Mojtaba Lotfi; Mohammad Farsi; Amin Mirshamsi Kakhki; Javad Janpoor
Abstract
Introduction: Because of their high protein and mineral contents and low fat, calories and cholesterol, edible mushrooms such as Agaricus bisporus are an important part of the people diet in many countries, but in Iran, the yield of this mushroom is less than the average of yield in the world. Phase ...
Read More
Introduction: Because of their high protein and mineral contents and low fat, calories and cholesterol, edible mushrooms such as Agaricus bisporus are an important part of the people diet in many countries, but in Iran, the yield of this mushroom is less than the average of yield in the world. Phase change from the vegetative to the reproductive stage and fruit body initiation of this mushroom depends on special physical, chemical and microbial properties of casing layer. Phase change is initiated by decreasing oftemperature and CO2 concentration and presence of some bacteria (such as Pseudomonas putida) in the casing layer. It is believed that P. putida may cause this process and increase the yield of A. bisporus by siderophore and hormone-like compounds secretion, decreasing the level of ethylene via ACC deaminase activity and dissolution of insoluble phosphate. The objective of this work was to identify P. putida isolates as growthpromoting bacteria isolated from A.bisporus casing soil and to evaluate their effect on mushroom yield.
Materials and Methods: In this study, 81 individual bacterial isolates were collected by screening the casing layer of 6 edible mushroom farms. Luria Bertani (LB) medium supplemented with sodium lauroyl sarcosine (SLS) and trimethoprim were used for isolation of Pseudomonas bacteria by plating serial dilutions of each soil sample. Finally, using species-specific primers, 33 isolates that identified as P. putida were selected and were used toinoculate
A. bisporuscasing layer. Inoculations were performed in a completely-randomized design with two replicates. The harvesting began when buttons were fully-grown (but not yet open), and the number of mushrooms and fresh (wet) weight of them were recorded after harvesting of each flush. In the next experiment IAA and siderophore production ability, ACC deaminase production capacity and ability of dissolving of insoluble phosphate in isolates and the correlation between these factors and number and fresh weight of mushroom were evaluated. Analysis of the data was carried out using JMP 8. Means were compared using Tukey’s test at p≤0.05.
Results and Discussion: The results of this study showed that the best stage for collecting P. putida is pinning, because the maximum number of identifiedP. putidawas recorded at this stage.Field experiment showed that different isolates have a significant effect on fresh weight and the number of mushrooms per kg compost compared to control (p≤0.05), so that the highest fresh weight observed in treatment of P27 and P13 isolates with 361.63 and 342.8 gr/kg compost respectively and the highest number of mushroom observed in treatment of P18 and P24 isolates with 21 and 20.83 mushroom per kg of compost,respectively. Interestingly, in this study, some isolates showed negative or no effect on mushroom yield which could be due to the interaction between bacteria and A. bisporus strain and/or complex conditions of casing layer. Other results showed that there is a positive and significant correlation between IAA production ability in P. putidaand fresh weight (r=0.58) and the number of mushrooms (r=0.50) in A. bisporus.Whereas there was no significant correlation between other factors and fresh weight and the number of mushrooms. IAA through promotion of cell elongation and differentiation increased mushroom growth and protein.This hormone is one of the needs of A.bisporus mushroom and it is very effective in growth and caused an increase in mushroom yield compared to other growth promoting factors.
Conclusions: In the present study, with the aim of investigation of the effect of P. putida on the yield of
A. bisporus and determining the most effective factor in this process, collectedisolatesinoculated to A. bisporuscasing layer and growth promoting factors in these isolates were evaluated. Results showed that the best stage for collecting P. putida is pinning. These bacteria havesignificant effects on fresh weight and the number of mushrooms.There is not significant correlation between other factors and fresh weight and the number of mushrooms. Based on the results, it could be said that the use of growth promoting bacteria in edible mushroom culturing could be resulted anincrease in mushroom yield and could be beneficial in production of healthy food. Finally, it could be said that P. putida isolates P27 and P13 may have the potential to act as a potential bio-fertilizer.
Rasul Najib; Mohammad Farsi; Amin Mirshamsi Kakhki; Saeid Reza Vessal
Abstract
Introduction: Homozygous doubled haploid lines production through induction of androgenesis is a promising method to accelerate the classical breeding program. However, this technology is relatively under - developed in tomato so that improvements in methodology are required. Tomato (Lycopersicon esculentum ...
Read More
Introduction: Homozygous doubled haploid lines production through induction of androgenesis is a promising method to accelerate the classical breeding program. However, this technology is relatively under - developed in tomato so that improvements in methodology are required. Tomato (Lycopersicon esculentum Mill) is one of the most important vegetables which in addition of it is importance as a food, is utilized as a model plant for cytological and cytogenetic studies. Tomato breeding programs are often based on the production and selection of hybrid plants. To produce hybrid plants and application of features that is needed to breed pure lines with high specific combining abilities, new technologies such as doubled haploid production through induction of androgenesis can be an effective strategy to provide pure lines in tomato. One of the critical factors for induction of androgenesis in tomato is to use of microspores being in appropriate developmental stage. Cytological examination is one of the most accurate methods for determining the correct stage of microspore development. In this study, a number of characteristics were evaluated including the cytological properties of normal microspores development and pollen grains as well as the relationship between length of flower bud and anther length.
Materials and Methods: In this study, four varieties of tomato including Mobil - Netherlands, Baker, U. S. Agriseed and Khoram were chosen. To determine the appropriate stage of microspore development for Anther culture, cytologycal studies were accomplished at different size length of flower buds (2. 0 - 7. 9 mm). Collection of flower buds to conduct experiments was done during 10 - 40 days after flowering for each cultivar. Flower buds collected early in the morning hours and within the containers closed - door ice were transported to the laboratory. To investigate the correlation between the length of flower bud and anther length, randomly selected from within each group of three flower buds, and their length was measurement. Then anthers were removed and anther length was measured for each flower buds. A total of 240 anthers, sixty anthers from each cultivar, were examined by microscope. In order to examine the development stage of microspores and pollen grains, flower buds at different length (5 - 10 mm) were calculated. Flower buds were incubated at 4 oC for 15 minutes and stained in acetocarmin %4 solution and squashed. In order to determine the relative frequency of each stage of the development of microspore and pollen, microspores at least 100 randomly in different parts of prepared slides were counted. Average relative frequency of different stages, meiosis, tetrads, microspores young and old and young and mature pollen grains with a standard deviation was calculated. Cytological studies were accomplished by microscopy research Olympus B X 51 and photographed by a digital camera D P 70. All analysis was conducted using statistical software JMP 8.
Results and Discussion: The time of anthers collection for the induction of haploid is very crucial. In order to determine the appropriate steps to carry out pre - treatment induced changes in the normal development of microspores embryogenesis and cytological properties in various stages of division and development should be monitored. The results showed that there was a significant correlation between the length of flower bud and the anther length (r = 0.8, P
Rasul Najib; Mohammad Farsi; Amin Mirshamsi Kakhki; Saeid Reza Vessal
Abstract
Introduction Tomato (Lycopersicon esculentum Mill) is one of the most important vegetables which in addition of its importance as a food, is utilized as a model plant for cytological and cytogenetic studies. Tomato breeding programs are often based on the production and selection of hybrid plants. Producing ...
Read More
Introduction Tomato (Lycopersicon esculentum Mill) is one of the most important vegetables which in addition of its importance as a food, is utilized as a model plant for cytological and cytogenetic studies. Tomato breeding programs are often based on the production and selection of hybrid plants. Producing hybrid plants and application of features that is needed to breed pure lines with high specific combining abilities, is highly required.New technologies such as doubled haploid can be an effective strategy to provide pure lines in tomato. Generation of homozygous doubled haploid lines through induction of androgenesis is a promising alternative method to the classical breeding programs. However, this technology is poorly developed in tomato so that some improvements in methodology are required. Genotype and stages of microspore development are critical factors for induction of androgenesis in tomato. Among them, the genotype is more important than other factors. The purpose of this study was to investigate the possibility of callus induction from anthers in some tomato genotypes.
Materials and Methods: In order to investigate the androgenic response and callus induction through anther culture in tomato, four varieties including Mobil-Netherlands, Baker, U. S. Agriseed and Khoram were chosen. To determine the appropriate stage of microspore development for anther culture, cytologycal studies were accomplished at different size length of flower buds (2-7.9 mm). Flower buds were incubated at 4oC for 15 minutes and stained in acetocarmin %4 solution. Based on cytological studies in four tested cultivars, flower buds with size length 4-4.9 mm were chosen, as they had the highest frequency of meiotic microspores to microspores mid uninucleate. Pretreatments were colchicine solution (250 mgr/L) at 4 °C for 48 h. The anthers were cultured on MS medium containing 2 mgr/L IAA and 1 mgr/L 2ip. All changes in frequency of callus induction and diameter of callus were recorded for eightweeks. Diameter of callus was measured using a microscope equipped with a camera and Dino Capture 2.0 software version 4.1. Cytological studies were accomplished by microscopy research Olympus BX51 and photographed by a digital camera DP70. To determine the presence or absence of a significant difference between the observed proportions a chi-square test was used. All analysiswas conducted using statistical software JMP 8. Charts were providedusing Excel software.
Results and Discussion: Anther development stage is one of the factors determining the success of anther culture in the production of embryos. The results of most studies showed that the stage between meiosis and mid-stage of unicellular microspores is optimum to androgenesis response in tomatoes. Since microspores in the anthers are at various stages of development, to determine the appropriate size of flower buds, the relative frequency of each of the stages of development should be understood. Based on the obtained results, in all study cultivars, flower buds with a length of 4-4.9 mm (Containing anthers with an approximate length of 3-4 mm), due to having the highest frequency of meiotic and unicellular microspores, can be used for anther culture. Study of deformation and induced callus in this experiment showed that both the Baker and U. S. Agriseeds did not show callus induction. Anthers of varieties over three weeks after culture gradually became yellowish-brown and in the fourth week of the increased frequency of haploid were brown. After six weeks of culture, all anthers in both became brown and died. The anthers of the varieties, Mobil-Netherlands and Khoram, inflated at the second to fourth week, anther wall was eventually broken and callus was observed. At third week the frequency of deformed anthers were gradually increased. Four weeks after culture, the frequency of callus induction reduced and after five weeks of callus induction no change in frequencyof callus induction was observed. The results showed that frequency of callus induction was significantly different among genotypes (P
Mohsen Alipoor; Mohammad Farsi; Amin Mirshamsi Kakhki
Abstract
The white button mushroom, Agaricus bisporus, is a commercially important cultivated filamentous fungus. Strain stability is of great importance to both spawn producers and mushroom growers. Mushroom strains are usually propagated via vegetative method on nutritionally rich substrates. Abnormal growth ...
Read More
The white button mushroom, Agaricus bisporus, is a commercially important cultivated filamentous fungus. Strain stability is of great importance to both spawn producers and mushroom growers. Mushroom strains are usually propagated via vegetative method on nutritionally rich substrates. Abnormal growth and poor yield are the consequences of this replication method. The reason for this phenomenon is still unknown. The use of molecular markers is one way of assessing and understanding the genetic changes. In this study, for the first time we reported the application of amplified fragment length polymorphism (AFLP) marker to assess genetic variation in single spore progeny and to assist selection of superior cultivars based upon the use of monosporous cultures of A. bisporus commercial strain, Holland737. We isolated 30 single spores that differed in growth rate, productivity and AFLP inheritance pattern. Nine EcoRI / TaqI primer combinations identified a total of 353 AFLP bands from 19 single-spore isolates, of which 53 were polymorphic. Results showed that the single spore selection is an effective method for strain improvement in A. bisporus, so that two isolates averagely performed 47% increased yield over the maternal strain and AFLP showed enough sensitivity to detect polymorphisms among single spore isolates.
Zahra Nemati; Ali Tehranifar; Mohammad Farsi; Amin Mirshamsi Kakhki; Seyyed Hossein Nemati
Abstract
Pomegranate (Punica granatum L. that one Punicaceae) is one of the important economical and commercial horticultural plants cultivated in arid and semiarid parts of Iran. Also, due to the long history of pomegranate cultivation in Iran, genotypes from different regions with obvious similarities in appearance ...
Read More
Pomegranate (Punica granatum L. that one Punicaceae) is one of the important economical and commercial horticultural plants cultivated in arid and semiarid parts of Iran. Also, due to the long history of pomegranate cultivation in Iran, genotypes from different regions with obvious similarities in appearance but with different names can be observed. Thus, the precise discrimination between .genotypes is essential for effective management for future pomegranate breeding programs. In this study, AFLP markers based on seven primer combinations (EcoRI/Tru1I) were used to evaluate genetic variation and Phylogenic relationship among 31 different .genotypes of native pomegranate belonging to seven of Iran provinces. According to the cluster analysis, a relatively low genetic diversity was observed across the .genotypes studied. Also, the results showed that the clustering of the cultivars didn’t concerne to morphological traits. The derived dendrogram proved that .genotypes are clustered independently from their geographical origin and their denomination. Heterozygosity index, Principal co-ordinates analysis (PCoA), Gst Index and analysis of molecular variance (AMOVA) revealed noticeable similarity among studied populations and observed variation within populations was very low and near zero. The high level of morphological traits diversity in Iranian pomegranate and low level of polymorphism in genome organization of these .genotypes determined by AFLP markers may be related to the somatic propagation and also type of pomegranate pollination.
Somayeh Heydari; Seyyed Hassan Marashi; Mohammad Farsi; Amin Mirshamsi
Abstract
Abstract
Seedless barberry (Berberis vulgaris L. var. asperma) is one of the few crops that is cultured only in Iran and southern parts of Khorasan provinces. The Origin of this variety is unknown and there has not been any study aiming to identify phylogenic relationships of this plant with other species ...
Read More
Abstract
Seedless barberry (Berberis vulgaris L. var. asperma) is one of the few crops that is cultured only in Iran and southern parts of Khorasan provinces. The Origin of this variety is unknown and there has not been any study aiming to identify phylogenic relationships of this plant with other species existing in Iran. In this study, AFLP markers based on four primer combinations (EcoRI/Tru1I) were used to evaluate genetic variation and Phylogenic relationship among 30 different samples of wild and cultured barberry belonging to Khorasan provinces namely: Shomali (north), Razavi and Jonubi (south), together with 2 species of ornamental barberry and one sample Mahonia aquifolium. Data resulted from cluster analysis, showed that these two genera (Berberis and Mahonia) form 2 completely distinct groups with a significant genetic distance. These results can clarify the ambiguity of separation procedure between Mahonia and Berberis genera. Heterozygosity index, Principal co-ordinates analysis (PCoA), Fst Index and analysis of molecular variance (AMOVA) revealed significant difference among wild barberry populations existing in Khorasan provinces; so that, as was expected, observed variation within cultured barberry population was very low and near zero. The results also showed that Berberis integerrima is the predominant species in Khorasan provinces. Therefore further molecular and morphological investigations aiming better understanding of the relationships between species and genera of Berberis family looks necessary.
Key words: Berberis, AFLP, Genetic diversity
