RESUMOO objetivo principal da presente pesquisa é avaliar a pegada hídrica da produção do cacau Colombiano (Theobroma cacao L.). A exigência hídrica da cultura, tanto quanto a de irrigação, foi avaliada com base nas condições de clima, solo e da cultura no país. A estimativa da necessidade de água foi baseada em dados de seis municípios selecionados pela representatividade dos seus maiores níveis de rendimento, produtividade e dinâmica comercial do Brasil. De acordo com os resultados a pegada hídrica atingiu 17,100 m3 t-1. A nível de província, o maior recorde para este parâmetro foi observado em Tolima com 23,239 m3t-1 enquanto Huila registrou o nível mais baixo, com 13,475 m3 t-1. O consumo de água por unidade de cultura pode ser influenciado não só pelas condições agro-meteorológicas, mas também pelo nível de produção; portanto, regiões com baixos valores de pegada hídrica para uma cultura específica geralmente têm condição climática favorável. A evapotranspiração é relativamente baixa e os maiores rendimentos foram obtidos na agricultura com maiores níveis de produção; em razão da complexidade de um fenômeno hidrológico, como a evapotranspiração de uma cultura, a magnitude dessas diferenças pode ser considerada pequena.

ABSTRACTThe main objective of the present research was to calculate the water footprint of the Colombian cocoa (Theobroma cacao L.) production. The evaluation of crop water requirement and irrigation requirement were based on climate, soil and crop conditions in the country. The water requirement estimation was based on data from six municipalities selected for their representativeness of the highest yield, productivity and commercial dynamics of the country. The results show that the Water footprint reached 17,100 m3 t-1. At the province level, the highest record for this parameter was observed in Tolima, with 23,239 m3t-1, while Huila registered the lowest level, with 13,475 m3t-1. Water use per crop unit can be influenced not only by agro-meteorological conditions, but also by the level of production. Therefore, a region with a low water footprint value for a specific crop usually has a favorable climatic condition. Crop evapotranspiration was found to be relatively low, and the highest yields were obtained in association with more productive cropping levels. Given the complexity of a hydrological phenomenon like crop evapotranspiration, the magnitude of these differences may be considered to be small.

Bromus setifolius var. pictus (Hook) Skottsb., B. setifolius var. setifolius Presl. and B. setifolius var. brevifolius Ness are three native Patagonian taxa in the section Pnigma Dumort of the genus Bromus L. AFLP and RAPD analysis, in conjunction with genetic distance measurements and statistical techniques, revealed variation within this group and indicated that B. setifolius var. brevifolius was closely related to B. setifolius var. pictus, with both taxa being more distantly related to B. setifolius var. setifolius. Cytogenetic analysis confirmed the chromosomal number of B. setifolius var. pictus (2n = 70) and B. setifolius var. setifolius (2n = 28) and showed for the first time that B. setifolius var. brevifolius had 2n = 70. The combination of molecular genetic and cytogenetic evidence supported a species status for two of the three taxa and suggested hypotheses for the evolutionary origin of these complex taxa. Species status was also indicated for B. setifolius var. setifolius. Based on these findings, we suggest that B. setifolius var. pictus be referred to as B. pictus Hook var. pictus, and B. setifolius var brevifolius as B. pictus Hook var brevifolius. The correlation between AFLP diversity and variation in ecological parameters suggested that this marker system could be used to assess breeding progress and to monitor the domestication of Patagonian Bromus species for agronomic use.

The present study is a revision of our work on evolutionary cytogenetics of the genus Zea, including several new experiments which give a deeper insight into the nature of the DNA sequences involved in telomeric regions of Zea luxurians. These new experiments, based on the Southern blotting technique and in situ hybridization, have demonstrated the following: 1) in situ hybridization (FISH) demonstrated the presence of the 180-bp repeat maize-knob-repeat-sequence in DAPI-positive terminal heterochromatic blocks of Z. luxurians (ZL-THB region); 2) Southern blot analysis confirmed that the 180-bp repeat present in maize is also present in Z. diploperennis, Z. luxurians and Tripsacum dactyloides, but not in Z. perennis; 3) another sequence with targeted sites for endonucleases, but without recognition sites for the 180-bp repeat, may be interspersed with the 180-bp repeat in a tandem array sited in the ZL-THB region; 4) in situ hybridization (GISH) of probes and blocking-probes with chromosomes of Z. luxurians (using Z. luxurians as a probe and Z. diploperennis or Z. perennis as a blocking-probe) gave strong fluorescence in both cases. Since Z. diploperennis possesses the 180-bp repeat, fluorescence on Z. luxurians chromosomes was not expected. These results can be explained if the ZL-THB regions are composed not only of 180-bp repeats interspersed with other sequences, but also of other tandem arrays unique to Z. luxurians, which, according to our GISH results, are probably located at the subterminal position.