Cytology of pollen with particular reference to Impatiens and Allieae

From the foregoing accounts, a logical conclusion emerges, that while pollen mitosis cannot replace the cytological studies based on pollen mother-cells and root-tips, more often than not, it forms an excellent adjunct to them. Apart from the study of pollen nitosis there are many other very interesting problems in pollen cytology, about which we have no clear understanding. These pertain mostly to the problems of cytoplasmic gradient and differentiation within the pollen grain

Cytology of conifers. II

Chromosome numbers inPodocarpus falcatus (2n = 24),P. gracilior (n = 12, 2n = 24),P. latifolia (n = 11, 2n = 22) and P. macrophyllus var.Maki (n = 19, 2n = 38) have been recorded. Nothing conclusive can be said as to whether the chromosome number has increased or decreased or both increased and decreased during the course of evolution of the genus

Biosystematics of Indian plants. III. Veronica anagallis complex

Tetraploid and hexaploid races were discovered inV. anagallis Linn. from Kashmir and Punjab plains respectively. There are significant morphological differences between the two races. A cytotaxonomic investigation was, therefore, undertaken. Cytological studies reveal that the polyploid races are, in all probability alloploid in character. In view of their distinct morphological and cytological characteristics and geographical isolation, a consideration of the two races ofV. anagallis complex as two subspecies of the parent species, seems to be justified. However, before this is done, a comparison with the type material of the species needs to be undertaken. The races are geographically isolated. The pattern of distribution is indicative of the fact that the tetraploid prefers colder and northern areas, while the hexaploid is adapted to warmer and southern areas

Chemurgic studies on some diploid and tetraploid grain amaranths

Analytical data on four important species of grain amaranths show that polyploidy, apart from increasing significantly the grain size and weight without much loss of fertility, has generally maintained the nutritive value found at the diploid level. Lysine content is enhanced in polyploid A. edulis and A. caudatus so also the threonine content in the former

Biosystematics of the Sisymbrium irio Complex

S. irio Linn. is a polytypic winter annual which grows throughout the Panjab plains. It occurs in diploid, triploid, tetraploid, hexaploid and octoploid races. All these races get considerably modified in response to varying amounts of moisture and sunlight. The phenotypic plasticity has been studied experimentally using the conventional 'water-light' gardens