Abstract Detail



Ecology

Cocoletzi , Eliezer [1], Contreras-Varela, Ximena [2], García-Chavez, Juan [3], Fernandes, Geraldo [4], Aguirre, Armando [5].

The structure, physiology and consequences of galls in Parkinsonia praecox in a semi-arid region.

Galls are atypical plant growths that provide nourishment, shelter, and protection to the inducer or its progeny. Galls can be induced on any vegetative structures (leaves, stems, branches and roots) or reproductive organ. Fruit and flowers are poorly represented as host organs for galling insects. The impact of galling insects on their host plants is variable therefore the effects of fruit galls become particularly important in order to understand how the presence of galls affects the reproductive input and fitness of the plant. Our main question was: Does morphological traits, anatomical features and physiological characteristics differ between galled and healthy fruits of Parkinsonia praecox distributed in a Mexican semi-arid region? Galled and healthy fruits of P. praecox were characterized in terms of 1) morphological traits (length, diameter, thickness, and biomass); 2) anatomical features (trichomes, stomatal and pavement cells) and 3) physiological characteristics (stomatal conductance, gs). Generalized linear mixed models were used to evaluate the relationship between galled and healthy fruits in each of the morphological traits, anatomical features and physiological characteristics. We found that galled fruits were induced by Asphondylia sp. (Diptera: Cecidomyiidae). Approximately 20% of the fruits per branch had galls. Thickness, diameter and water content values of galled fruits were higher compared to healthy fruits. Length, biomass and pavement cells density of healthy fruits were higher. Each galled fruit was composed of parenchymatous tissue, this tissue surrounds a larval chamber that holds only one galling insect larva. Therefore, the normal structure of the fruit is modified thus producing galls with a spherical shape, mostly without seeds. The density of trichomes on galled fruits was higher, while the stomatal density and pavement cell size were not statistically different between galled and healthy fruits. The high density of trichomes in galled fruits could prevent excessive moisture loss in the larval chamber and may maintain the internal temperature. Furthermore, the gs rates of galled fruits were almost 3 times higher than in healthy fruits but the highest values were recorded after the sunrise. Galls on fruits of P. praecox modify negatively the morphology and anatomy of fruits, with consequences on plant fitness. Galling insects may stimulate physiological mechanisms in fruits in order to increase the water continuum from the host plant to the gall.


1 - Universidad Veracruzana, Centro de EcoAlfabetización y Diálogo de Saberes, Av. de las Culturas Veracruzanas, Xalapa, VE, 91060, MX
2 - Instituto de Ecología A. C., Red de Interacciones Multitróficas, Carretera Antigua A Coatepec 351, El Haya, Xalapa, VE, 91070, MX
3 - Benemérita Universidad Autónoma de Puebla, Facultad de Biología, Jardines de San Manuel, Puebla, Puebla, PU, 72570, MX
4 - Universidade Federal de Minas Gerais, Departamento de Biologia Geral, 486, Belo Horizonte, Belo Horizonte, BH, BR
5 - Instituto de Ecología A. C., Red de Interacciones Multitróficas, Carretera Antigua A Coatepec 351, El Haya, Xalapa, VE, 91070, Mexico

Keywords:
Fabaceae
fruit
pavement cells
gall plant
trichomes
water-content.

Presentation Type: Oral Paper
Number:
Abstract ID:101
Candidate for Awards:None


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