Correlation and Path Coefficient Studies in F2 Populations of Rice

This study performed to determine the association between grain yield and yield components in fifty-four selected rice genotypes at F2 populations. Results showed that traits, the panicles per plant (r = 0.751) and filled grains per panicle (r = 0.458) correlated significantly with grain yield, while grain yield was negatively associated with non-filled grains per panicle (-0.297). Path coefficient analysis revealed that grain yield was associated with panicles per plant and filled grains per panicle with the direct effects of 0.691 and 0.568, respectively. The greatest indirect effect belonged to panicle length (0.301) through filled grains per panicle. Stepwise regression analysis showed that 72.1 percent of yield variation could be explained by three characters: the panicles per plant, filled grains per panicle and panicle length. Information obtained in this study revealed that traits, the panicles per plant and filled grains per panicle, could be used as selection criteria for grain yield improvement at segregating populations of rice

Evaluation of Salinity Tolerance in allotetraploid Cotton (Gossypium sp.) Genotypes, Using Multivariate Statistical Methods and Stress Tolerance Indices at Germination Stage

Salinity is one of the most important factors limiting agricultural production. Cotton, as an oil-fiber plant, is one of the most important industrial plants and is sensitive to salinity, especially at germination and seedling stages. Therefore, in this study, 14 allotetraploid varieties of commercial and local cotton were selected. The study was carried out as factorial with a completely randomized design and three three replications, using the sandwich method. Germination tests were performed at three salinity levels of 0, 8 and 16 ds.m-1. Afterwards, root and shoot length, fresh and dry weight of root and shoot, germination percentage, allometric coefficient, seedling water percentage and seed vigor index were measured and stress tolerance indices were calculated based on yield (seedling dry weight) in stress and non-stress conditions. Given these indices, all cultivars were aalyzed at two levels of 8 and 16ds.m-1, using principal component analysis and biplot diagrams were drawn. Finally, the dendrogram classification of genotypes was plotted based on STI indices (stress tolerance index), SSI (stress susceptibility index), and the performance (dry weight plantlet) in stress and non-stress conditions. The result of variance analysis for genotype, salinity and salinity×genotype demonstrated that dry weight root, dry weight shoot, fresh weight root, stem length, vigor index seedling, allometric coefficient, dry weight seedling, and length seedling were significant in p-value 0.01, and fresh weight shoot, length root were significant in p-value 0.05. Clustering and the biplot of the genotypes based on STI and SSI indices at salinity levels of 8 and 16 ds.m-1 indicated that the Sepid and Giza genotypes were tolerant and that the Kashmar genotype was sensitive to salt levels at germination stage.    Highlights: The reaction of the cotton cultivars studied was different to levels of salinity stress. An increase in salt stress caused a significant reduction in the germination characteristics of cultivars of cotton studied. Bi-plot analysis and clustering based on STI and SSI indices turned out to be a suitable method for clustering cotton cultivars

High-efficient transgenic hairy roots induction in chicory: re-dawn of a traditional herb

<p>Plant roots can be manipulated by <em>Agrobacterium rhizogenes</em> to stimulate the production of heterologous proteins for pharmaceutical applications as green cell-factories. During the present study, four bacterial strains (A4, ATCC15834, ATCC11325 and A13) in combination with three co-cultivation media (MS, B5, LS) were examined to establish an efficient and reliable transformation system for chicory (<em>Cichorium intybus</em> L.) using <em>A. rhizogenes</em>. The maximum chicory hairy roots induction was achieved using A13 strain. The observation confirmed that MS medium was more effective on hairy root growth. Dried biomass accumulation of hairy roots infected by A13 strain was 1.10 g l^-1 in MS medium which was significantly higher than those grown in LS and B5 medium (0.88 and 0.72 g l^-1, respectively). Beta-glucuronidase (GUS) gene was introduced by A13 strain carrying the pCAMBIA1304 binary vector. The results showed that the highest frequency of transformation (63.15 %) was achieved using A13 strain and MS cultivation medium. Detection of GUS and <em>hpt</em>II genes by PCR and GUS histochemical localization confirmed the integrative transformation in hairy roots. In conclusion, the whole process was successfully optimized as a pre-step to manipulate the chicory hairy root cells to improve the unique potential of secondary metabolite production.</p

ORIGINAL ARTICLE Effect of NaCl on antioxidant enzymes and protein profile in halophyte Aeluropus littoralis leaves

Leila Haghighi, 1Ahmad Majd, 2Ghorbanali Nematzadeh, 3Masood Shokri, 4Sedigheh Kelij, 1Saeed Irian; Effect of NaCl on antioxidant enzymes and protein profile in halophyte Aeluropus littoralis leaves ABSTRACT The effect of increasing NaCl concentration on soluble protein content, electrophoretic profile of total protein and enzyme activity along leaves with different ages in Aeluropus littoralis was investigated. We compared protein content of selected leaves in all treatments. Analysis revealed that salinity induced changes in protein pattern in leaf 7 and 10 in comparison with leaf 4. Salinity caused proteins induction in leaf 4 unlike two others. Salt also decreased total soluble protein in leaf 10 which treated by 400 mM of NaCl. Activity of Peroxidase (POD), Phenylalanine ammonia-lyase (PAL) and Polyphenol oxidase (PPO) increased gradually up to NaCl concentrations of 400 mM. The highest enzyme activity was observed when plants were treated with 400 mM of NaCl. Increased PAL and POD activities in leaf 10 were positively correlated with increasing NaCl concentrations. Polyphenol oxidase showed differential activities in response to salt and types of leaves. A significant increase was detected in leaves 4, 7 and 10 under salt. Leaf 4 at 400 mM of NaCl had the greatest activity among the three leaves. These results suggested a correlation between the activation of above enzymes, protein changes and leaf age during salt treatments

Comprehensive analysis of calcium sensor families, CBL and CIPK, in Aeluropus littoralis and their expression profile in response to salinity

Plants have acquired sets of highly regulated and complex signaling pathways to respond to unfavorable environmental conditions during evolution. Calcium signaling, as a vital mechanism, enables plants to respond to external stimuli, including abiotic and biotic stresses, and coordinate the basic processes of growth and development. In the present study, two calcium sensor families, CBL and CIPK, were investigated in a halophyte plant, Aeluropus littoralis, with a comprehensive analysis. Here, six AlCBL genes, and twenty AlCIPK genes were studied. The analysis of the gene structure and conserved motifs, as well as physicochemical properties, showed that these genes are highly conserved during evolution. The expression levels of AlCBL genes and AlCIPK genes were evaluated under salt stress in leaf and root tissue. Based on the real-time RT-PCR results, the AlCIPK gene family had a higher variation in mRNA abundance than the AlCBL gene family. AlCIPK genes were found to have a higher abundance in leaves than in roots. The results suggest that the correlation between AlCBL genes and AlCIPK is tissue-specific, and different correlations can be expected in leaves and roots. Based on these correlations, AlCIPK3.1-AlCBL4.1 and AlCIPK1.2-AlCBL4.4 can be co-expressed in the root tissue, while AlCBL10 has the potential to be co-expressed with AlCIPK5, AlCIPK26, and AlCIPK12.3 in the leaf tissue. Our findings reveal valuable information on the structure and function of calcium sensor families in A. littoralis, a halophyte plant, that can be used in future research on the biological function of CBLs and CIPKs on salt stress resistance

Tabrizicola aquatica gen. nov. sp. nov., a novel alphaproteobacterium isolated from Qurugöl Lake nearby Tabriz city, Iran

A novel Gram-negative, aerobic, non-motile and rod-shaped bacterium was isolated from Qurugöl Lake near Tabriz city. The bacterium grew chemoorganolheterotrophically and chemolithoautotrophically. However, photo-organoheterotrophic, photo-lithoautotrophic and fermentative growth could not be demonstrated. The presence of photosynthesis genes pufL and pufM was not shown and photosynthesis pigments were not formed. Strain RCRI19T grew without NaCl and tolerated up to 3 % NaCl. Growth occurred at pH 6–9 (optimum, pH 7) and 15–55 °C (optimum 40–45 °C). Vitamins were not required for growth. The major fatty acids are C18:1 ω7C, 11-methyl C18:1 ω7C, C18:0 3-OH. The predominant respiratory quinone is ubiquinone Q-10. The G+C content of genomic DNA is 65.9 mol%. Analysis of 16S rRNA sequences showed that strain RCRI19T has the highest similarities with uncultured environmental sequences followed by members of the genera Rhodobacter (≤95.75 %), Haematobacter (≤95.53 %), Gemmobacter (≤95.17 %) and Falsirhodobacter (94.60 %) in the family Rhodobacteraceae. DNA–DNA relatedness between strain RCRI19T and the closest phylogenetically related strain, Rhodobacter blasticus LMG 4305T, was 20 %. Based on its phenotypic and chemotaxonomic characteristics and considering that it does not form photosynthetic pigments and is unable to grow phototrophically, it is concluded that strain RCRI19T cannot be included into the genus Rhodobacter and any of the other related genera. Therefore, we propose to place the new bacterium into a new genus and species for which the name Tabrizicola aquatica gen. nov. and sp. nov. is proposed. The type strain is RCRI19T (=BCCM/LMG 25773T = JCM 17277T = KCTC 23724T)

November 30, 2013 (Pages 7000-7060)

Additional file 3: Figure S3. Melt curve analysis of ten candidate reference genes in a root samples

Initial description of the genome of Aeluropus littoralis, a halophile grass

The use of wild plant species or their halophytic relatives has been considered in plant breeding programs to improve salt and drought tolerance in crop plants. Aeluropus littoralis serves as halophyte model for identification and isolation of novel stress adaptation genes. A. littoralis, a perennial monocot grass, grows in damp or arid areas, often salt-impregnated places and wasteland in cultivated areas, can survive periodically high water salinity, and tolerate high salt concentrations in the soil up to 1,100 mM sodium chloride. Therefore, it serves as valuable genetic resource to understand molecular mechanisms of stress-responses in monocots. The knowledge can potentially be used for improving tolerance to abiotic stresses in economically important crops. Several morphological, anatomical, ecological, and physiological traits of A. littoralis have been investigated so far. After watering with salt water the grass is able to excrete salt via its salt glands. Meanwhile, a number of ESTs (expressed sequence tag), genes and promoters induced by the salt and drought stresses were isolated, sequenced and annotated at a molecular level. Transfer of stress related genes to other species resulted in enhanced stress resistance. Here we describe the genome sequence and structure of A. littoralis analyzed by whole genome sequencing and histological analysis. The chromosome number was determined to be 20 (2n = 2x = 20). The genome size was calculated to be 354 Mb. This genomic information provided here, will support the functional investigation and application of novel genes improving salt stress resistance in crop plants. The utility of the sequence information is exemplified by the analysis of the DREB-transcription factor family