Volume 79, Issue 6
June 1974, pages 227-282
pp 227-229 June 1974
pp 230-235 June 1974
The U-shape variation pattern of glycerol-trioleate hydrolase activity during embryonic development ofPhilosamia ricini suggests its maximum activity during initial and final stages of embryogenesis and evinces the marked utilization of lipoidal energy both for development and tissue formation. High lipase activity during the enormous feeding larval period depicts its role in lipid transport to the site of utilization. During prepupal stage the enzymic activity declines and practically becomes nil during larval-pupal transformation. This is subsequently followed by a rise till day 9. After registering the minimum activity on day 13, the enzyme becomes very active after emergence of the adult suggesting the role of triglycerides as fuel for movement.
Fat body lipolytic activity pattern concurs with that for the entire tissue depicting an overall utilization of lipids during rest as well as movement. Thus triglycerides inPhilosamia ricini appear to play the role of an energy regulator during periods of high metabolic demands like oogenesis, development and flight and are transported to the active site under the influence of triglyceride hydrolases to provide the necessary supply of long chain fatty acids. The increase in triglyceride hydrolase activity during development could be correlated with the increase in general metabolic rate.
pp 236-250 June 1974
pp 251-256 June 1974
X-rays apart from inducing changes in morphology, have brought significant changes in the alkaloid content ofRauvolfia serpentina. Treatment with 51 kR proved to be the most suitable dose for the same.
pp 257-266 June 1974
The present study contradicts the observations of Laloraya (1970) about the disappearance of betacyanin or anthocyanin on the differentiation of guard cells from guard cell mother cells accompanied with the appearance of chloroplast pigments in the guard cells. Repeated observations on developing stomata ofCelosia, Coleus andEranthemum show that betacyanin or anthocyanin persists in the guard cells even after their maturation and the appearance of chloroplasts in them. Betacyanin does disappear in the guard cells of the cotyledonary stomata ofCelosia but long after their maturation and the appearance of chloroplasts in them. Anthocyanin is absent in the guard cell mother cells ofCodiaeum, Rhoeo andSetcreasea and in these plants the pigment neither appears nor disappears at any stage of development from the mature guard cells. The ontogeny of the stomata in all these plants is also described.
pp 267-282 June 1974
Morphology and embryology ofSpilanthes acmilla, Murr. has been investigated and its systematic position in the tribe Heliantheae is discussed. Floral parts arise in acropetalous succession. Stamens are four to five in number with bisporangiate anthers. Tapetum is of the plasmodial type. Pollen grains have an echinate exine and are shed at the three celled stage. Endothecium exhibits fibrillar thickenings at the time of anther dehiscence. Ovules are anatropous, unitegmic and tenuinucellate. Embryosac development conforms to the Polygonum type. In a great majority of cases organised embryosac is six celled with only two antipodals. Occasionally the number of antipodals may be three or four. There is a great variety in the nuclear behaviour in the micropylar antipodal in having a secondary multiplication and subsequent fusion resulting in the formation of a polyploid nucleus. Very rarely aposporic uninucleate embryosac-like structures are noticed at the chalazal end of the ovule. These however do not show any influence on the sexual behaviour of the gametophytes.
Fertilisation is porogamous, endosperm isab initio cellular and embryogeny conforms to thesenecio variation of the Asterad type.
In the mature fruit, the wall is five layered with the innermost layer infested with tannin. Endosperm persists as a thin layer adhering to the integument which itself is three layered.