Annals of Applied Biology最新文献

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.

Esca is a grapevine trunk disease (GTD) that is caused by filamentous fungi. It is responsible for considerable economic losses in viniculture on a global scale. Despite many unknown factors contributing to the development of symptoms in affected plants, Phaeoacremonium minimum (PMI), Phaeomoniella chlamydospora (PCH) and Fomitiporia mediterranea (FMED) are generally considered as the main causative fungal species. Early detection and specific identification of these pathogens therefore play an important role in disease control and evaluation of suitable countermeasures. In this study, loop-mediated isothermal amplification (LAMP) assays were developed for each of the three pathogens. A genome-based approach was applied for detection and selection of unique target DNA sequences. The designed primer sets showed overall good specificities, with some observed cross-reactions towards closely related Phaeoacremonium species for the PMI primer set. The developed assays had detection limits of 100 pg (FMED, PMI) and 1 pg (PCH) per reaction (corresponding to 1460 [FMED]; 1950 [PMI]; 342 [PCH] genome copies per reaction). The application of the assays to field samples was demonstrated by testing individual infected grapevine trunks from two European viticultural regions using crude DNA obtained in a rapid sample preparation step. LAMP assay results matched those of PCR following a conventional DNA extraction protocol. The study showed that LAMP-based rapid molecular detection of major Esca agents can serve as a useful tool for further research and surveillance of a highly devastating grapevine disease. The application of computer-based whole genome comparison between target and non-target species for the identification of unique target sequences as the basis for LAMP (or PCR) primer design was demonstrated to be a useful approach in species for which scarce sequence information is available. Moreover, the developed method for rapid DNA preparation from grapevine trunks may potentially be adapted to the DNA-based detection also of other fungal species that cause grapevine trunk diseases.

One of the most damaging pathogens of pinewood is the pinewood nematode, Bursaphelenchus xylophilus, which could cause an adverse effect on the ecosystems of forests and the commerce of timber. Therefore, it is crucial to realize rapid and accurate B. xylophilus detection. In this work, an accelerated strand exchange amplification method (ASEA) was established to detect B. xylophilus for the first time. By integrating with fast nucleic acid extraction, the whole detection procedure could be finished within 30 min, dramatically shortened the detection time. The ASEA method exhibited high specificity towards B. xylophilus and the detection limit for B. xylophilus plasmid DNA was as low as 1.0 × 10⁰ copies/μL. Furthermore, the ASEA approach also exhibited accurate detection for B. xylophilus when applied to actual pinewood samples, meeting the demand of B. xylophilus detection in realistic scenario. We believe the ASEA method has significant potential for B. xylophilus detection, and it will be helpful for controlling forest pest and quarantine regulations.

Understanding the phenological stages and thermal requirements of the seedling phase of forest species is crucial for sustainable nursery management. This study proposed an adaptation of a phenological scale based on the basic Biologische Bundesanstalt, Bundessortenamt, and Chemical industry, associated with the thermal requirement to describe the phenological stages during the seedling phase of three forest species: Cybistax antisyphilitica, Libidibia ferrea, and Platycyamus regnellii. The phenological scale of C. antisyphilitica and L. ferrea was defined and described through 22 seedling development stages ranging from dry seed to 20th visible leaf emitted on the main stem (from 00 to 120) and P. regnellii for 12 leaf development stages, from dry seed to 10th visible leaf emitted on the main stem (from 00 to 110). In addition, the duration (days) and thermal time (°C day) were determined for each seedling development stage. C. antisyphilitica needs to accumulate more energy (and days) to finish the seedling phase (1551.9°C day or 261 days) compared to L. ferrea (1127°C day or 175 days) and P. regnellii (1109.7°C day or 193 days). However, the three forest species exhibit similar energy demands throughout most stages of seedling development, except code 09–12 for C. antisyphilitica. This study provides important information for optimizing silvicultural techniques, evaluating the response of temperature on phenological stages, and assessing the impacts of global warming on forest seedling development.

Secondary sexual dimorphism (SSD) in flowering plants is expressed by sexual differences of characters that are not directly related to gamete production. The leaf C/N ratio, photosynthetic traits or clonal responses have never been studied in relation to SSD in yerba-mate. It was hypothesized that leaf and plant photosynthesis are higher in female than in male individuals because females must supply photoassimilates to compensate for the additional reproductive investments of SSD in biomass. Here, we investigated how two contrasting light environments (monoculture—MO and agroforestry—AFS) and plant genders change leaf and plant photosynthesis, plant architecture, leaf and branch biomass production and C and N investments of two male and two female clones. To model the 3D yerba-mate structure, virtual trees were constructed using measurements of plant morphology using VPlant modelling software. The light-response curves of leaf CO₂ assimilation were used to model instantaneous leaf and daily plant photosynthesis. Photosynthetic traits derived from light-response curves did not differ between MO and AFS. Some architectural traits were segregated sexually only in MO, while some physiological ones only in AFS. Leaf photosynthesis was higher in females than in males in AFS over a large part of the diurnal cycle, but SSD was not expressed in carbon gains at plant or daily scales. Leaf C/N ratio was higher in MO than in AFS, indicating MO as an ecosystem with higher degree of environmental degradation. Female clones had leaves with lower C/N ratio than males in both systems, relating to higher leaf photosynthesis on an area basis in females. SSD expressed in leaf photosynthesis over a large part of the diurnal cycle in AFS was not observed in carbon gains at plant or daily scales, indicating that the integration of physiology and architecture equalized the gender specificities. The insensitivity of photosynthetic traits derived from light-response curves indicated acclimation of yerba-mate leaves to a wide range of incoming light.

Stable isotopic determination constitutes a useful tool to identify the processes that control the dynamics of the carbon and nitrogen flow in plants, unravelling the mechanisms of their differential investment under different environments. This work aimed to evaluate the spatiotemporal variation of source-sink patterns of coffee trees under field conditions in response to climatic conditions through the assessment of stable isotopes. For this purpose, stems, leaves, and fruit samples from coffee trees were collected following a temporal pattern based on the region's climatic characteristics and the plant's phenology and a spatial pattern considering different parts of the canopy. The carbon and nitrogen percentage content, the C/N ratio, and the carbon and nitrogen isotopic compositions (δ¹³C and δ¹⁵N) were determined for all samples. The basal portion of the orthotropic branch was also considered for the isotopic analysis of the tree's growth rings. The results obtained were correlated with the climatic variables of the region through a Pearson correlation analysis (p < .05). Coffee plants showed traditional δ¹³C values of C3 plants. Temporal δ¹³C variation was associated with the different growth rates between phenological stages and the use of substrates produced at different times under different environmental conditions leading to differences in photosynthetic discrimination. Spatial δ¹³C variation was observed with heterotrophic tissues isotopically heavier than leaves, with a significant decrease trend in δ¹³C values from the top (upper third) to the bottom (lower third), associated with ecophysiological differences between the canopy, isotopic fractionation processes downstream of photosynthetic carbon discrimination, and the fixation of C from other pools. Temporal δ¹⁵N variation was associated with the precipitation rates in the region and the fertilization distribution across the tree, while the spatial variation was with the plant's nitrogen assimilation and translocation patterns. The tree growth rings isotopic analyses showed isotopic differences between growth rings of the same plant addressed by the climatic conditions, with precipitation being the primary climatic determinant influencing the fixation and discrimination against ¹³C. Our results highlight the importance of using stable isotope analysis as a reference point for coffee ecophysiological studies to characterize how the temporal and spatial patterns of δ¹³C and δ¹⁵N emerge and signal the influence of climate on the source-sink relationship of coffee trees under field conditions.

The coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), is one of the most important coffee pests, and is present in almost all countries producing this crop, causing annual losses of US$350 million. Natural factors regulate H. hampei populations in coffee crops. Ecological life table analysis is a robust tool that allows the estimation of the mortality caused by these factors. Therefore, the main objective of this study was to determine the critical stage and the key mortality factors affecting H. hampei in the field. Data for constructing life tables were collected over 2 years in six coffee plantations in the regions of Paula Cândido and Viçosa, Minas Gerais State, Brazil. The average mortality of H. hampei was 75.34% ± 5.85%. The mortality at each developmental stage was 24.32% ± 2.83% (eggs), 7.29% ± 1.01% (first instar), 11.58% ± 1.46% (second instar), 9.68% ± 1.10% (third instar), 7.45% ± 1.01% (pupa), and 15.02% ± 1.29% (adult; n = 124). The mortality factors observed and quantified in this study were parasitism by Prorops nasuta (Hymenoptera: Bethylidae), predation by ants (Crematogaster spp., Pheidole spp. and Solenopsis spp.), physiological disorders and fungal infection by Beauveria bassiana and Metarhizium anisopliae. The critical mortality stage of H. hampei was the adult stage. The key factors for mortality of H. hampei adults were predatory ants, followed by B. bassiana and malformations (these insects had deformities in the head, wings, legs, or abdomen). This information is essential to conserve the activities of natural enemies and, thus maintain H. hampei natural mortality factors in coffee plantations, reducing damage to the crops and the need for excessive insecticide interventions.

Atmospheric carbon-dioxide concentration ([CO₂]) is increasing rapidly, but its interactions with nitrogen (N) and phosphorus (P) fertiliser on wheat grain quality are not well understood. We investigated the effects of ambient CO₂ (aCO₂; ∼410 ppm) and elevated CO₂ (eCO₂; 760 ppm) on crop harvest index (CHI), nutrient harvest index (NuHI), shoot macro-nutrient content and grain macro-nutrient concentration of wheat grown under two contrasting amounts of N (0.5 and 6 mol m⁻³ NO₃⁻ N) and P (10 and 250 mmol P m⁻³) fertiliser supply (low and optimum, respectively). Our results highlighted interactions between [CO₂] and N and P fertiliser supply for the shoot biomass at anthesis and straw biomass at harvest maturity. This was because biomass yield did not respond to CO₂ level when fertiliser was deficient. However, shoot and straw yield increased (10.0–-34.0%) with increasing [CO₂] at optimum fertiliser rates. Across experiments, grain yield increased (15.6%) with increasing [CO₂], which resulted in grain nutrient concentration decreasing (3.0–-13.0%) with increasing [CO₂]. This was attributed to nutrient 'dilution' due to increased carbohydrate content in the grain. Overall, fertiliser supply impacted crop responses more than CO₂ treatments, and the impact was greater under N than P deficiency. This was reflected through conservative values for CHI, thousand grain weight and NuHIs suggesting plants allocated biomass and nutrients at similar rates for vegetative and reproductive organs independent of [CO₂].

Table beet (Beta vulgaris ssp. vulgaris) root suitability for processing into cans and jars is dictated by quality and shoulder diameter (crown width). For shoulder diameter, roots are sorted into six classes and those in the small (19.1–44.5 mm) and small/medium (44.6–40.8 mm) classes are considered suitable. Smaller (≤19 mm) roots are usually lost in harvesting while larger (≥40.9 mm) roots are typically discarded. Exogenous (foliar-applied) gibberellic acid 3 (GA₃) may alter source-sink carbohydrate partitioning with potential advantages for processing table beet producers. Small plot replicated trials were conducted in each of 3 years (2020, 2021 and 2022) to evaluate the effect and optimal timing of exogenous GA₃ on table beet yield components in New York, USA. GA₃ was applied as ProGibb at 30 ppm in all trials and as ProGibb at 30 ppm and FalGro 2X LV at 67 ppm (label rates) in 2022. GA₃ as ProGibb resulted in significant increases in foliar health attributes (leaf blade length and width, petiole diameter, normalized difference vegetative index and dry weight of foliage). GA₃ as ProGibb significantly reduced average root shoulder diameter and affected the percentage of roots in various size categories. The percentage of tiny roots (<19 mm) was significantly decreased while the percentage of small roots was increased. The percentage of small/medium roots were unaffected. In 2022, the percentage of small roots was significantly increased compared to nontreated plots but was not significantly different between GA₃ as either ProGibb or FalGro applied at 42 or 62 Days after Planting (DAP). Exogenous GA₃ had no consistent, significant effect on the severity of the foliar disease, Cercospora leaf spot. The significant increase in foliar health attributes from GA₃ is beneficial for harvest that relies upon top pulling machinery. Increases in the percentage of small roots and reductions in tiny roots can reduce wasted crop input investments. The optimal number of GA₃ applications was seasonally dependent, ranging from a single application at 40 or 62 DAP in 2 years, to two applications in 2021. GA₃ applications late (>80 DAP) in the cropping season had no significant effect on foliar health attributes or root yield components. The implications of these results on the New York table beet processing industry are discussed.

In a series of Interviews with people linked to the scientific community that Annals of Applied Biology launched in 2020, we are pleased to talk to Prof. Evgenios Agathokleous, who is a Full Professor at the School of Applied Meteorology, Nanjing University of Information Science and Technology (NUIST), China.