Volume 91, Issue 6
December 1982, pages 473-599
pp 473-478 December 1982
The floral anatomy ofPuya spathacea Mez. is described in detail. The outer floral whorls are united to develop a short hypanthium which is adnate to the base of the ovary. The sepals are five-traced and the petals, three-traced. The placentation is axile. The occurrence of numerous ovules in more than two rows as well as the extension of the carpellary ventrals into the style are less advanced features. The ovarian nectary is extensively developed and shows a transition between typical septal and epigynous nectaries of certain monocotyledonous taxa.
pp 479-486 December 1982
Cytological studies have been made on 19 species of Acanthaceae from Pachmarhi hills in Central India. Present studies reveal the first count of chromosome numbers for four species, namely,Dyschoriste depressa Nees,n=30;Lepidagathis fasciculata Nees,n=10;L. hyalina Nees,n=10 andJusticia diffusa Willd. var.prostrata Roxb.,n=9. New cytotypes have been located in three species asHemigraphis latebrosa Nees,n=28 (4x);Rungia parviflora Nees,n=13 (2x) andR. pectinata Nees,n=13 (2x). Diploid cytotypes of three species,viz., Blepharis maderaspatensis (Linn.) Roth,n=15;Justicia betonica Linn.,n=17 andThunbergia alata Bojer ex. Sims,n=9 have been detected for the first time from India. An analysis of the worked out species reveals the existence of only 10·53% polyploid species.
pp 487-493 December 1982
The heterotrophic bacterial population associated with seaweeds (Enteromorpha sp.,Chaetomorpha sp. andHypnea sp.) and water of the Vellar Estuary, Porto Novo, were estimated. Total heterotrophic bacteria associated with the seaweeds were found to be more abundant than in water samples. Representative cultures were isolated and their morphological and biochemical characteristics were studied. In addition, production of amylase, lipase and proteinase of the isolates was also studied.Bacillus, Corynebacterium, Vibrio, Alcaligenes andPseudomonas were the genera commonly encountered. The role of these bacteria associated with seaweeds is discussed.
pp 495-500 December 1982
The photosynthetically efficientC4 plantsviz Amaranthus viridis, Euphorbia hirta and aC3 plant,Acalypha indica with mosaic leaf pattern showed the maximum amount ofB vitamins when compared to the otherC3 plants. It is observed that photosynthesis and vitamin synthesis go hand-in-hand showing close correlation. The results also indicate that there is a close relation between chlorophyll content and vitamin content. However, there appears to be no relation between phyllotaxy and photosynthesis. Between the twoC3 plants,viz., Acalypha andCarica, the photosynthetic inefficiency of the latter might be due to more of chlorophyllb and less of chlorophylla as seen from chlorophylla/chlorophyllb ratios.
pp 501-508 December 1982
Application of morphactin,AMO-1618 andDPX-1840 to 20 day old plants of soybean caused the sprouting of almost all lateral buds. However, the follow-up growth of newly ensued buds was manifested only with morphactin and not withAMO-1618 orDPX-1840. The quantitative estimations of growth promoters, carried out 20 days after the application of inhibitors, revealed that the possible mechanism through which these substances exerted their influence on apical dominance varied with the type of regulator. It appeared that morphactin lifted the apical dominance mainly through the increase in endogenous levels of cytokinin and partly through lowering the levels of auxins.AMO-1618 checked the gibberellin turnover whiledpx-1840 suppressed significantly the levels of auxins. The data show that apical dominance and not the subsequent growth of newly evocated buds is regulated by the ratio of cytokinins (CK) to auxins (Au) plus gibberellins (GA) and any factor(s) which enhance(s)CK (like morphactin) or suppress(es)GA (likeAMO-1618) or Au (likeDPX-1840 or morphactin) would play a key role in the abolition of apical dominance.
pp 509-517 December 1982
InThespesia lampas andT. populnea, the foliar stomata are anisocytic, anomocytic and tetracytic, the first type being dominant. Further inThespesia lampas andT. populnea altogether eight trichome types are recognisable mostly on the basis of structure. The two species can be distinguished from each other by the presence of multiseriate aseptate stellate hair in the former and that of multiseriate aseptate peltate hair in the latter.T. populnea is also distinct from that ofT. lampas due to curved to wavy epidermal walls, striated surface, absence of mucilaginous cells on the leaf abaxial. The present evidence also supports treatment ofT. lampas underThespesia rather than inHibiscus.
pp 519-527 December 1982
The ovule is anatropous, unitegmic and tenuinucellate. Their funicular vascular strands extend almost to the base of the ovule. A large hypordermal archespoial cell functions directly as the megaspore mother cell. It divides to form a linear tetrad. The upper three megaspores degenerate while the chalazal develops into an 8-nucleate embryo sac of the Polygonum type. Endothelium differentiates at the megaspore tetrad stage. Fertilization is porogamous. Syngamy and triple fusion take place almost simultaneously. The endosperm is nuclear but it becomes cellular subsequently. The embryo is theSenecio variation of Asterad type. Occurrence of polyembryony has been recorded only in one ovule.
pp 529-549 December 1982
The structure of forests occurring within the north-western catchment of the river Gola in Kumaun Himalaya is quantitatively described. All the forestt indicated a total of four strata; two upper strata represented by trees, the third stratum represented mainly by shrubs, and the fourth of herbs. The tree heighs of theA2 (top most) stratum decreased with an increase in altitude. On the other hand, the proportion of trees devoted to the canopy in theA1 andA2 strata increased with an increase in altitude. In all forests, the crowns of theA1 andA2 strata were more deep than wide. In general, the shrub layer in three oak forests was comparatively dense and the crowns of the shrubs overlapped with each other. The canopy index, a relative measure of canopy coverage, of tree and shrub layers was maximum forQuercus floribunda forest and minimum forPinus roxburghii forest. Further, the cooler aspects developed a greater canopy index for these layers as compared to the warmer aspects. Oak forests exhibited a poor development of their herb layers. The trees in theQuercus lanuginosa forest weere more stable, while inPinus roxburghii forest they were specially susceptible to wind effect. In general the warmer aspects had more stable trees, while the cooler aspects showed a lower tree stability. The different forest types, presently studied, could be graded, as follows, in a decreasing order of potential for soil protection:Quercus floribunda > Quercus leucotrichophora > Quercus lanuginosa > mixed >Pinus roxburghii.
pp 551-599 December 1982
An account of 29 taxa comprising 24 species and five varieties of the genusEuglena collected from various localities in north-east, central and south India during 1937–76 is given. Of these, two,viz., E. vaginicola andE. pseudoehrenbergii have been considered as new species, one,viz., E. viridis var.maxima a new variety and one,viz., E. tuba var.pseudotuba f.minima a new form of a new combination variety. Four species,viz., E. vagans, E. helicoideus, E. granulata andE. hemichromata and three varieties,viz., E. tripteris var.klebsii, E. oxyuris var.playfairii andE. caudata var.minor appear to be new records for the Indian region.
By studying the taxa from different ecological habitats it is shown that there is considerable variation within species inE. acus andE. tuba and to a limited extent inE. oxyuris. SinceE. ehrenbergii as known at present is a composite species,E. srinagari has been separated from it, following Huber-Pestalozzi in this respect.
E. tuba Carter which had been incompletely known so far and considered by most authors as doubtful, was studied in detail and shown to be a well defined species needing an emended description.E. tuba johnson, which shows some essential differences from Carter’s species, is treated as a variety ofE. tuba, viz., var.pseudotuba with an Indian form which is new. There is also a possibility of polymorphism inE. tuba.
Meteorological and water conditions under which some of the species dominated are given. It is also shown that some species are characteristic of particular habitats.
The need to give all relevant details including proper illustrations while describing the taxa of this difficult genus is stressed. The author has made an attempt to fill the, gaps in existing descriptions of the Indian taxa given in this paper to help in proper identifications. A key to these taxa is also given.
A list of 29 other species reported from India by other workers is given with references and localities.