The increase of salinity tolerance in three turf grass species using trinexapac-ethyl

In most parts of Iran, the presence of water and soil salinity in urban area results in problems for grass growth. One way to solve this problem is the use of plant growth retardant, such as trinexapac-ethyl (TE), which is common and routine in turf management. This study was performed to investigate the response of Agrostis stolonifera L., Agropyron desertorum L. and Festuca ovina L., grown in sandy loam soil, to TE and irrigation water salinity. Resu-lts showed that spraying turf grass with TE increased most of the vegetative growth characteristics and content of chlo-rophylls, carotenoids and proline in clipping leaves, whereas increasing the NaCl concentration in irrigation water resu-lted in steady reduction in the values of these parameters, except carotenoids and proline content, compared with the co-ntrol group. Both TE and salinity treatments decreased the plant heights, as well as the fresh and dry weight of clip-pings. In the species which were studied, Agrostis stolonifera turned out to be the most tolerant turfgrass. Results also indicated that the application of TE enhances salinity resistance by improving the percentage of green leaf, chlorophyll concentration and proline content and reduce clipping in the species studie

Evaluation of expression changes, proteins interaction network, and microRNAs targeting catalase and superoxide dismutase genes under cold stress in rapeseed (

Rapeseed is the third-largest source of plant oil and one of the essential oil plants worldwide. Cold stress is one of the critical factors that affect plant yield. Therefore, improving cold stress tolerance is necessary for yield increase. The present study investigated BnCAT1 and BnCSD1 genes’ expression behavior in a tolerant and sensitive cultivar under cold stress (4 °C). Besides, protein-protein interaction networks of CATs and CSDs enzymes, and their association with other antioxidant enzymes were analyzed. Moreover, the microRNAs targeting BnCAT1 and BnCSD1 genes were predicted. This study indicated many direct and indirect interactions and the association between the components of the plant antioxidant system. However, not only did the CATs and CSDs enzymes have a relationship with each other, but they also interacted directly with ascorbate peroxidase and glutathione reductase enzymes. Also, 23 and 35 effective microRNAs were predicted for BnCAT1 and BnCSD1 genes, respectively. The gene expression results indicated an elevated expression of BnCAT1 and BnCSD1 in both tolerant and sensitive cultivars. However, this increase was more noticeable in the tolerant cultivar. Thus, the BnCSD1 gene had the highest expression in the early hour of cold stress, especially in the 12th h, and the BnCAT1 gene showed the highest expression in the 48th h. This result may indicate a functional relationship between these enzymes

QTL Analysis of Agronomic Traits in Rice Using SSR and AFLP Markers

A quantitative trait is a measurable trait that depends on the cumulative action of many genes and their interaction with the environment that can vary among individuals over a given range to produce a continuous distribution of phenotypes. The identification and mapping of QTLs for such traits has great significance for rice breeders. In this study, a genetic analysis of quantitative trait loci (QTLs) affecting 11 agronomical traits was performed using an F2 population of a cross between two Oryza sativa ssp. indica type cultivars, �Domsiah� and �IR44�, comprising 160 plants. A total of 22 QTLs were detected for 11 traits, including two for plant height (PH), one for full grain per panicle (FG), two for flag leaf width (FLW), three for 1000-grain weight (TGW), two for number of panicles per plant (NP), three for flag leaf length (FL), two for peduncle length (Pd), one for panicle exertion (PE), two for grain yield (GY), two for basal panicle length (BPL) and two for awn length (AL)

Assessment of Rice Genotypes Response to Drought Stress at the early Reproductive Stage Using Stress Tolerance Indices

Drought stress is one of the major abiotic stresses that limits rice productivity in the world. In this study 83 diverse rice genotypes were evaluated under reproductive-stage drought stress and non-stress conditions in a completely randomized design with three replications. Eleven well known stress tolerance and susceptibility indices were calculated based on the grain yield under stress and non-stress conditions. Also rank mean (RM) indices were calculated based on the ranks of genotypes for the former calculated indices. The highest seed yield under non-stress condition belonged to the genotypes Sangjo, Zenith, IR70445-146-3-3, Norin 22 and Ghasroldashti. Under stress condition, however, IR83750-131-1, IR74718-24-2-3, Sepidrood, TETEP and IR71739-24-3-5 genotypes showed the highest seed yield. STI, GMP, MRP and REI indices with positive and significant correlations with grain yield in stress and non-stress conditions were found to be the most suitable indices for selection of drought tolerant rice genotypes. According to these indices, IR83750-131-1, Sangjo, Sepidrood, Zenith and IR58 genotypes showed the highest ranks and had a higher tolerance to drought stress. Based on RM index, IR83750-131-1, IR74718-24-2-3, Sepidrod, TETEP and IR74720-13-1-2 obtained the highest ranks. Cluster analysis grouped the most drought tolerant genotypes in the second cluster

QTL Analysis of Agronomic Traits in Rice Using SSR and AFLP Markers

A quantitative trait is a measurable trait that depends on the cumulative action of many genes and their interaction with the environment that can vary among individuals over a given range to produce a continuous distribution of phenotypes. The identification and mapping of QTLs for such traits has great significance for rice breeders. In this study, a genetic analysis of quantitative trait loci (QTLs) affecting 11 agronomical traits was performed using an F2 population of a cross between two Oryza sativa ssp. indica type cultivars, Domsiah and IR44, comprising 160 plants. A total of 22 QTLs were detected for 11 traits, including two for plant height (PH), one for full grain per panicle (FG), two for flag leaf width (FLW), three for 1000-grain weight (TGW), two for number of panicles per plant (NP), three for flag leaf length (FL), two for peduncle length (Pd), one for panicle exertion (PE), two for grain yield (GY), two for basal panicle length (BPL) and two for awn length (AL)

Analysis and comparison of fragrant gene sequence in some rice cultivars

It is known that the fragrant trait in rice (Oryza sativa L.) is largely controlled by fgr gene on chromosome 8 and it has been specified that the existence of an 8 bp deletion and three single nucleotide polymorphism (SNP) in exon 7 is effective on this trait. In this study, sequence alignment analysis of fgr exon7 on chromosome 8 for 11 different fragrant and non-fragrant cultivars revealed that 5 aromatic rice cultivars carried 3 SNPs and 8 bp deletion in exon7 which terminates prematurely at a TAA stop codon. However, 5 of the non-aromatics showed a sequence identical to the published Nipponbare, being non-fragrant Japonica variety sequence. An exception among them was Bejar, which had 8 bp deletion and 3SNPs but it was non-aromatic. Sequencing can determine nucleotide alignment of a gene and give beneficial information about gene function. In silico prediction showed proteins sequences alignment of fgr gene for Khazar and Domsiah genotypes were different. Betaine aldehyde dehydrogenase complete enzyme belongs to Khazar non-fragrant genotype that has complete length and 503 amino acids while non-functional BADH2 enzyme for Domsiah fragrant genotype has 251 amino acids that result in accumulate 2-acetyl-1-pyrroline (2AP) and produces aroma in fragrant genotypes