Search

Summary: Pasteuria penetrans is a hyperparasite with potential as a biological control agent of root-knot nematodes, Meloidogyne spp. In this study two exotic Pasteuria isolates (PP-3 and PP-J) were developed on different Meloidogyne spp. collected from different districts of Punjab, Pakistan. The development of PP-3 and PP-J on different field populations of Meloidogyne spp. showed differential infectivity in terms of nematode reproduction variables. The development of PP-3 and PP-J was maximum on tomato as compared to cucumber. It was probably due to more invasion sites for nematodes present in the tomato roots. However, a bigger root system has not always been a guarantee for development of Pasteuria on Meloidogyne spp. For successful development of Pasteuria , the key parameters are the percentage of infected females, number of endospores (female)−1 or endospores (mg root powder)−1. The results of these parameters are greater in tomato as compared to cucumber. [ABSTRACT FROM AUTHOR]

Millions of dollars have been spent annually on quarantines, prevention, eradication and management programs around the globe. The present study was coined to record the incidence of the disease in the Sargodha districts of the Punjab province. Furthermore, isolated bacterium from diseased samples was characterized morphologically and molecularly. The relative efficacy of commercially available antibiotics against the pathogen was evaluated in the lab and in field conditions. A systematic survey of randomly ten localities/sampling sites was conducted for a reliable estimation of citrus canker disease in District Sargodha of Punjab Province. Nine sampling sites showed 90 % the presence of Xanthomonas axonopodis pv. citri and only one site was free of citrus canker disease. Total cellular DNA was isolated from freshly growing aqueous bacterial culture using CTAB protocol with modifications. Amplification of 581bp fragment from isolated DNA from bacterial isolates confirmed the presence of pathogen i.e. X. axonopodis pv. citri. The amplified PCR product was purified and further confirmed by sequencing which showed 100% similarity with 40 nucleotide sequences of X. axonopodis pv. citri submitted in NCBI. Relative efficacy of six antibiotics (Streptomycin sulphate, Oxytetracycline, Cefalexin, Kasugamycin, Kanamycin and Levofloxacin USP) against colony growth of X. axonopodis pv. citri was evaluated at 50, 100 and 150 ppm using disc sensitivity technique. Streptomycin sulphate was found most effective to inhibit the colony growth of the bacterium. Streptomycin sulphate and Oxytetracycline were evaluated against the disease in field conditions. Streptomycin sulphate was found relatively most effective as compared to the Oxytetracycline. [ABSTRACT FROM AUTHOR]