Agricultural Biotechnology
Year:2010 | Volume:9 | Issue:2|Papers Count:6

The objective of the present research was to study the effect of genotypes (2 commercial cultivars of repeseed, PF-7045-91 and SLM-046) and explant densities (15 and 30 cotyledons in 10 cm in diometer Petri dishes) on shoot regeneration. Results showed that there were significant differences between rapeseed cultivars and explant densities, but no significant interaction effect was observed between investigated parameters. The cultivar PF-7045-91 was better regenerated with average of 85% regenerated cotyledons than the other one with 62%. Higher percentage of regeneration (87%) was also recorded for treatment with 15 cotyledons in Petri dish rather than 30 cotyledons.

In this study, S-alleles of 16 almond cultivars and genotypes were determined using allele-specific and consensus primers. Likewise, the flowering coincidence among these cultivars and "Shahrood 12", "Shokoufeh" and "K-4-10" were determined. Twelve different S-alleles were distinguished in studied cultivars. Using allele-specific primers five S-alleles S1, S2, S7, S8 and S9, and compatibility allele, Sf, were amplified. In five cultivars both S-alleles, in seven cultivars only one S-allele and in four cultivars no S-allele were amplified. Using second intron consensus primers 31 out of 32 S-alleles of studied cultivars were identified. In 15 cultivars both S-alleles and in "Genotype 7" only one S-allele (S5) were distinguished. S1 and S3 were the most frequent S-alleles and found in eight and five cultivars, respectively. Beginning of flowering, full bloom and end of flowering of cultivars and genotypes were recorded and their flowering coincidence with "Shahrood 12", "Shokoufeh" and "K-4-10"were determined. Considering S-allele genotype and flowering coincidence of cultivars, suitable pollinizers were determined. For "K-4-10" genotypes "K10-11", "K14-12", "K-16-30", "K16-25", "K12-4" and cultivars "Shahrood 12" and "Marcona", for "Shahrood 12" genotype "K4-10" and "Marcona", and for "Shokoufeh" cultivars "Supernova", "Sahand", "Touno", and "Genotype 8", "Genotype 7", and "K16-25" are recommended as suitable pollinizers.

In this study the effect of four growth media including MS, NN, B5 and AM and three different hormone combinations were investigated on regeneration of two strawberry cultivars Camarosa and Selva. The experiment was done in factorial design for each cultivar separately. The meristem explants were introduced in culture media supplemented with different hormonal combinations and maintained in a growth room at a 16h photoperiod (36mmol.m-2.s-1), 25±1oC. After ten weeks, number of regenerated plantlets, biggest leave length, middle leaflet length and width, middle petiolate length, number of dent in middle leaflet and root length were studied. The results showed that number of regenerated shoots were higher in MS and NN medium. Hormonal combinations B1: (BA=1.0ppm+IBA=0.05ppm+GA3=0.05) and B2: (Kinetin=5ppm+2, 4-D=0.5 ppm+GA3=0.05ppm) were also resulted in higher regeneration number compared to B3. The results showed that Camarosa were more stable and had a higher regeneration in miropropgation process based on morphological traits.

Genetic diversity within and between 30 ecotypes of alfalfa (Medicago sativa L.) collected from North West of Iran was analysed at the DNA level by RAPD technique. DNA extraction was performed individually for 30 seedlings as well as bulked samples of 30 ecotypes. Using 10 arbitrary primers, 78 DNA fragments were scored and were varied between 36 to 68 bands. Varzeghan-Joshin and Tabriz-Sparakhon ecotypes showed the highest and the lowest genetic diversities, respectively. Marand-Zounragh with Bostanabad-Bashkand and Varzeghan-Joshin with Varzeghan-Alhord showed the highest genetic distance, respectively. The highest and the lowest genetic distances were belonged to Marand-Zounoragh with Bostanabad- Bashkand and Varzeghan-Joshin with Varzeghan-Alhord ecotypes, respectively. This result was in agreement with geographic distance of ecotypes. The results of molecular variance analyses showed 65.37% and 34.63% genetic diversity between and within ecotypes, respectively. This can be used for ecotype selection and improvement. Cluster analyses based on UPGMA algorithm, grouped 30 ecotypes into 4 clusters. Bostanabad-Bashkand ecotype was individually grouped in a separate cluster. The growth location of this ecotype was different from others, as it was located in a very cold region. Hence, might be cold tolerant ecotype. This may suggest that the altitude level of regions influences the ecotypes genetic structure much more than the environmental factors.

Fusarium solanif. sp. melongenae, the causal agent of egg plant wilt disease, has a wide host range which causes significant reduction in yield of eggplant (Solanum melongena). In a survey for finding biocontrol agents, 110 Actinomycetes strains were isolated from agricultural soils of Kerman province. Amony isolated strains 18 strain showed high level of chitinase activity Streptomyces griseus. Streptomyces isolate 401 significantly reduced the incidence of disease. Some biological and physiological characteristics of this isolate were investigated under green house condition. Moreover, the genomic DNA of this isolate was extracted by useing of CTAB method and a full chitinase gene (876 bp) was cloned and sequenced. The results showed high similarity between obrouned scyuence and seyuence of chitinasegene 19 fmily from.

Protein electriphoresis is one of the method for determinat genetic diversity in plants. In order to investigate protein pattern in rapeseed, sixteen genotypes of Brassica napus were studied in a randomized complete blocks design (RCBD) with three replications under drought and non-drought stress conditions. In complete flowering stage, leaves total protein of leaves was extracted in both conditions. The extracted proteins were seprated based on Laemmli method using SDS-PAGE in a 12.5% and 5% resolving and stacking gels, respectively. Mean genetic distance was estimated in normal and drought stress condition ranged from 0.056-0.632 and 0.0 to 0.5, respectively. Results of cluster analysis showed that the genotypes, according to protein pattern and based on Jaccard's similarity coefficient were placed in three groups in both conditions. Groups were different in drought and non-drought sites. Results of SDS-PAGE showed that protein pattern bands were almost different among of the genotypes. According to this reasearch results, Banding pattern and grouping genotypes in both normal and drought conditions were different.