Ibatsam Khokhar

Biological control of Aspergillus niger, the cause of black-rot disease of Allium cepa L. (onion), by Penicillium species.

Abstract The purpose of the study was to explore the control of the onion black rot pathogen, Aspergillus niger, with Penicillium species as biological control agents. Fourteen Penicillium species were isolated from the rhizosphere of different plants. In dual culture agar plate assays, these isolates showed very high antagonistic effects on the growth of A. niger mycelium. Penicillium roqueforti and P. viridicatum greatly inhibited the growth of A. niger by 66% and 60%, respectively, followed by P. bilaii (57%) and P. olsonii (53%). However, it was also observed that the Penicillium species completely overgrew the A. niger colony. The study revealed that some species of the genus Penicillium possessed a high antagonistic effect on the onion black rot pathogen.

Effects of Penicillium extracts on germination vigour in subsequent seedling growth of tomato (Solanum lycopersicum L.)

Penicillium spp. are well known to produce a variety of beneficial metabolites for plant growth and survival, as well as they defend their hosts from attack of certain pathogens. In this study, effects of culture filtrate of different Penicillium spp. were tested on tomato seeds. On the whole, presoaking of seeds in the filtrates of the nine Penicillium isolates tested significantly increased seed germination when compared with the control seeds. Cultural extracts of P. expansum and P. bilaii were highly effective in growth promotion up to 90%. It was also observed that P. implicatum and P. oxalicum significantly enhanced the root growth in tomato seedling as compared to other species. In case of shoot length, P. verrucosum (3.38 cm), P. granulatum (2.81 cm) and P. implicatum (2.62 cm) were effective. P. implicatum was quite promising in increasing shoot and root length in tomato seedlings, while P. simplicissimum and P. citrinum were less effective on seedling growth. The plant growth-promoting ability of Penicillium strains may help in growth promotion in other plants and crops. Penicillium spp. are already known for producing various mycotoxins and enzymes. Plant growth-promoting ability of Penicillium spp. will open new aspects of research and investigations. The role of Penicillium spp. in tomato plant growth requires further exploration.

Antifungal effect of Penicillium metabolites against some fungi

Microorganisms are increasingly exploited as a source of new biological control agents. Genus Penicillium is a source of novel bioactive molecules which can be used as antifungal agents. The objective of this study was to evaluate the antifungal potential of Penicillium strains. Culture filtrates of two Penicillium species were tested for their antifungal potential by well diffusion assays. Filtrate of Penicillium isolates showed high antifungal effects on mycelial growth of Fusarium oxysporum, Fusarium solani, Macrophomina phaseolina, Aspergillus japonicus var aculeatus and Cladosporium cladosporioides. But Penicillium italicum inhibit the fungal growth from 45 to 68% as compared to Penicillium simplissimum (25–68%). However in case of A. japonicus var aculeatus, Penicillium spp. extracts were equally effective and reduce the colony growth up to 68%. However, P. simplissimum extract was least effective in case of M. phaseolina, where it decreased the colony growth only 25%.

First Report of Penicillium adametzioides from Decayed Grapes (Vitis vinifera) in Pakistan

Penicillium is the major cause of degradation of fruits during pre harvesting and post harvesting stages, thus Penicillium cause substantial economic losses due to spoilage. In december 2011, during a survey of local fruit market in Lahore (Pakistan), samples of decayed grapes have been collected. To clarify the causal agents of those symptoms, fruit samples were obtained from a local fruit market, kotlakhpat, Lahore and examined at laboratory. From the necrotic areas, a bluegrey fungal growth was observed. Temporary slides of diseased tissues were made and observed under light microscope. Small pieces (3 mm) of rotting tissue were taken from the fruits and surface sterilized with 1 % Na(O)Cl then placed onto 2% malt extract agar (MEA) and incubated at 25°C in darkness for 5 days. As a result, a species belonging to the genus Penicillium subgenus Aspergilloides was consistently found associated to the described symptoms. A recent record proves that P. adametzioides Abe ex G. Smith (subgenus Aspergilloides) was the causal agent of a similar fruit rot in Korea (Jian Xin Deng et al., 2012). According to key (Raper and Thom, 1949; Pitt, 1979, 1985; Ramírez, 1982; Samson et al., 1995; Pitt and Hocking, 1997, 1999) this species is primarily characterized by its relatively slow growth on Czapek-based International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 5 Number 12 (2016) pp. 316-320 Journal homepage: http://www.ijcmas.com

Effect of Penicillium Extractsa on Germination Vigor in Subsequent Seedling Growth of Tomato (Solanum Lycopersicum L.)

Abstract Penicillium spp. are well known to produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. In this study, effects of culture filtrate of different Penicillium spp. were tested on tomato seeds. On the whole, presoaking of seeds in filtrates of the nine Penicillium isolates tested, significantly increased seed germination when compared with the control seeds. Cultural extracts of P. expensum and P. billi were highly effective in growth promotion up to 90%. It was also observed that P. implicatum and P. oxlalicam significantly enhanced the root growth in tomato seedling as compare to other species. In case of shoot length, P. verrucosum (3.38), P. granulatum (2.81) and P. implicatum (2.62) were effective. However P. implicatum was quite promising to increase shoot and root length in tomato seedlings. Where as P. simplicissimium and P. citrinum were leas effective on seedling growth. The plant growth promoting ability of Penicillium strains may help in growth permotion in other plants and crops. Penicillium spp. are already known for producing mycotoxin and enzymes. Plant growth promoting ability of Penicillium spp will open new aspects of research and investigations. The role of Penicil-lium spp. in tomato plant growth requires further exploration.