Annals of Applied Biology最新文献

Post-flowering diseases (PFDs), such as ear rot, stalk rot and smut, affect maize yield and quality by damaging the reproductive organs, stalks and seeds. We hypothesized that quantitative trait loci (QTL) associated with different PFDs colocalize and share similar defence mechanisms. Hence, to find a stable consensus meta-QTL (MQTL) for single or multiple PFDs, MQTL analysis was performed. QTL conferring resistance to PFD reported in 31 independent studies were collated to develop a consensus map. As many as 49 MQTL conferring PFD resistance were projected using appropriate algorithms. Most MQTL regions encompass genes encoding a wide range of defence-related proteins. MQTL1.1 and MQTL10.5 included QTL/genes for resistance to all PFDs, which supported our hypothesis. Candidate genes for PFDs in MQTL7.1 were associated with pathogenesis-related 1 protein and mitogen-activated protein kinase (MAPK) signalling. MQTL5.2 encompassed chalcone flavanone isomerase and cinnamoyl coenzyme A (CoA) reductase genes involved in flavonoid and phenylpropanoid biosynthesis, respectively. Furthermore, MQTL10.4 was found to harbour genes encoding E3 ubiquitin ligase, WRKY-TF11, calcium-binding domains and zinc finger motifs. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis reiterated the role of genes within MQTL7.1 in the MAPK signalling pathway, phytohormone signal transduction and plant–pathogen interaction. Hence, we propose that these genes are potential candidates for PFD resistance. Furthermore, 75% of the genes within the MQTL showed orthology with sorghum and rice, indicating that these genes were conserved across species. The role of 27 MQTL, including the six most significant MQTL, was confirmed with reported genome-wide association study (GWAS) results. Thus, the hotspots associated with PFDs identified in our study could be reliably used in marker-assisted breeding for PFD resistance.

Amaranthus palmeri S. Watson is a problematic weed that has been encountered almost all over the world because of its stronger adaptability, which causes huge economic losses and local plant diversity decline. As an invasive plant, A. palmeri has been found throughout China. We thus make a code system to describe the phenological growth process of A. palmeri according to the extended BBCH scale to better understand the phenological growth of this weed in China. The growth process of A. palmeri was divided into vegetative growth phases and reproductive growth phases. The vegetative growth phases are composed of seed germination (0), leaf development (1), formation of side shoots (2) and main stem elongation (3). Likewise, the reproductive growth phases include inflorescence emergence (5), blooming (6), fruit development (7), seed maturity (8) and senescence (9). Based on the extended BBCH scale, the first digit stands for the primary growth stages, and the third digit represents the secondary growth stages. In particular, the second digit defines the growth progress: the number 0, means the vegetative growth phases, and the number 1 stands for the reproductive growth phases. Owing to the fact that its seed can germinate multiple times within a year, a general illustration of the phenological development stages of A. palmeri germinating in different months was provided here to describe the growth dynamic characteristic at different times. These data are of great significance to develop effective strategies for weed control and management of A. palmeri.

Communicating results and ideas to a wider audience has been an important, but challenging component of scientists working in an academic environment. Particularly in recent decades, various social media platforms have become increasingly important to facilitate this. In addition, many scientists have used blogging platforms to communicate and discuss their work. Although the online dynamics of science communication are continuously changing, blogging has been used in a remarkably stable form for several decades. For this work, we brought several ecology bloggers to reflect on blogging as a science communication medium. We argue that blogging can be a powerful way to present new ideas and discuss them with a wide audience. Although blogs are not the same as scientific articles, they often serve as the initial brainstorm session. Importantly, we argue that blogs are most effective when bloggers and readers actively engage in conversations. We believe that blogging will be here to stay in science communication because of its unique and independent form of outreach.

Prof. Simon R. Leather with giant aphid (This figure has also been used by Azevedo & Millman, 2020.)

Aphids are among the most economically significant pests in cereal crops worldwide. Despite high interest in the natural control of aphids by applying natural enemies, intercropping and companion planting, the concurrent effects of the combinations of these methods due to their synergistic or antagonistic interactions remain largely unknown for both aphids and their host crops. Here we identify the relative effectiveness of simultaneous bottom–up and top–down factors in controlling one of the most economically important species of cereal aphids, the bird cherry-oat aphid Rhopalosiphum padi L. For this, we conducted microcosm experiments using a full-factorial design of three aphid-control treatments including predator presence (i.e., lacewing larvae of Chrysoperla carnea), host-plant intercropping (i.e., barley alone vs barley in combination with wheat and rye) and companion planting with an aphid-repellent plant (garlic), and estimated their direct, indirect and interactive effects on aphid density. Our results show strong simultaneous top–down control of the aphid population by predation and bottom–up control by both host-plant biomass and companion planting with garlic. The use of garlic as a companion plant for cereal crops in our study neither altered crop biomass nor suppressed the efficiency of aphid predator. Our findings suggest that the simultaneous application of aphid predator and companion planting with garlic holds promise as a potential strategy for the natural control of cereal aphid populations on grain crops, without generating related agroecosystem disservices, such as loss in crop production and deterioration of the natural enemies of pests. However, given the controlled lab conditions and limited timeframe of our study, further research is needed to confirm its effectiveness in field conditions to ensure its broader applicability in sustainable agricultural practices.

Citrus tristeza virus (CTV) is a causal agent of diseases that have challenged the global citrus production for more than a century. The disease named ‘tristeza’, which means ‘sadness’ in Portuguese and Spanish, has spread by aphids and vegetative propagation, resulting in costly pandemics that reshaped the world citrus production by forcing the adaption of disease-tolerant rootstocks. Furthermore, management of the second major CTV-induced disease, stem pitting, became a unique example of the use of cross-protection on a large nationwide scale, allowing many citrus growing regions to control the disease that could not be managed through horticultural practices. The information gathered in this review commemorates a hundred years of research on the virus and the respective diseases, which began with classical horticultural approaches and advanced toward the cutting-edge molecular biology studies. In this regard, it is proper to mention that CTV research greatly benefited from close international collaboration between research institutions and scientists from the affected and nonaffected citrus areas. Moreover, despite the considerable initial losses caused by tristeza, the world's fresh fruit and juice concentrate citrus industries reemerged as highly productive following the research advancements, a situation that changed throughout Florida and Brazil in the past two decades or so with the outbreak of the devastating citrus greening (Huanglongbing) bacterial disease. This review encompasses past and recent advances in the CTV research positioning the citrus-CTV pathosystem as a pivotal model system for investigating virus interactions with perennial woody hosts. The review will also serve as an updated version of the respective section on CTV in the Description of Plant Viruses that the Association of Applied Biologists manages. We dedicated this review to the 85th Birthday celebration of Prof. Moshe Bar-Joseph, a world-renowned plant pathologist whose half-a-century-long career devoted to citrus diseases yielded many important, pioneering discoveries on CTV and other closteroviruses. Many of those are highlighted in this review. Prof. Bar-Joseph retired from the Volcani Center, Agricultural Research Organization in Israel several years ago, yet he continues to be actively engaged in research and provides his expertise to citrus pathologists around the world in the present days.

Sorghum is a crop that is susceptible to low temperatures. However, due to the extreme global temperatures, new genotypes have been bred to adapt better to cold climates. Therefore, to better understand the metabolic and molecular differences that may contribute to the improved cold tolerance of these genotypes, it is essential to investigate whether specific molecules play a key role in determining the degree of sorghum tolerance. Furthermore, identifying genes associated with cold tolerance may assist in the development of more robust and productive sorghum cultivars. Here, we analysed the changes in selected elements of the antioxidant metabolism, genes, and miRNAs in two sorghum varieties with different degrees of tolerance to cold stress at different times of exposure to cold stress. The high expression of SbCBF6 in response to cold treatment in early time in the tolerant variety suggests its involvement in the cold response, thereby facilitating a better adaptation of the plant to cold conditions. MiR398 and miR394 showed contrasting behaviour in both varieties in low temperatures, resulting in interesting miRNAs in the degree of sorghum tolerance. MiR319, a marker for the selection of cold-tolerant cultivars, presents a decrease, suggesting that the better capacity to repress the expression of several members of TCP family of transcription factor genes might be involved in better tolerance to cold stress. This study shows the changes of molecules of interest in response to cold stress in sorghum, marking the difference between cold-susceptible and cold-tolerant sorghum plants, which can contribute to selecting tolerant genotypes, allowing new strategies to enhance crop productivity and food security, in regions where low temperatures significantly constrain crop growth and yield.

Leaf traits are known as indicative of species functional properties in angiosperms. Fern fronds are little studied in this concern, especially ex situ. We studied leaf mesophyll structure, pigments and gas exchange in four fern species grown in a glasshouse—Sphaeropteris cooperi (terrestrial tree fern), Phlebodium aureum (semi-epiphytic herbaceous), Asplenium australasicum (epiphytic shrubby) and Platycerium bifurcatum (epiphytic herbaceous). Saturated assimilation rate (A_sat) decreased and intrinsic water use efficiency (iWUE) increased from a terrestrial tree fern to epiphytic ferns. A_sat positively correlated with chloroplast number (N_chl/A) and their surface area per leaf area (A_chl/A). iWUE negatively related to N_chl/A and chlorophyll/carotenoid ratio. Most differences between species were found in the mesophyll thickness (MT) and mesophyll cell volume (V_cell) with the smallest values in S. cooperi and the largest ones in P. bifurcatum. We found that photosynthetic limitations in ferns were related to the chloroplast photosynthetic activity rather than to N_chl/A or pigment content which did not differ from most angiosperms. Epiphytic ferns showed larger values of V_cell per cell and per chloroplast compared to angiosperms and tree ferns. We concluded that an increase in MT and V_cell in the studied ferns was not associated with photosynthetic performance, but was related to volumetric cytoplasm–chloroplast ratio meaningful to light absorption and the water-storage function of fern fronds.

In the Americas, the palm weevils Rhynchophorus palmarum and Dynamis borassi are two of the most economically important palm pests, attacking crops including oil palms, coconut palms, Canary Islands date palms and peach palms. Mass trapping with aggregation pheromone-baited traps has been used for several decades as the main way to monitor and manage palm weevil populations worldwide. Given that several species of palm weevils have the same main aggregation pheromone and that one species can be attracted to the aggregation pheromones of other species, it is important to compare the efficacy of multiple pheromone lures on several species of palm weevils. Here, we tested the commercial pheromone lure Dynalure (ferruginol) independently, and the lures Rhyncolure (rhynchophorol) and Metalure (89% ferruginol and 11% 2-methyl-4-heptanol) jointly, for their efficacy at attracting R. palmarum and D. borassi in a palm growing area of Tumaco, Colombia. We found that Dynalure and Rhyncolure are effective at attracting both species, but traps with Dynalure attract more D. borassi, while traps with Rhyncolure attract more R. palmarum. Metalure had a repellent effect for both species, highlighting the importance of minor components in pheromone lures. For R. palmarum, captures were female-biased in traps with the lures Rhyncolure and Metalure, while for D. borassi captures were male-biased with all lures tested. While both species showed similar numbers of captures per trap at the beginning of the experiment, at the end of the 14-month observation period, R. palmarum was the most abundant species captured in traps. Our results highlight the importance of evaluating the field efficacy of lures with different aggregation pheromones for mass trapping of palm weevils and to consider the effect of minor components in the lures, especially with the potential invasion of the red palm weevil to the Americas, and the urgent need to develop an integrated pest management programme that covers multiple species of sympatric palm weevils.