Hassan Habibi, Mehdi Agihghi Shahverdi, Zahra Nasiri, Mohammadreza Chaichi, Mohammad Hossein Fotokian,
Volume 1, Issue 2 ((Autumn & Winter) 2015)
Abstract
The effect of seed rate of alfalfa (Medicago sativa L.) and efficiency of plant growth promoting bacteria (PGPR) that facilitates phosphorus uptake with different doses of phosphate fertilizer was evaluated on seed quality. For this purpose, the germination and seed vigor tests before and after accelerated aging were performed in a split split plot experiment based on randomized complete block design with three replications in 2010 in the field of education and research in the College of Agriculture and Natural Resources, Tehran University, Karaj. Phosphorus factor at 4 levels (0, 30, 60 and 90 kg Phosphorus.ha-1) in main plots, PGPR (Pseudomonas) in three levels (no bacteria, bacterial strains, No. 9 and bacterial strains No. 41) in subplots and rate of seed factors on three levels (2, 6, and 10 kg of seed per hectare) were the sub-subplots. The results showed the highest rate of germination and seed vigor obtained by use of 6 kg seeds per hectare, PGPR No.41 strains with 30 kg Phosphorus per hectare and after accelerated aging. The highest rate of germination and seed vigor at 10 kg of seed per hectare were found for PGPR No.41 strains, with 60 kg Phosphorus ha-1 treatments. After accelerated aging practices to achieve maximum germination index and vigor, seed rates and phosphorus requirement were more than standard conditions. Based on obtained results for the storage conditions, bacterial strains No. 41 had a better effect on increasing seed vigor than bacterial strains No. 9. To produce alfalfa seed with high vigor and obtain better results, use of optimum seed rates and phosphorus (6 and 30 kg.ha-1, respectively) along with PGPR (strain No. 41) could be considered in crop plants.
Ebrahim Gholamalipour Alamdari, Amir Ghorbani, Hossein Sabouri, Meisam Habibi,
Volume 7, Issue 1 ((Spring and Summer) 2020)
Abstract
Extended abstract
Introduction: Without a doubt, plant hetrotoxicity is one of the important factors in determining the distribution and abundance of some species in plant communities. Thus, the purpose of this experiment was to evaluate the effect of phenolic composition obtained from the methanol extract of Echinochola crus-galli on germination traits and cytogenetic behavior of rice.
Materials and methods: This experiment was done to assess hetrotoxic potential of various concentrations (0, 0.024, 0.048, 0.076 and 0.1 mM) of the phenolic composition obtained from the methanol extract of whole-organ of E. crus-galli on germination traits of rice as well as mitosis division of meristematic cells of radicle in a completely randomized design. To extract thephenolic composition, warm extraction method using a methanol solvent was used. For studying mitosis division, first rice seeds were germinated. Then, each of the steps such as fixation, hydrolysis, staining, squashing and microscopic studies were done on the end of the radicle. Mitosis indices and percentage of mitosis inhibition were calculated and also percentage of each of chromosomal abnormalities at four stages of prophase, metaphase, anaphase and telophase as compared to total cells was calculated.
Results: The lowest percentage and rate of germination and relative germination were found in two concentrations of the 0.076 and 0.1 mM of phenolic composition of E. crus-galli, so that no germination was observed in these treatments. In this study, mitosis division was normal in control samples, so that the rice plant included 12 chromosomes in the metaphase stage. Also the chromosomes were normal in the telophase stage and chromosomal abnormalities were not observed in meristem cells of radicle tip of the control. The lowest value of mitosis indices and the number of dividing cells were related to the concentration of 0.048 mM wuth 30.19 and 385 cells, respectively. In the present study, chromosomal abnormalities in the stages of metaphase, anaphase and telophase were increased with increasing concentration of phenolic composition, and were 28.85 and 16.95% in 0.048 mM concentration of phenolic composition, respectively. The most chromosomal abnormalities were of sticky and laggard type, which were related to the concentration of 0.048 mM of phenolic composition with 39.83 and 32.25%, respectively. The highest number of chromosomal bridges and clumping were obtained in 0.024 mM of phenolic composition with about 19.27 and 29.83%, respectively.
Conclusion: In this study, phenolic composition obtained from the methanol extract of E. crus-galli had asignificant inhibitory effect on germination traits and mitosis division in root tip cells of rice. Thus, the amount of E. crus-galli residues in the field should be considered in direct and indirect cultivation of rice.
Highlights:
1-Difference in impact of the phenolic composition obtained from the methanol extract of Echinochola crus-galli on germination and reduced cytogenetic behavior of rice is related to their threshold concentration.
2- It is advised to cultivate varieties of rice resistant to the remnants of harmful compounds of E. crus-galli as direct cultivation or under nursery condition.
Mohammad Reza Abbasi, Maryam Hajhassani, Abbas Mirakhorli, Ali Hamzehnejad, Azita Nakhaei, Gholamreza Khakizadeh, Ramezanali Alitabar, Rasoul Kanani, Maryam Asadipour, Fatholah Nadali, Hassan Mokhtarpour, Zargham Azizi, Ali Shahriari, Majid Rakhshandeh, Hassan Mostafaei, Sam Safari, Gholamreza Abadouz, Homa Manouchehri, Sahebdad Habibifar, Abdolnaser Mahdipour, Hassan Amirabadizadeh, Sahebdad Habibifar, Narges Kazerani, Seyed Norodin Lesani, Abdoul Houssein Askari, Asadolah Fathi, Mohammad Khamaledin Abbasi, Hassan Ghuchigh, Ali Soltani, Ahmad Ghasemi, Mohammad Javad Karami, Mohammad Zamanyan, Sadigheh Anahid, Mirjamaledin Pourpayghambar, Ali Reza Beheshti,
Volume 7, Issue 1 ((Spring and Summer) 2020)
Abstract
Extended abstract
Introduction: One of approaches to reach sustainable agriculture is to exploit crop diversity, especially in legume species. Since Melilotus spp. (sweet clover) is a forage crop with a suitable yield especially in the marginal lands; therefore collection and characterization of this germplasm is the first effective step for its conservation and utilization in the country. Few accessions of Melilotus genetic resources had been collected in the National Plant Gene Bank of Iran, before this study.
Materials and Methods: Sweet clover genetic resources were collected all over the country using standard descriptors during two years. Twenty-six characteristics of collection sites were recorded and their descriptive statistics were estimated. The collected materials were planted in an experimental field to identify their life cycle. The seeds of collected germplasms were conserved in mid (2-4 °C)- and long (-20 °C)-terms conditions for further using.
Results: A total of 258 accessions were collected. The geographical altitude of plant origin differed from -11 m in Babolsar to 3090 m in Noor Abad in Lorestan. The materials were mostly collected from non-saline habitats. However, eight accessions were collected from mid to high salinity locations. Taxonomically, M. albus, M. officinalis, and M. indicus were identified with a number of 21, 201 and 36 accessions, respectively. M. dentatus and M. sulcatus, which have been mentioned in the former researches in Iran, were not collected in the recent study.
Conclusion: The collected germplasms from marginal lands (saline, low drainage and low fertility lands) may be tolerant to such marginal lands, therefore they can be exploited for the future research. All M. indicus species were annual; whereas there were annual as well as facultative and obligate biennial accessions in the two other species. Lack of access to M. dentatus and M. sulcatus may be an alarm that they may be threatened species in the country. Collected materials in this study along with the former collection in the Iranian National Plant Gene Bank (80 accessions) have provided high potentials of Melilotus genetic resources for exploitation in the further.
Highlights:
1- The three-fold increase in the Melilotus germplasms in the ex-situ conservation system.
2- Alarm for M. dentatus and M. sulcatus which may be threatened with extinction in the country.
Ebrahim Gholamalipour Alamdari, Meisam Habibi, Mohammad Hadi Masoumi, Maral Babayani, Ali Asghar Saravani,
Volume 10, Issue 2 ((Autumn & Winter) 2023)
Abstract
Extended abstract
Introduction: In agricultural systems, many environmental stresses affect the growth, physiological, and biochemical responses of plants under stress. One of these factors is the biochemical reactions between plants along with the production of secondary compounds. Allelochemicals mainly have the role of defence and ligninization of the cell wall in plants and do not directly play a role in the growth processes of plants. An experiment was carried out to evaluate the effect of allelopathic stress of Hypericum perforatum on the germination, physiological, biochemical, and antioxidant activity characteristics of green pea the benchmark plant sensitive to allelochemicals.
Materials and methods: The treatments included different concentrations of H. perforatum at 11 levels (i.e., 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100% of the aqueous extract). This research was carried out as a completely randomized design with three replications in the weed science laboratory of Gonbad Kavous University in 2023.
Results: The results of this study showed that one of the influencing factors on the physiological, and biochemical characteristics of green pea is the concentration of the H. perforatum extract. In most cases, the percentage and rate of green pea germination, radicle and plumule length, and dry weight of radicle and plumule decreased with the increased concentration of aqueous extract as compared to the control, so that the greatest reduction of these characteristics was observed in 100% of H. perforatum extract. In contrast, the content of compatible osmolytes such as proline and soluble sugars, phenolic and flavonoid compounds, and antioxidant activity of green pea roots and plumules increased significantly in all studied treatments, which the highest increase in these characteristics observed at the concentration of 100% of H. perforatum aqueous extract. In general, the decrease in the dry weight of green pea seedlings due to the increase in the concentration of the aqueous extract of H. perforatum, despite the relative increase in the content of physiological and biochemical traits, indicates the high intensity of allelopathic stress of H. perforatum extract and their insufficiency, which leads to cytotoxicity against oxidative stress.
Conclusion: Considering the hetrotoxicity effect of H. perforatum on green pea sensitive to allelochemicals and its distribution in gardens, barren lands, and wheat and corn fields, the possible effect of their residues in the next planting and even in case of presence in mixed cultivation should be considered.
Highlights:
- Aqueous extract obtained from the H. perforatum significantly reduces the germination and seedling growth of green peas.
- The difference in the effect of the aqueous extract of H. perforatum on green pea the benchmark plant sensitive to allelochemicals depends on their concentration threshold.
- The high intensity of allelopathic stress of H. perforatum extract and insufficient non-enzymatic antioxidants lead to oxidative stress.
