Chilean journal of agricultural research vol. 84 num. 2 lang. es
- Modelling of Genotype × Environment interaction for grain yield of late maturity maize hybrids in Serbia by climate variablesel abril 26, 2024 a las 6:17 am
ABSTRACT With global climate change, including unpredictable geographic and temporal weather patterns causing significant Genotype × Environment interaction (GEI), modelling by climate variables can reveal their influence on phenophases of maize (Zea mays L.) development. The objectives of this study were dissection of the phenotypic variation of grain yield of late maturity maize hybrids grown in multi-environment trial, and quantification of the influence of climatic factors on the GEI for each vegetative and reproductive phenophase. Eight FAO 700 maize hybrids were evaluated across five locations in Serbia during 2020 and 2021 years. The hierarchy of sources of variation according to three-way ANOVA were: Year (Y) > Location (L) > Location×Genotype (G) > L×Y×G > G > L×Y > Y×G. The average maximum temperature (mxt, 22.1%), average minimum temperature (mnt, 19.2%), average mean temperature (mt, 18.2%) and relative humidity (rh, 15.1%) in April significantly influenced emergence stage. The mxt (21.1%) and mt (15.7%) in May influenced significantly vegetative phases V1-V9. June contributed the largest percentage of the sum of squares of the GEI with mxt (25.2%), mnt (20.9%), mt (16.1%) influencing vegetative phases V10-V18 and tassel emergence. In July mxt (17%), mt (15.6%), precipitation sum (15.2%), and sunshine hours sum (15.1%), influenced R1, R2, R3, and R4 reproductive phases. In August mxt (23.2%), mnt (20.8%), mt (15.7%), rh (17.1%) influenced R5 reproductive phase. The extreme heat as a stressor had a more critical role for late maturity maize hybrids production than drought in crucial phenophases of maize development.
- Assessing the allelopathic effect of Chrysopogon zizanioides (L.) Roberty root methanolic extract on Brassica rapa subsp. chinensis var. parachinensis using an untargeted metabolomic approachel abril 26, 2024 a las 6:17 am
ABSTRACT Chrysopogon zizanioides (L.) Roberty, or vetiver grass, is a deep-rooted perennial grass. An examination of allelopathy using a metabolomic approach offers valuable insights into vetiver extract’s mechanism of action and phytotoxicity. This study utilised an untargeted metabolomics approach through the use of choisum (Brassica rapa L. subsp. chinensis (L.) Hanelt var. parachinensis (L.H. Bailey) Hanelt) as target plant because it is easier to cultivate and susceptible to the extract. Vetiver root methanolic extracts at various concentrations (0, 0.1, 1, 10, 50, and 100 mg mL-1) were sprayed at 100 mL m-2 on choisum seedlings at the 2 to 3 leaves stage. After 21 d, the Soil Plant Analysis Development (SPAD) and chlorophyll content of exposed choisum were measured, and their metabolites were subjected to gas chromatography-mass spectrometer (GC-MS)-based metabolomics analysis. The result demonstrated that the 100 mg mL-1 methanolic extract significantly decreased SPAD reading by 57.29% and reduced chlorophyll content by 66.38% (chl a) and 73.49% (chl b) of choisum compared to the control. Furthermore, considerably reduced stomatal length of exposed choisum, up to 34.31%, was observed when exposed to maximum concentration (100 mg mL-1). In total, nine metabolites with variable importance in projection (VIP) > 1 and P < 0.05 were found and identified as amino acids and carbohydrates. The highest concentration of extract enriched pathways of propanoate, Se-compound, cysteine, and methionine metabolism in choisum, suggesting the extract induced plant stress. The findings confirm the allelopathic potential of vetiver root and provide insight into the response of choisum to the allelopathic activity of vetiver grass root methanolic extract.
- Growth of tamarind seedlings in different levels of shadowing and substrate compositionel abril 26, 2024 a las 6:17 am
ABSTRACT Tamarind (Tamarindus indica L.) is a species with promising potential for commercial production; therefore, studies involving practices of conducting culture in the initial stage are essential. The present study aimed to evaluate different shading levels and substrate compositions in the seedling production of tamarind. The experimental design was completely randomized in a 4×4 factorial scheme, four levels of shading (0%, 18%, 30%, and 50%) and four substrates (pine bark-based substrate pure and mixed with 50% vermiculite, and sphagnum peat-based substrate pure and mixed with 50% vermiculite), with four replicates of four seedlings. Growth and biometric relationships were evaluated at 40 and 98 d after transplantation (DAT). The results reported that seedlings formed on the sphagnum peat-based substrate on pure or associated with vermiculite at 98 DAT had a height greater than 35 cm and a total 8.5 g DM. In contrast, seedlings produced in pine bark-based substrate did not reach 20 cm in height and had less than 3 g total DM. The condition of 30% and 50% shading promoted greater growth in height, reaching an average height greater than 40 cm, while in the full sun environment, seedlings showed an average of less than 35 cm; however, for the other variables, full sun environment did not differ from 30% shading, producing good quality seedlings. Thus, the cultivation of seedlings in an environment with 0% or 30% shading, associated with the sphagnum peat-based substrate pure or mixed with 50% vermiculite promoted the production of tamarind seedlings with vigorous growth. In the best environments, the best substrates increased, on average, 41.3% number of leaves, 80.5% shoot dry mass, 56.8% root dry mass, and 71.0% total dry mass. In the best substrates, the best environments increased, on average, 18.0% number of leaves, 20.7% shoot dry mass, 8.7% root dry mass, and 14.3% total dry mass.
- Citrus volatiles induced by herbivory of Aleurothrixus floccosus (Hemiptera: Aleyrodidae) elicit attraction to the exotic ladybird Clitostethus arcuatus (Coleoptera: Coccinellidae)el abril 26, 2024 a las 6:17 am
ABSTRACT Plants undergoing insect infestation release herbivore-induced plant volatiles (HIPVs) into their environment, which are then used by natural enemies for their benefit. The pest Aleurothrixus floccosus, which affects citrus orchards in northern Chile, specifically at Pica Oasis, poses a year-round threat. Recently, the introduction of the exotic ladybird Clitostethus arcuatus has been noted as a predator of A. floccosus. This study delved into how HIPVs emitted from tangelo (Citrus reticulata × C. ×paradisi Macfad.) and lime (C. ×aurantifolia (Christm.) Swingle) infested-shoots impact the behavioral responses of C. arcuatus. The volatile compounds were collected using the headspace technique, revealing notable qualitative changes after herbivory. In two-choice bioassays, the HIPVs elicited an attractive response in C. arcuatus compared to A. floccosus. At concentrations of 10 and 100 µg mL-1, the predators displayed a distinct preference for methyl salicylate (MeSA). These findings underscore that C. arcuatus exploits the HIPVs emitted from citrus infested-shoots, fostering tritrophic interactions. Exploring the impact of whitefly attacks on other fruit trees, emerges as a significant avenue for future investigation.
- Optimization of water dispersible granules containing biocontrol bacteria and stress alleviation on cottonel abril 26, 2024 a las 6:17 am
ABSTRACT Cotton (Gossypium hirsutum L.) is economically important in Xinjiang, China, for many years; Verticillium wilt, arid climate, and soil salinization reduce cotton production, which has inhibited development of the cotton economy. Thus, creating a microbial agent specifically for cotton to resisting environmental stress is crucial. In this study, water dispersible granules strains (Bacillus tequilensis C-9 and B. sphingosporium A1) were screened for antagonistic bacteria of Verticillium dahliae from the rhizosphere soil of Ferula sinkiangensis K.M. Shen, and screened for carrier and auxiliary that could enhance the survival of strains A1+C-9. To test the efficacy and practicality of the water dispersible granules, their growth-promoting effect was examined. Meanwhile, bursts of reactive oxygen species and changes in the physiological indicators related to cotton growth were detected after the application of these granules to cotton that had been subjected to biotic and abiotic stresses to study the ability of the water dispersible granules to induce immunity in cotton. It was found that the treated group could increase the above-ground and below-ground fresh weight of cotton by 20.06% and 22.71% relative to the control group, and the biocontrol effect on cotton was increased by 46.55%. In salt and drought stress, catalase activity could be increased by 14.61% and 15.52%, respectively, relative to the control group. Comprehensive analyses showed that the application of water dispersible granules that contained A1+C-9 helped the cotton to grow and develop, inhibited V. dahliae from infecting cotton plants, reduced the damage from drought and salt stress, and increased the resilience of cotton to stress.