RESUMO O desenvolvimento de cultivares mais tolerantes à seca é essencial para a manutenção da produção agrícola mundial. Objetivou-se realizar uma seleção precoce de genótipos de Coffea arabica tolerantes à seca, avaliando-se sua divergência funcional por meio de análises morfológicas, anatômicas e fisiológicas. Mudas de 14 genótipos foram submetidas ao estresse hídrico imposto pela irrigação por 18 dias. Foram medidos parâmetros de crescimento e anatômicos, potencial hídrico foliar e trocas gasosas. Em condições irrigadas e seca prolongada (18 dias), a divergência entre os genótipos foi determinada principalmente por características morfológicas, como área foliar, diâmetro do caule e, consequentemente, massa seca da parte aérea. Sob seca moderada (14 dias), parâmetros como potencial hídrico, espessura da cutícula, densidade estomática, número de vasos do xilema e eficiência do uso da água foram importantes para a divergência do grupo com maior capacidade de manter seu estado hídrico. Os genótipos 1,2,4,11 e 12 possuem características que contribuíram para a manutenção do estado hídrico, como maior espessura de cutícula, densidade estomática, menor número de vasos xilemáticos e espessura do floema, maior comprimento de raiz e maior eficiência de uso de água. A divergência funcional combinando análises morfológicas, anatômicas e fisiológicas em resposta à seca moderada indicou a seleção precoce dos genótipos 1, 2, 4, 11 e 12 como mais tolerantes à seca durante a fase de muda.

ABSTRACT The development of more drought-tolerant cultivars is essential for the maintenance of global agricultural production. This study aimed to perform an early selection of drought-tolerant Coffea arabica genotypes by evaluating their functional divergence using morphological, anatomical and physiological analyses. Seedlings of 14 genotypes were subjected to the drought stress imposed by irrigation for 18 days. Growth and anatomical parameters, leaf water potential and gas exchanges were measured. Under irrigated conditions and prolonged drought (18 days), the divergence among the genotypes was determined mainly by morphological traits, such as leaf area, stem diameter and, consequently, shoot dry mass. Under moderate drought (14 days), parameters such as water potential, cuticle thickness, stomatal density, number of xylem vessels and water-use efficiency were important for the divergence of the group with the highest ability to maintain its water status. The genotypes 1, 2, 4, 11 and 12 have characteristics that contributed to the maintenance of water status, such as greater cuticle thickness, stomatal density, smaller number of xylem vessels and phloem thickness, bigger root length and greater water-use efficiency. The functional divergence combining morphological, anatomical and physiological analyses in response to the moderate drought indicated the early selection of the genotypes 1, 2,4, 11 and 12 as more drought tolerant during the seedling stage.

Abstract MGS Guaiçara e MGS Vereda are resistant to Meloidogyne paranaensis, one of the most aggressive nematode parasites of coffee. MGS Vereda is an early maturation cultivar, whereas MGS Guaiçara has a medium maturation cycle. Both cultivars produce red fruit, have high size, and high yield potential in infested areas.

Abstract Brazilian coffee cultivation was boosted over the last few decades by the mechanization of various field operations. Considering the influence of genetic factors on coffee harvesting efficiency, we aimed to evaluate the use of mechanized harvesting characteristics as a criterion to select progenies derived from ‘Icatu’ germplasm, previously evaluated for agronomic characteristics, resistance to rust and cercosporiosis. We also investigated genotypic and phenotypic correlations between semi-mechanized harvesting characteristics. Ten progenies of Coffea arabica L. were analyzed in two experimental farms during two consecutive harvests. Genetic parameters were evaluated to trace selection strategies. Four progenies that were suitable for mechanization were selected, supporting our hypothesis of the use of harvest characteristics as selection criteria.

Abstract In the northern Minas region, the dry-warm climate predisposes coffee plants to the occurrence of leaf miners, mites, cercosporiosis, and leaf scald. Aiming for the development of a cultivar adapted to these conditions, Coffea canephora Pierre ex A. Froehner clones were selected through genetic parameters under an irrigated system, without agrochemicals. Eighteen agronomic traits were evaluated. The survival rate, number of nodes per plagiotropic branch, leaf miner infestation and cercosporiosis incidence were chosen as characteristics for selection of ‘Vitória Incaper 8142’, once they have shown superiority of the genetic parameters. The survival rate variable was used to rank the EMCAPA 8141 Robustão Capixaba clones. Clones V2, V4, V6, V13, RC7, and RC9 were selected as more tolerant to pests and diseases and can provide genetic improvements in conilon breeding program for region. The genetic dissimilarity identified between clones allowed suitable clone combinations to be proposed for use in future crosses.