JOURNAL OF AGRICULTURAL BIOTECHNOLOGY
Year:2013 | Volume:5 | Issue:3|Papers Count:9

Increasing demand for aromatic rice causes their higher price and attracted plant breeder' s attention to recognize rice aroma-controlling genes. Highly linked markers with the genes controlling important agronomic traits help to make phenotypic selection, more efficient, effective, reliable and cost-effective compare to the more conventional plant breeding methods.The aim of conducting this research was identification of volatile compounds in rice and mapping their controlling QTLs using SSR markers. The harvested seed of 139 single F2 plants of cross between Mousa-Tarom and 304 were grown in 2010. Volatile compounds extraction, separation and identification of seed samples; harvested from each F2: 3 families; was conducted using the sensitive and efficient method of solid phase micro-extraction in gas chromatography coupled to a mass spectrometry apparatus. Alkane compounds of tetradecane, pentadecane, hexadeane and heptadecane were the general identified compounds. The identified QTLs controlling volatile compounds were located on chromosomes 1, 4, 6, 11, and 12. The chromosome number 4 included most of the volatile controlling loci. Out of 14 identified loci, 12 showed different situations of partial, complete or over dominance effects. Heptadecane compound showed the lowest heritability and tetradecane showed more than 50% heritability. Ultimately, in this study, several QTLs having less than 5.4 centiMorgan distances to the marker; the optimal recommended distance between the marker and QTL for selection; were identified.

For study polymorphism of POU1F1, IGF1 and Leptin genes and their relationships with daily gain, blood samples of 100 heads (65 males and 35 females) of Makui sheep breed were randomly collected. DNA was extracted from whole blood and polymerase chain reactions (PCR) were performed using three pairs of specific primers. Single Strand Conformation Polymorphism (SSCP) was used for detection of genotypes. Number of banding patterns (genotypes) for POU1F1, IGF1 and Leptin genes were 4, 3 and 5, respectively. A general linear model procedure was applied to determine association between genotypes with average daily gain in different stages. Genotypes of leptin, POU1F1 and IGF1 genes had significant effect (P<0.05) on the average daily gain. Banding patterns (genotypes) of AB and BB genotypes in IGF1 gene for average daily gain from birth to weaning (3 months) and average daily gain from 6 months to 9 months, respectively, CC and AA genotypes in POU1F1 gene for average daily gain from 6 months to 9 months and 9 months to yearling, respectively and BC genotype in Leptin gene for average daily gain from weaning to 6 months had higher performances than other genotypes.These results confirmed the potential usefulness of IGF1, POU1F1 and Leptin genes in markerassisted selection programs in Makui breed.

Biodiesel production processes from microalgae include biomass harvesting, lipid extraction and transestrification. Undoubtedly, selection of a high-quality cell disruption method increased the efficiency of lipid extraction and so biodiesel production. Various methods, including autoclaving, freezing, bead-beating, microwaves, sonication and high pressure homogenization, were tested to identify the most effective cell disruption method. The total lipids fromSpirulina platensis and Chlorella vulgaris were extracted using standard method. The total lipid contents from the tow species were 7.2-18.2 and 18.3-43.1 %DW respectively. Both microalgae showed the highest total lipid contents when the cells were disrupted using the microwave oven and autoclaving method. Thus, among the tested methods, the microwave oven method was identified as the most simple, easy, and effective for lipid extraction from microalgae.

In this study the effect of different levels of plant growth regulators (picloram, 2, 4-D, IAA and BAP) and explants type (root, stem and leaf) were examined on callogenesis and organogenesis of st John's wort with factorial experiment design on the basis of completely randomized design with five repeats and five explants. The explants were obtained from 30 days plantlets and transferred to media supplemented with picloram, 2, 4-D, IAA (0, 0.5, 1, 2 mgl-1) and BAP (0, 0.4, 0.8 mg l-1). Samples were kept in the growth chamber in the darkness condition at 23oC. After 28 days, the interactions between explants types and hormone levels were investigated. The significant effect at the 1 percent probability was observed between treatment levels of 2, 4-D, picloram, BAP and its interaction (2, 4-D * BAP) for the calluses size and shoot numbers. Also the significant effect at the 1 percent probability was observed between treatment levels of IAA, BAP and its interaction (IAA*BAP) for the calluses size, shoot and root numbers. The highest numbers of shoots (83 shoots) were achieved in the leaf explants treated with 0.4 mgl-1 BAP. The highest callus size (5 mm) was observed in media containing 0.5 mg l-1 picloram and 0.4 mg l-1 BAP and stem explants also greatest number (91 roots) of roots were observed in media supplemented with 2 mgl-1 IAA in the leaf explants.

Leaf growth and development characteristics are important factor for grain yield. In order to genetic analysis of Leaf growth and development characteristics of rice, a linkage map provided from F2 rice mapping population caused Gharib × Khazar and 111 microsatellite markers. Total number leaf, Days to flag leaf, leaf emergence rate, grain weight, grain number, length and width of flag leaf and branches number were mapped. qGW-1b, qFG-1b and qWFL-7 were identified as major effect on chromosome 1 and 7 and explained 14.30, 13.70 and 20.32% of total variation of grain weight, filled grain and width of flag leaf, respectively. The most of variation of total leaf number explained by 2 QTLs (over than 20%). According to these result, we can produced rice lines that have low vegetative growth periods and high total leaf number.

In order to evaluate the effects of changing in sucrose partitioning on salt tolerance of rice plants in the seedling stage, a pot experiment was conducted in a split plot based on a randomized complete block design with three replications in the fields of Shahid Chamran University of Ahvaz. The experiment consisted of six lines and cultivars including, wild type (Tai pai), three antisense lines for sucrose transporter SUT1 gene (37-184-8-1, 37-111-7-1 and 34-45-6-1), salinity tolerant (Pokali) and salinity sensitive (Nipponbare) which were exposed to three salinity levels (2, 5 and 16 ds/m sodium chloride).21 days after salt commencement, shoot dry weight, leaf relative water content, SPAD score, stomatal conductance and total soluble sugars in leaves were evaluated. Increasing in salinity led to increase in levels of soluble sugars and SPAD score and decrease in shoot dry weight, stomatal conductance and leaf relative water content. The results of this study showed that 37-184-8-1 and 37-111-7-1 antisense lines behaved similarly to pokali under salinity stress treatments and were superior in compare to Tai pai as wild type. The expression profiling experiment of sucrose transporter gene family of rice in antisense lines showed relatively reduction in expression of these genes after exposing to salinity. However, this reduction in antisense lines was less than the wild type. According to the results of this study it seems that manipulating the sucrose partitioning in rice plants may improve the salinity tolerance of transgenic lines at seedling stage and this could be suggested as a strategy in breeding programs.

In spite of rapid progress in plant biotechnology, somatic embryogenesis has been used as one of the most applicable techniques for micropropagation and plant regeneration, lack of comprehensive and systematic studies associated with the somatic embryogenesis still persists up to now. In this review paper, general aspects of in vitro somatic embryogenesis such as terminology, factors which are involved in somatic embryogenesis in different species and induction and development stages in the gymnosperm, dicots (globular, heart-shaped and torpedo) and monocots (globular, scuetellar, and coleoptilar stages) have been explained.Plant growth regulators functions, physiological condition of mother plants, application of somatic embryogenesis for transgenic crop production, genetically approaches such as gene expression pattern involved in somatic embryogenesis and finally molecular and physiological markers to distinguish the embryogenic competence cells have been discussed in the present paper.

CTCF is a highly conserved DNA-binding protein involved in transcription regulation, chromatin insulation, genomic imprinting, X-chromosome inactivation, higher-order chromatin organization, and alternative splicing. These multifunctional properties of CTCF suggest an essential role in development and disease. CTCF is unique protein that known to mediate insulation function in vertebrates. Recent studies proposed that CTCF can be a heritable component in epigenetic and regulating the interaction between DNA methylation, higher-order chromatin structure, and developmentally regulated gene expression. In this review, we discuss roles of CTCF in these critical aspects of genome regulation. All information indicates that CTCF can emerge as a master weaver of the mammalian genome.

To produce and purify movement protein ofCucumber green mottle mosaic virus (CGMMV MP), a plant viral vector engineered from anin vivo infectious clone of Zucchini yellow mosaic virus (ZYMV) was used. The CGMMV MP ORF was in frame inserted between the P1 and HC-Pro ORFs of the ZYMV vector. The infectious activity of the vector was approved by rubbing the plasmid on Chenopodium quinoa leaves and observing local lesions.Individual lesions were mechanically transferred to the systemic host plant zucchini squash at the stage of two-cotyledon. The stability of recombinant protein expression was assessed by successive passages of recombinant from infected plant and throughout the period of 30 days after inoculation in a single plant and after 10 serial passages. Then, the leaves tissues of inoculated plant were analyzed by RT-PCR and western blot analysis. Recombinant protein was purified using centrifuge method combine with gel extraction; each step was sampled and analyzed by western blotting and SDS-PAGE. The results showed approximately 1.8–2.2 mg recombinant MP per 100 g tissues were purified from leaves two weeks post inoculation. Also, the vector was remarkably stable in squash after 10 serial passages and 30 days. The procedure provides a convenient and fast method for production of large quantities of pure CGMMV MP in planta.