Iranian Journal of Genetics and Plant Breeding
Volume:4 Issue: 1, Apr 2015

The protein family of anion channel (ClC) constitute a family of transmembrane trnsporters that either function as anion channel or as Hﶩ exchanger. The expression of three genes of AtClCa, AtClCb and AtClCd in the model plant Arabidopsis thaliana were silenced by a T-DNA insertion . When the pH of the medium was slightly acidic the length of the primary root of plants with a disrupted AtClCa and AtClCd gene was reduced compared to the wild type and the plant with a disrupted AtClCb gene. The proton fluxes and pH were measured along the surface of the root at different positions, from root cap, through the transition zone, and up to the fast elongation zone, and at different pHs of the medium. A high proton influx was found in the apical part of the transition zone. Lower influxes or even small effluxes were found in the basal part of the elongation zone. At pH 6.2 the influx of protons in the apical part of the transition zone in the Atclca and Atclcd mutants was significantly lower than in wildtype and the Atclcb mutant. This will suggest a model for the interaction between endomembrane anion/H antiporters, plasma membrane proton fluxes and cell expansion in roots of Arabidopsis.

The combining ability analysis using Line × Tester model was conducted in chickpea to know the general and specific combining ability of the distingushing parents and their crosses, respectively and to select best material for further breeding programme and generation advanceme- nt. Two genetically diverse testers viz., JAKI-9218 and ICCV-2 as females and 8 males viz., HC-5, ICC-506, PKV Harita, Chandrapur Chanoli, JG-62, Gulak-1, AKG-10-1 and Bushy mutant and their 16 crosses along with two checks were evaluated in a Randomized Complete Block Design for seed yield per plant under unprotected condition and pod borer resistance under field conditions. The resistant genotypes had lower percentage of pod borer damage along with higher levels of malic acid contents. The malic acid content had significant and negative association with larval count at vegetative, flowering and pod formation stage in addition to the percentage of pod damage. The parent Gulak-1 was the best general combiner for seed yield per plant; ICC-506 for most of the traits associated with pod borer resistance and ICCV-2 for percent malic acid content. Therefore, these genotypes were considered as the good parental material for utilizing as one of the parents in further breeding programs as donors for the concerned traits. Two crosses viz.,ICCV-2 × Chandrapur Chanoli, JAKI-9218 × ICC-506 evinced significant sca effects in desirable direction at least for one of the traits associated with pod borer resistance along with one of the parents with a high gca effect and a high mean performance for the traits concerned, indicating opportunity for obtaining desirable segregation in further generations. A high heritability in broad sense was observed for all the traits except for larval count at the flowering stage. The non-additive variance was found predominant in inheritance of seed yield and additive variance for most of the traits associated with pod borer resistance. Hence, superior transgressive segregation may be obtained from this material either through biparental mating or diallel selective mating.

Elaeagnus angustifolia L. is a Eurasian tree that has become naturalized and has various ecological, medicinal and economical uses. In this study, a combination of morphological traits and RAPD markers were used to study the presence or absence of an association between genetic variation and morphological features among five populations of E. angustifolia collected from the East Azarbaijan of Iran. Data analysis of 19 different morphological traits, according to Nei’s genetic distance matrix using Nei’s in GenAlEx 6.5, showed that genetic distance coefficient ranged from 0.014 (between Jolfa and Ahar populations) to 0.86 (between Jolfa/Marand and Meianeh populations). The cluster analysis based on UPGMA and dendrogram plotted using NTSYSpc 2.02 software, revealed 4 main clusters. RAPD analysis using four random primers generated 29 polymorphic bands. Accordingly, the samples were placed in 4 groups. Based on Nei’s genetic distance matrix, a great genetic distance existed between Jolfa and Meianeh populations (0.167) and great genetic similarity existed between Jolfa and Marand populations (0.955). In this research, the results of morphological traits and RAPD markers showed more consistent with each other. Our results showed that RAPD analysis is a suitable method to study genetic diversity and relationships among E. angustifolia populations.

Pearl millet (Pennisetum glaucum (L.) R. Br.) and napier grass (Pennisetum purpureum Schumach) are the most economically important species in the genus Pennisetum. Knowledge of genetic diversity of these two species would enhance their potentials for utilization. The present work assessed the genetic diversity and phylogenetic relationship among Nigerian and Indian accessions of pearl millet and napier grass using microsatellite markers. We extracted genomic DNA from each accession and carried out Polymerase Chain Reaction using Inter-Simple Sequence Repeat markers. Data obtained were analyzed for genetic diversity using MEGA 4.0 software. A total of 48 loci consisting of 410 bands were generated with 56.25% polymorphism. Principal Coordinates analysis revealed three principal axis contributed significantly (70.20%) to the observed variations. Accessions of napier grass from Nigeria and India were plotted on a coordinate plane while pearl millets from both countries co-existed on different quadrants. Cluster analysis, showed that Nigeria and India accessions of napier grass were similar. Consistent link of COM-CO-3 with Nigeria napier grass and millet accessions suggested a common progenitor. The polymorphism obtained in this study showed that ISSR is an effective marker for assessment of genetic diversity and the connection between most accessions indicated that they have common progenitor.

Wild barley contains a wide genetic diversity and therefore is adaptable to all kinds of harsh environments. The aim of this research was to determine the extent of drought stress adaptation within Hordeum spontaneum L. genotypes from different climates of Iran. From the primary population of 193 genotypes, a core set consisting of 19 genotypes, were selected based on the highest squared Euclidean distance to represent the genetic diversity among wild barley genotypes. The selected genotypes were evaluated for drought stress adaptation. At the beginning of flowering time, two different water treatments; well-watered (90-100% field capacity) and drought stress (20-30% field capacity) were imposed to the plants. A negative correlation of stress tolerance index with phenological traits and relative water loss was observed. Genotypes with the highest relative water loss under drought stress condition were mainly from Mediterranean and Cool steppe climates and genotypes from desert climates seemed to have better adaptability to drought stress shown by less relative water loss. It seems that genotypes from unpredictable climatic conditions are more adapted to harsh environments.

An efficient Agrobacterium-mediate transformation method was developed by employing different duration of sonication, Agrobacterium strains, type of inoculation medium and concentrations of acetosyringone in Arya cultivar of wheat. Immature embryos were used as an explant for inoculation with Agrobacterium tumefaciens harboring the recombinant pBI121 plasmid. Among the durations of sonication the highest percentage of GUS positive immature embryos (54.58 ± 1.14%) and transformation (0.78 ± 0.07%) was observed in 10-seconds of sonication. Among the Agrobacterium strains, the highest GUS expression was 62.50 ± 1.55% and 0.39 ± 0.04% with LBA4404 strain. Between types of inoculation medium, the highest GUS positive immature embryos and transformation (1.86 ± 0.14% and 0.75 ± 0.04%, respectively) was observed in using the IM inoculation medium. Between concentrations of acetosyringone, the highest transformation was 0.75 ± 0.04% obtained at 200 µM acetosyringone. Also, the studying of simultaneous effects showed that the highest transformation efficiency (1.56 ± 0.06%) obtained from immature embryos inoculated with LBA4404 strain followed by 10-seconds sonication, immature embryos inoculated with Agrobacterium in IM inoculation medium after 10-seconds sonication and immature embryos inoculated with Agrobacterium in inoculation medium containing 200 µM acetosyringone after 10-seconds of sonication.