02093naa a2200253 a 450000100080000000500110000800800410001902200140006010000210007424501420009526000090023752013090024665000370155565000220159265000130161465000220162765300270164970000180167670000170169470000200171170000280173170000200175977300600177919409402023-05-25       2012    bl uuuu     u00u1 u    #d  a0102-33061 aVIEIRA, L. de J.  aViability, production and morphology of pollen grains for diff erent species in the genus Manihot (Euphorbiaceae).h[electronic resource]  c2012  a(Viability, production and morphology of pollen grains for different species in the genus Manihot (Euphorbiaceae)). Th e objective of this work was to characterize the viability, production and morphology of pollen for different species in the genus Manihot. Floral buds from Manihot accessions were collected from two germplasm banks at Embrapa Cassava & Fruits. The viability of the pollen was assessed via colorimetric, in vitro and in vivo assays. The diameter of the pollen grains was determined by measuring the transversal length of the grain. The experimental design was entirely randomized. Studies on pollen ultrastructure were performed via scanning electron microscopy. Pollen viability was high in the colorimetric tests and intermediate in vivo tests; there was no germination in the in vitro tests. The average production for all accessions was 1,253 pollen grains per fl oral bud. The size of the pollen grains varied from 132 to 163 µm in the wild accessions, and 129 to 146 µm in the cultivated accessions. Th e pollen grains for all accessions were very large, apolar, spherical as well as inaperturate, with an exine ornamented with pila organized in a Croton pattern. Th e wild accessions, in general, produced more and larger pollen grains compared with the cultivated accessions.  aBreeding and Genetic Improvement  aGenetic resources  aMandioca  aManihot Esculenta  aMelhoramento genético1 aSOARES, T. L.1 aROSSI, M. L.1 aALVES, A. A. C.1 aSANTOS, F. de A. R. dos1 aSOUZA, F. V. D.  tActa Botanica Brasilicagv. 26, n. 2, p. 350-356, 2012.