Some types of plant accumulate liquid in their inflorescences creating phytotelmata.These environments protect the flowers against florivory,although they may be colonized by aquatic or semiaquatic florivorous insect ...Some types of plant accumulate liquid in their inflorescences creating phytotelmata.These environments protect the flowers against florivory,although they may be colonized by aquatic or semiaquatic florivorous insect larvae,whose effects on the fitness of the plants remain unclear.We tested the hypothesis of floral antagonism by the occupants of phytotelmata,which predicts that florivory by the occupants of the phytotelmata represents a cost to the female fitness of the plant,reducing its fecundity.We manipulated experimentally the infestation by 3 florivores larvae species occupants of phytotelmata in inflorescences of Heliconia spathocircinata(Heliconiaceae)to test for negative direct trophic effects on the fecundity of the flowering and fruiting bracts.We found that the foraging of the hoverfly(Syrphidae)and moth(Lepidoptera)larvae in the inflorescences contributed to a decline in the fecundity of the plant.While the lepidopteran impacted fecundity when foraging in both flowering and fruiting bracts,the syrphid only affected the fruiting bracts,which indicates that the nectar and floral tissue are the principal resource exploited by the hoverfly.By contrast,soldier fly(Stratiomyidae)had a neutral effect on fecundity,while foraging in flowering or fruiting bracts.These findings corroborate our hypothesis,that herbivory by the larval occupants represents cost to the host plant having phytotelmata.The negative influence of this foraging on plant fecundity will nevertheless depend on the consequences of the exploitation of resources,which vary considerably in ephemeral habitats such as the phytotalmanta of flower parts.展开更多
In Mexico, the utilization of native heliconias germplasm for preservation and genetic improvement purposes, has been limited partly because of the unawareness between their population similarities and differences, an...In Mexico, the utilization of native heliconias germplasm for preservation and genetic improvement purposes, has been limited partly because of the unawareness between their population similarities and differences, and because of the degree of genetic divergence that exists among the interspecific and intraspecific ecotypes originated from different regions of the humid tropics. The objective of the present study was to morphological characterization wild species of the genus Heliconias in Mexico through some qualitative and quantitative morphological descriptors. Fifty-five qualitative and quantitative morphological characters were studied in 25 accessions from 11 native species. Characters of plant, leaf, inflorescence, flower, fruit, and seed were taken into account. Data was analyzed by Principal Component Analysis (PCA) and Hierarchical Cluster Analysis. Two analyses were carried out: the first one was for the 25 accessions that included characters of flower (55 variables), whereas the second was for only 19 accessions (66 variables) concluded until seed. The first six components explained a 69.4% of the total variation based on PCA. The variables which contributed most significantly were: leaf length (p < 0.001), limb width (p < 0.001), limb's petiole length (p < 0.001), pseudostem thickness (p < 0.05)/width at 60 cm (p < 0.05), rachis width (p < 0.05)/thickness (p < 0.001), second bract width (p < 0.001), growth (p < 0.001) and type of inflorescence (p < 0.05), petiole (p < 0.05) and peduncle length (p < 0.05), rachis color (p < 0.05), and wax in limb (p < 0.05) and in pseudostem (p < 0.05). Thirty-eight descriptors were suggested to differentiate wild species of heliconias in Mexico.展开更多
基金Funding for this study was provided by the Brazilian Coordination for Higher Education Personnel Training(CAPES:Coordenacao de Aperfeic¸oamento de Pessoal de Nıvel Superior)for providing C.C.C.M.with a doctoral research scholarship(this study was financed in part by CAPES—Finance Code 001).The Rio de Janeiro State Research Foundation(FAPERJ:Fundacao Carlos Chagas Filho de Amparo aPesquisa do Estado do Rio de Janeiro)provided C.C.C.M.with a grant(DSC-10 process E_01/201.955/2017)supported the research of M.A.S.A.(CNE processes E-26/203191/2015,E-26/202.835/2018)The Brazilian National Research Council(CNPq:Conselho Nacional de Desenvolvimento Cientıfico e Tecnologico)provided M.A.S.A.with a research fellowship(PQ processes 305798/2014-6,306.579/2018-9).
文摘Some types of plant accumulate liquid in their inflorescences creating phytotelmata.These environments protect the flowers against florivory,although they may be colonized by aquatic or semiaquatic florivorous insect larvae,whose effects on the fitness of the plants remain unclear.We tested the hypothesis of floral antagonism by the occupants of phytotelmata,which predicts that florivory by the occupants of the phytotelmata represents a cost to the female fitness of the plant,reducing its fecundity.We manipulated experimentally the infestation by 3 florivores larvae species occupants of phytotelmata in inflorescences of Heliconia spathocircinata(Heliconiaceae)to test for negative direct trophic effects on the fecundity of the flowering and fruiting bracts.We found that the foraging of the hoverfly(Syrphidae)and moth(Lepidoptera)larvae in the inflorescences contributed to a decline in the fecundity of the plant.While the lepidopteran impacted fecundity when foraging in both flowering and fruiting bracts,the syrphid only affected the fruiting bracts,which indicates that the nectar and floral tissue are the principal resource exploited by the hoverfly.By contrast,soldier fly(Stratiomyidae)had a neutral effect on fecundity,while foraging in flowering or fruiting bracts.These findings corroborate our hypothesis,that herbivory by the larval occupants represents cost to the host plant having phytotelmata.The negative influence of this foraging on plant fecundity will nevertheless depend on the consequences of the exploitation of resources,which vary considerably in ephemeral habitats such as the phytotalmanta of flower parts.
基金Rescue,preservation and genetic improvement of native heliconias in South-east Mexico,which was funded by the National Forestry,Crops and Livestock Research Institute(INIFAP).
文摘In Mexico, the utilization of native heliconias germplasm for preservation and genetic improvement purposes, has been limited partly because of the unawareness between their population similarities and differences, and because of the degree of genetic divergence that exists among the interspecific and intraspecific ecotypes originated from different regions of the humid tropics. The objective of the present study was to morphological characterization wild species of the genus Heliconias in Mexico through some qualitative and quantitative morphological descriptors. Fifty-five qualitative and quantitative morphological characters were studied in 25 accessions from 11 native species. Characters of plant, leaf, inflorescence, flower, fruit, and seed were taken into account. Data was analyzed by Principal Component Analysis (PCA) and Hierarchical Cluster Analysis. Two analyses were carried out: the first one was for the 25 accessions that included characters of flower (55 variables), whereas the second was for only 19 accessions (66 variables) concluded until seed. The first six components explained a 69.4% of the total variation based on PCA. The variables which contributed most significantly were: leaf length (p < 0.001), limb width (p < 0.001), limb's petiole length (p < 0.001), pseudostem thickness (p < 0.05)/width at 60 cm (p < 0.05), rachis width (p < 0.05)/thickness (p < 0.001), second bract width (p < 0.001), growth (p < 0.001) and type of inflorescence (p < 0.05), petiole (p < 0.05) and peduncle length (p < 0.05), rachis color (p < 0.05), and wax in limb (p < 0.05) and in pseudostem (p < 0.05). Thirty-eight descriptors were suggested to differentiate wild species of heliconias in Mexico.
