Volume 67, Issue 4
April 1968, pages 141-194
pp 141-147 April 1968
pp 148-156 April 1968
An account of sporogeneses, development of gametophytes, endosperm and embryo inEriocaulon quinquangulare Linn. is presented.
The unisexual flowers are borne on a terminal globose head. The development of floral parts is acropetal.
The hypodermal archesporium in an anther is one to two-celled. The wall of the mature anther is four-layered; the innermost of these layers functions as the glandular tapetum. The microspore tetrads are of isobilateral and decussate type. A well-developed stomium is present. The pollen grains are generally shed at two-celled stage.
The tenuinucellar ovules are bitegminal and pendulous. The primary archesporium is hypodermal and functions directly as the megasporocyte. The megaspore tetrads are of linear, obliquely linear and T-shaped type. The chalazal megaspore is functional and develops into a Polygonum type of embryo-sac. The antipodals form the most conspicuous part of the embryo-sac and are linear in arrangement.
Endosperm is free nuclear and becomes cellular later. Embryo development is of Asterad type.
pp 157-164 April 1968
The present investigation deals with the epidermal structure and development of stomata for seven species of Oleaceae. The epidermal cells are either polygonal isodiametric or elongated in various directions and irregularly arranged. The anticlinal walls are thick, mostly straight, rarely sinuous. The surface of the cuticle shows parallel or corrugated striations. The mature stomata are anomocytic, perigenous and paracytic. In some cases the stomata with a single subsidiary cell have also been observed. The development of the paracytic and the stomata with a single subsidiary cell is mesogenous. The retention ofNyctanthes arbortristis Linn. in the Oleaceae is also substantiated by the study of stomatal development.
pp 165-173 April 1968
The present paper is the second contribution to the embryology of genusPhoenix L. The development of inflorescences, anthers, ovules, female gametophyte, endosperm and embryo was studied and the results obtained are given in this paper. Previous literature and methods followed have been given in the paper dealing with the embryology ofP. sylvestris (Proc. Ind. Acad. Sci., 1968,67 B, 77–96) and hence are not repeated here. The embryo-sac is of the monosporic octonucleatePolygonum type and embryo development follows theGeum variation of the Asterad type. The embryology in these three species thus broadly agrees with that inP. sylvestris.
pp 174-179 April 1968
The occurrence of some nickel silicate minerals as encrustations along joint planes and shear zones of the chromite bearing ultrabasic rocks of Nuggihalli schist belt is described. Chemical and X-ray study shows besides amorphous nickel silicate, the presence of granierite, nepouite or nickel antigorite. The nickel minerals are secondary developed by the action of circulating waters. The source of nickel is olivine, in the structure of which Ni is known to be present, either as camouflaged or captured ion.
pp 180-186 April 1968
The degree of heterosis as expressed in respect of grain yield and eight other related quantitative traits (length and diameter of peduncle, surface area of primary ear, density of grain, yield of primary ear, plant height, tillering capacity and yield of straw) as compared to the value of mid-parent, the higher parent of the cross and the best of the lot studied was estimated for all the hybrids of a ten-parent pearl millet diallel cross. The percentage frequency of hybrids with significant heterosis was calculated for all the characters. Parents capable of producing highly heterotic hybrids were marked out.
The four parents which were outstanding in their ability to produce highly heterotic hybrids belong to different geographical regions. Only the vegetative characters,viz., length of peduncle, plant height and yield of straw exhibited marked reciprocal differences.
pp 187-194 April 1968
A complete diallel cross study of ten pearl millet inbred parents was used to estimate g.c.a. and s.c.a. for grain yield and eight other related characters (length and diameter of peduncle, surface area of primary ear, density of grain, yield of primary ear, plant height, tillering capacity and yield of straw). General combining ability effects were of a lesser order than those of s.c.a. for most of the characters studied. Highly significant s.c.a. effects for many characters point to the immense practical value of utilising the same in the exploitation of heterosis. Lines with superior g.c.a. and hybrids manifesting outstanding s.c.a. in respect of each character could be marked out.