Issue Information
Annals of Applied Biology, Volume 183, Issue 2, Page 105-107, September 2023.
Challenges in pea breeding for tolerance to drought: Status and prospects
Major knowledge gaps identified in pea breeding for drought tolerance, available tools to address these challenges and possible solutions that will enable the increase of genomic resources available for drought tolerant pea plants.
Abstract
Drought is increasingly frequent in the context of climate change and is considered a major constraint for crop yield. Water scarcity can impair growth, disturb plant water relations and reduce water use efficiency. Pea (Pisum sativum) is a temperate grain legume rich in protein, fibre, micronutrients and bioactive compounds that can benefit human health. In reducing pea yield because of drought, the intensity and duration of stress are critical. This review describes several drought resistance mechanisms in pea based on morphology, physiology and biochemical changes during/after the water deficit period. Drought tolerance of pea can be managed by adopting strategies such as screening, breeding and marker-assisted selection. Therefore, various biotechnological approaches have led to the development of drought-tolerant pea cultivars. Finally, the main objective of the current research is to point out some useful traits for drought tolerance in peas and also, mention the methods that can be useful for future studies and breeding programmes.
Exploiting volatile organic compounds in crop protection: A systematic review of 1‐octen‐3‐ol and 3‐octanone
Exploitation of the volatile organic compounds (VOCs) 1-octen-3-ol and 3-octanone show potential for use in future crop protection. Key interactions between naturally occurring biosynthesised 1-octen-3-ol and 3-octanone and a range of invertebrate targets has been identified. Development of 1-octen-3-ol and 3-octanone for use in crop protection should focus on the exploitation of synthesised nature identical variants of these compounds for use as a biopesticide.
Abstract
The 21st century has brought new challenges to the agri-food industry due to population growth, global warming, and greater public awareness of environmental issues. Ensuring global food security for future generations is crucial. However, pests, weeds, and diseases still significantly contribute to crop losses, and the availability of effective conventional synthetic pesticides is decreasing. To address this, new and diverse pest management tools are needed. One pest management tool showing potential for invertebrate pest management is the exploitation of volatile organic compounds (VOCs)—in particular, the compounds 1-octen-3-ol and 3-octanone. This review aims to explore the extent to which 1-octen-3-ol and 3-octanone show potential in the future management of invertebrate crop and animal pests. A significant increase in the rate of publication of literature on the use of 1-octen-3-ol and 3-octanone in crop protection since 2018 is identified by this review, therefore, showing the potential importance of these compounds for use in future pest management. This review also identifies key interactions between naturally occurring biosynthesised 1-octen-3-ol and 3-octanone, and a range of invertebrate targets. Many of these interactions with key crop pests are sourced from the taxonomic families Lamiaceae, Fabaceae, and Trichomaceae. However, analysis of the practical application of these sources in an integrated pest management programme identifies clear limitations with the use of naturally occurring biosynthesised 1-octen-3-ol and 3-octanone. Rather, future focus should be placed on the development and exploitation of synthesised nature identical 1-octen-3-ol and 3-octanone for use as a biopesticide product. Overall, 1-octen-3-ol and 3-octanone show potential for exploitation in future crop protection, being abundant in source and diversity of invertebrate interactions. However, their use as a naturally occurring biosynthesised chemical is likely not practical for direct implementation in crop protection. Rather, focus should be placed on the development and exploitation of synthesised nature identical variants of these compounds for use as a biopesticide.
Heterosis and reselection for pyrethroid resistance trait maintenance in the lady beetle Eriopis connexa (Germar)
Heterosis from panmictic mating resistant and susceptible Eriopis connexa phenotypes enhances offspring performance. Fecundity and survival were higher in the offspring, but higher fecundity was not sustained after reselection. Resistance maintenance in E. connexa after release will depend on insecticide exposure and selection pressure.
Abstract
Exposure of Eriopis connexa (Germar) to pyrethroid residues in agroecosystems has resulted in selection for resistance (R). Pyrethroid resistance allows E. connexa to survive lambda-cyhalothrin applications. Following a field release of E. connexa, development of resistance in an incipient population may depend on three major factors such as the maintenance of: (i) selection pressure, (ii) frequency of mating with susceptible phenotypes (S) and (iii) differential reproductive performance due to the fitness costs associated with resistance. To investigate the potential effects of these three factors on the development of pyrethroid resistance by progeny of field released E. connexa, our experiments included panmictic mating between R and S phenotypes, followed by descendant rearing with and without insecticide selection pressure, reselection and determination of resistance levels. In addition, we measured the reproductive performance of the parental R and S phenotypes and their descendants to assess the cost of resistance after crossing and reselection. Survival of R × S descendants exposed to lambda-cyhalothrin was reduced across successive generations in the absence of selection pressure, but still enhanced after four generations indicating the persistent presence of resistant phenotypes in the population. Under selection pressure with exposure to lambda-cyhalothrin applied at label rates, descendant survival was >50%. Fecundity and survival were higher in the first-generation of crossed R × S females, but higher fecundity was not sustained after reselection. Adults of the R population exhibited a fitness cost, reduced longevity, when compared to S phenotypes and R × S crossed populations. Therefore, resistance maintenance in E. connexa after release will depend on selection pressures imposed by insecticide exposure. In the absence of selection pressure, the phenotype for resistance was reduced, but not completely lost. Further, resistant phenotypes can be reselected following insecticide exposure and this can explain, in part, the high frequency of field-evolved resistance to lambda-cyhalothrin in E. connexa.
The post‐registration monitoring of glyphosate‐treated plants using anecic earthworms
Earthworm midden building activities were influenced by the use of glyphosate-based herbicides, and there were significant differences in biomass resulting from feeding earthworms in the lab with these plant materials.
Abstract
Glyphosate N-(phosphonomethyl) glycine is a widely-used herbicide in agriculture. The anecic earthworm, Lumbricus terrestris feeds and forages for surface plant materials meaning that this species has a unique and direct exposure to agrichemicals. At the recommended product rates, significantly (F1,44 = 8.67, p = .005) higher numbers of L. terrestris middens were found in the glyphosate treated areas of an arable crop field. Laboratory feeding assays using field aged plant materials indicated that previous glyphosate treatment was a statistically significant factor affecting earthworm L. terrestris biomass (F1,12 = 5.75, p = .03). Negligible glyphosate residues were detectable, and the field aged plant materials were encrusted with fungal hyphae. This suggests that glyphosate influences the colonisation of plant material by a litter-fungus complex which improves the food quality to earthworms. Concentrations of epoxiconazole, a fungicide, were detected in some plant materials and may influence overall food quality to earthworms. Glyphosate treatment on fresh volunteer plant leaves (unwanted crop seedlings) was not a statistically significant factor affecting earthworm L. terrestris biomass (F1,6 = 0.16, p = .92). These results indicate fungal communities influence feeding behaviours, and plant materials are a direct source of agrichemicals to anecic earthworms.
Shedding light on a hot topic: Tuberisation in potato
Schematic overview of how tuber size, tuber number and indirectly total tuber weight were affected by light and temperature, with + indicating an increasing effect on the tuber trait, and − indicating a decreasing effect. Increasing the difference in day/night temperature led to an increase in tuber size, while increasing the average temperature reduced tuber size as well as tuber number. Changes in the light spectrum affected tuber number: increasing the percentage of far-red light in the spectrum led to a higher tuber number. Also increasing the light intensity led to an increase in tuber number.
Abstract
Growing small seedling tubers from true seed, comparable with mini tubers, in controlled conditions could be a method to multiply healthy starting material of potato. In indoor farming systems, the conditions can be optimised for high production. In field trials, it is impossible to investigate the effects of environmental factors such as temperature and light separately. In this study, we performed three climate room experiments in which the effects of light intensity, temperature and percentage of far-red light in the light spectrum on tuber production were assessed. We found that increasing the average temperature reduced tuber number and tuber weight. Increasing the diurnal temperature variation while keeping the average temperature equal resulted in increased tuber size. The light treatments on the other hand only affected the number of tubers per plant: increasing light intensity and increasing the percentage of far-red light in the spectrum enhanced the number of tubers. Moreover, interaction in tuber production between inbred lines and temperature was significant, with some inbred lines being relatively tolerant to high temperature. These findings will help breed for heat tolerant varieties and optimise growing conditions for tuber production in indoor farming systems.
Identification of multiple symptoms of huanglongbing by electronic nose based on the variability of volatile organic compounds
Identification of multiple symptoms of huanglongbing (HLB) by electronic nose (E-nose) based on the variability of volatile organic compounds (VOCs). (1) Headspace solid-phase microextraction gas chromatography–mass spectrometry-based analysis demonstrates the potential of E-nose for HLB detection. (2) The best feature extraction method and pattern recognition method were confirmed. (3) Optimal VOCs pick-up conditions are temp. 40°C, time 20 min, W 0.2 g, and vol 200 mL. (4) HLB can be detected based on E-nose (98.75% for HLB+, 97.50% for Zn deficiency and HLB+).
Abstract
Huanglongbing (HLB) is highly contagious and cannot be cured, resulting in a decrease in the commercial value of citrus. Timely detection and removal of diseased trees is an effective way to reduce losses. Complex symptoms of HLB, such as nutrient deficiencies often accompany HLB; as a result effective and accurate identification of HLB remains a challenge. In this study, 175 volatile organic compounds (VOCs) were detected in three categories (healthy, HLB, and Zn-deficiency) of samples using headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC/MS), highlighting the variability of VOCs present in different categories of samples. In order to simplify the testing steps and reduce the cost in practical agricultural production, a method based on electronic nose technology to collect VOCs from citrus leaves for HLB detection was proposed. Among them, limiting value features and linear discriminant analysis were identified as the best combination of feature extraction and pattern recognition methods. Multiple sets of comparison experiments were set up and the collection conditions of VOCs were optimized. The results showed that the best classification performance was achieved for a 0.2 g sample at a collection time of 20 min when the collection temperature was 40°C and the headspace volume was 200 mL. Four types of samples (healthy, HLB-positive, Zn-deficiency, Zn-deficiency and HLB-positive) were used for model reliability validation, with an accuracy of 97.79% for HLB samples for multiple symptoms (including HLB-positive and Zn-deficiency and HLB-positive) identification. In addition, the accuracy of samples with a combined effect of Zn-deficiency and HLB was 96.43%. The results show that the E-nose-based HLB detection method is conducive to suppressing the spread of HLB, which can ensure the quality of citrus products and reduce the economic loss to horticulturists, and has good practical value.
Wood distillate (pyroligneous acid) boosts nutritional traits of potato tubers
Potato is the fourth most widely consumed staple food in the world. This study investigated the effectiveness of 0.2% wood distillate (WD), a biostimulant derived from the pyrolysis of waste plant biomass, in boosting the nutritional quality of potato tubers.
Abstract
Potato is the fourth most widely consumed staple food in the world. This study investigated the effectiveness of 0.2% wood distillate (WD), a biostimulant derived from the pyrolysis of waste plant biomass, in boosting the nutritional quality of potato tubers. The results showed that application of WD significantly increased the content of soluble sugars (sucrose +56.3%; glucose +44.9%; fructose +62.2%), starch (+35.1%) and total carbohydrates (+16.8%). Antioxidants (total antioxidant power, polyphenols, flavonoids) and most mineral elements (K, Mg, Ca, Na, Fe, Zn) were not affected. A lower content of Cu (−17.8%) and P (−24.5%) was found in WD-treated potato.
Phenological growth stages of Gleditsia sinensis Lam. (Fabaceae) using the extended BBCH scale
The extended BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) coding method to describe the morphology of the Gleditsia sinensis over two consecutive years in southwest China. Eight main growth stages were photographed, including bud development (0), leaf development (1), shoot development (3), inflorescence emergence (5), flowering (6), pod development (7), maturity of pod (8) and senescence (9). Besides, management activities were listed for each stage to allow plantation managers to better manage their trees.
Abstract
Gleditsia sinensis is a species endemic to China, an ecologically economic multipurpose tree with great development potential, which could be used as medicine, food, industrial materials and wood. It is well known that the standardized description of plant development stages according to their phenological characteristics not only is crucial for conduct of various agronomic practices, but also facilitates the exchange of new findings based on the same understanding of the plant. However, a uniform phenology scale of G. sinensis has rarely been reported, despite its expanding plant area and rapid development of this industry over the past few years. Thus, phenological events of G. sinensis were monitored based on the BBCH scale during two consecutive years in this study. Eight of the 10 BBCH stages described in detail by combining numbers and letters based on its species characteristic were accurately recorded, including bud development (0), leaf development (1), shoot development (3), inflorescence emergence (5), flowering (6), pod development (7), maturity of pod (8) and senescence (9). As far as we know, it is the first time that a special phenological rhythm for G. sinensis has been developed using an extended BBCH scale, which not only provides the basis for other basic research, but also assists growers in conducting planting management practices.
Clinical and patient‐reported outcomes from the first 4 years of a Psoriasis Biologics Registry in Singapore
Abstract
Interim analysis of the National Skin Centre Singapore Psoriasis Biologics Registry (SINGPSOR) from August 2017 to May 2021, in which 58 patients were analysed, showing that those receiving biologic treatment had significantly more severe psoriasis based on PASI (Psoriasis Area and Severity Index), BSA (body surface area) and PGA (Physician Global Assessment) measures at baseline, demonstrated a statistically non-significant trend towards greater improvement with treatment, and had a lower percentage of adverse events compared to those receiving conventional systemic therapy. Future analyses of SINGPSOR, with larger sample size and longer follow-up, will be invaluable to further characterize these patients and their treatment outcomes.