| the response of some common egyptian plants to ozone and their use as biomonitors. | relative sensitivity of five common egyptian plant species namely, senecio vulgaris, malva parviflora, sonchus oleraceus, medicago sativa and melilotus indicus to elevated levels of ozone has been studied. the plants were exposed to charcoal filtered air (cfa) and different levels of o3 (50 and 100 ppb) for 5 h per day. the studied parameters were recorded for five consecutive days after fumigation. the foliar injury varied significantly among species in a dose-dependent manner. severe injury sy ... | 2003 | 12758022 |
| stable low molecular weight rna profiling showed variations within sinorhizobium meliloti and sinorhizobium medicae nodulating different legumes from the alfalfa cross-inoculation group. | four different low molecular weight (lmw) rna profiles, designated i-iv, among 179 isolates from medicago, melilotus and trigonella species growing in a field site in northern spain were identified. from sequence analysis of the 16s rrna, atpd and reca genes as well as dna-dna hybridization analysis with representatives of each lmw rna profile it was evident that isolates with lmw rna profiles i and ii belonged to sinorhizobium meliloti and those displaying profiles iii and iv to sinorhizobium m ... | 2008 | 18399993 |
| perspectives on allelopathy in mexican traditional agroecosystems: a case study in tlaxcala. | agroecosystems in tlaxcala, mexico, are surrounded by trees and water channels and have a great variety of cultivated and noncultivated plants. the main results of a study carried out on a traditional agroecosystem in santa inés, tlaxcala are presented. some ecological aspects of polycultures, plant covers (dry leaves ofalnus firmifolia, berula erecta, andjuncus sp.), and the allelopathic potential of crops and noncultivated plants (fresh and dry material) were analyzed. the main plants (trees, ... | 1987 | 24301542 |