the aim of this study was to evaluate the effect of different potassium (k) and nitrogen (n) concentrations in nutrient solution and their interaction on growth and quality of tomato transplants. a full factorial experimental design was carried out with three potassium concentrations (1.5, 3 and 6 meql-1) and three nitrogen concentrations (1.5, 3 and 6 meql-1) for 27 days after seed germination...

Plants need to allocate some of their limited resources for defense against herbivores as well as for growth and reproduction. However, the priority of resource allocation within plants has not been investigated. We hypothesized that plants with extrafloral nectaries (EFNs) invest more chlorophyll around their EFNs-to support a high rate of carbon fixation there-than in other leaf parts of youn...

In order to understand the response of Lotus corniculatus to salt stress, ions content and some growth factors were analyzed in three varieties of this plant, namely, Ardebil, Karaj, and Jolfa. Lotus corniculatus plants were exposed to 0, 50, 100, and 150 mM NaCl in hydroponic condition. The amounts of anions (Cl-and NO3-) and cations (K+ and Na+) in leaves as well as shoot and root dry weights...

Efficient use of space and high yields are critical for long-term food production aboard the International Space Station. The selection of a full dwarf wheat (less than 30 cm tall) with high photosynthetic and yield potential is a necessary prerequisite for growing wheat in the controlled, volume-limited environments available aboard long-term spaceflight missions. This study evaluated the phot...

Background: Achillea tenuifolia Lam. (Compositae) with small yellow flowers and several times pinnately divided leaves in worm shape is known for many years in the folk medicine. It has been used to reduce sweating and to stop bleeding. It helps regulation of the menstrual cycle and reduces heavy bleeding and pain. Materials and Methods: Plant material (flower, leaf and stem) was collected in...

In the identification process of weed materials available in "IRAN" herbarium, a specimen belonging to the genus Lactuca (Asteraceae) had the following characteristics: Plant annual, many stemmed from base; stem erect-slightly procumbent, slender, glabrous, whitish and leafy. Basal leaves dried; stem leaves ca. 7 × 0.5 cm, glabrous, linear-lanceolate, entire at margin, sessile, auriculate, auri...

Coordination of water movement among plant organs is important for understanding plant water use strategies. The hydraulic segmentation hypothesis (HSH) proposes that hydraulic conductance in shorter lived, 'expendable' organs such as leaves and longer lived, more 'expensive' organs such as stems may be decoupled, with resistance in leaves acting as a bottleneck or 'safety valve'. We tested the...