Search

Potato farming is a vital component of food security and the economic stability especially in the under developing countries but it faces many challenges in production, blackleg disease caused by Pectobacterium atrosepticum (Pa) is one of the main reason for damaging crop yield of the potato. Effective management strategies are essential to control these losses and to get sustainable potato crop yield. This study was focused on characterizing the Pa and the investigating new chemical options for its management. The research was involved a systematic survey across the three district of Punjab, Pakistan (Khanewal, Okara, and Multan) to collect samples exhibiting the black leg symptoms. These samples were analyzed in the laboratory where gram-negative bacteria were isolated and identified through biochemical and pathogenicity tests for Pa. DNA sequencing further confirmed these isolates of Pa strains. Six different chemicals were tested to control blackleg problem in both vitro and vivo at different concentrations. In vitro experiment, Cordate demonstrated the highest efficacy with a maximum inhibition zones of 17.139 mm, followed by Air One (13.778 mm), Profiler (10.167 mm), Blue Copper (7.7778 mm), Spot Fix (7.6689 mm), and Strider (7.0667 mm). In vivo, Cordate maintained its effectiveness with the lowest disease incidence of 14.76%, followed by Blue Copper (17.49%), Air One (16.98%), Spot Fix (20.67%), Profiler (21.45%), Strider (24.99%), and the control group (43.00%). The results highlight Cordate's potential as a most effective chemical against Pa, offering promising role for managing blackleg disease in potato and to improve overall productivity. [ABSTRACT FROM AUTHOR]

Cucumber mosaic disease (CMD), caused by Cucumber mosaic virus (CMV) is the most devastating disease that can cause 100% losses in severe cases. CMV transmission is accomplished through mechanical or contact inoculation and sometimes through aphid in stylet borne manner. After entry into the host, CMV interrupts with normal physiology of cucumber plants resulting in mosaic patterns on leaves, reduction in leaf area leading to reduced yield. This review paper aims at assessment of yield losses caused by CMV, efficient disease diagnosis, finding the existing resistance sources and breeding potential for sustainable disease management. Various methods of diagnosis, symptomology, ecology, epidemiology and management tactics of CMV have been studied in this review. Usage of insecticides, for CMV management is not rational because it is occasionally transmitted through aphid and too in a non-persistent manner. The efforts for vector control even though through botanicals and organic oils is not as much effective due to quick virus transmission. CMV impairs the plant photosynthetic activity resulting in yield reduction, however the damages could be managed by using different nutrients. It is focused upon boosting the plant defense by using external application of different resistance inducing chemicals. CMV impairs the plant photosynthetic activity resulting in yield reduction, however the damages could be managed by using different nutrients. It is focused upon to boost the plant defense by using external application of different resistance inducing chemicals. Hence this review covers the aspects of ecofriendly management of CMV through genetic resistance and innovative cultural practices, which is the major future research area. [ABSTRACT FROM AUTHOR]

Okra yellow vein mosaic virus (OYVMV) is vectored by sucking insect whitefly into the phloem of the okra plant. It devastates the fruit quality and production if infection started at early growth stages. Commonly, the virus is tried to manage by using chemical insecticides against the whitefly that has adverse effects on the ecosystem. The present study was to explore the non-chemical ways to fight against OYVMV and it vector. The available germplasm consisting of 11 cultivars was sown in augmented design to estimate the level of resistance under natural conditions where no whitefly control measure was used. Based upon the results of disease severity, the cultivars were categorized into highly resistant, resistant, moderately resistant, moderately susceptible, susceptible and highly susceptible; the most effective and highly resistant variety was "Sabz Pari" that showed minimum disease incidence (60.58%) and disease severity (7.72%). A separate experiment was conducted to evaluate the role of plant extracts in the management of OYVMV disease and whitefly where 5 moderately resistant to moderately susceptible varieties were sown. Among the plant extracts applied garlic extract showed more significant results in controlling whitefly (79.23%) and OYVMV transmission (88.27%). It could be concluded that "Sabz Pari" is the most suitable and high yielding okra variety against OYVMV disease and garlic extract could be applied as a best bio-pesticide against sucking insects. [ABSTRACT FROM AUTHOR]

Okra (Abelmoschus esculentus L.) belongs to family Malvaceae and it is a rich source of carbohydrates, minerals and vitamins. Okra yellow vein mosaic disease (OYVMD) is a devastating biotic stress that is caused by okra yellow vein mosaic virus (OYVMV). This virus is vectored by whitefly (Bemisia tabaci) in a persistent and circulative manner. The current study aims to evaluate the effect of OYVMV on biochemistry of okra plants. An extensive survey about the epidemiology of OYVMD in geographical location of Tehsil Sahiwal, District Sargodha (Punjab Province-Pakistan) on okra fields was conducted. Symptomatic samples subjected to OYVMV confirmation were collected. The healthy and infected samples were processed for determination of biochemical parameters such as total phenolic contents (TPC), total soluble sugars (TSS), and enzymatic antioxidants i.e. superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) to assess the effect of virus infection on okra plants. TPC were measured by using Folin-Ciocalteu reagent (FCR); TSS determined through anthrone sulfuric acid assay and enzymatic antioxidants by using nitroblue tetrazolium (NBT) solution. The quantity of TPC was decreased while TSS and enzymatic antioxidants increased in diseased plants. TPC in healthy bark and leaves was 0.12 and 0.14 mg/g as compared to 0.2 mg/g of diseased samples. TSS in diseased bark and leaves was 223 and 214 mg/g while enzymatic antioxidants SOD, POD and CAT were also higher. The present study would be helpful in developing environment friendly management approaches by using biochemical profiling of infected plants. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is one of the world's most important cereal crop in terms of cultivated area and quantity of grain produced. It is the most communal staple food in Pakistan, followed by rice and maize. Wheat is susceptible to a wide range of biotic and abiotic stressors, which can lead to severe yield reductions. Rusts are economically the most significant biotic factor of wheat crop. Leaf rust, commonly known as brown rust, is a severe wheat disease in Pakistan that results in production losses ranging from 10% to 40%. In the present study, the experiment was conducted in MNS-University of agriculture Multan, in which screening of wheat breeding lines against the natural inoculum of brown rust and the relationship of leaf rust with different environmental parameters was done in two years of data. The disease severity (DS), Coefficient of infection (CI) and average coefficient of infection (ACI) was recorded by using Modified Cobb's scale. During 2020-2021, among 100 breeding lines, 16 breeding lines revealed an immune response, 14 exhibited moderately resistant response, 5 showed a susceptible response and the remaining were moderately resistant-moderately susceptible response. In season 2021-22, 19 breeding lines were immune, 19 showed a moderately resistant response, 4 breeding lines were susceptible and the remaining were moderately resistant-moderately susceptible. Correlation clearly demonstrated the response of disease development to environmental factors. Maximum temperature, minimum temperature, wind speed and sunshine hours showed a positive relationship with leaf rust severity while a negative relationship was evident in relative humidity and disease severity during both year study. This study provided evidence that there is a strong relationship between environmental factors and leaf rust severity. The environmental conditions were not ideal during the early stage of the host plant that help them to withstand the building inoculum during March-April. Therefore, the breeding lines exhibiting immune and moderately resistant response could be utilized in future breeding programs to develop leaf rust resistant varieties/cultivars to combat this menace. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is a staple food for a significant portion of the world's population including Pakistan. Among all limiting biotic and abiotic factors, wheat rusts pose a substantial danger to production worldwide and can result in yield losses of over 90% in susceptible varieties or during epidemics. Yellow rust (Puccinia striiformis f. sp. tritici), one of several types of wheat rust, is particularly dangerous to wheat production in Pakistan and cause disease on 70% cultivated area of wheat. Keeping in view the devastating nature of yellow rust pathogen, two-year study 2020-2021 and 2021-2022 was conducted in order to screen out wheat breeding lines against yellow rust followed by its relationship with the environmental variables. In this study, one hundred wheat breeding lines were cultivated in the research area of MNS-University of Agriculture Multan and disease was observed in the months of January-April during 2020-21 and 2021-22. Very low level of disease severity (DS) and area under disease progress curve (AUDPC) recorded in all the breeding lines. Epidemiological variables play an important role in the disease progression. Hence, out of hundred breeding lines screened in 2020-2021, 88 breeding lines were supposed to be immune to all naturally occurring race(s) of yellow rust and 12 lines were categorized as moderately resistant to moderately susceptible. Similarly, 92 breeding lines were found immune and 8 showed moderately resistant to moderately susceptible response out of 100 breeding lines during 2021-2022. The findings showed that a high proportion of wheat breeding lines showed no response towards the disease and supposed to be immune. The results from the correlation and regression analysis showed that there was a positive correlation between the maximum, minimum temperature with yellow rust severity (%). While, there was a negative correlation of humidity during 2020-2021 and positive during 2021-2022. Sunshine hours showed the positive relationship with the yellow rust severity (%) during 2020-2021 and negative during 2021-2022. Current study revealed that breeding lines and pathogen were present, which was responsible for the disease in few breeding lines, while epidemiological factors were non-favorable for the disease to develop and progress at large scale. The findings of the current research clearly showed the importance of epidemiological factor which leads toward less disease development. The analysis of natural conditions with yellow rust helps to predict yellow rust outbreak and appropriate management strategies. [ABSTRACT FROM AUTHOR]

Cucumber mosaic virus (CMV) is a destructive and menace to a wide range of plant species including eggplant crop worldwide. This study was carried out to define the current status of CMV infecting eggplant crop in Pothwar region of Pakistan and characterization of CMV eggplant isolates as well as to recognize the sources of resistance in eggplant genotypes. A total of 660 leaf samples with the virus and virus-like symptoms were collected from different sites of Pothwar region and subjected to CMV specific DAS-ELISA using monoclonal antibodies. ELISA results indicated that approximately 56% of samples were positive for CMV infection and the disease incidence was highest (62.50%) in Jhelum district followed by Rawalpindi (58.33%), Chakwal (58.33%) and Attock (55.55%) districts with the lowest disease incidence (46.15%) was recorded in Islamabad district. Two ELISA positive samples from each district were further confirmed by RT-PCR and subsequently sequenced based on their coat protein cistron. All isolates were identical to each other so the nucleotide sequence of one eggplant isolate (CMV-Pak) was deposited in GenBank with accession number MH119063. BLAST and phylogenetic analysis revealed that CMV-Pak eggplant isolate shared 90-94% nucleotide and 80-100% amino acid similarities with other isolates available in GenBank. Moreover, 10 eggplant genotypes were tested against CMV-Pak eggplant isolate, ELISA results categorized three genotypes (Singh Nath 666, Neelum, and Brinjal Jamak) as moderately resistant, two genotypes (Round Black, and Global Brinjal PPL) as susceptible and rest of the five genotypes (Bemissal, Brinjal Shilpa, Short Purple, Brinjal PPL, and Namyal Ratchburi) as moderately susceptible. Therefore, the three moderately resistant genotypes could be recommended to farmers for farming and plant breeders for developing new eggplant resistant genotypes to CMV. To the best of our knowledge, this study is the first time provided evidence that CMV infects eggplant in Pakistan. [ABSTRACT FROM AUTHOR]

Just like animals and human beings, plants also accommodate a countless number of microorganisms as hosts. Microorganisms enjoy this hospitality by developing an interaction with the plants either in a synergistic way benefiting each other or in an antagonistic manner damaging their hosts. Such types of mutualistic and pathogenic interactions also take place among microbial community. Proteins, metabolites and certain molecular mechanisms determine whether the intruder is a symbiotic or pathogenic microorganism. Various bacteria and fungi interact symbiotically and play significant role in plant growth promotion. Certain species of fungi, oomycetes, bacteria and nematodes are also pathogenic in nature and cause impact on soil and plant. Soil serves as a big substrate for microbial community, which are important in a number of ways owing to their role in mineralization, nutrient availability and are sources of industrial products such as enzymes, hormones, antibiotics, vitamins etc. This review will improve our understanding about relationships between plants and their microbial friends and foes. The mechanisms adopted by soil microbes to contribute in the betterment of soil leading towards enhanced plant growth as well as pathogenicity caused by these microbes have also been discussed. Recent advances to recognize the molecular mechanisms involved in such interactions have also been discussed. Recent advances made in this field and the areas needing further research have also been mentioned. [ABSTRACT FROM AUTHOR]

Just like animals and human beings, plants also accommodate a countless number of microorganisms as hosts. Microorganisms enjoy this hospitality by developing an interaction with the plants either in a synergistic way benefiting each other or in an antagonistic manner damaging their hosts. Such types of mutualistic and pathogenic interactions also take place among microbial community. Proteins, metabolites and certain molecular mechanisms determine whether the intruder is a symbiotic or pathogenic microorganism. Various bacteria and fungi interact symbiotically and play significant role in plant growth promotion. Certain species of fungi, oomycetes, bacteria and nematodes are also pathogenic in nature and cause impact on soil and plant. Soil serves as a big substrate for microbial community, which are important in a number of ways owing to their role in mineralization, nutrient availability and are sources of industrial products such as enzymes, hormones, antibiotics, vitamins etc. This review will improve our understanding about relationships between plants and their microbial friends and foes. The mechanisms adopted by soil microbes to contribute in the betterment of soil leading towards enhanced plant growth as well as pathogenicity caused by these microbes have also been discussed. Recent advances to recognize the molecular mechanisms involved in such interactions have also been discussed. Recent advances made in this field and the areas needing further research have also been mentioned. [ABSTRACT FROM AUTHOR]

Begomovirus is one of the most prevailing threats to mungbean crop in Pakistan. Mungbean yellow mosaic virus spread in a persistent manner through Bemisia tabaci. Mungbean crop was sown in natural field condition with randomized complete block design. Influence of whitefly population on disease incidence was studied through correlation and regression analysis. Botanicals (onion, garlic) at the rate 3% and insecticides (acetamiprid, imidacloprid) were tested against whitefly population. Among botanicals and insecticides onion and imidacloprid gave 73% and 82% control respectively, over whitefly population and virus progression, as compared to other treatments. Results of current study indicated that the tolerant germplasm could be recommended for cultivation with appropriate management for whitefly population until genotypes with highly resistant characters were not developed through efficient breeding program. [ABSTRACT FROM AUTHOR]

Guava (Psidium guajava L.) belongs to family Myrtaceae, is the fourth most important fruit crop of Pakistan. In spite of its importance in the livelihood and upliftment of the economy of farmers, the production of guava has been reduced due to anthracnose problem thorought the Pakistan. Results of investigation revealed that C. gloeosporioides was established as major causal organism. In vitro biological control of Colletotrichum gloeosporioides by Aspergillus flavus gave good results and appeared to be the most effective against the test pathogen followed by Aspergillus niger and Trichoderma harzianum, while Aspergillus fumigatus gave poor results. Out of six fungicides tested against Colletotrichum gloeosporioides, systemic fungicides gave more good results than non systemic fungicides. Least colony growth was observed in case of Derosal which gave effective control against C. gloeosporioides followed by Bayletan, Daconil, Ridomil Gold, Mancozeb and Alliete. By the application of these strategies the anthracnose problem can be managed properly with better economic benefits and small risk of health hazard effects. These studies whould be useful for high quality guava fruit production and to control this disease. [ABSTRACT FROM AUTHOR]

Citrus canker epidemics were generated with 108 cfu/ml ofXanthomonas axonopodispv.citri(ex Hasse) onCitrus limoniacv. China lemon,Citrus reticulatecv. kinnow,Citrus jambhiri, Citrus reticulatecv. Feutral’s early andCitrus limettioidesusing four inoculation techniques. Natural inoculum was also relied upon for infection. Overall, the injection infiltration method led to maximum disease generation followed by spray, pinprick and smear inoculation methods. Citrus canker incidence along with environmental data were recorded and subjected to stepwise regression analysis. Except relative humidity, the relationship of weekly air temperature (maximum and minimum), rainfall and wind speed with citrus canker disease development in all citrus cultivars was positively correlated and best explained by linear regression. Overall, two environmental variable model containing maximum and minimum air temperature fit the data well explaining 93% variability in disease development. The observed citrus canker incidence values and those predicted by the model were close in most of citrus cultivars. This two environmental variable model can be used to issue advance warning forecasts for the timely management of the citrus canker in Pakistan. [ABSTRACT FROM PUBLISHER]

Urdbean (Vigna mungo (L.) Hepper) is an important pulse crop grown worldwide. ULCV is an important disease of urdbean in Pakistan, because it causes huge losses in production of urdbean. The susceptible germplasm and favorable environmental conditions also contribute towards the wide spread outbreak of viral diseases. Forty urdbean lines were screened against ULCV under field conditions. Correlation studies between environmental factors (temperatures & relative humidity) and ULCV infection in selected lines revealed positive interaction for maximum and minimum temperatures but a negative one for relative humidity. The comparative efficacy of 2% concentration of different plant extracts (neem, akk, garlic) against ULCV was determined. Plants sprayed with neem extract have least whitefly population followed by garlic and results showed that minimum disease severity was observed on plants that were sprayed with neem followed by akk. The results are helpful in the understanding of epidemiological factors that play vital role in disease spread. Furthermore, the plant extracts can be used to manage the vector populations, which ultimately reduce the disease incidence. [ABSTRACT FROM AUTHOR]