Papers by Hadi Darzi-Ramandi
Industrial Crops and Products
Scientific Reports, 2020
Two of the important traits for wheat yield are tiller and fertile tiller number, both of which h... more Two of the important traits for wheat yield are tiller and fertile tiller number, both of which have been thought to increase cereal yield in favorable and unfavorable environments. A total of 6,349 single nucleotide polymorphism (SNP) markers from the 15 K wheat Infinium array were employed for genome-wide association study (GWAS) of tillering number traits, generating a physical distance of 14,041.6 Mb based on the IWGSC wheat genome sequence. GWAS analysis using Fixed and random model Circulating Probability Unification (FarmCPU) identified a total of 47 significant marker-trait associations (MTAs) for total tiller number (TTN) and fertile tiller number (FTN) in Iranian bread wheat under different water regimes. After applying a 5% false discovery rate (FDR) threshold, a total of 13 and 11 MTAs distributed on 10 chromosomes were found to be significantly associated with TTN and FTN, respectively. Linked single nucleotide polymorphisms for IWB39005 (2A) and IWB44377 (7A) were high...
Water deficit is one of the most important abiotic factors limiting growth, which adversely affec... more Water deficit is one of the most important abiotic factors limiting growth, which adversely affect growth and crop production. In order to study the relationship between kernel size and phenological characteristics on grain yield, local bread wheat genotypes along with four varieties were evaluated in randomized complete block design with three replications under irrigation and water deficit stress conditions. Phenological characteristics including day to heading, day to flowering, day to maturity and grain filling duration, and kernel size traits including kernel length, kernel width, kernel thickness and kernel length/width ratio were measured. Analysis of variance revealed significant differences among genotypes for the studied traits. Results showed drought led to decreased grain yield (.), thousand grain weight (.), spike weight (.), peduncle weight (.), grain filling duration (.), kernel width (.) and increased kernel length/width ratio as compared with irrigated condition. Stepwise regression analysis revealed that under irrigated condition, spike weight, spike length and plant height justified the majority of grain yield variation, whiles under drought stressed condition grain filling duration and kernel width showed the highest impact on grain yield variation. Factors analysis identified four factors which explained. of the total variation. On the basis of these results, it is concluded that criteria such as grain filling duration, kernel width, peduncle weight and thousand grain weight could be considered as effective criteria for selecting to improve grain yield in water-limited environments.
Australian Journal of Crop Science, May 20, 2018
In order to evaluate several agro-morphological traits in 30 bread wheat genotypes, an experiment... more In order to evaluate several agro-morphological traits in 30 bread wheat genotypes, an experiment, based on randomized complete block design with three replications, was carried out under drought-stress and normal irrigation conditions in two locations. The traits, including grain yield, biological yield, harvest index, spike features, and peduncle characters were evaluated. The result of the combined ANOVA revealed that location and genotype effects were significant for all of the traits. Stress had a significant difference for all of the traits, except for spike density and spikelet per spike. The simple correlation results for each condition were significantly different, indicating that the relationships among traits were significantly influenced by drought stress and location. Factor analysis, based on principal component analysis and varimax rotation in the Shahed field under irrigation regimes showed that four significant factors accounted for about 78.2% and 77.7% of the total variation among characters for normal irrigation and drought stress conditions, respectively. The cumulative variation at the NIGEB field was 62.7% for four factors under normal irrigation, and 84.8% for five factors under drought stress conditions. With respect to the achieved results, characters such as plant height, peduncle length, spike density, 1000-grain weight, harvest index, and biological yield had the highest communality and, consequently, provide a high relative contribution to wheat grain yield, and can be used as selective criteria in bread wheat breeding programs.
Theoretical and Applied Genetics
Root system architecture (RSA) is an important factor for facilitating water and nutrient uptake ... more Root system architecture (RSA) is an important factor for facilitating water and nutrient uptake from deep soils and adaptation to drought stress conditions. In the present research, an integrated meta-analysis approach was employed to find candidate genes and genomic regions involved in rice RSA traits. A whole-genome meta-analysis was performed for 425 initial QTLs reported in 34 independent experiments controlling RSA traits under control and drought stress conditions in the previous twenty years. Sixty-four consensus meta-QTLs (MQTLs) were detected, unevenly distributed on twelve rice chromosomes. The confidence interval (CI) of the identified MQTLs was obtained as 0.11-14.23 cM with an average of 3.79 cM, which was 3.88 times narrower than the mean CI of the original QTLs. Interestingly, 52 MQTLs were co-located with SNP peak positions reported in rice genome-wide association studies (GWAS) for root morphological traits. The genes located in these RSA related MQTLs were detected, and explored to find the drought-responsive genes in the rice root based on the RNA-seq and microarray data. Multiple RSA and drought tolerance associated genes were found in the MQTLs including the genes involved in auxin biosynthesis or signaling (e.g. YUCCA, WOX, AUX/IAA, ARF), root angle (DRO1-related genes), lateral root development (e.g. DSR, WRKY), root diameter (e.g. OsNAC5), plant cell wall (e.g. EXPA) and lignification (e.g. C4H, PAL, PRX and CAD). The genes located both in the SNP peak positions and in the high-overview-index MQTLs for root architecture traits are suggested as novel candidate genes for further functional analysis.. The promising candidate genes and MQTLs would be applicable to genetic engineering and MQTL-assisted breeding of root phenotypes aimed at improving yield potential, stability and performance in a water-stressed environment.
International Journal of Fruit Science
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Papers by Hadi Darzi-Ramandi