MODERN GENETICS JOURNAL (MGJ)
Year:2009 | Volume:4 | Issue:3|Papers Count:8

The production of haploid/doubled haploid plants allows one to speed up breeding programs, improve selection efficiency, detect linkage and gene interactions, estimate genetic variance and the number of genes for quantitative characteristics, produce genetic translocations, substitutions and chromosome addition lines and facilitate genetic transformation. In breeding programs, besides doubled haploids production, the microspore culture can be used to produce and maintain malesterile plants via microspore embryogenesis, possibility to restore male-fertility via in vitro microspore maturation, to overcome self-incompatibility and to induce and select for mutants. In genetic engineering, Male Germ Line Transformation (MAGELITR) in which DNA is transferred into microspores and cultured in vitro to form mature pollen and then using the transformed pollen for pollination in vivo, is very efficient method. In basic studies, the microspore culture can be used to investigate pollination, pollen development, embryogenesis, totipotency, cell cycle, phase change and the role of stress in development. In this paper, various aspects of in vitro microspore culture are discussed.

Insulin-like growth factor I, IGF-I, plays important roles in different biological activities in fish. The present study was aimed at isolating cDNA encoding IGF-I and measuring relative gene expression levels in different tissues in the beluga, Huso huso one of the most important Iranian sturgeon. A fragment of 1229 nucleotides coding for IGF-I was cloned (AB512770.1) from liver using RACE-PCR. It included 483 nucleotides encoding sequences for deduced IGF-I protein (BAH85795.1). Deduced IGF-I involved 160 amino acids and included both the signal peptide and the proIGF-I. The proIGF-I consisted of B, C, A, D and E domains. Comparison of IGF-I in beluga and some animal species from different phyla showed high similarity especially with birds. Expression levels of IGF-I were analyzed in stomach, gill, liver, spleen, kidney, muscle, skin, intestine, heart and brain using real-time PCR. The results showed that although IGF-I expressed in all analyzed tissues, the highest IGF-I transcript levels were in the liver and intestine tissues. The lowest transcript level was measured in the muscle. The results of the present study can help scientists evaluate different aspects of molecular physiology in the beluga Beluga.

Mango is one of the most important tropical fruits, rich of nutrients and good components. That is cultivated in southern region of Iran. Molecular identification of mango genotypes helps in its germplasm management and avoiding misidentification of genotypes. In this study 16 Simple Sequence Repeats (SSRs) primers were used to analyze genetic relationship among 41 mango genotypes. A total of 55 alleles were detected with an average of 3.5 alleles per locus. The number of putative alleles ranged from 2 to 6. Observed and expected levels of heterozygosity ranged from 0.3 to 0.87 and 0.29 to 0.84 respectively. By paring banding patterns obtained from the 16 primers pakistanian and Indian genotypes could be separated. All genotypes with synonym names were placed at different groups, except ('Kalak 2' and 'Kalak 3'). Totally 18 taxon specific alleles were recorded that mostly belonged to 'Sendreri-2' and 'Langra-1'.

The chicken growth hormone (cGH) is a polypeptide hormone which is involved in a wide variety of physiological functions. To investigate the growth hormone gene polymorphism, 217 samples (129 samples of Isfahan and 88 samples of mazandaran) for intron 1 and 134 samples (91 samples of Isfahan and 43 samples of mazandaran) for intron 4 were analyzed. The genomic DNA was extracted using salting out technique. The quantity and the quality of the extracted DNA was examined using spectrophotometery and then analyzed on a 0.8% agarose gel electrophoresis. A fragment with the size of 776 bp from the intron 1 and a fragment with the size of 1170 bp from the intron 4 were amplified using two pair of specific primers and polymerase chain reaction. The PCR products digested with MspI restriction enzyme and then it analyzed on %2.5 agarose gel. The allelic frequency of intron 1 locus for M, N and O alleles in Isfahan native fowls was 0.60, 0.21 & 0.19 respectively and in Mazandaran populations was 0.28, 0.05, 0.67 respectively. The allelic frequency of intron 4 for A, B and C alleles in Isfahan native fowls populations were 0.28, 0.31 & 0.41 respectively and in Mazandaran population were 0.37, 0.24 & 0.37 respectively. Also D and E alleles were observed in Mazandaran population solely with 0.01 frequency for each allele. The result of current study indicated that the introns 1 and 4 of cGH is relatively highly polymorphic in Isfahan and Mazandaran native fowls.

Wheat seed contains gliadines and glutenins. Glutenins is consisted of high molecular weight and low molecular weight. Total protein was extracted from 27 substitutions Lines related to kapla – shayen substitutions lines and Chinese Spring as control samples using laemmli protocol. After protein extraction, the samples were electrophoresed using SDS-PAGE. The gels were stained using commassie blue R250 and silver nitrate methods; then similarity matrix was calculated using Jaccard coefficient. Payne scoring system was calculated for each line. The range of coefficients of similarity was 0.55 -1. The coefficients of similarity were 1 in the most of lines. The coefficients of similarity of substitution lines of kapla and parent were 1 but it was 0.736 for kapla 3A. The coefficient of similarity of kapla and other lines was low. These lines and controls were clustered to 3 groups that kapla 3A and shayen 4b were in 2 separately and single groups. Based on silver staining, the range of coefficients of similarity varied from 0.7-1. The coefficients of similarity of almost all lines were 1. Kapla 3A, kapla 4B and shayen 7B had lowest similarity. According to cluster analysis, these lines and controls were clustered to 2 groups that kapla 3A was in the separately group. Based on Payne scoring system, only kapla 3A had 2* and 10 bands that can be main reason of difference to other lines and control. According to these scoring the bands of all lines (except kapla 3A) were similar to parent kapla and Chinese Spring; but some of lines of shayen and control were different and these lines were clustered to 3 groups that shayen 7A, shayen 4B and kapla 3A were located in separately group. Totally, in the kapla, 3A chromosomes and in shayen, 7A and 4B chromosomes had high variations in the band patterns. 

I dentification of genomic homologies provides some important tools for improving conservation and management of plant genetic resources. In order to evaluate genetic diversity in wheat germplasm, 30 samples from bread wheat, durum wheat and diploid wild relatives (AA and DD) were randomly selected and analysed using 11 ten-mer RAPD primers. These primers amplified different parts of the genome as a total of 105 loci with 953 bands were obtained. C and E primers amplified higher loci compared to other primers, while primer UBC64 showed the highest amount of bands. All used primers were able to determine genetic differences among genotypes. Two special bands were introduced for DDdiploids by F primer. Cluster analysis using UPGMA and Jaccards’ similarity coefficient revealed that the nearest samples were in 0.9 similarity, while the farther samples were in 0.5 similarity. At 0.7 similarity, evaluated samples clustered in 4 and at 0.65 similarity clustered in 2 main groups. This research showed that the accessions under study have not high genetic diversity the results of PCoA, approximately was in agreement with cluster analysis.

In order to optimize embryogenic calli production in date palm, meristematic tissues were excised from 2-3 years old offshoots of Zahedi, Kabkab and Dayri genotypes and cultured on MS medium containing 100 mg/l 2,4-D, 3 g/l activated charcoal, 30 g/l sucrose supplemented with different concentrations of zeatin and TDZ as cytokinin resources. The samples were incubated at 25±2°C in the darkness. Initial calli were generated from explants cultured in various treatments which were able to produce embryogenic callus after 6-8 weeks of sub culturing in the same medium. The best callus production was observed in 0.5 and 3.0 mg/l of zeatin with respect to Zahedi and Kabkab cultivars and 0.1 mg/l of TDZ for Dayri. Meanwhile, the shortest callus generation time was correspondent to Kabkab, Zahedi and Dayri genotypes, respectively.