Possibilities of use of Hormones in Chromosome Analysis: (With Plates II and III)

Cytology of Different Species of Aroids with a View to Trace the Basis of their Evolution

Abstract: (1955). Cytology of Different Species of Aroids with a View to Trace the Basis of their Evolution. Caryologia: Vol. 7, No. 2, pp. 221-291.

Effects of Some Growth Substances on Mitosis

Abstract: Cytological effects of three growth substances namely, Gibberellic acid (GA), Indole-butyric acid (IBA), and 2, 4-Dichlorophenoxyacetic acid (2, 4-D) were studied on root tip mitosis of Vicia faba treated with 10 and 50 ppm concentrations and 3, 6 and 12 hours durations. GA enhanced cell division while 2, 4-D and IBA inhibited it and were more toxic than GA. Main effects at chromosomal level were chromosome breakage, bridge formation, C-mitosis, micronuclei formation, stickiness and chromosome condensation.

Effects of IAA with Malefic Hydrazide and Colchicine on Root Tip Mitosis

Abstract: The effects of maleic hydrazide MH, indole-3 acetic acid IAA and colchicine were studied on the mitotic division and induction of chromosomal abnormality in Allium cepa root tips treated with 25, 50 and 75 ppm concentrations for 4, 8 and 12 hour durations. Inhibition of mitosis was brought about under all treatments except IAA which at lower concentration stimulated the division. For the inhibition of mitosis IAA was most effective and MH was least effective. The capacity to produce chromosomal abnormality was evidenced by the presence of chromosome and chromatid breaks, bridge formation, spindle fibre inhibition resulting in the formation of polyploid cells; chromosome erosion, lagging of chromosomes, micronuclei, stickiness and swelling of the nucleus.

An investigation of the possibilities of the use of phenols in chromosome analysis

Abstract: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 1 Chemicals tried . . . . . . . . . . . . . . . . . . . . . . . . . 123 Materials investigated . . . . . . . . . . . . . . . . . . . . . . 124 Different methods of treatment including Tables I, II &I I I . . . . . . . 125 Procedure of different treatments . . . . . . . . . . . . . . . . . 127 Discussion of results . . . . . . . . . . . . . . . . . . . . . . . 131 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 References . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Cytological reactions induced by inorganic salt solutions.

Abstract: AN investigation has been carried on for some time in this Laboratory into the immediate cytological effect of salt solutions on root meristems of Allium Cepa. Salts, mostly nitrates, of some forty metals were tested. A dilution series of 10–16 concentrations were studied for each substance, covering the whole range from total lethality down to such weak concentrations that no cytological effect could be detected. Fixations of root tips were made after 4 and 24 hours respectively. All slides were stained with crystal-violet.

Reazioni di natura auxinica ed effetti rizogeni in Allium Cepa L.

Abstract: Summary The authors have studied growth responses and induction of laterals in onion roots subjected to various experimental treatments. The following reactions have been observed: C-tumours, coiling and bending responses, basal thickening, root hair formation and browning of roots. Fasciation, sometimes present in onion roots, is brought to greater evidence by many chemical treatments; none of these seems, however, to enhance its frequency. A more or less complete inhibition of growth and induction of lateral roots are generally concomitant phenomena; an exception to this rule are sulfathiazole and the threshold concentrations of 2,4-D (2,4-dichlorophenoxyacetic acid) and its sodium salt (see Table I). No relation has been found between degree of macroscopical growth responses and intensity of lateral root formation: treatments inducing the most intense growth reactions may show very poor « root-forming » effects (for ex., nicotinic acid and moist air). For most of the chemicals tested the threshold valu...