JOURNAL OF AGRICULTURAL BIOTECHNOLOGY
Year:2016 | Volume:8 | Issue:2|Papers Count:8

Drought stress is one of the most important limiting factors of crop plants in Iran and worldwide. To assess the response of mutant line MT149 to drought stress in comparison to parental cultivar Neda, a factorial experiment was conducted in a completely randomized design. Drought stress (-6 bar) was induced using poly ethylene glycol 6000 and leaf growth dynamics and chlorophylla and b contents were evaluated in different time series (0, 12, 24 and 36 hours after stress treatment). Results showed that effects of genotype, time and stress were significant on all investigated characters. Also, mean`s comparisons showed that mutant line MT149 was superior over than itself parental counterpart. Furthermore, assessment of catalase gene isoform A (OsCat A) in different times after stress showed that parental cultivar Neda experienced a significant down-regulation of catalase A gene, while MT149 experienced a significant up-regulation of the gene in the same time. Based on the results of this research it can be concluded that one of evidences on a higher drought tolerance of MT149 is probably up-regulation of OsCat A to scavenge the ROS toxicities.

Scrapie or transmissible spongiform encephalopathy (TSE), is an infectious fatal disease of sheep and goats which affects the central nervous system. In the present study, 300 blood samples were collected from three breeds of Iranian indigenous Ghezel, Harki and Makoei sheep breeds. A DNA fragment with the length of 173 bp from exon 3 of PrP gene was amplified with specific primer pairs. The banding pattern of each sample in the study population was identified by means of PCR-SSCP. Then, after sequencing, comparison and analysis of the observed polymorphism between different breeds were performed at codons: 136, 154 and 171. In the present study, tow haplotypes of ARR and ARQ were identified and the wild type scrapie-susceptible ARQ was the most frequent haplotype. In this study more than 98% of animals were with the genotype ARQ/ARQ which was classified as low resistance to this disease. Three novel alleles (L178, E147 and L173) were observed for the first time in this study. The comparison of genotype frequency between Makoei-Ghezel and Makoei-Harki sheep breeds were statistically significant (P<0.05).The data from the current study may help to establish a breeding program for controlling of scrapie in Iranian sheep population.

Lepidium drabathrough the production of anti-cancer and anti-microbial compound, sulforaphane, is considered a valuable medicinal plants.Therefore, optimization of in vitro tissue culture to facilitate genetic transformation and improvement of traits in this plant is important. This study was conducted, by cotyledon, stem and root explants inMSmedium in the form of two separate tests. Data were analyzed in a factorial experiment based on completely randomized design. In the first experiment with different concentrations of growth regulators NAA and BAP, the highest response rate, direct shoot regeneration rate and direct shoot generation were related to root explants. The highest root production rate and root generation were showed in cotyledons explants.1 mgl-1 BAP without NAA induced the highest direct shoot generation in root explants. Cotyledons explants in 2 mgl-1 NAA and 0.5 mgl-1 BAP produced the highest Root production rate and the highest root generation. Callus induction rate and callus initiation of stem explants were more than others, but the callus regeneration rate in three studied explants showed no significant difference. The highest shoot generation from regenerated callus was observed in the cotyledons explants. The second experiment with a combination of different concentrations of 2, 4-D and BAP, under the influence of two treatments darkness and 16h photoperiod was performed. The highest investigated traits was in the 16h photoperiod. Cotyledons and stem explants were showed the highest callus induction rate and leaf explants showed the greatest weight of callus; While the highest callus regeneration rate and callus growth rate were obtained from the root explants. From leaf explants, the highest callus weightwas obtained from 0.5 mgl-1 2, 4-D with 3 mgl-1BAP and the most growth rate of callus was obtained from 0.5 and 1 mgl-1 2, 4-D and 3 mgl-1BAP. Also the combination of 2 mgl-1 2, 4-D with 2 mgl-1 BAP and 3 mgl-1 BAP, produced the highest callus regeneration in root explants.

In applications of population genetics, classi fication of individuals in a sample into populations is important. With the development of high throughput genotyping technologies many markers such as SNPs are available which useful in the study of genetic diversity and structure population. The purpose of this research was to study of population structure and stratification buffaloes from different areas of the two ecotypes (Azari and North) using data SNPChip 90K. A total of 258 buffalo from Ardabil, West Azarbaijan, East Azarbaijan and Guilan provinces were sampled and genotyped. The result showed weak population stratification with  l=1.056 for GC method. Also the plots obtained from PCA and MDS showed separation of different provinces based on genetic distance and these animals have closed genetic relationship. Admixture method represents same results and admixture between individual from different provinces of two ecot ypes and k=3 have low error cross validation. These methods are generally able to separate the animals. The results showed the close genetic relationship between two ecotypes from 4 different provinces.

In this study, we proposed the artificial operon which is capable of reversible transcriptional regulation control in Bacillus subtilis. Firstly, the creup and credown were mutated to release from CCR phenomenon. Then, the structural genes of gnt operon were placed under the control of constitutively strong promoter to degrade gluconate constitutively. In addition, the reporter gene (lacZ) was introduced under control of gnt promoters to evaluate functionality of the artificial operon. The results of pulse induction system showed no enzyme activity of each strain in the absence of inducer. By addition of 1 mM gluconate, the highest enzyme activity was shown at 1h after addition of inducer, and then the inducer degraded to turn off the operon. The maximum activation of enzyme was observed in 2h and 4h after addition of 2.5 and 5 mM gluconate into culture media, respectively. Our data indicated that the longer degradation of inducer and higher enzyme activity was appeared by more concentration of gluconate as well as growth arrest. It is suggested to use the pulse induction system and reversible artificial operon to achieve huge amount of special metabolite at short period of bacterial growth.

In whole genome association study, genomic selection, Determining of extent and level of linkage disequilibrium (LD) is important in sample size and marker density. In this experiment, the blood and sperm samples were collected form 1089 Holstein bulls and 2030 markers on chromosome 6 were genotyped by using Illumina Bovine SNP50K Bead Chip based on UMD3.1 genome assembly. Data were corrected for missing genotyped SNP and individual with unknown genotype by Plink. After correction 1606 markers remained (79%). The average observed heterozygosity was 0.37 and 80% of the markers had minor all frequency more than 0.2. The LD was calculated with rP 2 P and Dˊ by Haploview v4.2. The extent of LD in this study was 40 kb with r P 2 P=0.3. The r P 2 P value was decreasing to 0.2 (moderate level) in 80kb and 0.1 (background level) in 300 kb. The effective population size has been decreased to 100 individual in 10 generations ago. The 49 haplotype blocks with range 18-472 kb were detected that covering the 10.6 Mb of whole chromosome. These results showed that between 4000-70000 markers or one marker per 40-75 kb will be need for whole genome association study in this Holstein population.

Pomegranate (Punica granatum L.) is native to Iran with several ecotypes which have been adapted to various climatic conditions and diseases. Although it is one of the important exported fruits, there is not a precise identification criteria to determine the authenticity of genetic inheritance and proprietary rights in the country. In the present study the genetic relationships of 47 pomegranate genotypes, including 9 cultivated genotypes (from the collection of Yazd) and 38 wild genotypes (from Mazandaran, Gilan and Golestan provinces), were investigated with AFLP markers. Using 10 primer combinations, 825 bands were obtained of which 697 showed polymorphism. Among the primers, primer combination of M-CTT and E-ACG showed the highest number of bands (148) and primer combination of E-ACC, M-CTG produced the lowest number of bands (40). The average value for PIC was 0.21, while Average Marker Index (MI) was 17.33 that the highest one belonged to primer combination of M-CAC and E-AAG. Maximum genetic similarity belonged to Bahnamir with Shirin Kan Tehran samples and the minimum genetic similarity observed between Berenjestanak and Khosh Darreh. Principal component analysis showed that 57% of the total variance was explained by first three components. The identified primer combinations in this study could be used as a powerful tool for determination of genetic relationships between Pomegranate genotypes.

Foot-and-mouth disease (FMD) is a severely contagious viral disease that mainly affects cloven-hoofed livestock and wildlife. Foot-and-mouth disease is an endemic disease in Iran that sometimes caused considerable losses of livestock, especially in young animals. In this study mRNA expression of interleukin-2 (IL-2) and interleukin-12 (IL-12) cytokines was evaluated in vaccinated guinea pigs with inactivated type O FMD vaccine (without adjuvant). Blood samples were collected from saphenous vein of eight male guinea pigs (at control and vaccinated groups) at 7 and 28 days after the first vaccination. Total mRNAs were extracted using the column RNA isolation kit and subsequently reverse-transcribed into cDNA. Then relative real-time PCR assay was used to analyze of quantification of IL-2 and IL-12 expression. The expression of IL-2 gene had not significant difference in vaccinated animals compared to the control group in the first and second blood samples but IL-12 gene expression significantly increased (P<0.05). Evaluation of cytokines genes expression can be as a valuable adjunct for assessment of effects of new vaccines on immune system in future studies.