Application of Plant Cell and Tissue Culture To Agriculture dan Industry

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New Vistas are Opened for Sorghum Improvement by Genetic Transformation

Transgenic fertile sorghum plants (Sorghum bicolor L. Moench) were obtained by microprojectile bombardment of immature embryo and immature inflorescence explants. Regeneration from the calli was through embryogenesis and organogenesis pathways, resulting in both the uniformly transformed and chimeric plants. Plant regeneration occurred on media supplemented with bialaphos. Microprojectile bombardment resulted in plants resistant to the herbicide and exhibited phosphinothricin acetyltransferase activity. The presence of bar, uMa and luc genes in the T[o] plants was confirmed by Southern blot analysis of genomic DNA. The herbicide resistance was inherited in T[1] plants.Les plantes transgeniques fertiles de surgho (Sorghum bicolor L. Moench ) etaient obtenues par bombardement de microprojectiles d'embryons immatures et d'explants d'inflorescences immatures. La regeneration a partit de cales a lieu a travers l'embryogenese et l'organogenese qui resultent en la formation des plants uniformement transformes et des chimeres. La regeneration des plantes se fait sur des milieux ayant obtenu un supplement de bialaphos. Le bombardement des microprojectiles a abouti a la production des plants resistants aux herbicides et presentant l'activite phosphinothricine acetyltransferase. La presence des genes bar, uida et luc sur les plants T[o] a ete confirmee a l'aide de l'analyse southern blot du DNA genomique. La resistance a l'herbicide etait herite par les plants en T[1]

Psychological and Biological Perspectives on Altruism

This paper presents the case for viewing altruism as an inherent part of human nature. The argument is first made that 'inclusive fitness', the key concept in modern evolutionary biology, dictates that (a) humans are programmed not only to be egoistic but also, under certain conditions, to help another at cost to themselves; and (b) what was selected was not altruistic action but mediators of action, because this provided the necessary flexibility. Psychological evidence is then presented that complements this view. Thus (a) there appears to a general human tendency to help others in distress, which has properties analagous to egoistic motivation and yet comes into play independently of egoistic motivation; and (b) the evolutionary requirements for a mediating mechanism appear to be met by empathy, e.g., it is reliably aroused in humans in response to misfortune in others, it predisposes the individual toward helping action and yet is amenable to perceptual and cognitive control, and its physiological basis may have been present in early humans. The social implications of a biological basis for human altruism are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66763/2/10.1177_016502547800100403.pd

Crescimento de calos embriogênicos de milho submetidos ao estresse salino<A NAME="top"></A> Embryogenic callus growth of maize submitted to salt stress

A salinidade do solo é um problema muito importante em áreas irrigadas do semi-árido brasileiro, onde o milho é uma cultura de subsistência. Este trabalho teve como objetivo estudar o efeito de concentrações de NaCl sobre calos embriogênicos, da cultivar Jatinã C3 Anão, uma importante cultivar de milho no Nordeste do Brasil. A indução dos calos foi feita a partir de embriões imaturos assepticamente retirados das sementes e inoculados em meio de cultura N6 suplementado com 2 mg L-1 de 2,4-D. Os calos embriogênicos foram submetidos a diferentes concentrações de cloreto de sódio (0; 50; 100; 150 e 200 mmol L-1 de NaCl), com três repetições durante 60 dias. Os calos submetidos a 100 mmol L-1 de NaCl apresentaram aumento no conteúdo de prolina na ordem de 37% quando comparado com o nível de 50 mmol L-1 de NaCl, sugerindo um efeito positivo da acumulação deste aminoácido em resposta ao estresse salino. Por outro lado, em elevadas concentrações salinas (150 e 200 mmol L-1) observou-se decréscimo no crescimento dos calos, bem como redução nos teores de prolina, provavelmente em função de um aumento da fração não embriogênica dos calos.<br>Soil salinity is a very important problem in irrigated areas of the brazilian semi-arid area, where maize is a subsistence crop. To study the effect of NaCl concentrations in embryogenic calli of Jatinã C3 Anão, an important maize cultivar of the Northest of Brazil, calli were induced using immature embryos aseptically removed from the seeds and grown on N6 medium supplemented with 2 mg L-1 of 2,4-D. To study the effect of salinity in vitro, embryogenic calli were subjected to different concentrations of sodium chloride (0; 50; 100; 150 and 200 mmol L-1 of NaCl), in three replicates, during 60 days. Calli subjected up to100 mmol L-1 NaCl showed proline concentration 37% higher than callus treated with 50 mmol L-1 NaCl. This result suggests a positive effect of proline accumulation at salt stress conditions. However, at the highest concentration tested (150-200 mmol L-1 NaCl) as lower growth and also a lower proline accumulation was observed, probably due to an increase of the non embryogenic fraction of calli