Year:2005 | Volume:18 | Issue:(66 IN AGRONOMY AND HORTICULTURE)|Papers Count:15

Genetic diversity of 54 populations from 22 species of genus Medicago collected from Iranian natural habitat was studied. DNA was extracted from bulked leaf samples of each population and used for RAPD-PCR. RAPD marker produced by 11 UBC random primers was analyzed according to Maximum Parsimony method. Using the computer software PAUP (Swofford 2000) a phylogenetic tree with 5 main cluster was generated. Populations of M aculeala, Mcanstricta, M.riglduloidos and M. rigidula with hard pod walls and spongy texture were classified in one cluster. Populations of M. sauvagei, M laciniata and M. polymorpha which had soft and flexible pod walls were classified together in a separate cluster. Populations of each species were also classified together in sub clusters indicating that RAPD marker were capable of identifying genetic diversity at the species level. Populations of one species grown under similar climatic conditions were grouped together under the cluster of that species. This indicates that genetic diversity correlates with geographical distribution of wide spread annual medic species in Iran. Results of this student showed that RAPD marker are applicable as a complementary tool in taxonomic identification of genus Medicago at both species and population levels.

Importance of clover in Iran agriculture and also dry climate of most agricultural regions, evolution of different species in different water supply conditions specially in water deficit conditions seems to be necessary. The best dry tolerant species possess highest number of nodes. In this study germination rate of three species of clover were tested to evaluate their germination potential in different water deficit conditions. Results indicates that in different osmotic potentials (artificially caused by polyethylene glycol) among clover species Trifolium subterraneum represents highest average germination rate and percent as well as, high hypocotyl and radical length, and T. michelianum exhibits the lowest averages. In seedling stage of clover species T. subterraneum showed highest number of nodes, dry root weight dry stem weight, hypocotyl and radical length. Finaly between clover species, Trifolium subterraneum exhibited highest tolerance to drought condition and possess highest yield in comparison with other species.

Due to evaluation of tolerance to the salt stress of the four new and prolific varieties of winter rapeseed (Brassica napus L.)Cocktail, Parade, Okapi and the hybrid of Regent x Cobra in germination and embryo growth stages, a factorial experiment was carried out using Randomized Complete Block Design-with three replicates in crop physiology laboratory of faculty of Agriculture of Urmia University. In this research some characters as percent of germination, germination rate, gemule length, radicle length, gemule weight and radicle weight were studied. Salt treatment were control 0, 4, 8, 10and 12mmosh/cm. The results of data analysis showed salt effect on studied cultivars and interaction of cultivar x salt on the studied characters were significant in I% level. With increasing of salt all evaluated characters decreased. The Regent x Cobra was superior cultivar in all attributes unless germination percentage, and Okapi was lower from other cultivars. study on the interaction of salinity and cultivar effects indicated germination percentage of Cocktail variety was higher from others until dose of 10 mmohs/cm but in salinity of 12mmohs/cm the Parade cultivar was superior from other cultivars. The salt had a negative correlation with all evaluated characters. The most negative correlation was between salt and percent of germination and the most positive correlation was between percent of germination and germination rate characters and there was a positive correlation between percent of germination with gemule length.

A factorial experiment was laid out to determine an effective planting density and N fertilizer rate for a hybrid rice cultivar, GRH1 in a randomized complete block design (RCBD) with three replications at the Rice Research Institute of Iran (RRII), Rasht. The two factors that were considered for this factorial experiment were N fertilizer with four levels and three planting densities. ANOVA revealed highly significant differences for different N fertilizer dosage levels on comparison of yield, plant height and days to 50% flowering (DFF). While for the planting density the ANOVA showed highly significant differences for DFF and only significant differences for yield and number of unfilled grain. However, the two way interaction between N level and planting density showed non significant differences for all the traits studied. Interestingly, an application of higher N fertilizer level of 175 kg N/ha did not show any significant yield advantage over the 125 kg N/ha level for this hybrid indicating the hybrid to be highly efficient in N  usage. The ideal planting density of25x 25 cm was determined with an efficient N dosage level of 125 kg N/ha for this hybrid.

The effects of forage harvest at different phonological growth stages on biological yield and soil seed bank reserves of different annual medic cultivars were evaluated in climatic research station of Khoramabad during 1380 and 1381 growing seasons. The treatments were arranged as split plots based on a Complete Randomized Block Design with three replications. Six annual medic cultivars (Robinson, Kelson, Rigidula, Caliph, Orion and Mogul) were assigned to the main plots and forage harvest at different phonological growth stages (early and 50% flowering) to the subplots. Forage harvest at early flowering stage significantly increased biological yields as well as soil seed bank reserves compared to 50% flowering stage. Annual medic cultivars performed different reactions to harvest treatments due to their growth periods. The long season cultivars produce more seed while harvested at early growth stage. However, forage harvest at 50% flowering stage caused their re-growth encountered with unfavorable weather conditions, which caused a poor soil seed bank. Caliph cultivar produced the richest soil seed bank while Rigidula was the best biological yield producer among different annual medic cultivars.

This research has been performed to determine the salt tolerance in three species' Salsola dendroides, Alhagi persarum and Aeluropus lagopoides. These species are native to Iran, prennial and could be used as a forages for livestock's. Completely randomise design used the species in replication. All the seeds were collected form Nouredin Abad Garmsar in hot and dry (xerothermo) climate. Different experiments on germination and vegetative growth stages were carried out in laboratory and greenhouse condition. The effects of salt on percentage and rate of germination were measured. The result showed that increase of salt concentration caused delay in germination rate and decreases of germination. Complete germination was observed in A. persarum and S. dendroides when treated with 100mM NaCl. However the maximum percentage of germination in A. lagopoides was 80% while treated with 50 mM NaCl. This maybe proves that all the species are halophytes. Morphological, physiological and anatomical studies were conducted in vegetative growth stage. Two different aspects in morphological studies were characteristics of appearance (e,g. various effects on leaves' weaknesses in bushes) and measuring parameters such as shoot and root fresh and dry weight, number of leave and leaf surface area. These studies resulted that the optimal growth of S. dendroides occurred in 200 mM NaCl but in two other species (A. persarum and A. lagopoides) it occured in absence of salt. All the three species strctural changes in roots, steam and leaves were observed in anatomical studies. For example decrease of diameter and number of vessels, increase of protective systems' such as scleroid formation' thickness in cuticles, increasing number and length of trichomes. According to these observations, S. dendroides showed the highest resistance to salt   (germination stage: 700mM NaCl and vegetative growth 650mMNaCl and A. lagopoides, showed lowest resistance to salt (200mM NaCl). Probabely S. dendroides could be considered as an obligatory halophyte and A. lagopoides as a salt acclimation plant.

To evaluate the effects barley of pore and mixed cropping of annual medic (Medicago scutellata cv. Robinson) with barely on forage yield, seed production and soil seed bank, two experiments were simultaneously conducted in Kangavar and Khoramabad during 1382 -1383 growing season. Experimental treatments were arranged as factorial and the data were analysed using a complete randomized block design with three replications. The experimental treatments consisted of harvest systems in two levels: T1 (control- no forage harvest all through the growing season) and T2 (forage harvest on early flowering stage of annual medic). Mixed cropping systems of MO(bore cropping of annual medic), Ml (mixed cropping of 10kg of annual medic and 50 kg of barely) and M2 (mixed cropping of5 kg of annual medic and 50 kg of barely). Forage harvest significantly reduced total dry matter as well as seed production and soil seed bank in all cropping systems compared to control. Forage and seed production in Khoramabad was significantly higher than Kangavar because of more favorable climatic conditions. TlMl treatment not only produced more forage than medic sole cropping, but also produced enough seed to support soil seed bank reserves to ensure a successful re-stablishment of medic pasture in ley-fanning system.

There has been a steady demand for production and supply of olive sapling of different varient varieties for olive gardens in Iran but with regard to the fact that some varieties of olive such as kalamata and amigdafolia and conservalia which possess suitable characteristics are found to be rather difficult in rooting for various reasons. Therefore, attempts have been made to adapt and grow them in different climatical areas of the country for restoration or development purposes and would be continuing in the future. For a survey of the rooting capabilities of the above mentioned varieties, a study was carried out in the framework of RCBD (Randomized Complete Block Design), having 64 treatments and 4 replications in a factorial. Proper treatments were made by means of feeding (spraying solutions) on the mother plants with microelements, (Zinc and Boron), during a period of one month prior to the preparation of the cuttings of the varieties and also by applying IBA (Indul-3-butiric acid) plant growth regulators with different   concentrations and by application of Split on bark of the end of cuttings for enhancing the rooting process in the different varieties, such as kalamata, amigafolia, conservalia, and zard. Also zard were chosen as control. As a result of the study it has been found that prior spraying of the mother plants with the nutritional concentration Zinc and Boron had major effects on the improvement of rooting process and treatments with IBA hormones having a solution of 4500 ppm and also with IBA plant growth regulators having a solution of 4500 ppm together with Zinc as a microelement were the most influence for the above said varieties. Furthermore, the split on bark of the end of cuttings of the varieties had major effects the rooting process though the rooting percentage of the bark splitting treatments were significant effects than non- bark splitting treatments and finally significant difference with respect to the percentage of rooting among the varieties under study was observed. The rooting percentage of concervalia, zard, amygdalifolia and kalamata were counted 62. 03,58. 4,50.47 and 40.94 respectively.

In order to investigate the effects of different levels of nitrogen rates yield and yield components of 3 wheat cultivars an experiment was conducted on Shahid Bahonar University of Kerman Research farm during 2002-2003. The experiment was carried out using split plot design in rhandomized complete block with three replications. Nitrogen rates were arranged as main plot in 3 levels (50, 100, and 150 kg/ha) and 3 wheat cultivars as subplots in 3 levels (Ghods, Roshan and a native cultivars Shahdad). Yield, yield components, plant height, 1000 seeds weight, %seed protein, harvest index, biological yield and dry weight were investigated. Higher level of nitrogen increased yield, seed weight, spikes/m2, dry weight in fertilized stage, seeds/spikelet, %seed protein and biological yield significantly. However harvest index decreased as nitrogen increased. The effects of cultivars on all aspects were statistic significant. Ghods cultivar showed higher biological yield, seed yield and harvest index, but its plant hight, seed weight and % seed protin was lower. Shahdad cultivars had highest spikes I m2and Roshan had highest percent seed protein. Seed yield had negative correlation (r=-0.779) with % seed protin, but positive correlation with biological yield (r=0.874), dry weight (r=0.821) and harvest index (r=0741). It was concluded that 100kg of nitrogen/ha, and Ghods cultivar had best results in this experiment in Kerman, but Roshan was the best in % seed protein.

Saline-sodic land in the margin of Kaveer Namak in Bajestan is one of the most important factors limiting agriculture in this region. In an attempt to examine the improvement of soil. A research project in the form of a fully random block project with five leaching treatments, 25. 50. 75. 100. cm water and marker in four interactions were performed. First, on four cubic meter plots in accordance with the trial plan the related leaching treatment was performed. After the soil moisture had reached the extent of field capacity, soil sample for analysis of the amount of saline existing in soil was prepared. From this analysis before and after the experiment, it is understood that soil classification before the trial was S4A4 and after applying various amounts of water it changed into S2A2. Precise determination of water amount for leaching requirement of every depth of soil is only possible through saline curves and dealkalization. Average of acidity (PH), electrical conductivity (EC) and exchange of soil percent (ESP) of the depth of one meter soil was respectively from 8.1, 39.1 ds/m and % 61 before leaching. to 8.4,10.6 ds/m and %25 after applying one meter of leaching water had changed. and soil doesn't take the process of alkalization with respect to the relative light texture of soil. And bivalent salts dissolved in irrigation water and soil, It was concluded that for the improvement of these soils, there's no need to soil conditioning agents and it is possible to improve them through using suitable water.

21 crosses of 3 tester lines and 7 inbred lines of maize were inoculated with Fusarium moniliforme in 1999. Crosses were planted using randomized compelete block design in four replications and their reaction to Fusarium ear rot were evaluated. According to the analysis of variance, effects of crosses and interaction of Line x Tester were significant at probability level of 1%. The lines K3640/2 and B73, showed a negative and K3640/1, K3547/1 and K3495/2 showed a positive general combining ability. Also, testers Kl8 and M017 showed a positive and a negative general combining ability, respectively. The analysis of genetic variance indicated the contribution of additive and dominance variances.