C-mitotic Effect Research Articles

The Response to Colchicine of Meristems of Roots ofVicia Faba

SUMMARYThe effect of colchicine on the meristems of roots of Vicia faba has been investigated with special reference to the behavior of those advanced lateral root primordia which would normally emerge as lateral roots within 48 hours of water recovery of root systems treated with colchicine for 1 to 3 hours. The observations made do not support DAVIDSON'S (1965) view that these primordia (Type II in his classification) are resistant to colchicine and that their resistance is confined to a particular stage in their growth. It has been shown that Type II primordia respond to the C-mitotic effect of colchicine as all other meristems of the root system do, provided that the drug is allowed to penetrate the primordium and develop its effect for the necessary duration.

Nova técnica para a contagem de cromossomos em amendoim (Arachis Hypogaea L.)

Dificuldades constantemente encontradas na determinação do número de cromossomos em Arachis trouxeram a necessidade de pesquisar novos métodos. Uma técnica eficiente foi então desenvolvida no laboratório de Citologia do Instituto Agronômico de Campinas e que consta do seguinte: a) pré-tratamento das raízes com solução saturada de paradiclorobenzeno à temperatura de 16 a 20°C durame 4-8 horas ou por uma solução 0,002 mo/1 de oxiquinoleína a 16°C durante 6 a 7 horas; b) hidrólise em orcenína acética (2% de orceína em ácido acético a 70%) e ácido clorídrico na proporção de 9:1; c) coloração e esmagamento em orceína acética a 1% em ácido acético a 45%. Tanto o paradiclorobenzeno como a oxiquinoleína produzem o eteito c-mitótico sôbre os cromossomos do amendoim, aumentando o número de células em metáfase e produzindo o espalhamento e o encurtamento dos cromossomos. Isso permite contá-los com a maior facilidade. São apresentados os detalhes da técnica bem como comentários sôbre o modo de ação do paradiclorobenzeno no material em questão.

Action of some Acenaphthene Derivatives on Mitosis in Pisum Roots

IN a previous communication1 I reported the c-mitotic effect of 3-(5′-acenaphthyl)-propanol and 4-(5′-acenaphthyl)-butanol on onion root-tips. This work formed part of a programme of investigations of the structure-activity relationships in the acenaphthene series. The work of Wilson and co-workers2–6 on the use of Pisum as test material for chemically induced abnormal mitosis has led me to attempt its use for evaluation of the acenaphthene derivatives.

Detection of Trace Quantities of Acenaphthene by Gas Chromatography

IN the course of investigations into the c-mitotic effect we wished to determine the acenaphthene uptake in the root tips of onions grown in a saturated water solution of acenaphthene. As the quantities expected were of the order of μ, the very sensitive flame ionization detector described by McWilliam and Dewar1 was used. A 6-in. long -in. bore column packed with 60–80 mesh brick dust carrying 15 per cent w/w silicone oil was used for the analysis, and pure hydrogen was used as the carrier gas.