Morphogenetic Potential of Embryo- and Seedling-Derived Callus of Elaeis guineensis Jacq. var. pisifera Becc.

The oil palm of commerce, Elaeis guineensis (tenera), derivesfrom hybridization of variety dura x pisifera. Germ plasm ofpisifera is limited, however, because of varying degrees offemale sterility. Efforts to increase the range of availablepisifera male germ plasm have thus far been limited to fertilepisiferas but it is anticipated that clonal multiplication ofembryos and explanted organs from less female-fertile, but nonethelessfertile, male, plants could play a significant role in breedingprogrammes. Callus has been produced from mature pisifera embryosand leaf explants from young plantlets using a half-strengthMurashige and Skoog medium supplemented with inositol, caseinhydrolysate, activated charcoal and varying concentrations ofauxins. After sub-culture on media of similar composition, organizedstructures can develop. Those which form in stale nutrient media(e.g. left in the same medium for up to 3 months) give riseto embryonal structures which do not readily develop furtherand can be regarded as neomorphs. If callus once formed is transferredto media with lower auxin concentrations (40–0 mg l^–1)embryonal buds and well-formed shoots are produced; additionof gibberellic acid (GA₃) fosters the production of well-organizedshoots accompanied by roots. Elaeis guineensis var pisifera, oil palm, tissue culture, micropropagation, embryo development, morphogenetic potential, callus     

Active transport of l-aspartic acid in Neurospora crassa

Transport of l-aspartic acid in Neurospora crassa conidia is shown to be mediated by neutral and general amino acid transport systems. The transport activity is dependent on pH and results in accumulation of l-aspartic acid against a gradient. Mutants deficient in transport of l-aspartic acid are described.     

Reconstitution of Bacterial Spore Coat Layers In Vitro

The spore coat layers of Bacillus cereus T can be at least partially restored by mixing spores stripped of their coat with solubilized coat protein.