Journal of Applied Biology
Year:2004 | Volume:17 | Issue:1|Papers Count:8

Geographical and altitudinal distribution of 234 populations belonging to 13 species of Aegilops in Iran after chromosome counting was studied. The relation between different ploidy levels, genome types and altitudinal distribution was estimated. Results indicate that D genome type and tetraploids are much frequent at higher altitudes. Among the Aegilops species in Iran, Ae. kotschyi and Ae. tauschii Are low land elements while Ae. crassa prefers the highest altitude from the sea level.

In this study, the effect of salicylic acid (SA) on seed germination and growth of radish seedlings (Raphanus sativus L.) and it's interaction with plant hormones were investigated. The results of experiments showed that SA at high concentrations inhibited seed germination and at 4 mM reduced it to zero. Meanwhile, with increasing the SA concentration, root length, α- amylase activity reduced but auxin oxidase activity increased. In order to investigate, the reasons of root length reduction, the interactions of SA with IAA, GA, ABA and cytokinin were studied. GA alone was not limiting to root groWth but showed synergism with SA and further reduced seedling root growth. IAA at 10-8, 10-7 and 10-6 mM concentrations promoted root growth and at 10-8 and 10-7 mM along with 0.5 and 1 mM SA increased root growth, but could not overcome to reducing effect of 2 mM SA. ABA alone was limiting to root growth and at 1 mM completely blocked seed germination. Interestingly, ABA at 10-6 and 10-4 mM showed antagonism with reducing effect of SA, and increased root growth. Cytokinin alone at 10-6 and 10-4 mM increased root growth but at 1 mM decreased it drastically. Cytokinin at 10-6 and 10-4 mM acted as antagonist with SA and increased root growth.

The protective functions that have been ascribed to anthocyanins in leaves can be performed as effectively by a number of other compounds. Daisy plants (Bellis perennis L.) accumulaed the anthocyanin of cyanidine 3-malonyl-glucuronosylglucoside in their leaves in the response of salicylic acid and pathogens. Results showed that the different concentrations (3, 7, and 11µM) of salicylic acid were effective. Salicylic acid have significantly reduced disease severity and the concentrations of 3 and 7 µM salicylic acid of increased the amounts of anthocyanins in infected plants by Pseudomonas marginalis and Erwinia carotovora. It can be concluded that the effect of salicylic acid on daisy plants results in the increased amounts of anthocyanins and the decrease of disease symptoms.

This paper describes and compares two species of Aphanius consisting A. vladykovi from Chaghakhor wetland (Chaharmahal-va-Bakhteyari province) and A. sophiae from Qomy-Abad Of varamine (Tehran province). In total, 59 morphometric and meristic characters were measured for each specimen. Ordination based on first and second factors resulted from Principal component analysis (PCA) revealed that two species are significantly different.(Males and females were compared separately to obviate sexual variation (A. vladykovi. 30 males and 26 females) (A. sophiae 22 males and 20 females). In females the characters consisting of predorsal length, preanal length, body depth, total length, head length, head width, prepelvic length and head depth were associated with the first component which accounted for 27% of the total variance. In males the characters consisting of head length, pre dorsal length, total length, preanal lengtn, head depth, postorbital length, head depth, pre pelvic length, caudal peduncle depth, mouth width and anal fin length were associated with the first component which accounted for about 33 % of the total variance in scores.

The Buxaceae family consists of a single genus Buxus L. with only one species as B. hyrcana Pojark. in Iran. This species is represented of Mediterranean element in Northern forests of hyrcanian region and one of endangered plant species in Iran. Pojarkova (1947) introduced B. hyrcana from hyrcanian region and B. colchica from Caucasia as a distinct species from B. sempervirens. There has been dis-agreement about the taxonomic position of B. hyrcana as a separate species by various authors (Grossheim 1962; Rechinger 1966; Davis 1982; Browicz 1986 and Guseinova 1996). In this research, anatomy of leaf, petiole and stem of three species of Buxus L. were studied. A description of anatomical characters for each species is presented.

Citric acid was produced from grapes pomace by Aspergillus niger using a solid-state fermentation system. Effect of some selected factors on the fungal production of citric acid was investigated: spore age, pH value, initial moisture content and particle size of the substrate. Addition of methanol was also studied. Substrate initial moisture content and optimum pH were 65% and 5, respectively. This method produced about 97g of citric acid per kg of grapes pomace in the presence of 3% methanol at 300C in 5 days. The yield was 81% based on the amount of sugar consumed.