Iranian Journal of Genetics and Plant Breeding
Volume:9 Issue: 1, Apr 2020

Sainfoin (Onobrychis vicifolia Scop.) is one of the most important forage legumes cultivated as high quality forage. Fifty three species have been identified in this genus in Iran. A field experiment was conducted using randomized complete block design to compare yield and forage quality of 20 populations of sainfoin in Isfahan Agricultural and Natural Resources Center, Iran during 2013 – 2014. Populations were evaluated at three cutting dates (29 April, 20 July and 26 October, 2014). Dry matter yield and forage quality indices such as crude protein (CP), water-soluble carbohydrates (WSC), neutral detergent fiber (NDF), acid detergent fiber (ADF), dry matter digestibility (DMD), and ash content were determined. Results showed that populations were different in the majority of traits. Means of interaction effects indicated that the maximum and minimum dry matter yield were 5612.7 kg ha-1 at the third cutting and 118.5 kg ha-1 at the first cutting in 8199 and 9263, respectively. According to the results of quality analysis in the majority of populations, maximum DMD, CP and WSC were obtained at the third cutting and maximum ADF and NDF were obtained at the first cutting. In terms of forage yield some populations, such as 8199, 3800, Oshnavieh, 9147, 8799 and Isfahan camposit were superior to other populations. High digestibility populations (2759, 19402, PLC, 12542, 3001 and Oshnavieh) and high protein populations (8199, 15353, 2759, 3062, 15364 and 19402) had the best forage quality among populations. Regarding quantitative and qualitative characteristics of forage, these populations could be considered as desired parents for developing synthetic varieties.

Nitraria schoberi (Ghar-e-Daghin in Persian) from Zygophyllaceae (Nitrariaceae) family is considered as a wonderful exquisite plant in terms of its economical, medicinal, animal feed, significant values and also its unique characteristics of being tolerant to the soil salinity, drought and erosion. On the other hand, this plant is challenging with severe problems such as seed dormancy, plant growth inhibitors and also hard seed coat which lead to retard germination and subsequently to reduce the chance of life and reproduction. The present study was conducted for the first time to cope with its seed germination obstacles and to induce plantlet regeneration in N. schoberi through tissue culture method. Effect of cotyledonary leaf and hypocotyl explants and various concentrations of plant growth regulators were studied on shoot and root induction and further development. Based on the obtained results, culturing seeds after removing its seed coat effectively improved germination rate (80%) within a week. Whereas, germination of seeds with seed coats required a longer time (4 weeks) and showed a sharp decline in percentage (10%). At the next step, culturing cotyledonary leaf explants on shoot induction media including MS medium supplemented with BAP (2.0 mgL-1) and IBA (0.5 mgL-1) gave the highest shoot regeneration rate (93.33%), with average shoot number per explant (3.67) and shoot length (4.6 cm) after 60 days. Hypocotyl explants showed no response to shoot induction treatments even after 60 days. Regenerated shoots were rooted on the MS medium supplemented with IAA (1.0 mgL-1) alone or in combination with IBA (2.0 mgL-1). Finally, all regenerated plantlets were acclimatized and transferred to the green house successfully with 70% survival rate.

Woodland sage (Salvia nemorosa) is an important native medicinal plant in Iran and is considered as a rich source of phenolic and flavonoids compounds. The present research was conducted with respect to the optimization of medium for biomass accumulation and secondary metabolite production in cell suspension culture of S. nemorosa. In this research the effects of total nitrogen content (0, 15, 30, 60, 90, and 120 mM) and NH4+/NO3- ratio (0:60, 10:50, 20:40, 30:30, 40:20, 50:10, and 60:0) were studied in the Murashige and Skoog Medium on biomass growth, total phenolic, flavonoid and rosmarinic acid contents. The maximum accumulation of fresh biomass (294.80 g/l) and total phenolic content (76.61 mg GAE/g DW) was obtained in the medium supplemented with 90 mM nitrogen. The highest rosmarinic acid content (16.41 and 16.16 mg/g DW) was recorded in the medium containing 30 and 60 mM nitrogen. Increasing total nitrogen above 30 mM resulted in a decline in rosmarinic acid production. The ammonium to nitrate ratio also affected the biomass growth and secondary products accumulation. The highest fresh biomass accumulation (296.52 g/l), total phenolic content (87.30 mg GAE/g DW) and Rosmarinic acid content (18.43 mg/ DW) were recorded in 10:50 ratio of NH4+/NO3-. Increasing the NH4+ level or complete elimination of it from culture medium reduced the rosmarinic acid and total phenolic content of S. nemorosa. Our findings revealed that Woodland sage cell suspension needs both nitrogen forms, but ammonium is required at low concentration and nitrate at high levels. The results of the current study are beneficial for medium optimization for the establishment of large scale and bioreactor assisted cell culture of woodland sage for the production of phenolic acids.

Drought stress is one of the most important environmental stresses that have limited the production of wheat, especially in arid and semi-arid regions of the world. To recognize drought tolerant rain-fed wheat genotypes and to determine the best tolerance/susceptibility indices, a study was conducted at the Agricultural Research Station of Miandoab for two cropping years (2013-15). The experimental materials included 12 rain-fed wheat genotypes investigated in two separate field experiments based on randomized complete blocks design with three replications under both rain-fed and supplemental irrigation conditions. The combined ANOVA for grain yield and agro-physiological traits showed that there was a large genetic difference between wheat genotypes for grain yield and studied traits in response to drought stress among years and moisture regimes. The different drought tolerance/susceptibility indices were used to characterize drought tolerance of genotypes. Generally, a reduction of RWC in drought tolerant genotypes (genotypes 6, 2, 11, and 10) was lower compared to the sensitive genotypes (genotypes 4 and 8). Cluster analysis based on drought tolerance indices categorized genotypes into two main groups. The genotypes belonging to the cluster 1 could be introduced as tolerant to the drought conditions. According to MSI (Multiple scoring index), genotypes 10 (Seafallah/3/Sbn//Trm/K253) and Saein had the best combination of productivity and resistance to drought stress. The significant correlation between MSI with grain yield under drought conditions indicated the superiority of MSI as a useful tool for efficient selection of drought-tolerant genotypes. In the present study there was no significant correlation between RWC and RWL with MP, GMP, STI and MSI indices under both conditions.

Sunflower (Helianthus annuus L.) is one of the four important sources of edible oil in the world. Fungal diseases are considered as major constraints for its seed yield and quality. Basal stem rot resulted by Sclerotinia sclerotiorum (Lib.) de Bary fungus, is known as a serious disease on oily sunflower, worldwide. In this project, genomic region linked with partial resistance to basal stem rot disease was identified using a population of recombinant inbred lines (RILs) created from the hybridization between PAC2 (♀) and RHA266 (♂) lines. Nine phenotypic characters related to disease resistance including PN4D, PN8D, PN12D, NCW100S, CW100S, NCPY, CPY, DP100S and DPY were measured under artificial infection in the field conditions. Newly developed genetic linkage map of sunflower was used for detecting and mapping QTLs. The linkage map includes 210 SSR and 11 SNP markers distributed in 17 groups. The analysis was carried out using composite interval mapping (CIM) procedure. High coefficient of variation (CV) was detected for those studied characters that reveal high genetic variability for susceptibility to disease in the studied sunflower RIL population. Totally, 56 putative QTLs were identified for the studied nine quantitative characters. The number of QTLs for each character ranged from 1 to 9, explaining 0.91 to 80.75% of phenotypic variation (R2). Additive effect sign was positive for 17 QTLs, suggesting that the promising allele has been transmitted from male parent (RHA266). In this project, major QTLs (LOD≥2.5 and R2≥10%) were identified for all of the studied characters, exceptifor NCW100S and CW100S characters. The major QTLs are important for running marker-aided selection (MAS) in resistant breeding programs.

Wheat is the first and the most important grain of the world and its bakery property depends on gluten quality. Gluten is a part of endosperm hard proteins that causes increased stickiness quality. Wheat glutenin is divided into two groups according to their molecular weight, glutenin subunits with high molecular weight (HMW-GS) and glutenin subunits with low molecular weight (LMW-GS). In the present study, 97 Iranian wheat landraces were analyzed for diversity in high and low molecular weight glutenin subunits. In hexaploids, 11 different high molecular weight subunits were identified, three of which were related to Glu-A1, five for Glu-B1 and three were related to Glu-D1. Interestingly, the subunit 2.1+10* was observed in three landraces.In tetraploids, nine subunits were identified, of which two were related to Glu-A1 and seven were related to Glu-B1. Low molecular weight glutenin subunit encoding genes were investigated using seven DNA primer pairs for Glu-A3, Glu-B3 and Glu-D3 loci. Five alleles were identified for Glu3-A.2 with frequencies ranging from 3.092 to 96.907.Two alleles were identified by Glu3-A3 with relative frequencies of 0.412 and 0.608%.For Glu3-B.1, 10 alleles were identified, with frequencies ranging from 1.030 to 92.783. However, three alleles a, b and c were identified by Glu3-B.2 with frequencies of 0.01, 0.78 and 0.20, respectively. Three specific primers were used for Glu-D3 locus and because durum wheat lacks DD genome, it was not estimated in this genetic block. Using PCR amplification, nine alleles were identified for Glu3-D1 with frequencies ranging from 5.34 to 86.67. Also two and three alleles were identified using Glu3-D.3 and Glu3-D.4, respectively.

Being a large genus in the Asteraceae family, the genus Centaurea is a complex and problematic taxon. Centaurea virgata Lamark is a widespread and invasive species of the Centaurea genus. This species is found in different regions of Iran. However, there are limited studies on this plant, especially at the morphologic and genetic level. The present study aimed to investigate the intraspecific variations of C.virgata collected from different regions of Iran based on morphological data. A morphometric study based on 27 quantitative and 28 qualitative morphological characters was carried out on 65 specimens from 31 populations. Cluster and principal coordinates analyses (PCO) of morphological characters showed that the 31 populations could be divided into three main groups and two subgroups. The analyses of variance (ANOVA) of morphological characters indicated that most of the evaluated characters were significantly different (P˂0.05) among C. virgata populations. It also demonstrated that there were not significant differences (P˂0.01) among populations of C. virgata for six morphological characters, including the width of the inflorescence leaves, inner phyllaries width, outer phyllaries width, outer phyllaries cilia length, phyllary rows number, and stamen number. It could be concluded that there is a high morphological variation among various populations of C. virgata collected from different regions of Iran. These morphological variations of C. virgata populations can be related to different ecological and environmental conditions or endogenous factors such as genetics, and the presence of adaptation mechanisms to specific situations.

Genotype×environment interaction is one of the most important production challenges for plant breeders. Line selection with desirable yield is severely affected by genotype×environment interaction. In order to consider this interaction, 13 M8 mutant genotypes derived from Tarrom-Mahalli rice land races along with 3 control, Tarrom-Mahalli, Tarrom-Jelodar and Neda were used to evaluate their grain yield stability and adaptability using a RCBD design with 3 replications and two regions in Mazandaran province in 2016-2017. Analyses were carried out using the AMMI method. Effects of genotype, environment and their interactions were significant. Two components of the first model covered more than 91% of the interaction variance. The bi-plot showed that genotypes 15, 18, 31, 30 and 33, Tarrom-Jelodar and Tarrom-Mahalli were the stable genotypes. Results of AMMI model statistics showed that according to AMGE statistics, Neda, genotypes 26 and 31, based on ASI, MASI and MASV statistics, genotypes 33, 26 and 30 and based on AVAMGE, DA, FA, SIPC and ZA statistics, genotypes 33, 30 and 31 had the highest stabilities, respectively. According to the results of the indices of simultaneous selection for grain yield and stability for each of AMMI statistics it is observed that genotypes 33, 31, Tarrom-Jelodar, genotypes 26 and Neda cultivar are identified as the stable high yielding genotypes. Results showed that most of stability statistics based on the AMMI model are appropriate stability indices for identifying stable genotype with high grain yield.

Chili pepper (Capsicum annum L.) is a self-pollinating plant from Solanaceae family and one of the most important vegetables for food and medicinal consumption. Iran is one of the regions with the highest production level of this product. Estimates of combining ability are useful in determining breeding value of chili pepper lines by proposing the correct breeding method to produce new hybrids with high yield and quality. This study was conducted to evaluate general and specific combining ability in 7 inbred lines recommended for chili pepper breeding, based on a previous research. Analysis of variance revealed significant differences among genotypes for the studied traits. The highest number of fruit per plant (145) was observed in ‘2×5’ hybrid. For fruit per plant, the highest specific and general combining abilities were observed in ‘1×5’ hybrid and line ‘2’, respectively. The highest mid- and max-heterosis for the number of fruit per plant was observed in ‘2×3’ and ‘1×4’ hybrids. The highest heterosis for fruit length and diameter was observed in ‘2×6’ hybrid. Yield heterosis is the primary target for increasing productivity but the biological complexity of yield as a trait frequently makes it difficult to draw meaningful conclusions in order to track individual causal elements involved in heterosis. Therefore, chili breeders might develop F1 cultivars based on high specific combining ability for yield-related characteristics such as fruit number per plant and fruit length. Crossing lines ‘2’ and ‘6’ are suggested for hybrid production due to high values of this hybrid for many characters related to chili pepper yield and quality.

Drought stress causes changes in morphology, physiology and gene expression profile in the plants. One of the ways to respond to this stress is to change the synthesis of specific polypeptides such as LTP (Lipid transfer proteins). For this purpose, LTp expression level was investigated under three osmotic potentials of -2, -4 and -6 bar in combination with different time courses of 0, 3, 6, 10, 24, 48 and 72 h after applying stress using RT-qPCR in DN-11 and Marvdasht genotypes. Also, the soluble sugar content in both genotypes was measured by the phenol-sulfuric acid method after each stress level. Furthermore, promoter analysis of LTp was studied using bioinformatics tools. The results showed that the highest expression level of LTp in both genotypes occurred at -6 bar osmotic potential level and 48 h after stress in DN-11 and 72 h after stress in Marvdasht. There was no significant difference between 48 h and 72 h after stress in the DN-11 genotype and between 72 h and 3 h after stress in Marvdasht genotype at P-value of ≤ 0.01, but there was a significant difference among other time courses at P-value of ≤ 0.01. Besides, the soluble sugar content increased with increasing stress levels in both genotypes, so that its amount was higher than control at -6 bar stress level. The promoter analysis showed that several domains and motifs in the LTp promoter region are activated in response to drought stress and increase its expression. Therefore, it can be concluded that LTp gene can be used as a drought resistance gene in gene transformation and genetic engineering programs.

Nanoparticles have unique physicochemical properties and provide great opportunities in plant science studies. In this study, we investigated the impact of ZnO, TiO2 and CuO nanoparticles (0, 20, 40, 60, and 80 mg/L) and sampling times (2, 4, and 6 days) on cell suspension growth and azadirachtin accumulation and production. Factorial experiments based on a completely randomized design with three replications were used. Results demonstrated that different nanoparticles had a different effect on the studied characters. When ZnO nanoparticles were used, the highest fresh (540.73 g/L), dry cell weight (15.93 g/L), azadirachtin accumulation (5.15 mg/g DW) and production (68.27 mg/L) were obtained at control condition, 80 and 40 mg/L ZnO nanoparticles, and control condition after 6 days, respectively. The highest amount of fresh (526.95 g/L) and dry (17.05 g/L) cell weight and azadirachtin production (82.21 mg/L) and accumulation (5.93 mg/g DW) were observed in 20 mg/L TiO2 nanoparticles, 40 mg/L of TiO2 nanoparticles after 2 days, 20 mg/L TiO2 nanoparticles in 4 days and 60 mg/L of TiO2 nanoparticles, respectively. With applying CuO nanoparticles, the highest fresh cell weight and azadirachtin accumulation were 422.59 g/L and 4.00 mg/L, achieved in control conditions respectively. Also, the highest amount of azadirachtin production was 68.27 mg/L, observed in control conditions on the 6th day of treatment. It seems that suitable cell growth, except in some cases, occurred in the absence of elicitors, but azadirachtin accumulation and production were stimulated by nanoparticles treatment. However, the results showed that the CuO nanoparticles caused a decrease in overall azadirachtin accumulation and production in the cells.

Drought stress as one of the major growth limiting factors in natural environments influences photosynthetic components and electron transfer process, elevating the production of reactive oxygen species (ROS), leading to damage to the cell. Furthermore, ROS are toxic by-products resulted from stress and are involved in signaling pathways, causing major transcriptional changes. ROS scavenging enzymes, localized in the thylakoid membrane of chloroplasts, play a key role in the detoxification of ROS. The capacity of ROS-scavenging enzymes depends on several factors including plant species, duration and intensity of drought stress, stages of plant development, and gene expression patterns of various isoforms. In this regard, novel functional and regulatory genes related to ROS-scavenging enzymes in plants are identified that play a key role in response to drought stress. These genes are differentially expressed in sensitive and tolerant species that may be related to the drought tolerance level of plant species themselves; but the overexpression of those genes in transgenic plants mainly improves drought stress tolerance. However, in some conditions, high drought stress severely damages the photosynthesis apparatus. This damage has a direct relationship to photochemical activities of both PSII and PSI that are required for protecting photosystems against photoinhibition. The photosystem protections are related to precise regulation in D1 protein accumulation under high light conditions, contributing to avoid excessive ROS accumulation. This review describes the influence of drought stress on photosynthetic characteristics, also discusses that the overexpression of genes associated with ROS scavenging enzymes in transgenic plants results in higher drought tolerance and improved photosynthetic characteristics.