Category Archives: Annals of Applied Biology

Shedding light on a hot topic: Tuberisation in potato

Posted on 18 August 2023 by nJulia E. Stockem, nMichiel E. de Vries, nPaul C. Struikn

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.

The post‐registration monitoring of glyphosate‐treated plants using anecic earthworms

Posted on 18 August 2023 by nJacqueline L. Stroud, nKirstie Halseyn

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 (F_1,44 = 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.

Heterosis and reselection for pyrethroid resistance trait maintenance in the lady beetle Eriopis connexa (Germar)

Posted on 18 August 2023 by nDeividy V. Nascimento, nRogério Lira, nJorge B. Torresn

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.

Challenges in pea breeding for tolerance to drought: Status and prospects

Posted on 18 August 2023 by nMaryam Bagheri, nCarla S. Santos, nDiego Rubiales, nMarta W. Vasconcelosn

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.

Issue Information

Posted on 18 August 2023 by Wiley: Annals of Applied Biology: Table of Contents

Annals of Applied Biology, Volume 183, Issue 2, Page 105-107, September 2023.

Is there a relationship between enchytraeids diversity and community with soybean (Glycine max L.) productivity in no‐till system in subtropical soils of Brazil?

Posted on 18 August 2023 by

All genera were more abundant in high productivity than low productivity. The points with high productivity presented highest average richness. Enchytraeids demonstrating potential bioindicators of soil quality and consequently of soybean productivity in the no-tillage system for subtropical soils in Brazil.

Abstract

The relationship between the productivity of crops of agricultural interest and their interactions with physicochemical soil properties is widely explored. However, there is still a gap concerning the contribution of biological soil attributes and especially the relationship between crop productivity and the structures of organism communities within the soil, such as the enchytraeids. This paper aimed to evaluate the diversity and structures of enchytraeids communities in subtropical soils and their relationship with soybean productivity and soil properties within a no-tillage system. This study was conducted in soybean growing grounds working under no-till farming systems in southern Brazil. Samples were collected according to ISO 23611-3 and extracted with the hot–wet methodology. The organisms were identified up to their genus level. Enchytraeids density increased with the increase of soybean productivity for both evaluated crops. Enchytraeus, Fridericia, and Hemienchytraeus were more abundant in high productivity and genus Achaeta was only found in the second crop and was not a sensitive indicator toward changes in soybean productivity. Regarding the relationship between the enchytraeid community and soil attributes, the variables clay, phosphorus, moisture contents, pH, Ca/Mg as well as carbon and nitrogen from soil and litter, affected Enchytraeidae distribution. Enchytreids showed significant correlations with soybean productivity in the no-tillage system for subtropical soils in Brazil, demonstrating potential bioindicators of soil quality and consequently of soybean productivity.

Phenological growth stages of Gleditsia sinensis Lam. (Fabaceae) using the extended BBCH scale

Posted on 17 August 2023 by nQiao Liu, nJu Yang, nYupeng Liu, nYang Zhao, nRong Zou, nXiurong Wangn

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.

A review of sources of resistance to turnip yellows virus (TuYV) in Brassica species

Posted on 15 August 2023 by

Turnip yellow virus (TuYV) is an important/damaging pathogen for brassicas, including oilseed rape (Brassica napus; A+C genomes). Annual UK losses of 67 million GBP have been estimated in oilseed rape; losses in mainland Europe must be much greater. Many resistant commercial varieties are available, however they are all based on the same resistance source (TuYR1 from the A-genome). New sources of resistance combined from both A- and C-genomes are available in resynthesised B. napus lines (e.g., by combining TuYR7+TuYR8).

Abstract

Turnip yellows virus (TuYV; previously known as beet western yellows virus) causes major diseases of Brassica species worldwide resulting in severe yield-losses in arable and vegetable crops. It has also been shown to reduce the quality of vegetables, particularly cabbage where it causes tip burn. Incidences of 100% have been recorded in commercial crops of winter oilseed rape (Brassica napus) and vegetable crops (particularly Brassica oleracea) in Europe. This review summarises the known sources of resistance to TuYV in B. napus (AACC genome), Brassica rapa (AA genome) and B. oleracea (CC genome). It also proposes names for the quantitative trait loci (QTLs) responsible for the resistances, Turnip Yellows virus Resistance (TuYR), that have been mapped to at least the chromosome level in the different Brassica species. There is currently only one known source of resistance deployed commercially (TuYR1). This resistance is said to have originated in B. rapa and was introgressed into the A genome of oilseed rape via hybridisation with B. oleracea to produce allotetraploid (AACC) plants that were then backcrossed into oilseed rape. It has been utilised in the majority of known TuYV-resistant oilseed rape varieties. This has placed significant selection pressure for resistance-breaking mutations arising in TuYV. Further QTLs for resistance to TuYV (TuYR2-TuYR9) have been mapped in the genomes of B. napus, B. rapa and B. oleracea and are described here. QTLs from the latter two species have been introgressed into allotetraploid plants, providing for the first time, combined resistance from both the A and the C genomes for deployment in oilseed rape. Introgression of these new resistances into commercial oilseed rape and vegetable brassicas can be accelerated using the molecular markers that have been developed. The deployment of these resistances should lessen selection pressure for resistance-breaking isolates of TuYV and thereby prolong the effectiveness of each other and extant resistance.

Photosynthetic nitrogen utilization of Robinia pseudoacacia, an invasive species, grown in contrasting light conditions: A leaf scale approach

Posted on 10 August 2023 by

To understand the lifeform of the invasive temperate legume tree, Robinia pseudoacacia (black locust) grown under both open and shaded sites (a), we investigated their growth and nitrogen use characteristics (b, c).​ Our results (b, c) suggested that individuals in shaded sites, would not be well acclimated to their growth environment.

Abstract

Robinia pseudoacacia (black locust), an alien species in Japan, has been commonly planted to rehabilitate degraded land and as a resource for the production of honey. Although very few R. pseudoacacia adult trees are found in established mature forests, the management of R. pseudoacacia is a vital and urgent matter because of astounding growth potential, which negatively affects biodiversity and native vegetation. For this reason, we evaluated the seasonal shade-acclimation capacity of black locusts from the viewpoint of photosynthetic nitrogen use (PNU) and their partitioning. We assessed in situ photosynthetic N use traits of R. pseudoacacia leaves at open sites (relative photosynthetic photon flux density: (rPPFD) > 90%) and shaded sites (rPPFD < 22%) on the forest floor in larch (Larix kaempferi Carr.) plantations. Leaf unfolding started in late May and leaves turned yellow by mid-October just before leaf shedding. Shoot length at open sites was three times longer than at shaded sites. R. psudoacacia at open sites has more the leaflet number of each pinnate compound leaf than shaded sites from mid-August to October, and the size of leaflets at shaded sites was about 20% smaller than it was at the open sites. Leaf mass per area showed (mean ± standard deviation) 40.00 ± 2.14 g m⁻² at the open sites and 22 ± 1.56 g m⁻² at the shaded sites from June to October. The light-saturated photosynthetic rate peaked at 22 μmol m⁻² s⁻¹ at the open sites in July. At the shaded sites, it gradually increased to 7–10 μmol m⁻² s⁻¹ around August, and then decreased at both sites toward zero in mid-October. The total N content during the growth period was 1.60 ± 0.17 g m⁻² at open sites and 1.16 ± 0.15 g m⁻² at shaded sites. Unlike other tree species, N partitioning to photosynthetic organs was not affected by light conditions. These findings suggested R. psudoacacia cannot acclimate to shady conditions.

Efficacy of different lures for Phloeosinus aubei and other native and exotic bark and ambrosia beetles

Posted on 10 August 2023 by nTomáš Fiala, nPetr Pyszko, nJaroslav Holušan

Phloeosinus aubei may be a potential pest of junipers, thujas and cypresses in nurseries and cities. P. aubei beetles are attracted to juniper branches with ethanol placed in traps.

Abstract

Phloeosinus aubei is invasive in Central Europe, spreading northward from the Mediterranean region because of climate change. P. aubei has the potential to become a pest of mature, naturally occurring juniper trees (Juniperus communis) in protected areas, as well as junipers, thujas and cypresses in nurseries and urban environments. In 2020 and 2021, we conducted two experiments to compare various lures for trapping P. aubei. In the first experiment, we compared four lures: α-pinene; turpentine; a mixture of cade oil, juniper berry oil and ethanol; and a juniper branch (8–10 cm long, 3–5 cm wide) deployed with ethanol. In the second experiment, we compared Hostowit® with a juniper branch (8–10 cm long, 3–5 cm wide) deployed with ethanol. In both experiments, juniper branches deployed with ethanol attracted a greater number of P. aubei beetles compared to the other lures. In total, we captured 1056 individuals belonging to 36 species of Scolytinae. Among the most abundant species, Xyleborinus saxesenii, Xyleborus monographus and Anisandrus dispar were lured by ethanol in combination with other substances or deployed with juniper branches. Xyleborus dryographus showed a positive association with turpentine. Ips typographus was positively associated with α-pinene, while Orthotomicus laricis, Hylastes attenuatus and Gnathotrichus materiarius were positively associated with Hostowit® lure.