Browsing by Author "Chorbadjian Alonso, Rodrigo Armen"

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    Mating behavior of Pseudococcus calceolariae and Pseudococcus longispinus (Hemiptera: Pseudococcidae): are asexual reproduction and hybridization possible?
    (2023) Chorbadjian Alonso, Rodrigo Armen; Ballesteros Cataldo, Carolina; Zaviezo Palacios, Tania
    The study of insect reproduction is important from both basic and applied perspectives, particularly in mealybugs (Hemiptera: Pseudococcidae), because of the diversity of reproduction modes and also because they are important agricultural pests. Sex pheromone control strategies are currently being developed for many species. Pseudococcus calceolariae (Maskell) and Pseudococcus longispinus (Targioni Tozzetti) are closely related species that often coexist in the same host plant. In this study, mating behavior, the possible occurrence of asexual reproduction, and hybridization between them were investigated. We confirmed that both species did not show asexual reproduction and required the presence of a male to reproduce. When couples of the same species were put together, males had a highly stereotyped mating behavior, and females showed an active role in mating success by accepting or rejecting males with abdominal movements. In hybridization trials, no progeny was obtained for any of the interspecific combinations. Moreover, in interspecific pairs, malesmainly moved randomly in the arena without direct contact with females and females showed no willingness to mate, escape, or not move in the presence of the male. Therefore, courtship and copulation success in both species were directly related to the specificity of the mating pair and, there was no evidence of hybridization. This information is useful for the understanding of reproduction in this family and supports the development of management techniques based on sex pheromones to disrupt reproduction or to monitor these mealybug species populations.
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    Solicoccozyma aeria YCPUC79 Promotes Tomato Seedling Root Growth by Volatile Organic Compounds Emission
    (2024) Carvajal Contardo, Maria José; Albornoz Gutierrez, Francisco Javier; Catrileo, Daniela; Chorbadjian Alonso, Rodrigo Armen; Gebauer Hernández, Marlene Gloria; Godoy Olivares, Liliana
    Beneficial microorganisms promote plant growth through different mechanisms, such asthe production of plant hormones, the synthesis of 1-aminocyclopropane-1-carboxylic aciddeaminase (ACCD), or, through volatile organic compounds (VOCs) emission. There are numerousstudies describing a biostimulant action mediated by VOCs released by bacteria and filamentousfungi. However, in soil yeasts, research in this regard is still incipient. In a previous study, wepresent the stimulatory action of Solicoccozyma aeria YCPUC79 on tomato seedling growth byinoculating the rootzone with this yeast. The positive effect of S. aeria was related to the synthesis ofindole acetic acid (IAA) and the presence of ACCD activity by the yeast. In the present study, weevaluated whether S. aeria is capable of emitting VOCs with biostimulant activity. For this, anexperiment was conducted to test the release of VOCs in four treatments: S. aeria (Sa), tomatoseedlings (T), tomato seedlings sharing the ambient with S. aeria but with no physical contact (TSa)plus a control with no yeast nor tomato seedlings (C). Tomato seedlings exposed to S. aeria inoculum(TSa) presented 1.2-fold shorter main roots but increased the number of lateral roots by 80%compared to T. Regarding the analysis of VOCs, 59 compounds were identified excluding thosefound in the control treatment. These compounds represent twelve chemical families, includingalcohols, esters, furans, hydrocarbons, ketones and terpenes. The treatment TSa shows an increasedabundance of ketones, alcohols, esters, sulfur-containing compounds, and pyrazines in comparisonto T treatment. Three compounds (butyl hept-4-yl ester-phthalic acid, (E)1.3-pentadiene and 1-propenylthiol) were exclusively present in the TSa treatment. This study provides, for the first time,information on a soil yeast capable of promoting the production of lateral roots in tomato throughVOCs.