Ghazala Nasim

Response of arbuscular mycorrhizal mungbean plants to ambient air pollution

The experiments were conducted in open top chamber system installed at the University of the Punjab, Quaid-e-Azam Campus, Lahore, Pakistan. The mungbean (Vigna radiata (L.) Wilczek var.M28) seeds were sown in earthen pots and were kept in filtered air, unfiltered air and ambient air. The ozone concentration was monitored daily during 1000hrs till 1600 h. The data for light intensity and relative humidity was also regularly collected. The sets of plants growing in FA chambers (without ozone and dust particles) responded well as regards growth and yields are concerned. Unfiltered air reduced the number of nodules, their biomass and nitroginase activity in mungbean plants. The present study documents that the species of mycorrhizal fungi sensitive to tropospheric ozone failed to reproduce in ambient air and unfiltered air chambers (without dust particles). Out of a total of 24 species, eighteen species belonged to the genus Glomus, two each to Sclerocystis, to Acaulospora and one each to Gigaspora and Scutellospora. The total number of species was variable during the growth phase. The total number of species reduced in soil of UFA chambers with the passage of time. Species richness reduced to almost half in UFA plants as compared to FA plants. Species of the Genus Glomus were highly abundant species at various harvests in all air treatments. Amongst most abundantly recovered Glomus species were G. fasciculatum, G. mosseae, G. aggregatum, G. caledonicum, G. deserticola, G. geosporum, and G. monosporum. The pattern of abundance kept on varying at various harvests for different air and mycorrhizal treatments. In the case of plants of UFA treatment, only two species of Glomus were abundant namely G. fasciculatum and G. geosporum. Species of Acaulospora and Gigaspora in particular and Scutellospora and Sclerocystis in general were sensitive to polluted air.

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.