Iranian Journal of Crop Sciences
Year:2012 | Volume:14 | Issue:3 (55)|Papers Count:6

To assess the effects of terminal drought stress on phonological traits, grain yield, yield components, and to determine phenotypic variation and relationship between grain yield with other traits in 64 Kabuli genotypes an experiment was carried out using simple lattice design (8×8) under two conditions (terminal drought stress and normal) in 2011 at Research Field of Faculty of Agriculture, University of Tehran, Karaj, Iran. Results showed that there were significant differences among chickpea genotypes which revealed genetic variation for different traits. According to the results of phenotypic correlations, stepwise regression, path analysis for both normal and stress conditions, it can be concluded that, expected that biological yield and harvest index, seed and pod weight, number of filled pods, number of seed.plant-1, 100 seed weight and number of seed.pod-1 were the most important and effective traits affecting yield. Therefore selecting and breeding for these traits could be considered for improving grain yield in Kabuli chickpea. Based on factor analysis using data in both conditions four factors were selected that explained 78.96% and 81.6% of total variation under normal and drought stress conditions. The first and second factors were introduced as yield and yield component factors. Genotype grouping in both conditions was conducted using UPGMA method and the square Euclidean distance. Genotypes were grouped in three clusters in both conditions.

Integration of foreign genes into plastid genomes occur through homologous recombination between flanking sequences of gene in plastid vectors. In this study, by analysis of plastid genomes using bioinformatics databases, we succeed to select a region of plastome as alien gene targeting sequence including the appropriate length for homologous recombination and integration in plastome, specific plastid origin of replication, targeting gene to inverted repeat region of plastid genome and unique restriction enzymes recognition sites in the center of flanking region sequences for alien gene integration. Since similarity (%) of the flanking region sequences would increase transformation efficiency of plastome dramatically, therefore, a pair of primers was designed to isolate the plastome flanking regions. These primers were 100% similar to all plant plastomes, but the length and sequence of their amplified fragments were variable in different plant plastomes. Flanking region sequence from tobacco, cotton, corn, lettuce, tomato, carrot, and even the canola and lemon plastomes that still their plastome sequences are not available in Gene Bank were isolated and cloned. The accuracy of cloning, present and direction of flanking regions fragment from different plant plastomes were confirmed by enzymatic digestion analysis using Hind III and Bam HI. Then different types of chloroplastid vectors using different regulation elements were constructed. The regulation elements that could be used for efficient expression of any alien genes in different plastids were including plastid constitutive or inducing promoters and terminators, suitable untraslated regions, Ribosome binding sites of plastid, suitable restriction enzyme recognition sites for cloning and expression of desired gene in single or polycistronic status, reporter genes, antibiotic or non-antibiotic markers and sequences for removing of marker gene. These recombinant chloroplast plasmids including pFNGi and pFNG can be used as universal and specific vectors for chloroplast transformation. Thus, in this study we succeeded to design the high efficient and specific plastid vectors, not only for plants which their plastomes were completely sequenced, but also for other plant species that there is not any sequence of their plastomes available in databanks.

Forty nine tobacco genotypes, selected from Tobacco Research Center of Rasht, Iran, were evaluated for genetic diversity on the basis of 14 characters (No. of leaf, leaf length, leaf width, leaf area coefficient, leaf shape index, flowering duration, days to flowering, plant height, stem diameter, fresh leaf yield, dry leaf yield, revenue, price of one kilogram dry leaf and SPAD value) using simple lattice design (7×7) with two replications in 2010. Cluster analysis using UPGMA method assigned the 49 genotype in five different groups consisting of 6, 1, 25, 4 and 13 genotypes, respectively. Grouping results were confirmed by canonical discriminate function analysis and Fisher Linear method (87.8%). C258×MC944 hybrid had the highest values for most economical traits. The fifth group included genotypes that had low value for most economical characteristics. Factor analysis results based on principal component analysis after Varimax rotation showed that four factors; economic yield, phonology, price and leaf characteristics determined 79.19% of variation from the total observed variation.Fourth region was detected as desirable region on the basis of the first and second factors evaluation. Results of the present experiment could be used for selection of suitable parents in crossing programs to increase dry leaf yield in tobacco.

To evaluate the relationship among different agronomic characteristics and grain yield in hull-less barley genotypes under rainfed conditions of Koohdasht, Lorestan, Iran, this experiment was conducted in 2003 to 2005 cropping seasons. Twenty spring hull-less barley genotypes were evaluated in Randomized Complete Block Design with four replications. Relationship between agronomic characteristics and grain yield were investigated.Results showed that spike weight had the highest correlation coefficient with the number of grain.spike-1 (r=0.96**). Correlation coefficient between grain yield and biological yield was (r=0.81**). To determine the most effective characters on grain yield, stepwise regression analysis was performed. Five traits including; spike weight, number of grain.spike-1, peduncle length, plant height and number of days to heading, were the most effective traits on grain yield. The path analysis showed that spike weight (r=0.89**) and plant height (r=0.82**) had highest positive and direct effects on grain yield in hull-less barley genotypes.

To study the effects of drought stress and nitrogen fertilizer levels on some physiological traits and grain yield of two red kidney bean genotypes, a field experiment as split factorial arranged in randomized complete blocks design with three replications was carried out at Research Field of Faculty of Agriculture, University of Tehran, Karaj, Iran in 2010. The main plots were three irrigation levels (irrigation after 60, 90 and 120 mm evaporation from open pan class A) and factorial combinations of N fertilizer at four levels (0, 50, 100, and 150 kg N ha-1) and two red bean genotypes (Akhtar and D81083) were assigned in sub-plots. Results showed that drought stress×genotype interaction was significant (p£0.01) on total chlorophyll and chlorophyll a, proline content and canopy temperature depression (CTD). Similarly, the drought stress×nitrogen fertilizer interaction was significant (p£0.01) on chlorophyll a, b and total, proline content and CTD). Results indicated that drought stress reduced grain yield, LAI, leaf water content, chlorophyll a, b and total and carotenoids, but increased CTD and proline content. However, nitrogen fertilizer application increased all of the measured traits except the canopy temperature. Akhtar red bean cultivar showed higher carotenoid, proline, leaf water content and canopy temperature whereas the D81083 genotype produced higher grain yield under the drought stress conditions.Generally, application of nitrogen fertilizer increased LAI, leaf water content, pigment content, proline content and grain yield of red kidney bean and led to reduction in canopy temperature in drought stress conditions.