فهرست مطالب

Plant Ecophysiology - Volume:3 Issue: 1, 2011

Journal of Plant Ecophysiology
Volume:3 Issue: 1, 2011

  • تاریخ انتشار: 1391/07/13
  • تعداد عناوین: 8
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  • A. Asghari, M.H. Ansari, H. Shahbazi Page 1
    For the evaluation of salt tolerance of rapeseed cultivars, an experiment was conducted in the greenhouse at Sari Agricultural Science and Natural Resources University (SANRU). In this experiment, seven rapeseed cultivars were examined under three levels of salt stress (0, 7 and 14 ds.m-1). The experiment was a factorial based on a completely randomized design with four replications. Characteristics such as vegetative growth, shoot Na+ and K+ contents, K+/Na+ ratio and grain yield were measured and the cultivar response to salinity was evaluated using statistical parameters like stress susceptibility index (SSI) and salt tolerance index (STI). In general, tolerant cultivars (LSG2 and LSN) showed higher agronomic performance and presented lower Na+ and higher K+ and K+/Na+ ratio like Sarigol and RGS003. An increase in shoot Na+ content correlated negatively with yield (r = -0.38, p<0.05) and STI (r = -0.39, p<0.01) but in turn positively with SSI (r = 0.40, p<0.01). These two droughts could be considered efficient criteria for screening salt tolerance of rapeseed cultivars.
    Keywords: rapeseed, cultivars, screening, salt tolerance, STI, SSI
  • S.S. Hemayati, M.H. Shirzadi Page 5
    The current study was carried out in Kamalabad Agricultural Research Station of Karaj, Iran in 2011 in order to investigate the effect of genetic parameters on the components of solar radiation interception. Three sugar beet cultivars including domestic cultivars Jolgeh and 428 and foreign cultivar DS-4027 were sown on the basis of a Randomized Complete Block Design with three replications. The studied cultivars did not exhibit significant difference in intercepted solar radiation (fi). Radiation use efficiency of domestic cultivars (1.434 g.m-2.MJ-1) was lower than that of foreign cultivar (1.853 g.m-2.MJ-1) which was mainly resulted from higher RUE of the foreign cultivar for root production (1.536 g.m-2.MJ-1) than that of domestic cultivars (1.098 g.m-2.MJ-1). However, no significant difference was observed in RUE for shoot production between foreign and domestic cultivars (0.336 and 0.317 g.m-2.MJ-1, respectively). In total, given the superiority of diploid cultivars compared to triploid cultivars, it can be concluded that breeding programs in temperate regions (like Karaj, Iran) should focus on breeding diploid cultivars. On the other hand, the main flaw of domestic cultivars, i.e. their low R/S ratio, should be improved in breeding studies.
    Keywords: sugar beet, cultivar, radiation extinction coefficient, radiation use efficiency
  • M. Palizdar, B. Delkhosh, A.H. Shirani Rad Page 15
    In order to study the effect of irrigation regimes on agronomic traits of safflower (Carthamus tinctorius L.) under different levels of K fertilization, a factorial experiment was carried out in research field of Qazvin, Iran in 2009-2010 based on a Randomized Complete Block Design with three replications. The studied factors included irrigation treatment at four levels (based on 60, 100, 140 and 180 mm cumulative evaporation from Class-A evaporation pan) and K fertilization levels at four levels (including 0, 50, 100 and 150 kg.ha-1 from potassium sulfate source). Results showed that the increase in irrigation level significantly increased 1000-seed weight, seed yield, seed oil content, oil yield, biological yield and harvest index, so that they were increased by 58, 110, 9, 126, 85 and 14% with the increase in irrigation level from irrigation based on 60 mm evaporation to irrigation based on 180 mm evaporation, respectively. Also, higher K fertilization levels resulted in significant increase in all traits except harvest index, so that these traits showed 34, 58, 15, 79, 54 and 3% increase with the increase in K fertilization level from 0 to 150 kg.ha-1 and only the increase in harvest index was not significant. The interaction between irrigation treatments and K fertilization levels was insignificant for all studied traits but 1000-seed weight, seed yield and oil yield. Under the treatment of irrigation based on 60 mm evaporation, the increase in K fertilization level from 0 to 150 kg.ha-1 resulted in 20, 35 and 52% increase in 1000-seed weight, seed yield and oil yield, respectively. But under the treatment of irrigation based on 180 mm evaporation, the increase in K fertilization level led to 53, 130 and 168% increase in these traits, respectively. Results revealed that the increase in K fertilization level mitigated the adverse effects of low-irrigation regimes on agronomic traits of safflower.
    Keywords: safflower, irrigation regimes, potassium, agronomical traits
  • M. Khayatnezhad, M. Zaefizadeh, R. Gholamain Page 23
    Since coefficients of correlation may not provide thorough information about the relations of different traits and given the various advantages of multivariate statistical analyses for deep understanding of data structure, factor analysis can be used. Accordingly, to evaluate the potential grain yield of durum wheat genotypes under drought stress conditions and to examine the relationship of some quantitative traits with grain yield for selecting superior genotypes, a study was carried out on 30 durum wheat genotypes originated from Iran and Azerbaijan in Agriculture Research Station of Islamic Azad University – Ardabil Branch, Ardabil, Iran in 2008. Results of analysis of variance revealed significant differences in the measured traits under stress and no stress conditions. In addition, genotypes showed significant differences in plant height, main spike length, 1000-grain weight and yield. According to factor analysis through decomposition to main components, five factors altogether explained 82.58% of variations. Results of factor analysis proved the importance of fertile tiller number, main spike grain weight, 1000-grain weight and harvest index in selecting optimum genotypes for drought conditions.
    Keywords: factor analysis, drought, durum wheat
  • S. Hajimobin, A. Rajabi, M. Nasri Page 29
    In order to determine the correlation of morphological traits with growth indices of sugar beet monogerm cultivars, a study was carried out in Abdolrasool Motahari Research Station, Karaj, Iran in 2010. The studied cultivars included Zarghan, Shirin, Rasoul, Jolgeh, Gadouk, SBSI001 and SBSI002. The study was based on a Randomized Complete Block Design with four replications. All quantitative and qualitative morphological traits were recorded on 15 plants per plot. During growing season, the roots and shoots of the studied cultivars were sampled four times for estimating physiological growth indices. Results of analysis of variance showed significant differences between the cultivars with respect to all quantitative morphological traits except root position in soil at 1% probability level. Also, with respect to the physiological growth indices, the cultivars showed significant differences at 1% probability level except specific leaf area, net assimilation rate, relative growth rate and crop growth rate. Analysis of correlation of the traits revealed that as leaf area duration and biomass duration (dry matter production during growing season) increased, crop growth rate as well as root and shoot biomass and consequently, total biomass showed an ascending trend. Furthermore, specific leaf area increased with the increase in leaf length and leaf blade width. Therefore, in order to increase the yield in breeding programs, breeders should look for cultivars with longer leaf area duration and biomass duration and higher crop growth rate.
    Keywords: correlation, morphology, growth indices, monogerm cultivars, sugar beet
  • Sh. Jamaatie., Somarin, M. Panahyane., Kivi, R. Zabihie., Mahmoodabad Page 37
    In order to study the effect of different N fertilization levels on dry matter remobilization of durum wheat cv. Seymareh at different planting densities, a study was conducted at Agriculture Research Station of Islamic Azad University, Ardabil Branch, Ardabil, Iran in 2009 as a split plot experiment based on a Randomized Complete Block Design with three replications. The main plot included plant densities at three levels of 300, 350 and 400 seeds.m-2 and the sub-plot included N fertilization at four levels of 0, 70, 140 and 210 kg.ha-1. Results revealed that as N fertilization level was increased, straw dry weight and biological yield were increased whereas dry matter remobilization rate from whole plant and stem to grain and contribution of dry matter remobilization and stem reserves to grain yield were decreased. Also, the application of 140 kg N.ha-1 gave rise to the highest grain yield, the highest number of spikes, 1000-grain weight and harvest index and further increase in N fertilization level resulted in loss of grain yield and other traits. As plant density per unit area was increased, all studied traits were increased except 1000-grain weight and harvest index. Therefore, in order to increase the contribution of dry matter remobilization and grain yield, to avoid environmental contamination and to decrease (excessive) fertilization application which increases production costs, it is recommended to use N fertilization level of 140 kg.ha-1 and the density of 400 plants.m-2 under the conditions of the current study.
    Keywords: remobilization, plant density, yield, durum wheat, nitrogen
  • G.A. Amiri Mijani, H. Heidari Sharifabad, B. Panahi Page 47
    In order to determine the most appropriate N and P fertilization levels for flower yield and essential oil percentage of German chamomile, a field study was carried out in Jiroft, Iran as a factorial experiment based on a randomized complete block design with three replications in which the factors were pure N from urea source (46%) at four levels of 25, 50, 75 and 100 kg.ha-1 and pure P from superphosphate triple source at four levels of 25, 50, 75 and 100 kg.ha-1. Results showed that different levels of N and P and their interaction significantly affected essential oil percentage, essential oil yield per ha and flower number per plant at 1% probability level. Auxiliary branch number was significantly affected by N fertilization level at 5% probability level and by P fertilization level at 1% probability level. N fertilization significantly impacted dry flower yield per ha at 1% and 5-flower dry weight at 5% probability level. Also, P fertilization level significantly impacted the former at 5% and the latter at 1% probability level. In order to realize the maximum essential oil yield per ha, it is recommended to use fertilization level of 75 kg N.ha-1 + 25 kg P.ha-1.
    Keywords: German chamomile, flower yield, essential oil percentage, fertilization level, N, P
  • M.H. Shirzadi, S. Rezaei, S.S. Hemayati, M. Abedi Page 53
    This research was carried out to evaluate the performance of fenugreek (Trigonella foenum-graecum L.) and lentil (Lens culinaris Medikus) intercropping system during the growing season of 2009-2010 at a research field located in Kerman, Iran. The experiment was done based on a randomized complete block design with three replications. Treatments were five different intercropping arrangements consisted of T1: 100% lentil (eight rows per plot), T2: 75% lentil and 25% fenugreek (three rows lentil-two rows fenugreek-three rows lentil), T3: 50% fenugreek and 50% lentil (alternating rows of fenugreek and lentil), T4: 25% lentil and 75% fenugreek (three rows fenugreek-two rows lentil-three rows fenugreek) and T5: 100% fenugreek (eight rows per plot). Results showed that different intercropping arrangements had significant effects on all the traits except number of fenugreek grains per pod, lentil harvest index and 1000-grain weight of both plants (p≤0.05). T3 indicated the highest values of the evaluated traits in both plants. Proportionately, yield declined with decreasing the proportion of each intercropped plant. The maximum land equivalent ratio (LER) and net income which related to T3 were 1.77 and 34379000 (Rs/ha), respectively, that showed an overall advantage of this intercropping arrangement in comparison with monoculture. Relative value total (RVT) was greater than one in all intercropping treatments, indicating the economical advantage of the intercropped lentil and fenugreek compared to monoculture and the highest RVT (1.65) was ob-tained from T3.
    Keywords: intercropping, fenugreek, lentil, LER, net income, RVT, yield