Chromosomal alterations in relation to speciation

Cytotaxonomic Studies in Apocynaceae and Delineation of the Different Evolutionary Tendencies Operating within the Family

“…SHARMA (1956) has recently stressed the 'importance of detailed karyotypic study to find out structural changes in the chromosomes, in vegetatively propagated plants where gametic unbalanced conditions are not eliminated. SHARMA and SHARMA (1959) All of them are vegetatively propagated. SHARMA (1956) has emphasised that such altered nuclei play a distinct role in the origin of new types through the formation of daughter shoots.…”

Cytology of Two Members of Campanulaceae and Lobeliaceae and Their Interrelationships

“…It is quite established that polyploidy is often asso ciated with reduction in chromosome length as recorded in a large number of species (vide Stebbins 1950, Sharma andSharma 1959). This reduction has been attributed to several reasons including compact spiralization.…”

Cytological studies in the genus Indigofera L.

“…Singh and Roy (1970) also supported the view that x=8 should be regarded as the primary base number and the other base numbers like x=4, 6, 7 should be considered as derived. Further, it was observed that there is relationship between increase in chromosome number and reduction in chromosome size (Dowrick 1952, Darlington 1955, Sharma and Sharma 1959, Singh and Roy 1970.…”