Wheat Cv Research Articles

Occurrence of the Fusarium incarnatum-equiseti Species Complex Causing Fusarium Head Blight of Wheat in Mexico.

Fusarium head blight (FHB) is one of the most important diseases affecting wheat production worldwide. In Mexico, Fusarium boothii and F. avenaceum are the dominant species causing FHB of wheat (Cerón-Bustamante et al. 2018). During the 2017 to 2019 surveys, FHB symptoms were observed in wheat fields in the Highlands region of Mexico. Symptomatic spike samples were collected from 19 wheat fields in five states (Tlaxcala, Hidalgo, Puebla, Estado de México, and Morelos). Fusarium-like colonies were consistently isolated on potato dextrose agar (PDA) and 95 monoconidial isolates were obtained. Morphological features of seven isolates were consistent with the description of the Fusarium incarnatum-equiseti species complex (Xia et al. 2019). On PDA, colonies exhibited white and fluffy aerial mycelia, with diffused pink pigment on the reverse side after 7 days of incubation at 25℃. On carnation leaf agar (CLA), macroconidia (n = 100) were hyaline, falcate, with 3 to 6 septa, measuring 25.2 to 43.1 × 2.8 to 5.1 μm, and foot-shaped basal cell. Chlamydospores were ellipsoidal or subglobose and produced in chains. These seven isolates were selected for multilocus phylogenetic analysis and pathogenicity tests. Isolates were deposited in the Culture Collection of Phytopathogenic Fungi of the Department of Agricultural Parasitology at the Chapingo Autonomous University under acc. nos. UACH428 to UACH434. For molecular identification, genomic DNA was extracted, and the internal transcribed spacer (ITS) region, partial sequences of translation elongation factor 1-alpha (EF1-α) and the second largest subunit of RNA polymerase II (RPB2) genes were amplified, and sequenced with the primer sets ITS5/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and RBP2-5F/RPB2-7R (Liu et al. 1999), respectively. A phylogenetic tree, including published ITS, EF1-α, and RPB2 sequence data, was constructed for the Fusarium incarnatum-equiseti species complex (FIESC) based on Maximum Likelihood. Three species of the FIESC were identified into F. pernambucanum (five isolates), F. sulawesiense (one isolate), and F. clavum (one isolate). The sequences were deposited in GenBank with accession nos. OL347713 to OL347719 for ITS, OL365078 to OL365084 for EF1-α, and OL365072 to OL365077 for RPB2. The pathogenicity of the isolates was confirmed on wheat cv. Nana F2007 at the flowering stage in a glasshouse assay. The heads of 20 wheat plants were sprayed with a conidial suspension (1 × 105 spores/ml) of each isolate. Ten plants mock-inoculated with sterilized water served as the controls. All plants were placed in a moist chamber for 48 h. At 10 days after inoculation, typical FHB symptoms were visible on the inoculated plants, whereas the control plants remained asymptomatic. The pathogenicity test was repeated twice with similar results. The fungi were reisolated from the infected heads and found to be morphologically identical to the isolates used for inoculation, fulfilling Koch's postulates. Previously, three isolates of Fusarium sp. belonging to the FIESC, were associated with FHB of wheat in Mexico (Cerón-Bustamante et al. 2018); however, this is the first report of F. pernambucanum, F. sulawesiense, and F. clavum causing FHB of wheat in Mexico and worldwide (Farr and Rossman 2021). Further studies should be focused on determining the distribution, prevalence, and toxigenic potential of the isolates of the FIESC associated with wheat diseases in Mexico.

Application of Smart Agricultural Practices in Wheat Crop to Increase Yield and Mitigate Emission of Greenhouse Gases for Sustainable Ecofriendly Environment

The present study was based on the hypothesis that “the use of classical farming techniques is the cause of emission of greenhouse gases (GHGs) in the study area, which can be mitigated by employing smart agricultural practices (SAPs)”. The study comprises experimental trials, which were carried out over two consecutive years (2020–2021) on two experimental areas (site 1: Koel, site 2: Moel) in District Bhimber of Azad Jammu and Kashmir, Pakistan. Wheat cv. Punjab-2018 was used in the experiment. The experiment was performed in a split-plot factorial arrangement with the main experimental plot bisected into two subplots. Within the two halves of the experimental plot, one side experienced the original tillage practice (PT––by ploughing at a depth of 4–6 cm; HT––by harrowing at 12–15 cm; NT––no tillage, of subsoil or soil ploughing). The subsoiling technique applied included subsoiling ploughing tillage (SPT), subsoiling harrow tillage (SHT), and subsoiling of no-tillage (SNT). Subsoiling was performed by means of ploughing land utilizing a vibrating subsoil trowel to a depth of 14 to 14.5 inches. As a result, each subplot was divided into three replicates. So, a total of six replicates, each 35 m in length and 4 m in width were chosen for the experiment. The results depicted that the influx of COx uptake increased in all subsoiling treatments: that is, SPT, SHT, and SNT. The uptake of COx was comparatively lower in HT, RT, and NT. In the same manner, GWP for NOx was recorded to increase when the soil was subjected to subsoiling, that is, HTS, RTS, and NTS. Along with this, the trend of soil temperature and soil content also fluctuated with R2 = 0.78 at p < 0.01 from February to April and R2 = 0.66 from December to January, which shows that SAP causes higher emission of NOx and more uptake of COx. Subsoiling maintains soil moisture content (SMC) and soil organic carbon (SOC), which allows limited release of NOx from soil, maintaining the soil nitrogen content. In the case of SOC and pH, it was found that higher pH causes reduced absorption of COx into soil and NOx emission from soil while higher SOC causes more absorption of COx into soil and more emission of NOx. The application of smart agriculture in the form of subsoiling leads to an increase in the yield of wheat crops and is recommended in agriculture in the context of climate change.

Exploring the Potential of Moringa Leaf Extract for Mitigation of Cadmium Stress in Triticum aestivum L.

Cadmium (Cd) is one of the most toxic metals accumulated in wheat grains. Daily intake of Cd through food is posing serious health problems. There is an urgent need to reduce the uptake and accumulation of Cd in wheat and other cereal crops. In this study, we investigated the potential of moringa leaf extract (MLE) in decreasing the Cd toxic effects in wheat (Triticum aestivum L.) cv. A.S. 2002. Sowing was carried out in pots under shade and natural light conditions. Two Cd concentrations (500 µM and 1000 µM) were applied with and without MLE (0 and 3%). Results revealed that plant growth parameters viz diameter of stem, number of leaves, leaf area, photosynthetic pigments were improved with MLE application under Cd stress. Moreover, biochemical attributes and osmolytes such as total soluble sugars, and soluble proteins, phenolic content and flavonoids were negatively effected by Cd stress and were improved under MLE treatment. Moreover, Cd stress enhanced phytotoxicity as higher ROS accumulation is observed under both stress conditions, whereas after MLE application MDA and H2O2 accumulation was significantly decreased. Based on current observations, MLE was effective in mitigating the biological and toxic effects of Cd by promoting the growth attributes and mineral contents in wheat. Further experiments are needed for discovering the molecular mechanisms underlying MLE and host plant interactions involved in Cd stress mitigation.

Germination, physio-anatomical behavior, and productivity of wheat plants irrigated with magnetically treated seawater.

Salinity is an abiotic stress that reduces the seed germination and productivity of wheat. The objective of this study was to assess the impact of irrigation with magnetically treated seawater on the germination, growth, certain physiological and anatomical parameters, and production attributes of wheat (Triticum aestivum L.) cv. Sakha 93 plants. Experiments were conducted in the Experimental Farm of the Faculty of Agriculture, Menoufia University, Egypt, during two consecutive winter seasons. Pot experiments involved ten treatments with non-magnetized and magnetized water with various degrees of salinity. Plant samples were taken 95 days after sowing. Irrigation with magnetically treated seawater was found to have beneficial effects on plant growth, water relations, biochemical characteristics, and yield components compared with untreated plants. The germination of wheat seeds increased 13% when treated with magnetic seawater. On the yield scale, the spike length was increased by 40% in season one, and 82% in season two when compared to the control, while the weight of 100 grains increased by 148% and 171%, in each season, respectively, when treated with magnetic water. The anatomical leaf and stem parameters of the plants were markedly improved by watering with magnetically treated seawater at 10 dS m−1 compared to the control. However, the leaf water deficit, transpiration rate, and abscisic acid content in the plant shoots decreased significantly (p < 0.05). The use of magnetically treated seawater of up to 7.5 dS m−1, instead of tap water, is recommended due to benefits to germination and seedling parameters, growth, yield, and physiological, chemical, and anatomical characteristics. In conclusion, magnetic treatment of seawater improved germination performance, growth, and yield of wheat under saline conditions.

Oxidative Stress Mitigation by Chitosan Nanoparticles in Durum Wheat Also Affects Phytochemicals and Technological Quality of Bran and Semolina.

In our previous work, durum wheat cv. Fabulis was grown over two consecutive seasons (2016–2017 and 2017–2018) in an experimental field in the north of Italy. With the aim of mitigating oxidative stress, plants were subjected to four treatments (deionized water, CHT 0.05 mg/mL, CHT-NPs, and CHT-NPs-NAC) three times during the experiment. Chitosan nanoparticles (CHT-NPs) reduced symptom severity on wheat leaves and positively influenced the final grain yield. The present work aimed at investigating whether CHT treatments and particularly N-acetyl cysteine (NAC)-loaded or -unloaded CHT-NPs, while triggering plant defense mechanisms, might also vary the nutritional and technological quality of grains. For this purpose, the grains harvested from the previous experiment were analyzed for their content in phytochemicals and for their technological properties. The results showed that CHT increased the polyphenol and tocopherol content and the reducing capacity of bran and semolina, even if the positive effect of the nano-formulation remained still unclear and slightly varied between the two years of cultivation. The positive effect against oxidative stress induced by the chitosan treatments was more evident in the preservation of both the starch pasting properties and gluten aggregation capacity, indicating that the overall technological quality of semolina was maintained. Our data confirm the role of chitosan as an elicitor of the antioxidant defense system in wheat also at the grain level.

Smart Agronomy of Wheat Cultivation in Riverbed of Betawa through Natural and Organic Farming under Changing Climate

The present innovative and introductive experiment was laid out during two consecutive rabi seasons of 2009-10 and 2010-11 under “Farmers Participatory Action Research Project on Water/Water Harvesting” (Scheme funded by Central Water Commission, New Delhi). Since, the extensive farming almost closed up because all cultivable land saturated under cultivation of crops and other agricultural enterprises. During the visit of Bundelk hand region of U.P. for scheme work, the riverbed open after water receding of Betawa river was seen. The open riverbed was found suitable for cultivation of winter season crops. Riverbed was suffered from the nodulation of rocks (Maurang), but siltation was fertile. Therefore, the site was selected for cultivation of wheat because it has better nutrients status. The riverbed soil was fertilized with organic manure i.e., FYM @ 200 q/ha, vermi cost + vermi-eggs@10 q/ha and mustard cake @ 5 q/ha for major and minor plant nutrients and loosened the riverbed soil. Wheat cv. WH-147 was planted on 15 November and harvested 20 March after 125 days of planting in both experimental seasons.

A comparative study of plant growth promoting rhizobacteria (PGPR) and sowing methods on nutrient availability in wheat and rhizosphere soil under salinity stress

An experiment was conducted to evaluate the role of plant growth promoting rhizobacteria and sowing methods on physicochemical properties, nutrients and heavy metals content of rhizosphere soil and their translocation to plant. Wheat cv. Inqlab-91 seeds were inoculated with cultures of Pseudomonas mendocina Khsr2, Pseudomonas putida Khsr4, Pseudomonas stutzeri Khsr3 and Azotobacter vinelandii Khsr1 3 h prior to sowing. Broadcast, drill and ridge methods of sowing were applied. The PGPR inoculations significantly decreased the pH, electrical conductivity and sodium adsorption ratio of rhizosphere soil of inoculated plants over that of uninoculated soil. The applied bacterial strains significantly improved the transfer of K,Ca, Mg and Zn from soil to plant shoots and reduced the transfer of Cr .In contrast K and Ca transfer factor was much lower but Cr transfer factor was higher for plants experiencing differing sowing methods. The ridge sowing enabled the plant to have better transfer factor for K and Ca, Mg and Zn as compared to other sowing methods. Pseudomonas putida Khsr4 inoculated plant leaves also exhibited significantly higher Zn and Fe content. The maximum K+/Na + ratio of rhizosphere soil and wheat leaves were recorded in Pseudomonas putida Khsr4 inoculation. The effect of Pseudomonas putida Khsr4 was more pronounced on yield and size of grain as measured by 1000 grain weight of plant. The applied PGPR helped in selective uptake of K over Na and enhanced transfer of nutrients resulting in higher yield. Yield of ridge sown plot was 3.59% higher than drill sown plot, and 10.87% higher than broadcast sown plot respectively. The Ridge method of sowing was better than drill and broadcast to combat salt stress and also influenced the nutrient uptake by plants and reduced heavy metal uptake. It is inferred that growing PGPR inoculated plants using ridge sowing can better induce salt tolerance to plant through selective uptake of K, Ca, Mg and Zn and suppressing heavy metal uptake resulting in higher yield and large sized grains.

Impact of Spent Mushroom Substrate on Glomus mosseae Establishment in Wheat (Triticum aestivum) and Pearl Millet (Pennisetum glaucum)

The application of spent mushroom substrate (SMS) in soil increases yields and improves quality of agriculture produce. Glomus mosseae is a predominant species of arbascular mycorrhizae (AM) fungus in soils and it help the plant in many ways. The substrate from the production process of cultivated mushrooms is a material with a high lignocellulosic content and rich in organic matter, which, when incorporated into the soil, changes its chemical attributes. Thus, this substrate can be used in the preparation of organic compounds, the manufacture of biofertilizers and chemical soil conditioner in semi-arid regions. Thus, the research tried to evaluate the presence of the substrates at different concentrations in the growth, development and establishment of G. mosseae fungi at 45 and 60 days after sowing to help the productivity of wheat and pearl millet for three consecutive years from 2018-19 to 2020-21under screenhouse conditions.&#x0D; One year old button mushroom SMS was mixed in sterile sandy loam soil at 10, 20, 30% (w/w basis) and pure culture of G. mossea was applied at 450-500 sporocarp/kg of soil and then filled with earthen pots of 30 cm diameter. Twenty seeds of wheat cv. WH 1105 were sown in each pot during the third week of November every year and maintained. Similarly, twenty seeds of pearl millet cv. HHB 67 (I) was sown in each pot in first week of July every year and maintained. The plants raised in soil without SMS but inoculated with G. mosseae served as control. The treatments were replicated ten times and the experiments were laid out as per RCBD design. The observations on mycorrhizal colonization (%) and sporocarps numbers per 100g soil were taken at 45 and 60 days after sowing (DAS) in wheat and pearl millet.&#x0D; In wheat cv. WH 1105, the root colonization (%) and sporocarp numbers/100 g soil of G. mosseae were higher when SMS at 30% was applied in soil and lowest in control. These increased further in all treatments at 60 DAS as compared to 45 DAS stage during three years of experimentation. The root colonization at 60 DAS was significantly high at 24.9, 34.8 and 27.9 % when SMS applied in soil at 30% and it was lowest at 20.2, 30.1, 23.1% in control during 2018-19, 2019-20 and 2020-21, respectively. The sporocarp numbers at 60 DAS were also found to be high at 255, 195 and 325 sporocarps/100 g soil when 30% of SMS was applied in soil and lowest at 210, 172, 265 sporocarps/100 g soil in control during 2018-19, 2019-20 and 2020-21, respectively.&#x0D; In pearl millet hybrid HHB-67 (Improved), the root colonization and sporocarp numbers/100 g soil of G. mosseae were higher when SMS at 20% was applied in soil and lowest in control. These increased further in all treatments at 60 DAS as compared to 45 DAS stage during three years. The root colonization at 60 DAS was significantly higher in 34.0, 35.3 and 34.7% when SMS was applied at 20% and it was lowest at 34.3, 33.2, 31.1% in control during 2018-19, 2019-20 and 2020-21, respectively. The sporocarp numbers at 60 DAS were also found to be high at 229, 250 and 174 /100 g soil when SMS at 20% was applied and it was lowest at 219, 205, 150 sporocarps/100 g soil in control during 2018-19, 2019-20 and 2020-21, respectively.

Introgression of the Triticum timopheevii Genome Into Wheat Detected by Chromosome-Specific Kompetitive Allele Specific PCR Markers.

Triticum timopheevii (2n = 28, AtAtGG) is a tetraploid wild relative species with great potential to increase the genetic diversity of hexaploid wheat Triticum aestivum (2n = 42, AABBDD) for various important agronomic traits. A breeding scheme that propagated advanced backcrossed populations of wheat-T. timopheevii introgression lines through further backcrossing and self-fertilisation resulted in the generation of 99 introgression lines (ILs) that carried 309 homozygous segments from the At and G subgenomes of T. timopheevii. These introgressions contained 89 and 74 unique segments from the At and G subgenomes, respectively. These overlapping segments covered 98.9% of the T. timopheevii genome that has now been introgressed into bread wheat cv. Paragon including the entirety of all T. timopheevii chromosomes via varying sized segments except for chromosomes 3At, 4G, and 6G. Homozygous ILs contained between one and eight of these introgressions with an average of three per introgression line. These homozygous introgressions were detected through the development of a set of 480 chromosome-specific Kompetitive allele specific PCR (KASP) markers that are well-distributed across the wheat genome. Of these, 149 were developed in this study based on single nucleotide polymorphisms (SNPs) discovered through whole genome sequencing of T. timopheevii. A majority of these KASP markers were also found to be T. timopheevii subgenome specific with 182 detecting At subgenome and 275 detecting G subgenome segments. These markers showed that 98% of the At segments had recombined with the A genome of wheat and 74% of the G genome segments had recombined with the B genome of wheat with the rest recombining with the D genome of wheat. These results were validated through multi-colour in situ hybridisation analysis. Together these homozygous wheat-T. timopheevii ILs and chromosome-specific KASP markers provide an invaluable resource to wheat breeders for trait discovery to combat biotic and abiotic stress factors affecting wheat production due to climate change.

GmTDN1 improves wheat yields by inducing dual tolerance to both drought and low-N stress.

SummaryGenetically enhancing drought tolerance and nutrient use efficacy enables sustainable and stable wheat production in drought‐prone areas exposed to water shortages and low soil fertility, due to global warming and declining natural resources. In this study, wheat plants, exhibiting improved drought tolerance and N‐use efficacy, were developed by introducing GmTDN1, a gene encoding a DREB‐like transcription factor, into two modern winter wheat varieties, cv Shi4185 and Jimai22. Overexpressing GmTDN1 in wheat resulted in significantly improved drought and low‐N tolerance under drought and N‐deficient conditions in the greenhouse. Field trials conducted at three different locations over a period of 2–3 consecutive years showed that both Shi4185 and Jimai22 GmTDN1 transgenic lines were agronomically superior to wild‐type plants, and produced significantly higher yields under both drought and N‐deficient conditions. No yield penalties were observed in these transgenic lines under normal well irrigation conditions. Overexpressing GmTDN1 enhanced photosynthetic and osmotic adjustment capacity, antioxidant metabolism, and root mass of wheat plants, compared to those of wild‐type plants, by orchestrating the expression of a set of drought stress‐related genes as well as the nitrate transporter, NRT2.5. Furthermore, transgenic wheat with overexpressed NRT2.5 can improve drought tolerance and nitrogen (N) absorption, suggesting that improving N absorption in GmTDN1 transgenic wheat may contribute to drought tolerance. These findings may lead to the development of new methodologies with the capacity to simultaneously improve drought tolerance and N‐use efficacy in cereal crops to ensure sustainable agriculture and global food security.

Intra- and interspecies competition of blackgrass and wheat in the context of herbicidal resistance and environmental conditions in Poland

Blackgrass (Alopecurus myosuroides Huds.), one of the most aggressive grass weeds in Europe, is also a strong competitor of crops. This study aimed to assess the impact of environmental conditions on the competition between (1) ACC-ase and ALS herbicide-resistant (BR) and herbicide-susceptible (BS) blackgrass biotypes, (2) BR and winter wheat cv. Arkadia (W), and (3) BS and W. In the replacement series model, the experiment was conducted at seven sites across Poland during two seasons (2018/19 and 2019/20). In the BR-BS experiment, the BS biotype was in majority more competitive toward the BR biotype. However, in the regime of optimal hydrothermal conditions and at a higher sand content in the soil we observed a higher competitiveness of BR towards BS. The combined interactions between W and BR or BS were also affected by environmental conditions, i.e., soil texture and hydrothermal coefficient, as explained by PCA and k-means cluster analysis. At most sites, W was more competitive toward both BS and BR, which could result from earlier emergence of W in relation to B in majority of sites. Except for two cases, located on heavy, clay soils, during humid seasons, where B was more competitive toward W. We summarize that blackgrass competitiveness towards other biotypes and wheat depends to some extent on environmental conditions; however, the phenomenon should be explored in more detail.

Residual Effects of 50-Year-Term Different Rotations and Continued Bare Fallow on Soil CO2 Emission, Earthworms, and Fertility for Wheat Crops.

In this study, our investigated hypothesis was that different pre-crops would have different effects on earthworm activity and soil CO2 emissions. We also hypothesized that a pre-crop clover–timothy mixture would perform best in terms of increasing the share of organic carbon in soil and, in this way, contribute to improving the sustainability of agroecosystems. The aim of this study was to explore the residual effects of using a 50-year-term of three different crop rotations and a continuous bare fallow period on soil CO2 emissions by investigating the soil earthworm populations, soil agrochemical properties, and winter wheat yields. A field experiment was carried out from 2016 to 2017 at Vytautas Magnus University in Lithuania (54°53′ N, 23°50′ E). The experiment was conducted in crop stands of winter wheat cv. ‘Skagen’, which were sown in three crop rotations with different pre-crops and a continuous bare fallow period. The pre-crop used for winter wheat in the cereal crop rotation (CE) was a vetch and oat mixture for green forage, LEG-CER; the pre-crop used for winter wheat in the field with row crops (FWR) crop rotation was black fallow, FAL-CER; the pre-crop used for winter wheat in the Norfolk (NOR) crop rotation was a clover–timothy mixture, GRS-CER; and finally, continuous bare fallow, FAL-CONTROL, was used as well. The highest soil CO2 emission intensity was determined after the pre-crops that left a large amount of plant residues (clover and timothy mixture) in the soil. Plant residues remaining after the pre-crop had the greatest effect on the number of earthworms in the soil after the harvesting of winter wheat. Winter wheat had the best yield when grown in grass and legume sequences. Crop rotation sequences that included perennial grasses accumulated higher contents of total nitrogen and organic carbon. The best values for the productivity indicators of wheat were obtained when it was grown after a fallow crop fertilized with cattle manure. An appropriate crop rotation that promotes the steady long-term contribution of organic matter and increases the content of organic carbon in the soil will have a positive effect on the agrochemical, biological, and physical properties of soil and agroecosystem sustainability; moreover, these effects cannot be achieved by technological means alone.

Wheat productivity and its profitability as influenced by targeted yield approach versus nutrient management practices

Field experiments were conducted on wheat cv. HD-2967 at farmer’s field during 2015-16 and 2016-17 to evaluate fertilizer management practices vis-a-vis farmer’s practice on wheat productivity and its profitability in Rajpura village of Aligarh, (U.P.) wherein three trials for each site were studied. Results indicated that, maximum average yield of wheat was 4.58 and 4.60 t ha-1 at site I and II, respectively under targeted yield approach for 5.5 tonne (TY5.5t) which were higher by 39.5% at site-I and 41.8% at site-II over farmer’s practice (FP). The application of nutrients under soil test based targeted yield approach; nearly 39-42% wheat yield could be increased over FP. Moreover, the higher net profit was recorded as Rs. 32,110 ha-1 and 28,400 ha-1 at site-I and II, respectively with targeted yield approach fertilizer management. The improvement in available nitrogen, phosphorus and potassium was noticed at both sites (I and II) under targeted yield based fertilizer management approach in post-harvest soil after two years of trials.

Wheat productivity and its profitability as influenced by targeted yield approach versus nutrient management practices

Field experiments were conducted on wheat cv. HD-2967 at farmer’s field during 2015-16 and 2016-17 to evaluate fertilizer management practices vis-a-vis farmer’s practice on wheat productivity and its profitability in Rajpura village of Aligarh, (U.P.) wherein three trials for each site were studied. Results indicated that, maximum average yield of wheat was 4.58 and 4.60 t ha-1 at site I and II, respectively under targeted yield approach for 5.5 tonne (TY5.5t) which were higher by 39.5% at site-I and 41.8% at site-II over farmer’s practice (FP). The application of nutrients under soil test based targeted yield approach; nearly 39-42% wheat yield could be increased over FP. Moreover, the higher net profit was recorded as Rs. 32,110 ha-1 and 28,400 ha-1 at site-I and II, respectively with targeted yield approach fertilizer management. The improvement in available nitrogen, phosphorus and potassium was noticed at both sites (I and II) under targeted yield based fertilizer management approach in post-harvest soil after two years of trials.

Agronomic assessment of the durum

The wheat Green Revolution Rht-B1b and Rht-D1b dwarfing alleles are associated with increased grain yields but also with reduced early growth and seedling emergence, especially if sowing conditions are unfavourable. The gibberellic acid-responsive, mutagen-derived Rht18 dwarfing gene was backcrossed from durum wheat (Triticum turgidum subsp. durum L.) cv. Icaro into tall bread wheat (Triticum aestivum L.) cv. Halberd using phenotypic selection for reduced plant height. The Rht18 allele was confirmed among homozygous BC1F2-derived, F5:7 recombinant inbred lines by using a chromosome 6AS-linked, microsatellite molecular marker (Xwms4608), and then assessed for agronomic performance across multiple field sites ranging in yield from 3.6 to 6.4 t/ha. The Rht18-containing lines were significantly (P &lt; 0.05) shorter in height (−24%) and reduced in plant lodging (−51%) compared with tall sister lines. Reductions in plant height were associated with significant increases in grain yield (+16%), reflecting increases in grain number (+21%), number of spikes (+7%) and number of grains per spike (+12%). Coleoptile length, early shoot biomass and ground cover percentage were unaffected by the presence of the Rht18 dwarfing gene. Comparisons of effects of gibberellic acid-insensitive Rht-B1b and Rht18 on early growth and agronomic performance were assessed separately for a set of 30 BC5F6-derived Halberd near-isogenic lines in the field in 2015. Ground cover and coleoptile length were significantly greater for Rht18 lines, whereas plant height, lodging, harvest index, grain number and yield were similar for Rht-B1b and Rht18 sister lines. Reduced lodging and increased grain number and yield, together with greater coleoptile length, indicate a potentially useful role for Rht18 in improving wheat performance.

Assessment of elite wheat germplasm for resistance to Fusarium head blight -a threat to wheat production in north-west Pakistan

Fusarium head blight (FHB), caused by Fusarium graminearum, affects both quality and quantity of wheat produce. In Pakistan, due to favorable environmental conditions during spring, FHB can cause significant losses to wheat. Recently, we observed FHB in wheat fields, having 34-84% incidence, along river Swat, Northwest Pakistan. Therefore, elite wheat cultivars and candidate lines in Pakistan as well as exotic-near isogenic lines were screened for FHB resistance using molecular markers, specific for Fhb-1, 2 and 3. Furthermore, all the germplasm was screened for 2NS Translocation - from Triticum ventricosum segment containing cluster of resistance genes for many diseases including FHB. Among Pakistani wheat varieties, Marvi-2000 showed presence of Fhb-2 and 3 specific bands while wheat cv. Saleem-2000 displayed presence of Fhb-1 and 2 specific bands. However, among the candidate lines, L-112, L-105, L-106, L-103 and L-129 exhibited Fhb-1 and 2 specific bands while L-111 alone amplified bands specific to Fhb-1 and Fhb-3. Moreover, 2NS translocation was validated in 2NS near isogenic lines (NILs) obtained from Kansas State University using 2-NS specific marker VENTRIUP and LN2, however, no 2-NS translocation was found in Pakistani varieties as well as candidate lines. In conclusion, none of the Pakistani varieties or candidate lines possessed all sources of FHB resistance in altogether; however, one aliens NIL (Yaccora-Rojo-2NS) surprisingly not only exhibited 2NS translocation but also Fhb-1, 2 and 3 resistant genes.

Overexpression of the autophagy-related gene

Context Salt stress harms plant growth and limits crop productivity. Autophagy is a material decomposition and metabolism pathway that is central to regulating plant responses to environmental stimuli and may be employed in plant breeding for stress tolerance. The autophagy-related gene ATG8 has become an essential tool for monitoring autophagic activity. Aims We aimed to determine the effects of increased autophagic activity via overexpression of ATG8 on tolerance of wheat (Triticum aestivum L.) seedlings to NaCl stress. Methods Salt-tolerant wheat cv. Jimai22 was used to produce TaATG8a-overexpressing wheat seedlings using Foxtail mosaic virus based virus-mediated overexpression technology. TaATG8a-overexpressing seedlings were exposed to NaCl stress for 6 days. Key results Overexpression of TaATG8a enhanced autophagic activity and improved salt stress tolerance of wheat seedlings. Overexpression of TaATG8a also reduced damage to photosystem II, reduced excess accumulation of reactive oxygen species, increased the activities of superoxide dismutase, peroxidase and catalase, and suppressed programmed cell death in wheat seedling leaves during NaCl treatment. Conclusions Overexpression of TaATG8a conferred higher tolerance of wheat seedlings to NaCl stress and suppressed salt-induced programmed cell death, accompanied by increased autophagic activity. Implications This study provides genetic resources and a theoretical basis for stress tolerance breeding in wheat.

Morphological, Cultural, Molecular and Pathogenic Variation of &amp;lt;i&amp;gt;Bipolaris sorokiniana&amp;lt;/i&amp;gt; in Wheat

One hundred and twenty isolates of Bipolaris sorokiniana of wheat were isolated, identified and characterized based on morphological, cultural, pathogenic and ITS (Internal Transcribed Spacer) based molecular parameters. Collected isolates differed in respect of radial mycelial growth rate, color of the colony, surface texture of the colony, shape of the colony, conidia production ability and shape and color of conidia. ITS1 and ITS4 based PCR products yielded a species-specific band of 600 bp (base pairs) on agarose gel for the confirmation of B. sorokiniana. The mycelial growth rate of the isolates ranged from 1.39 to 4.46 mm/day. The septation of conidia ranged from 1.4 to 8.6. On the basis of conidia morphology, the isolates were grouped into five different groups, whereas the isolates were grouped into 12 cultural groups based on cultural characteristics. Cultural group 8 [CG (Cultural Group)-8] was the most virulent [38.5% LAD (Leaf area diseased)] and [CG (cultural Group)-4] was the less virulent [2% LAD (Leaf area diseased)] group among 12 groups when inoculated at tillering stage of wheat cv. Kachan.

TaMYB29: A Novel R2R3-MYB Transcription Factor Involved in Wheat Defense Against Stripe Rust.

Members of the R2R3-MYB transcription factor superfamily have been implicated in plant development, improved disease resistance, and defense responses to several types of stresses. To study the function of TaMYB29 transcription factor—a member of the R2R3-MYB superfamily—in response to an avirulent race of stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst), we identified and cloned the TaMYB29 gene from wheat cultivar (cv.) AvS+Yr10 following infection with Pst. The TaMYB29 protein, comprising 261 amino acids, contains two highly conserved MYB domains. We first showed that TaMYB29 is a transcription factor, whose transcriptional levels are significantly induced by salicylic acid (SA), abscisic acid (ABA), jasmonic acid (JA), ethylene (ET), and Pst. The results showed that TaMYB29 is involved in the wheat response to stipe rust. The overexpression of the TaMYB29 gene resulted in the accumulation of reactive oxygen species (ROS) and pathogen-independent cell death in Nicotiana benthamiana leaves. The silencing of TaMYB29 gene in wheat cv. AvS+Yr10, containing the stripe rust resistance gene Yr10, promoted hyphae growth, significantly downregulated the expression of pathogenesis-related (PR) genes, and substantially reduced the wheat resistance to Pst compared with the non-silenced control. In addition, the accumulation of hydrogen peroxide (H2O2) significantly decreased, and the activity of catalase, an enzyme required for H2O2 scavenging, was elevated. Altogether, TaMYB29 positively regulates the defense response against stripe rust in wheat AvS+Yr10 by enhancing H2O2 accumulation, PR gene expression, and SA signaling pathway-induced cell death. These results provide new insights into the contribution of TaMYB29 to the defense response against rust pathogens in wheat.

Risk of heavy metals accumulation in soil and wheat grains with waste water irrigation under different NPK levels in alkaline calcareous soil.

A field study was conducted on the reuse of wastewater from Mardan city to evaluate its risk of contaminating soil and wheat grains at different NPK levels. Three irrigation sources i.e. waste water (WW), canal water (CW) and alternate waste + canal water (WW+CW) were applied to wheat (cv Atta Habib 2010) grown at 0, 50, 75 and 100% NPK levels of 120:90:60 kg N:P2O5:K2O ha-1 at Palatoo Research Farm, Amir Muhammad Khan Campus, Mardan during 2015.The results showed higher grain and biomass yields in WW irrigated plots as compared to CW at NPK levels up to 50% of recommending dose revealing supplementing nutrient requirements in deficient conditions. However, irrigation of WW at higher NPK levels especially at or beyond 75% of recommended dose tended to reduce the crop yield that could be associated with heavy metals toxicity and nutritional imbalances. The use of WW substantially increased AB-DTPA extractable Zn, Mn, Pb, Ni and Cd indicating a potential threat to soil contamination. Similarly, WW irrigated wheat had higher concentrations of these heavy metals as compared to CW which limits its use for production purposes without any remediation measures. The alternate use of CW and WW as revealed by its comparative lower contamination in soil and wheat than sole WW could be one of the possible solutions and may increase the time required for threshold soil contamination.