جستجوی مقالات مرتبط با کلیدواژه "پیچک صحرایی" در نشریات گروه "زیست شناسی"

In order to study the allelopathic potential of six medicinal plants Valeriana officinalis, Rosmarinus officinalis, Artemisia absinthium, Melissa officinalis, Juglans regia, Dracocephalum kotschyi on Beta vulgaris and its two important weeds (Convolvolus arvensis and Avena fatua) and also to find a model of natural herbicides, a factorial experiment was conducted based on randomized complete block design. Shoots of B. vulgaris, C. arvensis and A. fatua were sprayed with water extracts (0 and 100 percent) of the allelopathic plants twice in 48h. Two days after spraying, the changes of dry weights, total water content, electrolyte leakage, concentrations of malondialdehyde (MDA), hydrogen peroxide, chlorophyll a, b, total chlorophyll and carotenoids were assessed in the target plants. Results of mean comparisons showed the water extracts of all studies medicinal plants had allelopathic effects on the target plants, but in different degrees. Amongst, D. kotschyi caused to make the least level of MDA (%11.6), H2O2 (%42), electrolyte leakage (%8.5) and the least reduction of total chlorophyll (-%13.1) in B. vulgaris. These values were –in turn- (%32.3, .6 folds, %50 and -%48.4) in C. arvensis and (%34.8, folds, %70.8 and -%56) in A. fatua. Generally, it is concluded that utilization of allelopathic ability of D. kotschyi would be a promising model to produce natural herbicide for sugar beet farms.

An experiment was condacted To study the allelopathic effect of saffron genotyps on bindweed in the department of agronomy and plant breeding of Isfahan University of Technology, Iran in 2012-2013. Experiment was arrange as a factorial in a completely randomized desiggn with three replication. Factors included 20 saffron genotypes obtained from different regions in Iran, ( Hamedan, Nishapur1, Nishapur2, Nishapur3, Nishapur4, Sabzevar, Mashhad1, Mashhad2, Natanz, Khaf, Khorasan, Torbatejam, Kashan, Gonabad, Torbat heydaryeh, Birjand, Yazd, Shiraz, Isfahan, Kashmar) and Aquous extracts were prepared from aerial parts of these saffron genotypes in concentrations of 0, 3, 6, 12.5, 25, 50 and 100%. Seedling traits of the attributes of Bindweed (as a target species) including radicle and plumule lengthes, radicale and plumule fresh weights, plumule dry weight, germination percent and velocity were measured.. Results showed that the effect of genotype and extract concentration and their interaction on measured traits were significant. Saffron genotypes had a different effect on the triats of bindweed. Genotypes "Khaf and Nishapur3" were proven to be the most allelopathic genotype, and genotypes "Kashan, Torbate jam and Gonabad" were found to leave minimal allelopatic effects on the target species. With increasing in aquous extracts concentration traits of target specie decreased, but the effect was diffreent. Maximum inhibition was observed in aquous extract concentrations of 100% and minimum inhibition was observed at aquous extract concentrations of 3% .

Field bindweed is a plant with scientific name Convolvulus arvensis L. This plant is a perennial plant of Convolvulaceae families. Developmental stages of generative meristem, pollen and microsporangium (early stages of pollen development) was studied using optical microscopy. The young flowers and buds were removed in different developmental stage, fixed in FAA70 and kept in 70% ethanol. Samples were embedded in paraffin after dehydration and sliced using microtome. Staining was carried out with Hematoxylin-Eosin. Prepared slides from different developmental stages were studied using light microscope and photographed. The results showed that anther is tetrasporangiated. Development of anther wall follows the dicotyledonous type, which is composed of an epidermal layerv, an endothecium layer, one middle layer and tapetum. The tapetum is secretory type at the beginning and plasmodial type at the end of anther development .Microspore tetrads is tetragonal and until the final stages of anther development is visible. Microspores were irregular in their early stages of development, but mature pollen grains are regularly. Pollen grains in polar view are spherical and equatorial view is ellipsoid, they are tricolpate and have three pores and bi- cellular at the mature form.

Allelopathic effects of aqueous extract of pagoda tree and creeping jenny on five crop plants including wheat (Triticum aestivum)، barley (Hordeum vuIgare)، corn (Zea mays)، millet (Pennisetum americanum) and chickpea (Cicer arietinum) were investigated in a series of experiments conducted at the faculty of Agriculture، SB University of Kerman، Iran. Experiments were based on RCBD with 3 replications in greenhouse condition and CRD in laboratory condition in which different concentrations of weed leaves extract including (0، 25، 50، 75 and 100% of a stock solution (10%W/V)) were applied on all crop plants at germination and seedling growth stages and different responses were measured. Results showed that the three way interaction effect of alkaloid × concentration × hybrid was significant on the traits in both greenhouse and laboratory. By increasing the concentration of alkaloid، inhibitory effect was also increased. The 100% concentration was most effect and control concentration was least effective. There was a significant difference between the two weeds in terms of allelopathic effects and creeping jenny reduced plants growth more compared to pagoda tree. However، all crops were significantly affected by allelopathic properties. It was concluded that pagoda tree and creeping jenny residues in the field had the potential of allelopathic effects on crop plants therefore should be removed from the field before planting.

This research was accomplished during 2005 to 2006 at Weed Resaerch Department، Iranian Plant Protection of Research Institute for identification of morphophysiological variation of field bindweed population، and introduction of this weed biotypes in Karaj. The study was done by Principal Component Analysis (PCA) and Cluster Analysis (CA) based upon 43 morphological and physiological variables. Due to Karaj climate، The most important variables were shoot dry weight (SDW)، (5. 71-34. 40 g) total biomass (10. 56-36. 91 g) and leaf area (557. 56-1948. 34 cm2)، respectively. The results of this experience showed 11 biotypes in Karaj. The variability in morphological and physiological of these field bindweed biotypes may explain their different adaptability as the environmental conditions and different management practices change.