revealed that the highest proportion of recombinant lines was obtained for number of capsules/plant, 1000-seed weight and oil percentage in the TTC2 cross and for seed yield/plant in TTC3.