Category Archives: Annals of Applied Biology

Aspects of the biocontrol activity of Aureobasidium spp. strain against Penicillium expansum of apple

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Aspects of the biocontrol activity of Aureobasidium spp. strain against Penicillium expansum of apple

The efficacy of a yeast, Aureobasidium spp. strain UC14 isolated during the winter season, against Penicillium expansum growth was tested by in vitro assays and on apples during the cold storage. The antagonism of UC14 was further demonstrated by the low amount of pathogen DNA detected in treated fruits by qPCR analysis and also by the reduction of patulin. Results displayed interesting aspects of the strain as candidate for use in the postharvest phase.


Abstract

Penicillium expansum is a fungal pathogen of pome fruit, causing the economically important disease of apple blue mould. The fungus is also important due to its ability to produce the mycotoxin patulin. A strain of Aureobasidium spp. (UC14) was assessed for controlling P. expansum and patulin production in a series of in vitro antibiosis experiments. Volatile and non-volatile metabolites reduced growth of P. expansum on average by 50%. To assess UC14 efficacy on apples in vivo, different concentrations of cellular suspension were assayed. The concentration 1 × 108 cells/mL was the most effective, completely suppressing apple fruits blue mould symptoms. The antagonism of UC14 was further demonstrated by the very low amount of pathogen DNA in treated fruits detected by qPCR. During cold storage, Aureobasidium strain UC14 persisted on fruits and reduced disease severity by 82.5% and 89.8%, for ‘Golden delicious’ and ‘Fuji’ apples, respectively. Aureobasidium strain UC14 reduced patulin on ‘Golden delicious’ and ‘Fuji’ apples by 98.1% and 96.2% with respect to the control, demonstrating good efficacy as a potential biological control agent (BCA), so becoming an interesting candidate for use as BCA in the postharvest phase.

Phenological coding of Crambe abyssinica Hochst. according to the BBCH system

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Phenological coding of Crambe abyssinica Hochst. according to the BBCH system

In the present study, a proposed scale of the phenological growth stages of crambe was applied according to the Biologische Bundesanstalt Bundessortenamt und Chemische Industrie coding system was applied.


Abstract

Crambe (Crambe abyssinica Hochst.) is an oilseed crop domesticated in the Mediterranean region that is becoming increasingly important worldwide. Crambe is now considered as an alternative to bioenergy crops and oleochemicals, because of its ability to acclimatise under inhospitable conditions. Despite the interest in the agronomic characteristics and applications of this crop, research on crambe is still scarce and has focused only on production, taking into account the phenological stages of this species. Therefore, a single criterion for quantifying the phenology of the species can be a useful tool for both researchers and growers. In the present study, a proposed scale of the phenological growth stages of crambe was applied according to the BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) coding system. The phenological stages were described using the one- and two-digit decimal coding of the BBCH system and corresponded to stage 0: germination; stage 1: leaf development; stage 2: lateral sprout formation; stage 5: inflorescence emergence; stage 6: flowering; stage 8: fruit ripening and stage 9: senescence. Growth stages 3 and 4 (main stem elongation and development of collectable vegetative parts, respectively) have been omitted. Figures have been included to illustrate the main stages, and plant growth has been represented by a technical botanical illustration. The BBCH system has been effective in providing phenological data on crambe, allowing for better growing management of the crop under varying climatic conditions, as well as contributing to the standardisation of research methods on the species.

Flock health planning: How to move from a plan to a reflective planning process in Northern Irish sheep flocks?

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Flock health planning: How to move from a plan to a reflective planning process in Northern Irish sheep flocks?

This is a predominantly qualitative study of the beliefs and behaviours of sheep farmers, and their veterinarians, from across Northern Ireland, surrounding their flock health plans and flock health planning process. Sheep farmers participating saw their health plan as a static, physical document rather than an ongoing continuous cycle of improvement. Veterinarians saw potential to improve flock health if they could engage farmers and develop an income stream from the work. Farmers and veterinarians concurred that incentivising engagement and support in implementation of the agreed plans was key to drive flock health planning forward.


Abstract

Flock health planning has been advocated as part of a wider drive within livestock production for veterinarians and farmers to adopt a prevention-focused approach to veterinary medicine. This approach has, at its core, a cyclical process of assessment, evaluation, action and re-assessment, and is documented, at least in summary, in a health plan (HP). The HP has become a defining pillar of farm quality assurance schemes (QASs), introduced to address calls for greater transparency and accountability in food production. There is limited current information on the attitudes and behaviours surrounding flock HPs in the sheep sector and the barriers to greater involvement in an active process of continual improvement through reflective flock health planning. This study aims to address these issues with reference to the national flock in Northern Ireland. A mixed-methods approach was used to explore farmers' and veterinarians' opinions and behaviours related to QASs and HP, with data obtained through an online scoping questionnaire, semi-structured interviews with 27 farmers and 15 veterinarians, and discussion groups with farmers and veterinarians. No evidence of a positive association between a farm having a HP and implementation of 12 industry-recommended flock health activities was identified using the Fisher's exact test. Farmers reported a reluctance to pay for veterinary advice while some veterinarians reported a lack of time to develop HPs for farmers, and sheep-related work generally. Farmers predominantly saw the HP as a static, physical document, which had limited impact on their management practices, rather than a proactive, reflective and collaborative planning process. Veterinarians tasked with completing HPs felt restricted by limited knowledge of on-farm practices, flock production data and a lack of confidence in the accuracy of on-farm medicine records. This led some to believe that the HPs may fail to address critical issues. A new approach to engage farmers and veterinarians together in active flock health planning needs to be developed. This will need a sustainable delivery plan. Then the focus can be shifted towards ongoing reflective health planning to drive change for the betterment of sheep health and welfare.

Mulch alleviates the continuous crop barriers of Codonopsis pilosula (Franch.) Nannf. by regulating the soil bacterial community

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Mulch alleviates the continuous crop barriers of Codonopsis pilosula (Franch.) Nannf. by regulating the soil bacterial community

This manuscript provides information using developed field experiments to systematically investigate the mechanisms of environment–microbe–plant occurrence of continuous cropping disorder of C. pilosula through 16S high-throughput sequencing in conjunction with actual production, and we explored the effect of the mulched film on the repair of C. pilosula continuous cropping obstacles and provided a theoretical basis for reducing C. pilosula continuous cropping obstacles. The findings of the study revealed a decline in organic matter and inorganic nitrogen content, as well as a decrease in soil microorganism abundance, following continuous cropping of C. pilosula. After mulching, the abundance of beneficial bacteria AKAU4049, Betaproteobacteriales and Gaiellales in the soil increased, and the content of organic matter and inorganic nitrogen was elevated, which improved the soil environment and promoted the growth of C. pilosula under continuous cropping conditions.


Abstract

Codonopsis pilosula (Franch.) Nannf. is an essential traditional medicinal herb in China. Soil sickness caused by continuous cropping is the main reason for the yield reduction of C. pilosula. However, because of the lack of systematic research on the mechanism of continuous cropping obstacles in C. pilosula, there is a lack of effective measures to reduce or even restrain the disorder of continuous cropping obstacles in C. pilosula. The root system, inter-root soil microorganisms and non-inter-root soil of C. pilosula under a continuous cropping system (e.g. crop rotation, two consecutive crops and three consecutive crops) as well as under different mulching methods (the mulched film and the uncovered) were used as experimental materials for the study. The plant growth of C. pilosula was significantly inhibited when continuous cropping reached 2 years. At the same time, the mulched film significantly (p < .05) promoted the development of C. pilosula under continuous cropping and considerably mitigated the plant death rate of C. pilosula in all fields. The content of soil nutrients, such as organic matter and inorganic nitrogen, decreased with increasing years of continuous cropping. In contrast, the mulched film improved this soil nutrient in continuous cropping. There was a tendency for the number of endemic operational taxonomic units (OTUs) to decrease in continuous cropping. Additionally, the mulched film altered the distribution of shared and endemic OTUs in the samples and had a recruiting effect on inter-root microorganisms in continuous cropping. Betaproteobacteriales flora abundance decreased with increasing years of continuous cropping, which showed a strong positive correlation with the immune system and environmental adaptation function. The mulched film increased the abundance of beneficial microorganisms, such as AKAU4049, Betaproteobacteriales and Gaiellales, to adapt and improve the continuous crop disorder of C. pilosula. In conclusion, mulching can enhance the soil environment and facilitate the growth and development of C. pilosula during continuous cultivation.

Sexual selection in Thaumatotibia leucotreta (Meyrick) is shaped by contrasting geographic adaptations, but does it matter for area‐wide sex pheromone control tools?

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Sexual selection in Thaumatotibia leucotreta (Meyrick) is shaped by contrasting geographic adaptations, but does it matter for area-wide sex pheromone control tools?

Geographically isolated populations of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) occur in South Africa, causing speculations of loss of sexual communication between these isolated populations and compromise the efficiency of sex pheromone tools. Investigations into these speculations were conducted, and results indicate that local adaptation and other selection forces in contrasting environments are important in sexual communication and selection in T. leucotreta but do not necessarily prevent recognition of sexual signals and attraction between geographically isolated populations.


Abstract

Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a quarantine pest for certain export markets due to its phytosanitary status in affected crops in sub-Saharan Africa, including citrus. Consequently, there is a zero-tolerance policy for T. leucotreta in export markets. In South Africa, an integrated pest management strategy, incorporating a systems approach is used to achieve complete control of T. leucotreta. Preharvest management is multi-faceted, including reliance on sex pheromone tools such as monitoring, attract-and-kill, mating disruptions, and sterile insect technique (SIT). Geographically isolated populations of T. leucotreta occur in South Africa, and there is speculation concerning the possible loss of sexual communication between these isolated populations, thereby compromising the efficiency of sex pheromone tools. To investigate this possibility, we collected samples from five geographically isolated populations of T. leucotreta and a population used for SIT in South Africa. These were subjected to sexual attraction trials under choice and no-choice scenarios in a semi-natural environment. Results of the choice tests revealed that males of each population preferred their corresponding population females, except irradiated males. However, when we deprived males of their preferred females, these preferences dissipated, and they were equally attracted to females from all populations. These results indicate that local adaptation and other selection forces in contrasting environments are important in sexual communication and selection in T. leucotreta but do not necessarily prevent recognition of sexual signals and attraction between geographically isolated populations. These findings are crucial for area-wide IPM and precision control of T. leucotreta.

Changes in the prevalence of fungal species causing post‐harvest diseases of carrot in Finland

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Changes in the prevalence of fungal species causing post-harvest diseases of carrot in Finland

Carrot post-harvest diseases were analysed in samples from 52 different field plots in Finland, during 3 years. After 5 months at 0–1°C, the average loss due to diseases was 20%–21% every year. Decay of the root tip was the most common disease symptom, followed by pits on the side and black rot in the crown, detected in 69.2%, 15.0% and 9.0% of the symptomatic samples, respectively. The frequency of different fungal pathogens varied between the years and the time points during storage. At first Fusarium spp. were prevalent, whereas Mycocentrospora acerina and Botrytis cinerea peaked later.


Abstract

Post-harvest diseases cause significant economic losses in the carrot production chain. In this study, storage losses and fungal pathogens causing them were analysed in the carrot yield from 52 different field plots in four areas in Finland in 3 years (2016–2018). Over 30,000 carrots were sampled and analysed at three time points during cold storage at 0–1°C. In March, after 5–6 months' storage, the average loss due to diseases was 20%–21% every year. Decay of the root tip was the most common disease symptom, followed by pits on the side and black rot in the crown, detected in 69.2%, 15.0% and 9.0% of the symptomatic samples, respectively. Both intensive carrot cultivation practice and early timing of harvest increased storage losses. Pathogens in 3057 symptomatic carrot tissue samples were isolated by culturing, and fungal species were identified. The most common fungal species detected were Mycocentrospora acerina, Botrytis cinerea and Fusarium spp., especially F. avenaceum. However, the frequency of different pathogens varied between the different years and time points during storage. Species-specific PCR tests revealed that M. acerina and F. avenaceum were present in many early time-point samples where they could not yet be detected by the culturing method. In Finland, this study on carrot post-harvest diseases is the first large-scale survey in which the fungal pathogens were isolated and identified by laboratory tests. In comparison with the previous studies, Fusarium spp. were detected more frequently in this study, while grey mould and Sclerotinia rot were less frequent.

Effects of food resources on the longevity, survival, and fecundity of Paracentrobia subflava adults, an egg parasitoid of the corn leafhopper pest Dalbulus maidis

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Effects of food resources on the longevity, survival, and fecundity of Paracentrobia subflava adults, an egg parasitoid of the corn leafhopper pest Dalbulus maidis

Process of evaluating longevity and survival to different artificial diets and honeydew of the corn pest Dalbulus maidis in the egg parasitoid Paracentrobia subflava (A). In addition, assess P. subflava's fecundity with food (honey) and without food (B).


Abstract

The diet consumed by adult parasitoids can affect longevity, survival, and fecundity. Honeydew from sap-sucking insects is an abundant food resource in the field; however, artificial diets such as commercial bee honey are often used in lab rearing. The parasitoid Paracentrobia subflava (Girault) (Hymenoptera: Trichogrammatidae) is a natural enemy of Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae). The longevity and survival of P. subflava when fed natural and artificial diets under controlled conditions have not been studied. Further, the fecundity of P. subflava when fed a diet of honey has not been investigated. Therefore, our first objective was to analyse the longevity and survival of P. subflava when fed (1) honeydew of the corn leafhopper D. maidis, (2) honey + water, (3) honey + water + pollen, (4) water, and (5) nothing (control). Our second objective was to evaluate P. subflava fecundity upon exposure to D. maidis eggs, comparing parasitoids fed with honey + water versus controls (no food or water). In the second objective, honey was chosen since it was determined during the first objective to be the optimal food. The longevity of adult parasitoids (laboratory-reared and field-collected) was high when fed on honey and low when fed other diets. The highest longevity was achieved with honey + water: 17 days, while the survival of adult parasitoids was only 3 days for honeydew. Interestingly, fecundity, in terms of the percentage of parasitism and the percentage of emergence, did not differ between parasitoid females that had access to honey + water as a food resource and those that had no food or water.

Constraints and solutions for development and uptake of integrated pest management in the UK

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Constraints and solutions for development and uptake of integrated pest management in the UK

Integrated pest management (IPM) yields agricultural improvements that support environmental aims. The IPM innovation system develops exciting products but encounters significant challenges in bringing them to market. This article reports the nine key recommendations emerging from an Association of Applied Biologists conference ‘Bringing Biocontrol and IPM to Market’, at which delegates from four key agricultural industry sectors discussed how to establish an effective IPM innovation system that links multiple stakeholders.


Abstract

Agricultural improvements that reduce conventional pesticide use and support environmental aims are a priority. Current approaches develop promising alternative products but meet significant challenges in bringing them to market. This article reports findings of an Association of Applied Biologists event at which delegates from relevant industry sectors discussed the establishment of an effective integrated pest management innovation system linking multiple stakeholders. Interrelated recommendations were agreed upon, focused on structured gap analysis, co-design processes reflecting the complete innovation system, the approval process, application equipment, enhancing grower confidence, integrating knowledge exchange activities, promulgation of public good information and the need for an overarching national action plan and supporting legislation.

Genomic dissection of brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae) resistance in Indica rice genotypes

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Genomic dissection of brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae) resistance in Indica rice genotypes

New Nilaparvata lugens resistant genotypes were reported. Six BPH resistance genes showed significant association and these genes either alone or in combination could be introgressed into elite varieties with genomic approach to develop robust resistant rice varieties against N. lugens biotype 4. The identified genotypes could be useful for novel R genes identification, host–insect interaction and genomic studies.


Abstract

The population growth and the regular breakout of Nilaparvata lugens pose a significant risk to rice cultivation. Four different N. lugens biotypes have been identified worldwide, with biotype 4 being the most destructive and prevalent throughout Asia, particularly in India. Therefore, a rice variety with multiple resistance genes/alleles is required for effective management of N. lugens. Hence, 191 rice genotypes collected from various parts of India were evaluated for resistance to N. lugens. Further, SSR markers representing 23 different N. lugens resistant (R) genes were assayed to identify genomic regions associated with resistance. The results of the genetic analysis showed that the average genetic diversity value of all markers was 0.165 and polymorphic information content of 0.145 for all the markers used. The population structure and cluster analysis divided the studied genotypes into three distinct groups, with resistant genotypes grouped separately. These findings were confirmed by the principal coordinate analysis, which categorized resistant genotypes, moderately resistant genotypes, and susceptible genotypes into distinct components. Additionally, 90% of the genetic variation was between individuals of populations and 10% between the populations. Marker-trait association study through mixed linear model and generalized linear model identified six SSR markers such as RM6732 (Bph15), RM314 (Bph6), RM16999 (Bph6), RM7 (QBph3), RM401 (bph4), and RM7102 (Bph1), which were significantly associated with various phenotypic parameters, such as feeding mark, honeydew excretion, percent damage and nymphal survival. The resistant genes identified in these genotypes could help in the marker-assisted rice variety development with durable resistance against N. lugens.

Antixenosis and antibiosis mechanisms of resistance to Asian rice gall midge, Orseolia oryzae (Wood‐Mason) in rice land races

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Antixenosis and antibiosis mechanisms of resistance to Asian rice gall midge, Orseolia oryzae (Wood-Mason) in rice land races

Rice gall midge resistance was governed by antixenosis and antibiosis mechanisms working in tandem. Antixenosis tests showed susceptible genotypes were preferred for egg laying and had faster adult emergence with a higher sex ratio. Resistant genotypes had higher levels of phenols, wax, flavonoids, and free amino acids, while susceptible ones had more sugars and protein. This study informs breeding for gall midge-resistant rice varieties.


Abstract

Asian rice gall midge is one of the important pests of rice, which attacks the crop from nursery to the end of the tillering stage. Managing this pest through plant resistance is the most viable and economical. Two hundred-two rice genotypes were phenotyped against Asian rice gall midge, Orseolia oryzae (Wood-Mason) and the mechanism of resistance in terms of antixenosis and antibiosis was studied. Antixenosis mechanism for adult settlement and egg laying indicated that the susceptible genotypes were preferred more than the resistant genotypes in a free choice test. First instar maggots were found and did not continue their growth on resistant genotypes further. However, in susceptible genotypes, they molted successfully and emerged as adults. No choice tests revealed that the emergence of adults in susceptible genotypes took less time than in resistant genotypes. Higher adult sex ratio was found in susceptible genotypes. Estimation of biochemical components in rice shoot apices of selected genotypes revealed that higher levels of total phenols, wax content, total flavonoids and total free amino acids were present in the resistant genotypes. Still, the number of total sugars, reducing sugars and total protein contents were significantly higher in the susceptible genotypes. Hence, the resistance mechanism in rice gall midge was displayed as a combination of antixenosis and antibiosis mechanism. The output of the study would be helpful in breeding for rice varieties resistant to Asian rice gall midge.