Hypericum perforatum L. (St. Johns’ wort) is the most commercially important species of the genus Hypericum and contains a wide range of components including naphthodianthrones, phloroglucinols, tannins, xanthones, phenolic acids and essential oil. In order to establish an efficient protocol for regeneration, the effects of explant type and plant growth regulators on direct and indirect shoot r...

The objective of this study was to determine the effects of lead (Pb) exposure on bioaccumulation, growth, and tolerance mechanisms in summer savory (Satureja hortensis L.). Plants were subjected to different levels of Pb concentrations including 0 (control), 5, 10, 25, 50 and 100 mg L-1 in growing medium. Pb treatment led to significant increase in root and shoot Pb content. Calculation of BF,...

This research was conducted to investigate the effects of low magnesium (Mg) with high potassium (K) supply on the Mg concentration, sugar partitioning and root growth of rice (Oryza Sativa L. cv. Wuyunjing 7) plants grown in hydroponics under greenhouse conditions, at Nanjing Agricultural University, China. The nutrient solution contained 0.01 and 1.0 mM Mg concentration, with K at 1.0 and 6.0...

Iron (Fe) and manganese (Mn) are essential nutrients for plants. Application of high levels of either Fe or Mn is often accompanied by relatively low levels of uptake for the other nutrient. The antagonistic relationship of these nutrient elements may occur either during absorption by roots or during translocation from roots to shoot. A greenhouse study was carried out to study the effect of so...

Residues of khat (Catha edulis Forskal) leaves in the soil showed an inhibitory effect on the dry mass, pectin and cellulose of wheat shoots and roots and cell wall-associated proteins of roots. The dry mass of shoots and roots significantly reduced and the reduction in roots was greater than in shoots. On the other hand, the contents of hemicellulose and lignin in both shoots and roots and cel...

Tobacco is a salt-sensitive glycophyte crop species. In this work effect of silicone (Si) supplementation (1 mM as Na2SiO3) was studied in Nicotiana rustica L. cv. Basmas grown hydroponically in growth chamber under control, low (25 mM) and high (75 mM) NaCl concentration for two weeks. Dry matter production of leaves was depressed by salinity level as low as 25 mM and higher salt concentration...

Studies on the function of root traits and the genetic variation in these traits are often conducted under controlled conditions using individual potted plants. Little is known about root growth under field conditions and how root traits are affected by agronomic practices in particular sowing density. We hypothesized that with increasing sowing density, root length density (root length per soi...

The ontogeny of carrots (Daucus carota cv. 'Spartan Premium') grown under greenhouse conditions in pots of organic soil infected with Meloidogyne hapla was influenced detrimentally as early as 4 days after seeding, as determined through analysis of plant surface area, dry weight, fresh weight, net assimilation rate, relative growth rate, and leaf-area ratio. Only 58% of the diseased carrots wer...

Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designe...