Volume 95, Issue 5
December 1985, pages 291-356
pp 291-294 December 1985
The anther development confirms to the dicotyledonous type. The tapetal cells are binucleate, glandular and dimorphic. The pollen tetrads are tetrahedral and decussate. The pollen grains are shed at 2-celled stage. The development of embryo sac is of the polygonum type. A weak hypostase is present. The micropylar haustorium develops lateral diverticulum. The endosperm isab initio cellular and its development conforms to ‘stachys type’. The embryo development follows Mentha variation of onagrad type. The seed coat is 1-layered. The pericarp consists of 3 zones. The outer epidermis is non-mucilagenous. At maturity, the hypodermal layer of inner epidermis forms the main protective layer. Seed is endospermic.
pp 295-301 December 1985
Young seedlings have two independent vascular systems which subsequently get fused with each other. The cambium originates in the form of patches in the pericycle of the root on 6th day of its growth inAmaranthus caudatus and on 10th inAchyranthes aspera. Later on, a complete ring is formed within the pericycle which subsequently differentiates acropetally and basipetally in the hypocotyl and root. This cambium is short-lived, bidirectional and has no relation with the fasicular cambial strips of differentiating vascular bundles. Successive cambia, originated from the innermost cells of the cortex, are also bidirectional in activity and have short span of life.
pp 303-307 December 1985
Cololejeunea furcilobulata has been discovered recently from South Indian territory (Kerala and Karnataka) which extends its range of distribution from Africa (Nigeria) to Asia. The Indian population shows a wide range of habitats as the plants may be corticolous, foliicolous and rupicolous. The taxon is characterised by somewhat ovate leaf with thin-walled leaf-cells devoid of trigones, biciliate lobule having undivided basal portion (inflated lobule also present often at base), autoecious as well as paroecious sexuality and compressed 5 plicate perianth.
pp 309-314 December 1985
Structure and distribution patterns of the trichomes occurring on the standard petals in 8 species ofIndigofera L. have been investigated. In all, 4 trichome types exhibiting 7 distribution patterns have been recognised. Their taxonomic significance has been shown by providing a key for the identification of the species studied.
pp 315-320 December 1985
Nitrogen-fixing cyanobacteria act as fertilizer plants providing nitrogenin situ for rice paddies. The filamentous heterocystous cyanobacteriaWestiellopsis iyengarii Jeeji Bai andMastigocladus laminosus Cohn are potential biofertilizers in the tropical region. Results presented in this paper show that combined nitrogen does not have any beneficial effect on the growth of bothWestiellopsis iyengarii andMastigocladus laminosus. While in the former this retardation in growth is seen in spite of an increase in pigmentation, proteins and photosynthesis, in the latter, the decrease in growth appears to be a direct consequence of the lowering in the cellular content of pigments and proteins.
pp 321-331 December 1985
With an increasing interest in the use of selected fungi for the production of sheathing (ecto-) mycorrhizas by controlled inoculations, attempts were made to identify collections ofLaccaria fruitbodies from woodland and forest sites in central Scotland and at high altitudes in southern India.
Although the sizes of individual fruitbodies within collections varied appreciably, it was nonetheless possible to sort the collections into 2 groups using mean sizes: one group with (i) stipes (stalks) about 7 mm long and 1 mm diam. and (ii) pilei (caps) 10 mm diam., and a second group with appreciably larger fruitbodies.
The group of larger fruitbodies was found to contain collections with either 2- or 4-spored basidia; the basidia in the group of small fruitbodies were all 2-spored.
Although of similar sizes, spores of the 4-spored specimens had different shapes as judged by the ratios (Q values) of spore length: spore width, separately assessed for each spore with its apiculus in view. They were either globose (Q=1·01) with 8·6 spines per 9 μm2, each spine being on average 1·01 μm tall—a description conforming toLaccaria laccata (Scop.: Fr.) Bk. and Br- or elliptical (Q=1·20) with 16·3 spines per 9 μm2, each spine being only 0·72 μm tall—a description conforming toLaccaria proxima (Boud.) Pat.
The spores of the group of large fruitbodies with 2-spored basidia were globose, like those ofLaccaria laccata, but slightly larger and with more spines per unit area, 11·3 per 9 μm2, a description conforming toLaccaria ohiensis (Mont.) Sing. The spores of the group of small fruitbodies with 2-spored basidia were similarly globose but, in contrast, were appreciably larger, 10·1×9·6 μm (compared with 6·3×6·3 μm forL. laccata), with taller (1·91 μm) and fewer spines, 4·2 per 9 μm2, a description conforming toLaccaria tortilis (Bolt.) S. F. Gray.
Laccaria laccata, Laccaria proxima andLaccaria tortilis were collected in Scotland;Laccaria proxima andLaccaria ohiensis in India. Contrary to expectationLaccaria laccata was found less frequently thanLaccaria proxima, the fruitbodies of both being sometimes outnumbered by those ofLaccaria tortilis in young stands ofBetula spp.
pp 333-340 December 1985
Net photosynthesis rate, ribulose-1,5-bisphosphate carboxylase activity, ribulose-1,5-bisphosphate carboxylase protein and total chlorophyll content in leaves which subtend the pods vis-a-vis the pattern of pod, podwall and seed growth were analyzed in chick pea. Three sets of plants namely control, deflowered and depodded were maintained. Accompanying the initiation of pod development in control plants, there was a decline in these photosynthetic characteristics in leaves of control as well as deflowered plants. The senescence rate was higher in control plants compared to plants from which flowers or pods had been removed. The early pod growth which was mainly constituted by podwall growth, was accompanied by a higher decline in leaf net photosynthesis rate. Ribulose-1,5-bisphosphate carboxylase activity and ribulose-1,5-bisphosphate carboxylase protein decreased predominantly at the later stage of pod growth, which was mainly constituted by higher seed growth. Loss of chlorophyll was also higher at later stages of pod growth. It is suggested that both nutrient remobilization and hormonal action are probably involved during monocarpic senescence in chick pea.
pp 341-347 December 1985
A pot experiment was conducted in a green house with soybean (cultivar lee) as a test crop to study the response of applied molybdenum in some acid soils. A significant increase in grain yield and molybdenum uptake by soybean grains was observed with increasing doses of applied molybdenum. The interaction effect of soils×molybdenum treatments on the uptake of molybdenum and grain yield was also found significant. The studies further revealed that molybdenum response could be obtained at available soil molybdenum levels ranging from 0·025–0·290 ppm. The results further revealed that in most of the soils under study the interaction of soil factors namely pH, low available and total molybdenum, and texture may be the contributing factors to yield response of soybean to applied molybdenum.
pp 349-356 December 1985
Zonation in the shoot apex ofMatthiola incana was studied histochemically from the mature embryo to flowering. The plumular apex of the mature embryo shows a single-layered tunica covering a homogeneous mass of cells. The first evidence of zonation is seen in the shoot apex of the 2-day old seedling. Zonation is well established on the fourth day after seed wetting with a single-layered tunica covering a lightly stained central mother cell zone, a subjacent pith meristem and a densely stained peripheral zone. In the transitional apex zonation is less marked and there is increased stratification. At 6-weeks, the apex changes into the indeterminate inflorescence apex showing acropetally developing floral primordia. The axially located cells of the inflorescence apex are lightly stained. The histological and histochemical data indicate that zonation resembling that in the vegetative apex is retained to a lesser degree in the inflorescence apex as well.