Abdollah Mohammadi

The karyotype of six Iranian ecotypes of Nigella sativa, which is a member of the Ranunculaceae family, was studied. The results showed that all studied ecotypes contained 12 chromosomes (2n=2x=12). The karyotype formulas for the ecotypes are: G1: 5m+1T, G2: 4m+1sm+1st, G3: 5m+1st, G4: 5m+1T, G5: 4m+1sm+1T and G6: 3m+2st+1sm. The total form percentages (TF%) of the ecotypes observed were as follows: G1 40.64, G2 41.04, G3 43.83, G4 41.36, G5 39.60, G6 38.94. The largest total haploid length was detected in G6 (51.76 µm) while G4 demonstrated the least (32.56 µm). The first two principal component analysis (PCA) justified over 89% of the total variations of cytological characteristics. UPGMA cluster analysis was carried out for chromosomal parameters which classified the studied ecotypes into five classes.

Capsicum (pepper) is a member of the Solanaceae family and this genus has a great economic importance in food, drug, spices and industry. In this study, seeds of ten ecotypes of Capsicum spp. were obtained from the plant gene bank of Seed and Plant Improvement Institute of Karaj, Iran. The standard karyotype was prepared for the ecotypes and the characteristics of the chromosomes including long arm, short arm, total length (TL), arm ratio and centromeric index were calculated and chromosome types were determined. The number of chromosomes in somatic cells of all genotypes was 24 (2n=2x=24). All genotypes had a pair of satellite chromosome. The first 2 principal component analysis (PCA) justified over 99% of the total variations determined for cytological parameters. The highest total haploid length (51.65 μm) was detected in G7 while G8 demonstrated the least (43.46 μm). Cluster analysis was carried out for chromosomal parameters, classifying genotypes in three classes.

This study was carried out to study effects of super absorbent polymer and plant growth promoting rhizobacteria (PGPR) on yield and some physiological traits of maize (double cross 370) in Karaj region/Iran in 2009. Experiment was conducted as a randomized complete block design with 4 replicates and in two separate experiments under drought stress and normal conditions. Seven different treatments studied in this research, including: T₁: Grain inoculation with biofertilizer (Azospirillum lipoferum+Pseudomonas putida), T₂: Applying super absorbent polymer as gel in rows, T₃: Applying super absorbent polymer as powder in rows, T₄: Grain inoculation with biofertilizer (Azospirillum lipoferum +Pseudomonas putida) and applying super absorbent polymer as powder in rows, T₅: Grain inoculation with biofertilizer (Azospirillum lipoferum + Pseudomonas putida) and applying super absorbent polymer as gel in rows, T₆: Mixing biofertilizer (Azospirillum lipoferum+Pseudomonas putida) with super absorbent polymer (as gel) and applying in rows and T₇: Non-application of super absorbent polymer and biofertilizer (control). Results indicated that drought stress decreased ear dry yield. Application of super absorbent polymer (powder or gel) and biofertilizer (Azospirillum lipoferum+Pseudomonas putida) increased ear dry yield in both stress and normal conditions. The highest content of oxidative damage biomarkers Malondialdehyde (MDA), dityrosine achieved in stress condition (T₇). Application of super absorbent polymer (treatments T₂ and T₃) in drought stress condition, decreased content oxidative damage biomarkers (MDA, dityrosine and dihydroxy-guanozine) that indicate the positive effect of this polymer in reducing drought stress effects. Application of biofertilizer alone (T₁) or with super absorbent (T₄, T₅, T₆), decreased the content of oxidative damage biomarkers in drought stress condition, but increased the amount of proline. It seems inoculated plants with increasing of proline scavenge produced free radicals under drought stress.