Ecophysiology Of Campos Rupestres Plants

Campos rupestres are rocky seasonally-dry environments that occur over mountaintops in central Brazil. Plant growth is limited and prone to fire during the dry winter, and soils are severely nutrient-impoverished. Plants in these habitats exhibit a wide range of strategies to cope with these limitations. Campos rupestres plants show different rooting depths, according to plant habit and substrate. Water status in plants varies between stable water potentials in isohydric species to water potentials changing according to air humidity in anisohydric plants, some of them being dessication-tolerant and dormant during the dry season (resurrection plants). Carbon assimilation in the dry season is therefore limited by water availability, especially in dessication-tolerant species. A wide variety of mineral nutrition strategies allow effective nutrient acquisition in campos rupestres: mycorrhizas, non-mycorrhizal sand-binding root specializations, symbiotic nitrogen fixation, carnivory, parasitism. The incidence of natural fires may have played a role in the ecological and evolutionary processes that have molded the current flora of campos rupestres, as well as the occurrence of specific functional traits in these habitats. Unveiling the relative importance and prevalence of in situ adaptation and adaptive divergence in the lineages that diversified in campos rupestres will allow us to further discuss mechanisms related to trait evolution and adaptive radiation in campos rupestres. © Springer International Publishing Switzerland 2016.22727

Ecology Of Neotropical Mistletoes: An Important Canopy-dwelling Component Of Brazilian Ecosystems [ecologia De Ervas-de-passarinho Neotropicais: Um Importante Componente Do Dossel De Ecossistemas Brasileiros]

Mistletoes have been studied in temperate countries regularly because they can be pests of cultivated plants and forest plantations. In comparison with temperate habitats, little is known about the ecology of mistletoes in the Neotropics. More emphasis should be given to neotropical mistletoes because they could be important elements of plant communities, acting as key resources for pollinators, seed dispersers and herbivores. Using a combination of findings from early mistletoe studies and empirical evidence from several recent case studies, we report emerging patterns of mistletoe interactions with associated organisms and propose aims for further studies. There has been increasing interest in working with mistletoes in Brazil. Although there are some data on the ecology of mistletoe seed dispersal, reproductive biology studies are scarce and represent a wide range of fieldwork to be explored. Knowledge of the basic biology of mistletoes will be very important for modeling their spatial distribution using metapopulation or epidemiological approaches. In this review, we summarize the studies conducted in the neotropical region in order to provide a framework for current research and new ideas for future investigations of mistletoes, especially in Brazil.262264274Aizen, M.A., Harder, L.D., Expanding the limits of the pollenlimitation concept: Effects of pollen quantity and quality (2007) Ecology, 88, pp. 271-281Almeida Jr., E.B., Olivo, M.A., Araújo, E.L., Zickel, C.S., Caracterização da vegetação de restinga da RPPN de Maracaípe, PE, Brasil, com base na fisionomia, flora, nutrientes do solo e lençol freático (2009) Acta Botanica Brasilica, 23, pp. 36-48Amico, G., Aizen, M.A., Mistletoe seed dispersal by a marsupial (2000) Nature, 408, pp. 929-930Andrade, M.J.G., Caires, C.S., Tun-Garrido, J., Paula, C.H.R., Melo, E., Loranthaceae (2009) Catálogo de plantas raras do Brasil, pp. 240-242. , In: Giulietti, A.M.Rapini, A.Andrade, M.J.G.Queiroz, L.P. & Silva, J.M.C. (Orgs.), Belo Horizonte, Conservation InternationalAraujo, A.C., Sazima, M., The assemblage of flowers visited by hummingbirds in the "capões" of Southern Pantanal, Mato Grosso do Sul, Brazil (2003) Flora, 198, pp. 427-435Arruda, R., Carvalho, L.N., Especificidade de hospedeiros por Struthanthus polyanthus (Loranthaceae) em uma área de Cerrado do Parque Estadual da Serra de Caldas Novas, GO, Brasil (2004) Bioscience Journal, 20, pp. 211-214Arruda, R., Carvalho, L.N., Del-Claro, K., Host specificity of a Brazilian mistletoe, Struthanthus aff. polyanthus (Loranthaceae), in cerrado tropical savanna (2006) Flora, 201, pp. 127-134Arruda, R., Fadini, R.F., Mourão, F.A., Jacobi, C.M., Teodoro, G.S., Natural history and ecology of Neotropical mistletoes (2009) Tropical Biology and Conservation Management: Natural history of tropical plants, pp. 133-154. , In: Del-Claro, K.Oliveira, P.S. & Rico-Gray, V. (Orgs.), Oxford, Eolss Publishers Co. LtdAukema, J.E., Vectors, viscin and Viscaceae: Mistletoes as parasites, mutualists, and resources (2003) Frontiers in Ecology and Environment, 1, pp. 212-219Aukema, J.E., Martínez del Rio, C., Mistletoes as parasites and seed-dispersing birds as disease vectors: Current understanding, challenges, and opportunities (2002) Seed dispersal and frugivory: Ecology, evolution and conservation, pp. 99-110. , In: Levey, D.J.Silva, W.R. & Galetti, M. (Eds.), New York, CABIAukema, J.E., Martínez del Rio, C., Variation in mistletoe seed deposition: Effects of intra-and interspecific host characteristics (2002) Ecography, 25, pp. 139-144Aukema, J.E., Martínez del Rio, C., Where does a fruit-eating bird deposit mistletoe seeds? Seed deposition patterns and experiment (2002) Ecology, 83, pp. 3489-3496Azpeitia, F., Lara, C., Reproductive biology and pollination of the parasitic plant Psittacanthus calyculatus (Loranthaceae) in central México (2006) Journal of Torrey Botanical Society, 133, pp. 429-438Baptista-Maria, V.R., Rodrigues, R.R., Damasceno Junior, G., Maria, F.S., Souza, V.C., Composição florística de florestas estacionais ribeirinhas no Estado de Mato Grosso do Sul, Brasil (2009) Acta Botanica Brasilica, 23, pp. 535-548Barea, L.P., Nest-site selection by the Painted Honeyeater (Grantiella picta), a mistletoe specialist (2008) Emu, 108, pp. 213-220Barros, M.G., Rico-Gray, V., Castelazo, C.D., Sincronia de floração entre Lantana camara (Verbenaceae) e Psittacanthus calyculatus (Dc.) G. Don (Loranthaceae) ocorrentes nas dunas de La Mancha, Veracruz, México (2001) Acta Botanica Mexicana, 57, pp. 1-14Bell, T.L., Adams, M.A., Attacks on all fronts: Functional relationships between aerial and root parasitic plants and their woody hosts and consequences for ecosystems (2011) Tree Physiology, 31, pp. 3-15Bronstein, J.L., The evolution of facilitation and mutualism (2009) Journal of Ecology, 97, pp. 1160-1170Caires, C.S., Loranthaceae (2009) Plantas da Floresta Atlântica, pp. 312-313. , In: Stehmann, J.R.Forzza, R.C.Salino, A.Sobral, M.Costa, D.P. & Kamino, L.H.Y. (Eds.), Rio de Janeiro, Jardim Botânico do Rio de JaneiroCaires, C.S., Santalaceae (2009) Plantas da Floresta Atlântica, pp. 466-467. , In: Stehmann, J.R.Forzza, R.C.Salino, A.Sobral, M.Costa, D.P. & Kamino, L.H.Y. (Eds.), Rio de Janeiro, Jardim Botânico do Rio de JaneiroCaires, C.S., Dettke, G.A., Loranthaceae (2010) Catálogo de plantas e fungos do Brasil, 2, pp. 1172-1177. , In: Forzza, R.C.Leitman, P.M.Costa, A. et al. (Orgs.), Rio de Janeiro, Andrea Jakobsson Estúdio, Instituto de Pesquisas Jardim Botânico do Rio de JaneiroCaires, C.S., Dettke, G.A., Santalaceae (2010) Catálogo de plantas e fungos do Brasil, vol, pp. 1603-1606. , In: Forzza, R.C.Leitman, P.M.Costa, A. et al. (Orgs.), 2. Rio de Janeiro, Andrea Jakobsson Estúdio, Instituto de Pesquisas Jardim Botânico do Rio de JaneiroCaires, C.S., Andrade, M.J.G., Paula, C.H.R., Melo, E., Santalaceae (2009) Catálogo de plantas raras do Brasil, pp. 364-365. , In: Giulietti, A.M.Rapini, A.Andrade, M.J.G.Queiroz, L.P. & Silva, J.M.C. (Orgs.), Belo Horizonte, Conservation InternationalCaires, C.S., Uchôa-Fernandes, M.A., Nicácio, J., Strikis, P.C., Frugivoria de larvas de Neosilba McAlpine (Diptera, Lonchaeidae) sobre Psittacanthus plagiophyllus Eichler (Santalales, Loranthaceae) no sudoeste de Mato Grosso do Sul, Brasil (2009) Revista Brasileira de Entomologia, 53, pp. 272-277Calder, M., Bernardt, P., (1983) The biology of mistletoes, , Sidney, Academic PressCameron, D.D., Geniez, J.M., Seel, W.E., Irving, L.J., Suppression of host photosynthesis by the parasitic plant Rhinanthus minor (2008) Annals of Botany, 101, pp. 573-578Cameron, D.D., White, A., Antonovics, J., Parasite-grass-forb interactions and rock-paper-scissor dynamics: Predicting the effects of the parasitic plant Rhinanthus minor on host plant communities (2009) Journal of Ecology, 97, pp. 1311-1319Carlo, T.A., Aukema, J.E., Female-directed dispersal and facilitation between a tropical mistletoe and a dioecious host (2005) Ecology, 86, pp. 3245-3251Cazetta, E., Galetti, M., Frugivoria e especifidade por hospedeiros na erva-de-passarinho Phoradendron rubrum (L.) Grised (Viscaceae) (2007) Revista Brasileira de Botânica, 30, pp. 345-351Cooney, S.J.N., Watson, D.M., An experimental approach to understanding the use of mistletoe as a nest substrate for birds: Nest predation (2008) Wildlife Research, 35, pp. 65-71Cooney, S.J.N., Watson, D.M., Young, J., Mistletoe nesting in Australian birds: A review (2006) Emu, 106, pp. 1-12Davidar, P., Fruit structure in two Neotropical mistletoes and its consequences for seed dispersal (1987) Biotropica, 19, pp. 137-139Del-Claro, K., Torezan-Silingardi, H.M., Insect-plant interactions: New pathways to a better comprehension of ecological communities in Neotropical savannas (2009) Neotropical Entomology, 38, pp. 159-164Downey, P.O., An inventory of host species of each aerial mistletoe species (Loranthaceae & Viscaceae) in Australia (1998) Cunninghamia, 5, pp. 685-720Fadini, R.F., Non-overlap of hosts used by three congeneric and sympatric loranthaceous mistletoe species in an Amazonian savanna: Host generalization to extreme specialization (2011) Acta Botanica Brasilica, 25, pp. 337-345Fadini, R.F., Gonçalves, D.C.M., Reis, R.P.F., Consistency in seeddeposition patterns and the distribution of mistletoes among its host trees in an Amazonian savanna (2009) Australian Journal of Botany, 57, pp. 640-646Fadini, R.F., Lima, A.P., Fire and host abundance as determinants of the distribution of three congener and sympatric mistletoes in an Amazonian savanna (2012) Biotropica, 44, pp. 27-34Fleming, T.H., Geiselman, C., Kress, W.J., The evolution of bat pollination: A phylogenetic perspective (2009) Annals of Botany, 104, pp. 1017-1043Freckleton, R.P., Watkinson, A.R., Large-scale spatial dynamics of plants: Metapopulations, regional ensembles and patchy populations (2002) Journal of Ecology, 90, pp. 419-434Freckleton, R.P., Watkinson, A.R., Are all plant populations metapopulations? (2003) Journal of Ecology, 91, pp. 321-324Forstreuter, W., (1988) Zur Morphologie, Anatomie und Ökologie von Tripodanthus acutifolius (Ruiz & Pav.) Tiegh, , (Loranthaceae). German, Universitat MarburgForstreuter, W., Weber, H.C., Untersuchungen zur morphologie und anatomie des embryos und des keimlings von Tripodanthus acutifolius (Ruiz et Pav.) Tiegh. (Loranthaceae) (1991) Flora, 185, pp. 153-164Galetto, L., Bernardello, L.M., Juliani, H.R., Acerca del nectario, nectar y visitantes florales en Ligaria cuneifolia (Loranthaceae) (1990) Darwiniana, 30, pp. 155-161García, D., Rodriguez-Cabal, M.A., Amico, G.C., Seed dispersal by a frugivorous marsupial shapes the spatial scale of a mistletoe population (2009) Journal of Ecology, 97, pp. 217-229García-Franco, J.G., Rico-Gray, V., Distribution and host specificity in the holoparasite Bdallophyton bambusarum (Rafflesiaceae) in a tropical deciduous forest in Veracruz, Mexico (1996) Biotropica, 28, pp. 759-762Gonzáles, W.L., Suárez, L.H., Medel, R., Outcrossing increases infection success in the holoparasitic mistletoe Tristerix aphyllus (Loranthaceae) (2007) Evolutionary Ecology, 21, pp. 173-183Grenfell, M., Burns, K.C., Sampling effects and host ranges in Australian mistletoes (2009) Biotropica, 41, pp. 656-658Grewell, B.J., Parasite facilitates plant species coexistence in a coastal wetland (2008) Ecology, 89, pp. 1481-1488Guerra, T.J., Camarota, F., Castro, F.S., Schwertner, C.F., Grazia, J., Trophobiosis between ants and Eurystethus microlobatus Ruckes 1966 (Hemiptera: Heteroptera: Pentatomidae), a cryptic, gregarious and subsocial stinkbug Journal of Natural History, 45 (17), pp. 1101-1117. , in pressGuerra, T.J., Marini, M., Bird frugivory on Struthanthus concinnus (Loranthaceae) in Southeastern Brazil (2002) Revista Brasileira de Ornitologia, 10, pp. 187-192Hanski, I., A practical model of metapopulation dynamics (1994) Journal of Animal Ecology, 63, pp. 151-162Hanski, I., Metapopulation dynamics: From concepts and observations to predictive models (1997) Metapopulation biology: Ecology, genetics and evolution, pp. 69-91. , In: Hanski, I. & Gilpin, M.E. (Eds.), London, AcademicHiepko, P., Opiliaceae (2010) Catálago de plantas e fungos do Brasil, vol, p. 1344. , In: Forzza, R.C.Leitman, P.M.Costa, A. et al. (Orgs.), 2. Rio de Janeiro, Andrea Jakobsson Estúdio, Instituto de Pesquisas Jardim Botânico do Rio de JaneiroHudler, G.W., Oshima, N., Hawksworth, F.G., Bird dissemination of dwarf mistletoe on ponderosa pine in Colorado (1979) American Midland Naturalist, 102, pp. 273-280(2010) Mapa de biomas brasileiros, , http://www.ibge.gov.br/home/geociencias/default_prod.shtm#MAPAS, IBGE., (acesso em 1/11/2010)Janzen, D.H., The peak in North-American Ichneumonid species richness lies between 38 degrees and 42 degrees N (1981) Ecology, 62, pp. 532-537Jacobi, C.M., Carmo, F.F., Vincent, R.C., Stehmann, J.R., Plant communities on ironstones outcrops: A diverse and endangered Brazilian ecosystem (2007) Biodiversity and Conservation, 16, pp. 2185-2200Kelly, D., Ladley, J.J., Robertson, A.W., Is the pollen-limited mistletoe Peraxilla tetrapelata (Loranthaceae) also seed limited? (2007) Austral Ecology, 32, pp. 850-857Kuijt, J., A revision of Dendrophthora (Loranthaceae) (1961) Wentia, 6, pp. 1-145Kuijt, J., (1969) The biology of parasitic plants, , Berkeley and Los Angeles, University of California PressKuijt, J., Monograph of the Eremolepidaceae (1988) Systematic Botany Monographs, 18, pp. 1-60Kuijt, J., A second species of Ligaria (Loranthaceae) (1990) Brittonia, 42, pp. 66-69Kuijt, J., An update on the genus Dendrophthora (Viscaceae) (2000) Botanische Jahrbücher für Systematik, 122, pp. 169-193Kuijt, J., Monograph of Phoradendron (Viscaceae) (2003) Systematic Botany Monographs, 66, pp. 1-628Kuijt, J., Pusillanthus (Loranthaceae), a new monotypic genus from Venezuela (2008) Novon, 18, pp. 370-373Kuijt, J., Monograph of Psittacanthus (Loranthaceae) (2009) Systematic Botany Monographs, 86, pp. 1-361Lamont, B.B., Germination of mistletoes (1983) The biology of mistletoes, pp. 129-141. , In: Calder, M. & Bernhardt, P. (Eds.), Sydney, Academic PressLavorel, S., Stafford Smith, M., Reid, N., Spread of mistletoes (Amyema preissii) in fragmented Australian woodlands: A simulation study (1999) Landscape Ecology, 14, pp. 147-160López de Buen, L., Ornelas, J.F., Frugivorous birds, host selection and the mistletoe Psittacanthus schiedeanus, in central Veracruz, Mexico (1999) Journal of Tropical Ecology, 15, pp. 329-340López de Buen, L., Ornelas, J.F., Host compatibility of the cloud forest mistletoe Psittacanthus schiedeanus (Loranthaceae) in central Veracruz, Mexico (2002) American Journal of Botany, 89, pp. 95-102March, W.A., Watson, D.M., Parasites boost productivity: Effects of mistletoe on litterfall dynamics in a temperate Australian forest (2007) Oecologia, 154, pp. 339-347March, W.A., Watson, D.M., The contribution of mistletoes to nutrient returns: Evidence for a critical role in nutrient cycling (2010) Austral Ecology, 35, pp. 713-721Mathiasen, R.L., Nickrent, D.L., Shaw, D.C., Watson, D.M., Mistletoes: Pathology, systematics, ecology, and management (2008) Plant Disease, 92, pp. 988-1006Marvier, M.A., Parasite impacts on host communities: Plant parasitism in a California Coastal Prairie (1998) Ecology, 79, pp. 2616-2623Medel, R., Assessment of parasite-mediated selection in a hostparasite system in plants (2000) Ecology, 81, pp. 1554-1564Medel, R., Botto-Mahan, C., Smith-Ramírez, C., Méndez, M.A., Ossa, C.G., Caputo, L., Gonzáles, W.L., Historia natural cuantitativa de una relación parásito-hospedero: El sistema Tristerix-cactáceas en Chile semiárido (2002) Revista Chilena de Historia Natural, 75, pp. 127-140(2008) Lista oficial das espécies da flora brasileira ameaçadas de extinção, , MMA, Instrução Normativa de 06 de 23 de Setembro de 2008Moilanen, A., Hanski, I., Habitat destruction and competitive coexistence in a spatially realistic metapopulation model (1995) Journal of Animal Ecology, 64, pp. 141-144Moilanen, A., Hanski, I., Metapopulational dynamics: Effects of habitat quality and landscape structure (1998) Ecology, 79, pp. 2503-2515Monteiro, R.F., Martins, R.P., Yamamoto, K., Host specificity and seed dispersal of Psittacanthus robustus (Loranthaceae) in south-east Brazil (1992) Journal of Tropical Ecology, 8, pp. 307-314Mourão, F.A., Carmo, F.F., Ratton, P., Jacobi, C.M., Hospedeiras da hemiparasita Struthanthus flexicaulis (Mart.) Mart. (Loranthaceae) em campos rupestres ferruginosos, Quadrilátero Ferrífero, MG (2006) Lundiana, 7, pp. 103-110Mourão, F.A., Jacobi, C.M., Figueira, J.E.C., Batista, E.K.L., Effects of the parasitism of Struthanthus flexicaulis (Mart.) Mart. (Loranthaceae) on the fitness of Mimosa calodendron Mart. (Fabaceae), an endemic shrub from rupestrian fields over ironstone outcrops, Minas Gerais State, Brazil (2009) Acta Botanica Brasilica, 23, pp. 820-825Nickrent, D.L., Malécot, V., Vidal-Russell, R., Der, J.P., A revised classification of Santalales (2010) Taxon, 59, pp. 538-558Norton, D.A., Carpenter, M.A., Mistletoes as parasites: Host specificity and speciation (1998) Trends in Ecology and Evolution, 13, pp. 101-105Norton, D.A., de Lange, P.J., Host specificity in parasitic mistletoes (Loranthaceae) in New Zealand (1999) Functional Ecology, 13, pp. 552-559Norton, D.A., Reid, N., Lessons in ecosystem management from management of threatened and pest loranthaceous mistletoes in New Zealand and Australia (1997) Conservation Biology, 11, pp. 759-769Overton, J.M., Dispersal and infection in mistletoe metapopulations (1994) Journal of Ecology, 82, pp. 711-723Passinho, H.C.R., (1993) Efeitos de extratos de mata-cacau (Acanthosyris paulo-alvinii Barroso) na germinação e crescimento de plântulas de cacau (Theobroma cacao L.) e na germinação de milho (Zea mays L.) e feijão (Phaseolus vulgaris L.), , MSc Dissertation. Universidade Federal da Bahia, Bahia, BrazilPenning, S.C., Callaway, R.M., Impact of a parasitic plant on the structure and dynamics of salt marsh vegetation (1996) Ecology, 77, pp. 1410-1419Press, M.C., Graves, J.D., (1995) Parasitic plants, , London, Chapman and HallPress, M.C., Phoenix, G.K., Impacts of parasitic plants on natural communities (2005) New Phytologist, 166, pp. 737-751Ramos, L., (2002) Polinização por beija-flores e morcegos em duas espécies de Psittacanthus (Loranthaceae) no Pantanal Sul-Mato-Grossense, , MSc Dissertation, Universidade Federal de Mato Grosso do Sul, Mato Grosso do Sul, BrazilRestrepo, C., Sargent, S., Levey, D.J., Watson, D.M., The role of vertebrates in the diversification of new world mistletoes (2002) Seed dispersal and frugivory: Ecology, evolution and conservation, pp. 83-98. , (Eds.), New York, CABIRivera, G.L., Galetto, L., Bernardello, L.M., Nectar secretion pattern, removal effects, and breeding system of Ligaria cuneifolia (Loranthaceae) (1996) Canadian Journal of Botany, 74, pp. 1996-2001Rodal, M.J.N., Sales, M.F., Silva, M.J., Silva, A.G., Flora de um Brejo de Altitude na escarpa oriental do planalto da Borborema, PE, Brasil (2005) Acta Botanica Brasilica, 19, pp. 843-858Rossi, L., Olacaceae (2010) Catálago de plantas e fungos do Brasil, 2, pp. 1339-1341. , In: Forzza, R.C.Leitman, P.M.Costa, A. et al. (Orgs.), Rio de Janeiro, Andrea Jakobsson Estúdio, Instituto de Pesquisas Jardim Botânico do Rio de JaneiroRoxburgh, L., Nicolson, S.W., Patterns of host use in two African mistletoes: The importance of mistletoe-host compatibility and avian disperser behaviour (2005) Functional Ecology, 19, pp. 865-873Sargent, S., Seed fate in a tropical mistletoe: The importance of host twig size (1995) Functional Ecology, 9, pp. 197-204Sasaki, D., Mello-Silva, R., Levantamento florístico no cerrado de Pedregulho, SP, Brasil (2008) Acta Botanica Brasilica, 22, pp. 187-202Tadey, M., Aizen, M.A., Why do flowers of a hummingbirdpollinated mistletoe face down? (2001) Functional Ecology, 15, pp. 782-790Teodoro, G.S., (2010) Estrutura e dinâmica metapopulacional da ervade-passarinho Psittacanthus robustus Mart, , (Loranthaceae) em manchas de habitat em três áreas de cerrado. MSc Dissertation, Universidade Federal de Lavras, Minas Gerais, BrazilTeodoro, G.S., van den Berg, E., Santos, M.C.N., Coelho, F.F., How does a Psittacanthus robustus Mart. population structure relate to a Vochysia thyrsoidea Pohl host population? (2010) Flora, 205, pp. 797-801Thomson, V.E., Mahall, B.E., Host specificity by a mistletoe, Phoradendron villosum (Nutt.) Nutt. subsp. villosum, on three oak species in California (1983) Botanical Gazette, 144, pp. 124-131van Ommeren, R.J., Whitham, T.G., Changes in interactions between juniper and mistletoe mediated by shared avian frugivores: Parasitism to potential mutualism (2002) Oecologia, 130, pp. 281-288Veloso, H.P., Rangel Filho, A.L.R., Lima, J.C.A., (1991) Classificação da vegetação brasileira, adaptada a um sistema universal, , Rio de Janeiro, IBGEVenturelli, M., Estudos sobre Struthanthus vulgaris Mart.: Anatomia do fruto e semente e aspectos de germinação, crescimento e desenvolvimento (1981) Revista Brasileira de Botânica, 4, pp. 131-147Venturelli, M., Estudos sobre Struthanthus vulgaris Mart.: Aspectos anatômicos de raiz adventícia, caule e folha (1984) Revista Brasileira de Botânica, 7, pp. 79-89Venturelli, M., Estudos embriológicos em Loranthaceae: Struthanthus flexicaulis Mart (1984) Revista Brasileira de Botânica, 7, pp. 107-119Venturelli, M., Kraus, J.E., Morphological and anatomical aspects of the primary haustorium of Struthanthus vulgaris Mart. (Loranthaceae) in vitro (1989) Revista Brasileira de Botânica, 12, pp. 17-22Vidal-Russel, R., Nickrent, D.L., The first mistletoes: Origins of aerial parasitism in Santalales (2008) Molecular Phylogenetics and Evolution, 47, pp. 523-537Watling, J.R., Press, M.C., Impacts of infection by parasitic angiosperms on host photosynthesis (2001) Plant Biology, 3, pp. 244-250Watson, D.A., Mistletoe-a keystone resource in forests and woodlands worldwide (2001) Annual Review of Ecology and Systematics, 32, pp. 219-249Watson, D.A., Parasitic plants as facilitators: More Dryad than Dracula? (2009) Journal of Ecology, 97, pp. 1151-115

Grupo genético, sistema de acasalamento e efeitos genéticos aditivos e não-aditivos nas características de musculosidade da carcaça de novilhos oriundos do cruzamento rotativo Charolês × Nelore Genetic group, breeding system and additive and non-additive genetic effects on characteristics that express muscularity of steer carcasses derived from Charolais × Nellore rotative crossbreeding

Foram avaliadas as carcaças de 800 novilhos oriundos do cruzamento rotativo entre as raças Charolesa e Nelore abatidos aos 2 anos de idade. As características avaliadas foram: conformação, espessura de coxão, perímetro de braço, área de olho-de-lombo e área de olho-de-lombo dividida por 100 kg de peso da carcaça fria (AOL100). Na análise dos dados, consideraram-se dois modelos: o Modelo 1 incluiu os efeitos genéticos de sistema de acasalamento e grupo genético do novilho aninhado em sistema de acasalamento e o Modelo 2 correspondeu ao Modelo 1, porém o sistema de acasalamento e o grupo genético foram substituídos pelas covariáveis representativas da porcentagem da raça Charolesa no indivíduo e na sua mãe e da porcentagem de heterozigose no indivíduo e na sua mãe. Pela análise do Modelo 1, novilhos charoleses foram superiores aos nelores em todas as características avaliadas. A heterose retida foi significativa para conformação (4,2%), espessura de coxão (3,2%), perímetro de braço (4,2%), área de olho-de-lombo (7,3%) e AOL100 (-6,7%). O efeito genético aditivo individual da raça Charolesa em relação à Nelore foi de 1,89 pontos para conformação, 1,37 cm para espessura de cochão, 2,55 cm para perímetro de braço, 12,70 cm² para área de olho-de-lombo e 3,13 cm² para AOL100. O efeito genético heterótico individual (em relação à média dos definidos) foi de 3,9% para conformação, 3,8% para espessura de cochão, 3,1% para perímetro de braço e 9,8% para área de olho-de-lombo. A heterose materna é significativa apenas para perímetro de braço (1,6%) e AOL100 (-5,4%). Os efeitos genéticos não-aditivos, representados por epistasia e ligação gênica, não influenciam as características avaliadas.<br>The carcasses of 800 steers derived from rotational crossbreeding between Charolais and Nellore breeds, slaughtered at two years of age, were evaluated. The evaluated characteristics were the following: conformation, cushion thickness, arm perimeter, Longissimus dorsi area, Longissimus dorsi area divided by 100 kg of cold carcass weight (AOL100). Two models were used for the data analyses: Model 1 included the genetic effects of the breeding system and steer genetic group nested within the breeding system and Model 2 corresponded to Model 1, but the breeding and genetic group were substituted by the covariables corresponding to the percentage of Charolais breed of the individual and its mother and the percentage of heterozygosis of the individual and its mother. From the analysis in Model 1, Charolais steers were superior to the Nelores in all assessed traits. The retained heterosis was significant for conformation (4.2%), cushion thickness (3.2%), arm perimeter (4.2%), Longissimus dorsi area (7.3%) and AOL100 (-6.7%). The individual additive genetic effect of Charolais breed regarded to Nelore was 1.89 points for conformation, 1.37 cm for cushion thickness, 2.55 cm for arm perimeter, 12.70 cm&sup2; for Longissimus dorsi area and 3.13 cm&sup2; for AOL100. The individual heterotic genetic effect (regarded to the straightbred mean) was 3.9% for conformation, 3.8% for cushion thickness, 3.1% for arm perimeter and 9.8% for Longissimus dorsi area. Maternal heterosis is significant only for arm perimeter (1.6%) and AOL100 (-5.4%). The nonadditive genetic effects, represented by epistasis and linkage, do not influence the evaluated characteristics