Important Crop Research Articles

Physiological, genetical changes and cdc2 gene expression for osmotic stressed Vicia faba reveal the alleviation effect of gamma radiation and putrescine

Climate change caused increasing in soil salinity worldwide. Therefore, it is critical to enhance the capability of plant to tolerate salinity stress. For this goal, putrescine and irradiation by gamma radiation were used to improve the salt tolerance of Vicia faba (the most important human crop). The results indicated depression in mitotic division and all growth parameters associated with the induction of micronucleus (MN) when salinity increased to 100mM, while there was increase in mitotic aberrations. NaCl decreased total soluble sugar, while total N%, total free amino acid, proline and protein contents showed slight increase with increasing salinity stress. Putrescine and gamma radiation mitigated the effect of salinity on cell division and growth parameters. Salt stress decreased the expression of gene encoding cyclin-dependent kinase 2 (cdc2). Both putrescine and gamma radiation increased cdc2 expression. The genetic diversity has been detected among control and treated V. faba using ISSR and SCoT markers. Ten primers had successfully generated 129 reproducible polymorphic amplicons that were suitable for studying the genetic diversity between studied genotypes. ISSR markers provided more discriminating data and were more informative than SCoT markers. Besides, cluster analysis using UPGMA and PAC successfully explained the genetic diversity within studied genotypes. These findings emphasize the efficiency of putrescine and gamma radiation for alleviating the negative impact of salt stress. Moreover, prove the importance of assessing mitotic activity, chromosomes behavior, physiological parameters, the expression level of cdc2 and molecular diversity in V. faba under stress to improve the salt tolerance of it.

Classical and Molecular Methods of Identification as well as Estimating Nematodes: A Comparative Review

Changing climatic scenarios accompanied with harsh ecological conditions are forcing various groups of organisms to evolve and adapt in different dimensions. Predominantly in the field of agriculture and crop science, several categories of new pests along with diseases are emerging voraciously causing havoc and causing panic-stricken situations for the farmers. Among the pests, nematode is one of the unnoticed categories contributing significantly to economic loss to the farmers. Due to monotonous crop protection practices in some of the areas as well as drastic changes in the environmental factors, new species of nematode are evolving and attacking economically important crop species. For that, we have to understand the pattern of feeding, oviposition site, life cycle, host searching behaviour, parasitic stages and susceptible host stage for attacking in order to form proper management practices. For understanding its mechanisms and behaviour, our prime concern will be its identification and taxonomic classification by various conventional as well as molecular approaches. Molecular approaches are turning out to be a useful and vigorous tool for the identification of the phylum Nematoda replacing conventional ones.

Classical and Molecular Methods of Identification as well as Estimating Nematodes: A Comparative Review

Changing climatic scenarios accompanied with harsh ecological conditions are forcing various groups of organisms to evolve and adapt in different dimensions. Predominantly in the field of agriculture and crop science, several categories of new pests along with diseases are emerging voraciously causing havoc and causing panic-stricken situations for the farmers. Among the pests, nematode is one of the unnoticed categories contributing significantly to economic loss to the farmers. Due to monotonous crop protection practices in some of the areas as well as drastic changes in the environmental factors, new species of nematode are evolving and attacking economically important crop species. For that, we have to understand the pattern of feeding, oviposition site, life cycle, host searching behaviour, parasitic stages and susceptible host stage for attacking in order to form proper management practices. For understanding its mechanisms and behaviour, our prime concern will be its identification and taxonomic classification by various conventional as well as molecular approaches. Molecular approaches are turning out to be a useful and vigorous tool for the identification of the phylum Nematoda replacing conventional ones.

Genome-Wide Methylation Landscape Uncovers the Role of DNA Methylation in Ramie (Boehmeria nivea L.) Bast Fiber Growth

Ramie is one of the most important fiber crops in China, with fibers extracted from stem barks having been used as textile materials for thousands of years. DNA methylation is an important epigenetic modification involved in plant growth and development. However, the role of methylation in ramie fiber growth remains poorly understood. In the present study, we investigated the DNA methylation landscape of the nuclear genome in bark sections taken from the top (TPS) and the middle (MPS) of the stems of ramie plants, which represent different stages of fiber growth, using whole-genome bisulfite sequencing. We detected 7,709,555 and 8,508,326 5-methylcytosines in the TPS and MPS genomes, respectively. The distribution of methylation across three sequence contexts, CG, CHG, and CHH, varied greatly among gene elements, with methylation at CHH being the most prevalent. Comparison of methylation levels between the TPS and MPS genomes revealed 23.162 Mb of differentially methylated genomic regions, encompassing 9485 genes. Among these differentially methylated genes, 841 exhibited altered expression in the MPS genome. Notably, an SND2 ortholog Bni05G006779 showed a negative correlation between its expression and methylation levels. Overexpression of Bni05G006779 in Arabidopsis dramatically increased the number of xylem fibers and the secondary wall thickness of the fibers in the stems of transgenic plants. These findings provide important insights into the involvement of DNA methylation in regulating ramie fiber growth.

Genome-Wide Methylation Landscape Uncovers the Role of DNA Methylation in Ramie (Boehmeria nivea L.) Bast Fiber Growth

Ramie is one of the most important fiber crops in China, with fibers extracted from stem barks having been used as textile materials for thousands of years. DNA methylation is an important epigenetic modification involved in plant growth and development. However, the role of methylation in ramie fiber growth remains poorly understood. In the present study, we investigated the DNA methylation landscape of the nuclear genome in bark sections taken from the top (TPS) and the middle (MPS) of the stems of ramie plants, which represent different stages of fiber growth, using whole-genome bisulfite sequencing. We detected 7,709,555 and 8,508,326 5-methylcytosines in the TPS and MPS genomes, respectively. The distribution of methylation across three sequence contexts, CG, CHG, and CHH, varied greatly among gene elements, with methylation at CHH being the most prevalent. Comparison of methylation levels between the TPS and MPS genomes revealed 23.162 Mb of differentially methylated genomic regions, encompassing 9485 genes. Among these differentially methylated genes, 841 exhibited altered expression in the MPS genome. Notably, an SND2 ortholog Bni05G006779 showed a negative correlation between its expression and methylation levels. Overexpression of Bni05G006779 in Arabidopsis dramatically increased the number of xylem fibers and the secondary wall thickness of the fibers in the stems of transgenic plants. These findings provide important insights into the involvement of DNA methylation in regulating ramie fiber growth.

Discrete Element Model of Oil Peony Seeds and the Calibration of Its Parameters

Abstract: Oil peony is an important oil crop that is primarily sown by using artificial methods at present. Its seeder encounters the problems of low efficiency of seeding that significantly limits the highly efficient mechanized production of high-quality peony oil. In this study, Fengdan white oil peony seeds were used as the research object and repose angle as the response value to establish a discrete element model (DEM) and parameter calibration. The range of parameters of oil peony seeds was first obtained through an experiment, and their repose angle was obtained by an inclinometer. A three-dimensional DEM of oil peony seeds was then established. The Plackett–Burman (PB) test was utilized to screen the parameters that had a significant influence on the repose angle, and the steepest ascent (SA) test was applied to determine their optimum range of testing. Following this, based on Box–Behnken (BBD) test results, a second-order regression model between the important parameters and the repose angle was constructed. Finally, the absolute minimum difference between simulated and measured repose angles was utilized as the objective of optimization to obtain the following optimum combination of parameters: The values of the seed–steel collision recovery coefficient (CRC), seed–seed static friction coefficient (SFC), seed–steel SFC, and seed–seed rolling friction coefficient (RFC) were 0.704, 0.324, 0.335, and 0.045, respectively. This optimal combination of parameters was confirmed through simulations, and the error between simulated and measured repose angles was only 0.67%, indicating that the calibrated DEM of oil peony seeds was reliable.

Discrete Element Model of Oil Peony Seeds and the Calibration of Its Parameters

Abstract: Oil peony is an important oil crop that is primarily sown by using artificial methods at present. Its seeder encounters the problems of low efficiency of seeding that significantly limits the highly efficient mechanized production of high-quality peony oil. In this study, Fengdan white oil peony seeds were used as the research object and repose angle as the response value to establish a discrete element model (DEM) and parameter calibration. The range of parameters of oil peony seeds was first obtained through an experiment, and their repose angle was obtained by an inclinometer. A three-dimensional DEM of oil peony seeds was then established. The Plackett–Burman (PB) test was utilized to screen the parameters that had a significant influence on the repose angle, and the steepest ascent (SA) test was applied to determine their optimum range of testing. Following this, based on Box–Behnken (BBD) test results, a second-order regression model between the important parameters and the repose angle was constructed. Finally, the absolute minimum difference between simulated and measured repose angles was utilized as the objective of optimization to obtain the following optimum combination of parameters: The values of the seed–steel collision recovery coefficient (CRC), seed–seed static friction coefficient (SFC), seed–steel SFC, and seed–seed rolling friction coefficient (RFC) were 0.704, 0.324, 0.335, and 0.045, respectively. This optimal combination of parameters was confirmed through simulations, and the error between simulated and measured repose angles was only 0.67%, indicating that the calibrated DEM of oil peony seeds was reliable.

Assessment of the genetic diversity and population structure in Moringa oleifera accessions using DNA markers and phenotypic descriptors

Moringa (Moringa oleifera Lam.) is one of the multipurpose trees with significant promise as a high-value crop of industrial importance, having nutritional, therapeutic, and prophylactic properties. Genetic diversity is a cornerstone of any crop improvement program and plays a key role in the selection of promising parental lines for hybrid breeding. Morphological and molecular markers have been proven to be potential tools for the evaluation of genetic diversity, crop genetic improvement, and conservation of plant genetic resources. In the current study, morphological descriptors, RAPD, and SCoT markers were used to determine genetic diversity among 28 M. oleifera accessions. Significant morphological variations were noted for several economic traits across the accessions studied. Four primary clusters were visible on the dendrogram based on phenotypic markers, indicating clustering of accession from a shared geographical habitat. No correlation was estimated between morphological traits, indicating an environmental influence. Three RAPD and seven SCoT primer sets produced 37 and 46 markers, with 53.2 and 71.3% polymorphisms, respectively. Based on genotypic data and the UPGMA approach, all 28 accessions were separated into two major clusters in the phylogenetic tree, irrespective of any geographical areas. The clustering pattern indicates widespread plant species and rapid gene flow through cross-pollination in Moringa populations. Three subpopulations of the involved accessions were identified by population structure analysis; however, there was only a weak link with the location of plant cultivation. The expected heterozygosity for the three subpopulations varied from 0.23 to 0.32, as per R-based structural analysis. AMOVA's attribution of 86% and 19% of all variations to within- and between-populations, respectively, indicates that there has been gene flow across geographic regions. The PCA showed a wide distribution of genotypes in the scatterplot, also suggesting huge genetic variation among the M. oleifera population. The study revealed a significant level of genetic diversity among M. oleifera accessions, which can be harnessed to conserve plant genetic resources and develop high-yielding, nutrient-dense Moringa cultivars.

Comparative transcriptome provides new insights to the molecular regulation of olive trees to chilling stress.

Olive (Olea europaea. L), an economically important oil-producing crop, is sensitive to low temperature, which severely limits its productivity and geographical distribution. However, the underlying mechanism of cold tolerance in olive remains elusive. In this study, a chilling experiment (4°C) on the living saplings of two olive cultivars revealed that O. europaea cv. Arbequina showed stronger cold tolerance with greater photosynthetic activity compared to O. europaea cv. Leccino. Transcriptome analyses revealed that early light-inducible protein 1 (ELIP1), the main regulator for chlorophyll synthesis, is dramatically induced to protect the photosynthesis at low temperatures. Furthermore, weighted gene co-expression network analysis (WGCNA), yeast one-hybrid (Y1H), and luciferase (LUC) assays demonstrated that transcription factor bHLH66 serves as an important regulator of ELIP1 transcription by binding to the G-box motif in the promoter. Taken together, our research revealed a novel transcriptional module consisting of bHLH66- ELIP1 in the adaptation of olive trees to cold stress.

On Farm Performance of Finger Millet Varieties in Dera District of South Gondar Zone

Finger millet is an important food security crop and beneficial for human health. This study aimed to evaluate the on farm performance of the finger millet varieties in Dera district. The study took place in Korata Kebele and assessed grain yield and farmer feedback. The performance differences between the Necho variety (the demonstrated variety) and the farmers' variety were evaluated. Recent 10 years' grain yield data from the Dera district agriculture office was used to analyze the growth rates of area coverage, production, and productivity in the district using the compounded annual growth rate (CAGR). Furthermore, the performance of the Necho variety was compared to its potential and farmer variety using the technology gap, extension gap, and technology index. From 2014 to 2018, the annual growth rate of area coverage and productivity in Dera district declined by 1.6% and 1.7% per year, respectively. Moreover, from 2019 to 2023, the average annual growth rate of area coverage, production, and productivity decreased by 0.75%, 2.6%, and 3.4% per year, respectively. The technology index for the Necho variety in the production seasons of 2021, 2022, and 2023 was -4%, 16%, and 36%, respectively. The higher value in the 2023 season indicated a decline in the performance of the Necho variety compared to the farmer variety. This decline was attributed to the occurrence of blast disease. To address this issue, it is recommended to practice early planting and use recommended fungicides (Natura 250EW and Tilt 250EC). The district agriculture office must ensure easy accessibility of these fungicides in the market for farmers to utilize.

A High-Precision Identification Method for Maize Leaf Diseases and Pests Based on LFMNet under Complex Backgrounds.

Maize, as one of the most important crops in the world, faces severe challenges from various diseases and pests. The timely and accurate identification of maize leaf diseases and pests is of great significance for ensuring agricultural production. Currently, the identification of maize leaf diseases and pests faces two key challenges: (1) In the actual process of identifying leaf diseases and pests, complex backgrounds can interfere with the identification effect. (2) The subtle features of diseases and pests are difficult to accurately extract. To address these challenges, this study proposes a maize leaf disease and pest identification model called LFMNet. Firstly, the localized multi-scale inverted residual convolutional block (LMSB) is proposed to perform preliminary down-sampling on the image, preserving important feature information for the subsequent extraction of fine disease and pest features in the model structure. Then, the feature localization bottleneck (FLB) is proposed to improve the model's ability to focus on and locate disease and pest characteristics and to reduce interference from complex backgrounds. Subsequently, the multi-hop local-feature fusion architecture (MLFFA) is proposed, which effectively addresses the problem of extracting subtle features by enhancing the extraction and fusion of global and local disease and pest features in images. After training and testing on a dataset containing 19,451 images of maize leaf diseases and pests, the LFMNet model demonstrated excellent performance, with an average identification accuracy of 95.68%, a precision of 95.91%, a recall of 95.78%, and an F1 score of 95.83%. Compared to existing models, it exhibits significant advantages, offering robust technical support for the precise identification of maize diseases and pests.

Unearthing Grape Heritage: Morphological Relationships between Late Bronze-Iron Age Grape Pips and Modern Cultivars.

The grapevine was one of the earliest domesticated fruit crops and has been cultivated since ancient times. It is considered one of the most important fruit crops worldwide for wine and table grape production. The current grape varieties are the outcome of prolonged selection initiated during the domestication process of their wild relative. Recent genetic studies have shed light on the origins of the modern domestic grapevine in western Europe, suggesting that its origin stems from the introgression between eastern domestic grapes and western wild grapes. However, the origin of ancient grapevines remains largely unexplored. In this study, we conducted an extensive analysis of 2228 well-preserved waterlogged archaeological grape pips from two sites in Sardinia (Italy), dated to the Late Bronze Age (ca. 1300-1100 BC) and the Iron Age (4th and 3rd centuries BC). Using morphometrics and linear discriminant analyses, we compared the archaeological grape pips with modern reference collections to differentiate between wild and domestic grape types and to investigate similarities with 330 modern cultivars. Grape pips from the Late Bronze Age displayed a high percentage of similarity with domesticated grapevines, with a small percentage assigned to wild ones, while the majority of grape pips from the Iron Age were classified as domestic. Discriminant analyses revealed that both white and red grape varieties were cultivated during the Late Bronze and Iron Ages, suggesting a high level of diversification in grape cultivation. Furthermore, a high percentage of archaeological grape pips from both periods showed strong similarities with modern cultivars from the Caucasus and Balkans. This suggests that the great diversity of grapevines present in Sardinia could result from interbreeding between western Asian cultivars and local grapevines that began in the Late Bronze Age. Additionally, a substantial proportion of archaeological grape pips exhibited similar morphometric characteristics to two important Mediterranean grape cultivars: "Muscat à petits grains blancs" and "Garnacha".

Evaluating the Onfarm Performance of True Seed Shallot Varieties in Northwest Ethiopia

Shallot (Allium cepa L. var. aggregatum) is an important vegetable crop in Ethiopia, but its production has declined in recent years due to a lack of true seed-propagated varieties. This study aimed to demonstrate and evaluate the performance of true seed shallot varieties in three districts of the Amhara region: Fogera, Libokemkem, and Dera. The study involved the participation of host farmers in variety demonstrations and the evaluation of the demonstrated varieties by experienced farmers. Two true seed shallot varieties, DZsht-157-1B and DZsht-91-2B, were compared to the local Bombay red variety. Bulb yield data was collected from one-meter square quadrants, and farmers' preferences were assessed using a direct matrix ranking approach. The results showed that the true seed shallot varieties outperformed the local Bombay red variety in terms of bulb yield. In the Fogera district, DZsht-157-1B and DZsht-91-2B had 40.1% and 0.3% higher bulb yields, respectively, compared to Bombay red. In the Libokemkem district, DZsht-91-2B had a 4.2% yield advantage over the local variety. The farmer evaluation results revealed that the true seed shallot varieties were preferred over the local Bombay red variety in various aspects, such as higher bulb yield, redness, and prolonged food span. The findings of this study suggest that the true seed shallot varieties have the potential to improve shallot production in the study areas and potentially in other parts of Ethiopia. To promote the adoption of these varieties, it is crucial to ensure the availability and accessibility of high-quality seeds to farmers, as well as to educate them on the importance of maintaining the true seed to bulb and bulb to true seed cycle. This will enable the continuous propagation of the true seed shallot varieties and ensure a sustainable supply of high-quality planting material, contributing to the revitalization of shallot production in Ethiopia and enhancing the livelihoods of smallholder farmers.

Occurrence and Distribution of Plant Parasitic Nematodes in Mungbean in Jaipur District, Rajasthan, India

Aim: Mungbean (Vigna radiata (L.) R. Wilczek) is one of the important pulse crops grown in India. Considering the economic importance of nematodes as disease causing organism of mungbean the present investigation was carried out to know the distribution of plant parasitic nematodes in mungbean crops in Jaipur district of Rajasthan. Methodology: A total 139 soil samples were collected from mungbean fields of 12 different localities in Jaipur district. The samples were processed using Cobb's sieving and decanting technique followed by Baermann's funnel technique and nematode population was counted in suspension and identified on the basis of their morphological characters. Results: The samples were infected with mainly four genera of plant parasitic nematodes i.e., Meloidogyne spp., Helicotylenchus spp., Pratylenchus spp. and Tylenchorhynchus spp. etc. Out of 139 soil samples, 120 samples showed the presence of Meloidogyne javanica with 86.33 % occurrence, 18.82 % absolute density, 83.81 % relative density and 15.85 % prominence value and found most predominant in different surveyed localities in Jaipur district.

Evaluating the Onfarm Performance of True Seed Shallot Varieties in Northwest Ethiopia

Shallot (Allium cepa L. var. aggregatum) is an important vegetable crop in Ethiopia, but its production has declined in recent years due to a lack of true seed-propagated varieties. This study aimed to demonstrate and evaluate the performance of true seed shallot varieties in three districts of the Amhara region: Fogera, Libokemkem, and Dera. The study involved the participation of host farmers in variety demonstrations and the evaluation of the demonstrated varieties by experienced farmers. Two true seed shallot varieties, DZsht-157-1B and DZsht-91-2B, were compared to the local Bombay red variety. Bulb yield data was collected from one-meter square quadrants, and farmers' preferences were assessed using a direct matrix ranking approach. The results showed that the true seed shallot varieties outperformed the local Bombay red variety in terms of bulb yield. In the Fogera district, DZsht-157-1B and DZsht-91-2B had 40.1% and 0.3% higher bulb yields, respectively, compared to Bombay red. In the Libokemkem district, DZsht-91-2B had a 4.2% yield advantage over the local variety. The farmer evaluation results revealed that the true seed shallot varieties were preferred over the local Bombay red variety in various aspects, such as higher bulb yield, redness, and prolonged food span. The findings of this study suggest that the true seed shallot varieties have the potential to improve shallot production in the study areas and potentially in other parts of Ethiopia. To promote the adoption of these varieties, it is crucial to ensure the availability and accessibility of high-quality seeds to farmers, as well as to educate them on the importance of maintaining the true seed to bulb and bulb to true seed cycle. This will enable the continuous propagation of the true seed shallot varieties and ensure a sustainable supply of high-quality planting material, contributing to the revitalization of shallot production in Ethiopia and enhancing the livelihoods of smallholder farmers.

Characterization and Expression Analysis of Sugar Transporters through Partial Least Square Structural Equation Model (PLS-SEM) Revealed Their Role in Pepper (Capsicum annuum L.).

Pepper (Capsicum annuum L.) is one of the most important economic crops in the world. By controlling the transport and distribution of photosynthetic products between cells and organs, sugar transporters are widely involved in growth and development, environmental adaptation, and microbial interactions. The present study was carried out at the genome-wide level to systematically characterize sugar transporters. As a result, 50 MST, 3 SUT, and 29 SWEET genes were identified and classified. The expression pattern of sugar transporters in pepper was analyzed by transcriptomic data. The expression properties of sugar transporters were further explored in pepper varieties with significant differences in weight, shape, and pungency. It was shown that the pepper sugar transporter genes had obvious spatiotemporal specific expression characteristics and exhibited variety-specific expression preferences. We focus on analyzing candidate genes that may be involved in fruit development and expansion. We further explore the response of pepper sugar transporters to adversity stress using a structural equation model. Finally, we found that the MST, SUT, and SWEET families are collectively involved in balancing pepper resistance to abiotic stress by coordinating the expression strengths of different family members. Our study may contribute to the functional study of pepper sugar transporter genes and create the prospect of utilizing sugar transporter gene resources to improve pepper variety.

Occurrence and management of the emerging pathogen Epicoccum sorghinum.

Epicoccum sorghinum is a notorious fungal pathogen that causes leaf spot symptoms on a wide range of plants, leading to devastating losses in crop production and quality. Here, all reports regarding the occurrence and management of E. sorghinum are covered for the first time. E. sorghinum has been detected in tropical and subtropical climate areas during the rainy season, mainly from March to August, since 2016. Although E. sorghinum shows broad host spectrum, the disease incidence is especially notorious in cereal crops and ornamental plants, suggesting that these plants are especially susceptible. Control methods based on synthetic fungicides, plant extracts, and microbial biocontrol agents have been reported. However, most agents were applied using only in vitro conditions, restricting the information about their actual applicability in field conditions. Additionally, E. sorghinum can colonize cereal grains and synthesize the carcinogenic mycotoxin tenuazonic acid, posing an enormous hazard for human health. Furthermore, although E. sorghinum is an emerging pathogen that is currently causing yield penalties in important crops, there is lack of information about its pathogenic mechanisms and virulence factors, and there is currently no commercial antifungal agent to manage E. sorghinum. Collectively, it is imperative to conduct in vivo studies to determine the efficacy of antifungal agents and the most effective methods of application in order to develop suitable management strategies against E. sorghinum.

Minor Millets: Miracle Grain of South India

Minor millets are important traditional food crops for dry land farmers in India. India has the third largest area under minor millets cultivation in the world. Minor millets such as finger millet, foxtail millet, proso millet, kodo millet, little millet and barnyard millet are considered as a climate-smart crop. Since these crops are widely divergent for thermo and photoperiods and hence these are known for their climatic resilience and are relatively less prone to biotic stress factors. Added these crops are rich in protein, fat, crude fiber, iron and other minerals and vitamins with low glycemic index in comparison to cereals like wheat and rice. Hence they are labelled as nutri- cereals and act as the source of food, feed and fodder. Minor millets have curative and nutrient - rich properties in the form of antioxidants which prevent weakening of human health such as lowering blood pressure, risk of heart disease, obesity, prevention of cancer, cardiovascular diseases and diabetes etc. Owing to its health benefits, the minor millets output has increased recently due to the availability of high-yielding varieties, pest and disease - resistant varieties, and improved cultivation techniques, rising by 1.05 percent annually. This review aims to document the production status, demand, varietal diversity, current consumption pattern, processing, nutrient composition and therapeutic potential of minor millets for further research on various aspects.

Incidence, Characterization and Pathogenicity of Seed-Borne Fungi of Lentil (<em>Lens culinaris</em> L.) in Pakistan

Lentil (Lens culinaris Medik.) is an important protein-rich Rabi pulse crop after chickpea in Pakistan. Its area and production in the country is decreasing drastically due to its susceptibility to various biotic and abiotic stresses. Among biotic-stresses, seed-borne fungi are the most imperative issue and the accurate identification and characterization of target pathogen isolates/races is crucial for the management of plant diseases in lentils. Therefore, the current study was performed to identify the fungi associated with lentil seeds, to confirm their pathogenicity and to assess their incidence. For this purpose, isolation of fungal pathogens was made on potato dextrose agar medium (PDA) from 56 Lens culinaris L. genotypes. These pathogens were characterized using morphological and molecular techniques and their pathogenicity was performed following blotter paper and agar plate method. Seven fungi belonging to five genera were isolated from lentil seeds (Fusarium avenaceum, Alternaria alternata, Aspergillus flavus, Aspergillus niger, Aspergillus tubingensis, Penicillium citrinum and Bipolaris sorokiniana) of different genotypes. Of these seven fungal species, F. avenaceum, A. tubingensis and B. sorokiniana are new records for lentil seeds from Pakistan. Aspergillus flavus was found to occur in high frequency followed by A. niger, F. avenaceum, P. citrinum, A. alternata, A. tubingensis and B. sorokiniana. Under pathogenicity test on blotter paper and on PDA F. avenaceum, A. flavus, A. niger, A. tubingensis were highly pathogenic, while A. alternata, P. citrinum and B. sorokiniana were found to be less pathogenic. The presence of well-known toxigenic fungal pathogens in lentil seeds suggests the possible risk of contamination of the seeds and enhances the possibility of pre- and post-infections of crop. Therefore, the present study will help to devise effective management strategies to reduce contamination in seeds and also to control the further spread of these pathogens to reduce crop losses.

Retrotransposon-mediated disruption of a chitin synthase gene confers insect resistance to Bacillus thuringiensis Vip3Aa toxin.

The vegetative insecticidal protein Vip3Aa from Bacillus thuringiensis (Bt) has been produced by transgenic crops to counter pest resistance to the widely used crystalline (Cry) insecticidal proteins from Bt. To proactively manage pest resistance, there is an urgent need to better understand the genetic basis of resistance to Vip3Aa, which has been largely unknown. We discovered that retrotransposon-mediated alternative splicing of a midgut-specific chitin synthase gene was associated with 5,560-fold resistance to Vip3Aa in a laboratory-selected strain of the fall armyworm, a globally important crop pest. The same mutation in this gene was also detected in a field population. Knockout of this gene via CRISPR/Cas9 caused high levels of resistance to Vip3Aa in fall armyworm and 2 other lepidopteran pests. The insights provided by these results could help to advance monitoring and management of pest resistance to Vip3Aa.