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Colleters are secretory structures present in many dicotyledon families, but they have not yet been reported for the Orchidaceae. However, the orchid Rodriguezia venusta was observed to possess secretory trichomes on the adaxial side of the bracts subtending floral buds that can be interpreted to be colleters. The present work describes the anatomy and histochemistry of these structures. These bracteal trichomes are multicellular, uniseriate, and densely spaced near the region where the bract attaches to the inflorescence. The secretions of these trichomes are mucilaginous and apparently exclusively constituted by carbohydrates, and they appear to act as a lubricant that facilitates the young floral bud to slide over the bract as it grows. In light of these characteristics, it is proposed that these secretory trichomes should be considered to be ‘colleters’.

A total of 100 Chinese blood donors (50 from Shen-Zhen and 50 from Taiwan) were studied by the participants in addition to 9 reference samples. A new nomenclature for the CR1 structural alleles was recommended by the participants which would use a numbering system, e.g. CR1*1. The structural allele frequencies in the Chinese were: CR1*1 (190 kD) 0.96, CR1*2 (220 kD) 0.03, CR1*3 (160 kD) 0.01 and CR1*4 (250 kD) 0.00. The HindIII expression polymorphism was also studied and the high expressing allele had a gene frequency of 0.71 while the low expressor gene frequency was 0.28. Erythrocyte copy numbers were quantified and compared between laboratories with good correlation (R = 0.55–0.88). The mean (± SD) erythrocyte copy number was 463 (± 229) in the Taiwan donors and 446 (± 207) in the Mainland Chinese.

RESUMO -Com este trabalho objetivou-se investigar a aquisição da capacidade germinativa e o estabelecimento da dormência em sementes em desenvolvimento de Bixa orellana L. (urucum). Foram caracterizados 7 estádios de desenvolvimento das sementes, baseados nas características morfológicas, massa fresca, massa seca e teor de umidade dos frutos e das sementes. Sementes imaturas de B. orellana não germinaram durante os estádios iniciais de seu desenvolvimento. As sementes adquiriram a capacidade germinativa máxima quando os níveis de umidade declinaram para valores em torno de 60%. Nessa fase, as sementes apresentaram acúmulo máximo de massa seca. A dormência foi estabelecida quando as sementes exibiam um conteúdo de água em torno de 10%. TERMOS ADICIONAIS PARA INDEXAÇÃO: Tegumento, dessecamento, dormência GERMINATION IN DEVELOPING SEEDS OF Bixa orellanaABSTRACT -The objective of this work was to investigate the acquisition of germination capacity and the onset of dormancy in developing seeds of Bixa orellana L. (annatto). Seven stages of development were characterized with regard to morphology, fresh and dry mass and moisture content of the fruits and seeds. Immature seeds of B. orellana did not germinate during early stages of their development. The seeds achieved their maximum germination capacity after the moisture content had declined to around 60%. In this phase the seeds presented maximum dry mass. The onset of dormancy occurred when the seeds exhibited water contents around 10%. ADDITIONAL INDEX TERMS: Desiccation, dormancy, tegmen INTRODUÇÃODurante o seu desenvolvimento, a semente de uma angiosperma passa por três fases distintas: histodiferenciação ou morfogênese inicial, expansão celular concomitante à fase de acúmulo de reserva, e a fase final, que corresponde ao dessecamento (Thaker, 1999). O dessecamento constitui um evento integrante do processo do desenvolvimento da maioria das sementes, especialmente as ortodoxas (Kermode et al., 1986).