فهرست مطالب mohammad reza naroui rad

Licorice roots and rhizomes have numerous secondary metabolites, which are used as medicine. Cell and tissue culture of medicinal plants can be used for the production of secondary metabolites, and the use of elicitors, stimulates the production and increase of these valuable compounds. For this purpose, the effect of cellulase enzyme from Aspergilus Nigare as a fungal elicitor in cell suspension culture conditions as a completely randomized design with 3 replications, on traits such as phenol, flavonoid, antioxidant activity, carbohydrate, tannin, protein, nitrogen, and proline levels were tested in untreated, late-harvesting callus conditions, 24 hours, 48 ​​hours and 72 hours after treatment with cellulase. Variance analysis showed that there is a statistically significant difference between the studied treatments in all traits. A comparison of the mean traits also showed that phenol, flavonoid, antioxidant activity, tannin, and proline traits showed the highest increase in the treatment 72 hours after the treatment, and the carbohydrate, nitrogen, and protein traits showed a decreasing trend compared to the control treatment. Regarding the increase in the amount of phenol, flavonoid, tannin, and antioxidant activity during the treatment with cellulase, it can be said that cellulase, like other fungal elicitors, stimulates and induces the production of secondary metabolites in cell suspension culture conditions and confirms the possibility of the presence of secondary metabolites in callus and cell suspension of this plant in addition to Licorice root and rhizome. A decrease in nitrogen and protein and an increase in proline have also been reported due to the role of nitrogen in the accumulation of amino acids and stimulating the accumulation of flavonoids in plants.

Awareness of the extent of genetic diversity based on molecular markers is a rapid method that plays an important role in breeding programs. Cucumis melo L. is the scientific name for a melon that belongs to the Cucurbitaceae family (Kirkbride, 1993). This plant is a popular garden crop in warm and temperate climates across the globe, and Iran ranks fourth in the world in terms of output (FAOSTAT, 2019). Although several studies were conducted on the genetic structure of Iranian melons using various molecular markers including RAPD molecular markers (Feizian, 2004), ISSR (Maleki et al., 2018) and SSR microsatellite markers (Moayedi Nejad et al., 2010; Raghami et al., 2014) in recent years, due to the history of planting and the presence of huge genetic resources of melon, which makes Iran as one of the main centers of diversity of this crop in the world, research is inadequate.

Forty native melon stands used in this research were prepared from the melon germplasm of Iran Gene Bank. 4-5 leaves from each plant at the two- to three-leaf stage were collected and kept in a freezer at -80°C until DNA extraction. Their genomic DNA was extracted using the ZandBio plant kit. The markers used in this research were selected based on previous studies that were suggested by different researchers. Gradient PCR Vapo Protect thermocycler was used for polymerase chain reaction. PCR products were electrophoresed on 1.8% agarose gel in 1X TBE buffer and at 85 V for one hour. Observation and photographing of the gel was done with the help of UV-2100 geldoc device. Bands were scored as zero (not seeing a band) and one (observing a band). Evaluation of cluster analysis and genetic parameters such as observed heterozygosity, expected heterozygosity and number of effective alleles were obtained through Ntsys 2.1 and Popgene 1.32 software. To estimate the number of subpopulations (K) and distinguish pure and mixed genotypes, it was done using Structure software version 2.3 and using the Bayesian method (Pritchard et al., 2000).

All gene loci except CMCT44 primer were polymorphic. A total of 25 alleles with an average of 1.93 alleles per microsatellite gene locus were observed. The highest amount of polymorphic sites (84.62%) belonged to KC-357009 genotype.. The high amount of polymorphic sites confirms the effectiveness of SSR molecular markers in the genetic analysis of the investigated indigenous populations. The average content of polymorphism and expected heterozygosity information was obtained as 0.24 and 0.23, respectively. The observed high homozygosity values with an average of 0.84 indicate the low diversity within the investigated populations, which is a proof of the low level of variation between the populations and the high level of inbreeding. In the investigation of the genetic structure of the populations, the investigated populations were divided into two groups (sub-populations). The results of population structure analysis based on Bayesian method and UPGMA clustering showed that the classification of studied genotypes is independent of their geographical origin.

According to the values obtained from the above parameters, among the studied primers, gene locations CMCCA145, CMGA172 and CMCT134b are recommended for the analysis of melon germplasm collections in future research.The results of this study can be used in hybridization programs. Crossing between the figures that have the least similarity will lead to the best results in achieving hybrids or achieving maximum separation in the generations after F1. Although genetic distance is not the only effective factor in identifying suitable parents for hybrid production and factors such as compatibility and genetic distance based on morphological traits should also be considered.

The main aim of the present research was to evaluate the growth performance and genetic variation in diallel crosses of melon.

To investigate general and specific combining abilities and how genes act in eight melon populations, one-way diallel crosses were performed at Zahak Agricultural Research Station in 2019. Then, parental seeds and hybrids were planted in the spring of 2020 in a randomized complete block design with three replications. Fruit length, fruit width, number of fruits per plant, cavity diameter, fruit weight, total soluble solids, plant length, durability (number of days to crushing), flesh thickness, and yield were examined.

The results of the analysis of variance showed significant differences among the population for all traits. The results of diallel based on method 2 model 1 of a Griffing showed that general and specific combining abilities for the traits are statistically significant at the 5% level of statistical probability. The additive effects of genes on cavity diameter, total soluble solids, and shelf life were observed, expressing the possibility of selection in early generations for these traits. Research limitations: No limitations were founded.

Originality/value: 

The additive effects of genes on cavity diameter, total soluble solids, and shelf life were observed, expressing the possibility of selection in early generations for these traits also durability or shelf life is the most important trait in vegetables especially in melon so, based on these results cross Sefidak × Yellow ivaneki was the best cross for improvement of this trait.

A large part of Iran is affected by arid and semi-arid climate and drought has caused many problems in the agricultural sector. The present study aimed to investigate the characteristics of melon under drought stress conditions using manure and bentonite.

This experiment was conducted as a split-factorial based on a randomized complete block design with three replications in Hirmand city during the two cropping years of 2019-2020. Plants irrigated after 25, 50, and 75% of soil moisture depletion which considered as the main plot; and bentonite application (2, 3, and 4 ton/ha); and animal manure (20, 30, and 40 ton/ha) were used as subplots.

According to the results, in the first year of experiment, fruit yield increased by 2.02 times compared to the control under 50% soil moisture depletion with the application of 4 ton/ha of bentonite with 20 ton/ha of animal manure. Also, the leaf area index increased by 5.61 times, and the amount of glucose increased by 2.01 times compared to the control under 25% soil moisture depletion and application of 3 ton/ha of bentonite and 40 ton/ha of animal manure.

To achieve maximum fruit yield, irrigation after 50% soil moisture depletion, application of 4 ton/ha of bentonite, and 20 ton/ha of animal manure for cultivation in the region is recommended.