Mechanisms of endopolyploidization in Datura endosperm.

Abstract

Ever since the description of aneuploids in Datura (Blakeslee 1930) the genus has achieved considerable cytogenetic importance . The different species of Datura are sources of a number of therapeutic alkaloids . Datura fastuosa Linn. has be come an aggressive weed in many localities in South India . Fruit or seed sterility is seldom found in this species and normally the fruits have a luxurient growth . Hence a detailed investigation on the cytological constitution of the endosperm was worth pursuing. Materials and methodsDeveloping fruits of Datura fastuosa Linn. were collected from the Botanic garden of the Department and the young seeds were fixed in Carnoy's fluid in the noon. After sufficient fixation, the endosperm was dissected out on glass slides and acetocarmine squash preparations were made. Fixed seeds were also used for serial microtome sections by the routine paraffin method.Observations

Cytology of Endosperm in Oryza sativa L. and O.malampuzhenis Krishn. et Chandr..

“…C-mitosis type of division, endoreduplication, dispersion mitosis and nuclear fusion were the four mechanisms of endopolyploidy reported in the endosperm of angiosperms (Stephen 1980) and in most cases more than one of the above mechanisms may be operative in the same en dosperm.…”

Genome variability of plant somatic cells. 1. Variability during ontogenesis

“…Рассмотрим динамику этого явления на примере формирования нуклеарного эндосперма у некоторых, главным образом, однодольных растений [19,[22][23][24][25][26][27], учитывая при этом, что сходная картина отме чается и у двудольных, в том числе и у тех, у которых эндосперм в зна чительной мере редуцирован, например, у ряда представителей рода Lathyrus [28,29].…”