Volume 33, Issue 5
May 1951, pages 231-295
pp 231-256 May 1951
pp 257-267 May 1951
pp 268-276 May 1951
A general study of the lipase obtained from different oil seeds is made.
The optimum pH changes to a very small extent with the nature of the substrate and it does not change much with the nature of the buffer. Castor and groundnut lipases are the best active; groundnut oil is the best substrate and sodium acetate-acetic acid is the best buffer.
The optimum buffer concentration is 1–2 c.c.; the optimum substrate concentration is 1–2 c.c. and the optimum temperature is 35–37° C. depending upon the nature of the lipase.
The percentage hydrolysis of the oil goes on increasing with the enzyme concentration.
Organic substances like glycine, gum arabic and sodium taurocholate and inorganic salt MnSO4 accelerate the activity of the lipase.
The acetone dried sample of the lipase keeps its activity fairly constant for an appreciably long time.
pp 277-281 May 1951
Rapid germination, better growth and higher yield is obtained from apical sets. Vertical sets prove slightly inferior; the difference, however, is too small to claim much significance. Basal sets show poor performance and are likely to cause ‘missing hills’ in the field.
It is concluded that when planting is intended with cut pieces, sets should be prepared by cutting the seed tubers longitudinally, from the budend towards the stem-end, in order to include in each piece a part of the bud-end also.
pp 282-287 May 1951
In the process of nitrification both air and moisture play a very important role and it is only after a proper adjustment of these that a good fixation can be obtained. Sandy soils that provide a good aeration due to large non-capillary pore space, should be regarded as best for nitrification, yet they allow greatest leaching and no retention of water, thereby loosing all their nitrogen contents very easily. Finer soils that provide lesser amount of air, but proportionate retention of water in them are best fitted for nitrogen fixation. They also provide greater surface for reaction. More finer soils are impervious to oxygen supply and as such are not well suited for rapid nitrogen fixation. These soils are slow in action.
Only a medium is needed for a proper and rapid fixation of nitrogen. All these different soil conditions can be improved very easily with the application of different manures, e.g., green manure in clay soils, and carbonaceous matter in sandy ones.
pp 288-289 May 1951
pp 290-295 May 1951
The primary archesporial cell directly functions as the megaspore mother cell. Megasporogenesis proceeds normally and the embryo-sac conforms to the Polygonum type. Antipodals are formed as definite cells and persist for some time. At the mature embryo-sac stage the nucellus becomes characteristically differentiated.
Endosperm is free nuclear to start with. Later it becomes cellular.
The development of the embryo has been followed in detail and broadly corresponds to the Solanad type of Johansen (1945).