The impact of breeding on fruit production in warm climates of Brazil O impacto do melhoramento genético na produção de frutas em climas quentes do Brasil

Brazil is a very large country with a diverse climate. This fact allows a diversity of plants to grow ranging from tropical rainforest in the Amazon, passing through Atlantic Forest along the coast, the cerrados (Brazilian savannah) in the Central West region, and semi-arid area in the Northeast. Latitude ranges from 5º N to 33º S, with most of this territory in the tropical region. There are enough reasons to plant breeders devoting great amount of their effort to improve plants suitable for warm climates, though. Among fruit crops, results of breeder's work have been noticed in several species, especially on peaches, grapes, citrus, apples, persimmons, figs, pears and others not so common, such as acerola, guava, annonas (sour sop, sugar apple, atemoya, cherimoya) and passion fruit. Peach tree introduced at low latitude (22 ± 2ºS) requires climatic adaptation to subtropical conditions of low chilling. In Brazil, the first peach breeding program aiming adaptation of cultivars to different habitats was developed by Instituto Agronômico de Campinas (IAC) beginning in the end of the 40's. Apple low chill requirement cultivars obtained in a South state, Paraná, are now been planted at low latitudes. Banana and pineapple breeding programs from Embrapa units along the country are successfully facing new sanitary problems. Petrolina/Juazeiro, in the Northeastern region (9ºS), is the main grape exporting region with more than 6,000 ha. Grape growing in the region is based in the so called "tropical" rootstocks released by IAC, namely: IAC 313 'Tropical', IAC 572 'Jales'. Recently, Embrapa Grape and Wine released tropical grape seedless cultivars that are changing table grape scenario in the country.<br>O Brasil, com suas dimensões continentais, apresenta grande diversidade de climas. Este fato permite o crescimento de grande diversidade de plantas desde a floresta tropical úmida do Amazonas, passando pela Mata Atlântica ao longo da costa, os cerrados, na região centro-oeste e nas áreas de semiárido no nordeste. A maior parte do território encontra-se na região tropical onde a latitude abrange de 5º N a 33º S. Há, portanto, razões suficientes para os melhoristas de plantas devotarem boa parte de seus esforços para melhorar plantas apropriadas aos climas mais quentes. Entre as frutíferas, os resultados dos trabalhos dos melhoristas têm sido notados em diversas espécies, especialmente pêssegos, uvas, citros, maçãs, caquis, figos, pêras e outras, não tão comuns, como acerola, goiaba, anonas (graviola, pinha, atemóia, cherimóia) e maracujá. Pessegueiros introduzidos em baixas latitudes (22 ± 2ºS) requerem adaptação climática às condições subtropicais de baixa ocorrência de frio. No Brasil, o primeiro programa de melhoramento de pêssego visando adaptação de cultivares a diferentes habitats foi desenvolvido pelo Instituto Agronômico de Campinas (IAC) começando no final dos anos 1940. O melhoramento da macieira com baixa necessidade frio levado a cabo no IAPAR, Paraná, produziu cultivares que podem ser plantados com sucesso em regiões de baixa latitude. Os programas de melhoramento da banana e do abacaxi conduzidos em unidades da Embrapa em todo o país estão conseguindo fazer frente aos fortes problemas fitossanitários com as cultivares melhoradas. Petrolina/Juazeiro, na região nordeste (9ºS), é a principal região exportadora de uvas no país com mais de 6.000 ha. A viticultura na região está baseada nos chamados porta-enxertos "tropicais" lançados pelo IAC: IAC 313 'Tropical', IAC 572 'Jales'. Recentemente, a Embrapa Uva e Vinho lançou cultivares tropicais de uvas sem sementes que estão mudando o cenário da uva de mesa no país

Giants of the Amazon: How does environmental variation drive the diversity patterns of large trees?

For more than three decades, major efforts in sampling and analyzing tree diversity in South America have focused almost exclusively on trees with stems of at least 10 and 2.5 cm diameter, showing highest species diversity in the wetter western and northern Amazon forests. By contrast, little attention has been paid to patterns and drivers of diversity in the largest canopy and emergent trees, which is surprising given these have dominant ecological functions. Here, we use a machine learning approach to quantify the importance of environmental factors and apply it to generate spatial predictions of the species diversity of all trees (dbh ≥ 10 cm) and for very large trees (dbh ≥ 70 cm) using data from 243 forest plots (108,450 trees and 2832 species) distributed across different forest types and biogeographic regions of the Brazilian Amazon. The diversity of large trees and of all trees was significantly associated with three environmental factors, but in contrasting ways across regions and forest types. Environmental variables associated with disturbances, for example, the lightning flash rate and wind speed, as well as the fraction of photosynthetically active radiation, tend to govern the diversity of large trees. Upland rainforests in the Guiana Shield and Roraima regions had a high diversity of large trees. By contrast, variables associated with resources tend to govern tree diversity in general. Places such as the province of Imeri and the northern portion of the province of Madeira stand out for their high diversity of species in general. Climatic and topographic stability and functional adaptation mechanisms promote ideal conditions for species diversity. Finally, we mapped general patterns of tree species diversity in the Brazilian Amazon, which differ substantially depending on size class