O objetivo deste trabalho foi verificar a seletividade de herbicidas utilizados em áreas de eucalipto sobreo crescimento de Myracrodruon urundeuva. O experimento foi conduzido em casa de vegetação em duas épocas diferentes (2002 e 2003), em delineamento inteiramente casualizado, arranjado em esquema fatorial (5x4), sendo cinco herbicidas em quatro doses, com seis repetições. Os tratamentos, com as doses, foram: haloxyfop-methyl (0,00, 120, 240 e 480 g ha-1), sulfentrazone (0,00, 300, 600 e 1.200 g ha-1), isoxaflutole (0,00, 150, 300 e 600 g ha-1), oxyfluorfen (0,00, 720, 1.440 e 2.880 g ha-1); e glyphosate (0,00, 720, 1.440 e 2.880 g ha-1). Em ambos os experimentos foram avaliados: efeitos fitotóxicos do produto, número de folíolos, altura de plantas; no segundo, foi feita ainda a análise de clorofila a e b e de carotenóides. O herbicida que apresentou maior fitoxicidade e que comprometeu o desenvolvimento da aroeira foi o glyphosate, sendo, portanto, não recomendado para o controle de invasoras em áreas de plantio de aroeira. Os outros herbicidas não comprometeram o desenvolvimento desta planta, apresentando, por isso, potencial para uso no manejo de plantas daninhas no cultivo desta espécie.

An afforestation of mixed plantation was proposed to provide wood supply and minimise exploratory actions in a biological reserve. Eucalyptus plants were indicated for this purpose. This study was carried out to test the effect of volatile oils extracted from the leaves of Eucalyptus camaldulensis Dehn. and E. grandis Hill ex Maiden on the growth of Enterolobium contortisiliquum (Vell.) Morong. Under laboratory conditions, the Enterolobium plants showed tolerance to E. grandis oil, whereas E. camaldulensis oil caused loss of leaves, inhibition of height and diameter growth and a concomitant decrease in effective PSII quantum yield and the reduction of photosynthetic electron-transport chains. The field growth of E. contortisiliquum was not modified by intercropped E. grandis plants, confirming its tolerance. Inoculation with rhizobia and or mycorrhizal fungi significantly improved the height and diameter growth of these species. The results showed that E. contortisiliquum plants could be intercropped with E. grandis for reforestation and agroforestry systems.

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A cytogenetic study of Khanty from the lower Ob river in West Siberia has detected a high frequency of the Y chromosome heterochromatin subtotal deletion--del(Y)(q12). This morphologically identical deletion was found in 32 of 154 males examined (20.8%). The carriers had 10 different surnames. Taking into account the small size, isolation by distance, and historical peculiarities of the surname formation of the population, it has been concluded that the high frequency of the del(Y)(q12) results from the genetic drift of the marker chromosome.

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