Search

Objective The first step in understanding a species’ genome is to study the number and shape of its chromosomes. Determining the relationship between species of a genus, traits such as chromosome morphology, absolute chromosome size, diversity in coloring, centromere position chromosome base number, and numbers of satellites must be considered. This study aimed to investigate cytogenetic diversity and to determine the relationship between native garlic ecotypes of Iran (Shahroud, Bojnurd, Mashhad, Birjand, Talish) with foreign specimens (originated from Turkmenistan, Azerbaijan, Tajikistan) and to prepare genome analysis based on chromosomal information. Materials and methods From the mitotic cells in the metaphase stage, which were prepared from the terminal meristem of the root and stained with acetoorcein, five suitable metaphase cells were selected and the length of short and long arms and the total length of chromosomes were measured using Karyotype Analysis Software (ver.1.5). Data were analyzed by JMP8 statistical software in an unbalanced completely randomized design. Mean comparisons were performed by Duncan test. To classify ecotypes, based on all chromosomal parameters, cluster analysis was performed using the Ward method. Results The results showed that the basic number of chromosomes in Turkmenistan and Bojnurd ecotypes was x=7, 2n=2x=14, and in other ecotypes x=8, 2n=2x=16. Short arm length, long arm length, and total chromosome length were significantly different (P≤0.01) between ecotypes. Cluster analysis divided the ecotypes into two groups. Minimum Euclidean distance observed between Azerbaijan and Talish ecotypes, the smallest chromosome belonged to Mashhad and the largest chromosome belonged to Shahroud. The most symmetric karyotype was Azerbaijan and the most asymmetric karyotype was the Shahroud ecotype. Conclusions The results showed that the differences in the number of chromosomes could be explained by Robertsonian translocations. It seems that the ecotypes with 2n=2x=14 chromosomes had more antiquity, and the ecotypes with 16 chromosomes originated from them. Considering that the Bojnourd ecotype with 14 chromosomes this region could be possibly introduced as the oldest origin or nuclear center of variation for garlic in Iran. Chromosomes also differ in the size and location of the centromere, which is due to chromosomal breakdown and the formation of a new structure in their reconnections. This study revealed which ecotypes are distant among the studied ecotypes, and also showed to produce possible future hybrids, in which direction will be more successful.

Different enzymes in oyster mushroom (pleurotus oatreatus), can degradate the lignin compounds from the beginning of mycelium growth up to the end of fruiting period in the environment of compost and straw. Wood, plant residue and most of plant wastes in the nature are called lignocelluloses compounds. Lignocelluloses is mainly composed of cellulose, hemicelluloses and lignin. Magnesium peroxides enzyme (EC:1:11:1:13) is one the most common peroxides destroying lignin which produced by most wood decomposing mushrooms as well as many compost decomposing mushrooms. In order to cloning of mnp gene, RNA was extracted from oyster edible mushroom (P.ostreatus var.florida) and cDNA was synthesized and then the primers was designed based on the sequence of the mnp gene using Primer Premier (V.5.0) software and was amplified by PCR. First, the gene was inserted to pTG-19T plasmid and was confirmed using sequencing. In continue, mnp gene was cloned in to the p13H88 plasmid. Then it was transferred to Ecoli (DH5a) using ice-melt method and its presence was confirmed by enzymatic digestion. The results showed that mnp gene is cloned in p13H88 plasmid and the recombinant plasmid was named as p13H88-FM.

In hybrid seed production program based on three-line system, the use of fertility restorer line with desirable specific combining ability carrying fertility restoration (Rf) genes is indispensible. In this research, fertility restoration locus Rf3 was transferred into CMS line ‘Neda-A’ using marker-assisted backcrossing (MAB) method and simultaneously its effect on pollen and panicle fertility of recipient line was evaluated in each generation. For transferring the locus, a single F2 plant (derived from ‘Neda-A’ x ‘IR36’ cross) was selected based on Rf3-linked three markers (RM1, RM3233 and RM3873) and backcrossed to ‘Neda-A’ (as the recurrent parent). The BC1 progenies were screened for Rf3-linked markers and also phenotyped and subsequently screened for 15 background SSR markers. Only two BC1 plants with donor dominant allele at all three loci showed high panicle fertility (65% and 50%). BC2 progenies were developed after backcrossing these two plants to recurrent parent. Among BC2 progenies, a single plant having a higher fertility was self-pollinated and 170 resultant BC2F2 plants were screened with 3 foreground Rf3-linked markers (RM1, RM3233 and RM3873) and also evaluated in terms of seed setting. Seven plants were identified with a higher rate of recurrent parent genome (91.1% to 98.5%) and in complete homozygote state at three Rf3- linked markers. These plants had a high pollen and panicle fertility (75% to 97%), indicating that with increasing homozygosity of Rf3 locus, fertility restoration to WA cytoplasmic male sterility in the genetic background of CMS recipient line was further enhanced. Therefore, it can be concluded that Rf3 locus has an interaction to WA cytoplasmic male sterility in favor of increasing the rice pollen and panicle fertility, and hence it can be utilized along with other restoring fertility genes in hybrid seed production program of rice.

Actinomyces bacteria are the best parser microrganisms in environment and agriculture. These bacteria are frequent in compost and produce antibiotics & extracellular enzymes. In this study, some strains of actinomycetes were separated from different steps in composting process. After that, morphological, biochemical and molecular tests were performed for identification of them. Carboxy Methyl Cellulase assay was applied for endoglucanase activity. For optimizing conditions different treatments including pHs: 5.7, 6, 6.5, 7, 7/5, temperatures 45-65°C and times 30, 60 and 90 minutes were used. Optimum temperature for high endoglucanase activity was 60°C and isolate No.19 with 0.289 unit/ml showed the highest endoglucanase activity in this temperature. According to molecular result obtained from RFLP of 16SrRNA, most of actinomyces isolates were from streptomyces genus.