جستجوی مقالات مرتبط با کلیدواژه "pollen" در نشریات گروه "باغبانی"

 As a member of the Lamiaceae family native to Europe, Asia, and North Africa, Vitex agnus-castus is a popular medicinal plant. Despite much research, it is always essential to verify the safety of this valuable species, as it is among the world's best-selling plants. Several species in the genus Vitex do not exhibit recognizable morphologies, confusing their identification. The medicinal use of V. agnus-castus differs from that of other species. For effective pharmaceutical performance, the identification of this species is essential. This study used morphological, micromorphological, and molecular approaches to identify this medicinal plant.

 A total of 17 populations of the target species were investigated in Maraveh Tappeh, a city in the Golestan province located in the eastern region. Pollen samples were collected directly from the natural habitat of the target area. After acetolysis, 30-40 pollen grains were photographed from the polar and equatorial views with a light microscope and 40 and 100 magnification and with the help of a Canon digital camera. In order to study the seed morphology, fully ripe fruits were collected from each studied population during the fruiting season. Twenty seeds from each population were kept for photography with light microscopy and Scanning electron microscopy (SEM). Electron micrographs were prepared from suitable seeds and pollen at the Razi Metallurgical Research Center (RMRC) using an SEM electron microscope. Leaf cells from herbarium samples were extracted from DNA using a DNA extraction kit. Plastid trnL-trnF sequences and nrDNA ITS region sequences were used as barcodes. Polymerase chain reaction (PCR) was performed in 20 microliters with desired primers and a specific temperature program in a thermocycler. After performing the polymerase chain reaction, in order to ensure the amplification of fragments, the final product was electrophoresed. Strong single bands were sent to Codon Genetics Company in Tehran for sequencing.

 Pollen grains of all species are small (12-28 micrometers). According to Ertman's classification, Ghazan ghayeh pollen grains are prolate spheroidal (elongated spherical), and Ghoshe Tappeh pollen grains are subprolate (semi-elongated). All pollen grains are tricolporate. Ghazan ghayeh ornamentation is micro-perforated, while Ghoshe Tappeh ornamentations are reticulated-micro-perforated. With an average length of 3.84 mm and width of 1.52 mm, Ghazan ghayeh seeds are the largest. They are all almond-shaped, but in the Ghazan Ghayeh population, the outer surface of the seed is hollow; in the Ghoshe Tappeh population, the surface is wrinkled and striated. The trnL-trnF gene locus was found to have a multiplication success rate of 85% in the examined plants. There were 516 nucleotides in the amplified fragment in this species. For final registration, the sequence was sent to the GenBank. A 675 nucleotide fragment amplified from this species' ITS marker was sequenced, and the chromatograms were compared with the NCBI database. The gene bank has been notified of the sequence determination. The results showed the highest similarity (98%) with the Vitex agnus-castus species reported from America.

 Local herbal medicines are gaining popularity in different countries and play a significant role in treating diseases today. In order to make medicinal plants more accessible, we need to pay more attention to trust, marketing, and consumption. Barcoding and molecular approaches serve this purpose effectively. To compare plant samples available on the market with natural medicinal plants using DNA barcoding of correctly identified medicinal species. Hence, the sequences used in this study are essential for barcoding Vitex agnus-castus. The medicinal species has been correctly identified and can be used as a standard for evaluating the plants available on the market.

The date palm (Phoenix dactylifera L.) belongs to the family Arecaceae is a dioecious trees. Due to the problems of non-overlapping flowering of some male and female palm trees, commercial date production requires artificial pollination. Temperature is an important environmental factor influencing the pollination, fertilization and fruit set of the date palm. Availability of efficient male pollinators are of great importance in date palm production chain and for regular yearly bearing as the quantity and quality of pollen is a yield determining factor. The flowering and pollination period of date palm varies upon cultivar, geographic location and climatic conditions. However, frequent asynchronous flowering of date palm male and female trees occur due to climatic changes and abiotic stress. In such cases, farmers may pollinate their trees with pollen of a known male conserved at ambient conditions from the previous season; however, this is mostly result in a low fruit set and yield.

In this study, a factorial test was performed based on a completely random design with three replications at the laboratory of the Horticulture department at Ilam University to determine the rate of germination in five male date palm cultivars. The first factor consisted of nine temperature levels of 15, 18, 21, 24, 27, 30, 33, 36 and 39 and the second factor referred to the cultivar of the pollinator which had five levels of ‘Ghanami Sorkh’, ‘Ghanami Sabz’, ‘Sabz Parak’, ‘Nare Pakutah’ and ‘Khareji’. The pollen of the above-mentioned cultivars was obtained from the date palm Germplasm collection at the Date Palm and Iranian Tropical Fruits Institute in the city of Ahwaz. In the early days of the flowering season (March), the cultivars under study were identified and labeled. They were then checked on a daily basis and whenever the sheaths were ripe enough, they were picked and preserved in a sterile environment in room temperature. After the sheaths opened, the flower clusters were dried in the same environment and at the same temperature. Then, the cluster strings were separated and kept in a freezer at -18 °C until it was time for the test. Viability and vitality of the pollen was specified through the dying method using Acetocarmine solution.

The results showed that there was a significant difference among cultivars, temperature and interactions of them at the level of 1%. Among the studied temperatures, the highest germination of pollen grains in all cultivars occurred at 30 °C, followed by 33 °C and 27 °C, respectively, and the lowest germination percentage were obtained at 15 °C. Among cultivars, the percentage of pollen germination in ‘Ghanami Sorkh’ was quite high (92.45%), and ‘Nare Pakutah’ (87.33%), also, simultaneously ‘Sabz Parak’ (84.82%) and in the ‘Khareji’ cultivar was the lowest. However, the percentage of pollen germination in ‘Ghanami Sorkh’ cultivar was higher than 59% under a wide range of temperature from 21 to 39 °C. Furthermore, the percentage of Pollen germination was reduced rapidly at temperatures less than 21 Cº and reach 15.85% in 15 °C. The germination percentage of pollen grains in ‘Nare Pakutah’ cultivar in the temperature range of 21 to 39 degrees Celsius was higher than 57%. The germination percentage of pollen grains in ‘Sabz Parak’ cultivar decreased with less acceleration than ‘Ghanami Sorkh’ at lower and upper temperatures of 30 °C, so that at 36 and 39 °C had the highest amount of germination compared to the other cultivars. Also, the germination rate of pollens in ‘Ghanami Sorkh’ cultivar were investigated above 57% in the wide temperature range from 21 to 39 °C.

According to the findings of this study, the timing of pollination plays a crucial role in the fertility of male date palm cultivars, with the optimal temperature being around 30°C. It is essential to select cultivars that exhibit a high rate of pollen germination and contribute positively to fruit properties. Male cultivars such as 'Ghanami Sorkh', 'Sabz Parak', and 'Nare Pakutah' demonstrated a broader range of optimum temperatures for pollen germination. Therefore, these cultivars are recommended for climates characterized by significant temperature fluctuations during the flowering period of female date palms.

Identification of superior genotypes within the rich fruit trees germplasm in Iran is an important task. Eighty suitable genotypes were selected within the 600 genotypes that were grown in the Barzok, Kashan region, then 11 genotypes were considered as the superior genotypes. Besides recording the flowering periods of the 80 suitable genotypes, evaluation of the 11 superior genotypes was recorded during the 2017 and 2018 growing seasons. A 21 days difference at the beginning of flowering was recorded during two years of study. The high variability within the studied genotypes was observed in flower density. The genotype KB1045 with 158 flowers and genotype KB12939 with 60 flowers in 100 cm of shoot showed the biggest and lowest flower density, respectively. The highest fruit set record on 15 days after controlled self-pollination was recorded on genotype KB1045 (53.83 % fruit set) and the lowest was belong to genotype KB4541 (with 0 % fruit set). The microscopic examinations showed well germination of transferred pollens on the self-pollinated stigma. The microscopic fluorescence examination of pollen tube growth in the style at 48, 72, 96, and 120 h after self-pollination showed that very rare pollen tubes reached the ovary, so confirmed the incompatibility of the studied genotypes. Because the studied genotypes were superior in terms of many morphological traits, the obtained results can facilitate further apricot breeding programs on these genotypes.

Sour cherry (Prunus cerasuc L.) is one of the most important stone fruit of Rosaceae family which have a high nutritional value. Based on FAO statistics, Iran was ranked the 3rd to 6th among the main sour cherry producer countries in the world. Most of the sour cherry cultivars are self-compatible, but self-incompatible cultivars have been reported currently. Allotetraploidy of sour cherry complicates the self-incompatibility segregation in the progeny, so this studies have been less accomplished in Iran. The sour cherry is an allotetraploid species which possibly stand up as a result of usual hybridization between the dwarf cherry P. fruticosa and sweet cherry P. avium. Similar to other species of the Prunus, the phenomenon of gametophytic self-incompatibility (GSI) happens in sour cherry. It prevents self-fertilization and facilitate fertilization with pollen of other genotypes within same species. Self-incompatibility consists of arresting pollen-tube growth in the pistil if the pollen tube contains the same S-allele that is present in the pistil. The phenomenon of self-incompatibility in plants of Rosaceae family is controlled by two genes at the S-locus. The specificity of the pistil is encoded by a gene responsible for the synthesis of the ribonuclease protein (S-RNase), whereas the specificity of the pollen is controlled by the gene encoding an F-box protein (S-haplotype-specific F-box protein – SFB) 3a). The tightly linked genetic unit of the pistil S-allele (SRNase) and pollen S-allele is called S-haplotype.

In the present study, pollen-pistil compatibility relationships among some sour cherry cultivars and selected genotypes were investigated by controlled pollination and pollen tube penetration by fluorescence microscopy. Cultivars were include ‘Meteor’, ‘Mont Morency’, ‘Majarestani’ and ‘Mahalli’ so, genotype1 were selected. After controlled pollination fruit setting was studied and the pollen tubes growth along the style was studied using fluorescent microscope. Crosses were selected based on synchronized flowering time among cultivars and genotypes and included ‘Mont Morency’ × ‘Meteor’, ‘Meteor’ × ‘Mahalli’, ‘Meteor’ × ‘Majarestani’, ‘Meteor’ × ‘Genotype 1’, ‘Mont Morency’ × ‘Mahalli’, ‘Mont Morency’ × ‘Majarestani’, ‘Mont Morency’ × ‘Genotype 1’, ‘Mahalli’ × ‘Majarestani’, ‘Mahalli’ × ‘Genotype 1’ and ‘Majarestani’ × ‘Genotype 1’, respectively. For each cross, 2 branches were randomly selected in female cultivars in winter. On each branch, including 30 floral buds at ‘balloon stage’ were tagged and bagged to prevent the entrance of any foreign pollen. On the day of anthesis, ready-to-dehisce anthers were collected from male cultivar, maintained on a moist filter paper in petri plates at 4 ºC in refrigerator till they dehisce. Pollens from these anthers were used as a source of male gametes later. Once stigma turned receptive, cross-pollination treatments were carried out in the field as designed scheme for 12 successive days. After every 24 hrs. up to 120 hrs. post-pollination, 12 pistils per treatment were fixed in FAA (formaldehyde/glacial acetic acid/70% alcohol in the ratio of 1:1:18) for 24 hrs. Followed by washings with water to remove traces of alcohol, if any, and cleared in 5% KOH at 60 ºC for fluorescence microscopy. Staining regime, as described in Sabbaghpour et al. (2020) the number of pollen tubes in the upper and mid-parts of the style and in the ovary was employed to enable visualization of the pollen germination on the stigma. Percentage of pollen germination was determined as the proportion of pollen grains that germinated on the stigma to the total number present on a scale of 100. Pollen tube number at three levels was calculated as an average of 5 (n=10). For an easy understanding of growth pattern of pollen tubes inside the style and ovary, the stylar portion, which measures 1.8 ± 0.07 cm on an average, was divided into two parts: the middle and the base. A single, longitudinal incision was then carefully given on one portion of the style using a fine needle and made wide open. Pollen tubes inside the style were critically observed under fluorescence microscope at 100x magnification. Number of them was carefully recorded and data generated for different experimental sets.

Results showed that maximum pollen tube number penetrated to the ovary and final fruit set were observed in cross ‘Mahalli’בMajarestani’. Also, minimum pollen tube in the ovary and final fruit set were observed in ‘Meteor’בMahalli’ and ‘Meteor’בGenotype 1’ crosses.

Based on the obtained results cross-incompatibility was not observed among the studied cultivars and genotypes. Therefore, they could be planted in the sour cherry breeding programs and orchards establishment based on their blooming time.

Cuscuta is the only parasitic genus in Convolvulaceae family. This genus is globally distributed, with most species in the tropics, subtropics, and some in the temperate regions. In this study, the micro-morphological features and molecular evidencesof 12 populations from three species of Cuscuta (C. australis, C. campestris,and C. chinensis) have been considered. In total, seven quantitative and two qualitative characters of pollen were selected and measured. The most important characters include: shape, ornamentation of tectum, exine thickness and colpus length of the pollen. Based on this study, the seed shape and surface support at least for separation of C. australis from other two species. Using nuclear (nrDNA ITS) marker, we reconstructed phylogenetic relationships within three species of Cuscuta. This data set was analyzed by phylogenetic methods including Bayesian, Maximum likelihood, and Maximum parsimony. In phylogenetic analyses, all members of three species formed a well-supported clade (PP=1, ML/BS=100/100) and divided into two major clades (A and B). Clade A is composed of specimens of C. australis. Two species of C. campestris and C. chinensis are nested in clade B. Neighbor-Net diagram demonstrated separation of the studied populations.
The results showed that, micro-morphological and molecular data provide reliable evidence for separation of these species.

Assessment of the germination behavior of pollen is effective on increasing yield and quality and also selection of suitable cultivars. This study was carried out to evaluate the germination of different age pomegranate pollen in perfect and male types flowers as well as determinate fruit set with pollination of ‘Malas Yazdi’, ‘Rabab-e-Neyriz Fars’, ‘Poost Siah’, ‘Bihaste Dane Ghermez Ravar Kerman’, ‘Bihaste Kam Bar Najaf Abad’, ‘Bihaste Sangan Khash’, ‘Goroch Tafti’ and ‘Pishva Varamin’. The highest pollen quantity obtained in perfect flowers of ‘Goroch Tafti’. The highest pollen germination percentage and rate were observed in ‘Pishva Varamin’, ‘Goroch Tafti’, ‘Bihaste Sangan Khash’, ‘Malas Yazdi’, ‘Rabab-e-Neyriz Fars’ during first-six hours after releasing from anthers, although about ‘Goroch Tafti’, germination percentage unaffected up to 12 hours after release. Regarding to study of cultivar and flower type, the highest germination percentage obtained in male flowers of ‘Goroch Tafti’. Simple effect of pollen age, showed that germination percentage significantly reduced 6 h after release. Evaluation of effect of cultivar on germination rate showed the highest value in ‘Pishva Varamin’, ‘Goroch Tafti’, ‘Bihaste Sangan Khash’ and ‘Malas Yazdi’. The results indicated that ‘Malas Yazdi and ‘Rababe Neyriz’ flowers pollinated with ‘Bihasteh Ravar Kerman’ and ‘Goroch Tafti’ were led to 65 to 80 percent fruit set from fertilization fruits, respectively. Free pollination (control) with 90 percent fruit set in comparison with self-pollinated of commercial cultivars was significantly different at 1% level of probability. Therefore, it is concluded that some cultivars had low germination percentage and in some others pollen age had most effect on germinability that could be respected in variety selection for plantation. So compatibility pollen can affect fruit set and yield.

In this research, during three consecutive years (2010-2012), a series of diallel crossing was performed among wild type barberry genotypes and Iranian seedless barberry. Setting of seed and fruit in the crossing have been studied and then seedling survival were evaluated in several cultural systems. Results showed significant effects of pollen sources on setting of fruits, seed and seeded fruits in seedless barberry. Pollens of R2N1 genotypes with 46% fruit set and 2.22% seedset and pollens of R4N1 genotype with 69% fruitset and 20.22% seed set had the lowest and highest rates, respectively. Also, There was significant differences (p<0.01) among genotypes on setting of fruit, seed and seeded fruit when pollinated with seedless barberry pollens. In this study, the efficiency of seedless barberry pollens to set seed in wild type barberries was proved and its male sterility theory was rejected. Evaluation of seedling survival rate showed that planting barberry seeds in spring in Cocopeat mixed with Perlite under mist system could increase dramatically seedling survival rate.

Pollen analysis and AMS radiocarbon dating of a short sediment core from a mire in Veisar (Mazandaran province, N Iran) reveals the late-Holocene vegetation history of the area. High pollen values suggest that Caucasian alder (Alnus subcordata) has been present in the vicinity of the mire throughout the record. Wingnut (Pterocarya fraxinifolia), which was previously abundantly present, shows a dramatic decline around 900 BP and gradually disappears thereafter. Being also present in other palynological studies from the central Hyrcanian forests as well as from western Georgia, the Pterocarya decline might be attributed to a regional climate change, synchronous with the Mediaeval Climatic Anomaly. The high values of beech (FAGUS), hornbeam (CARPINUS), oak (QUERCUS) and elm (ULMUS) pollen imply the presence of species-rich forest on the slopes surrounding the study area over the past 1500 years. The occurrence of anthropogenic pollen grains, e.g. JUGLANS and CORYLUS, suggests long-term human impact in the region, whereas high values of ARTEMISIA and CHENOPODIACEAE AND AMARANTHACEAE pollen indicate open vegetation on or in the immediate vicinity of the peatland.