Volume 87, Issue 5
May 1978, pages 75-160
pp 75-81 May 1978
Two isolates ofAulosira were cultured under uniform laboratory conditions in order to make a taxonomic investigation. The isolates were grown in Chu 10 and biphasic soil water media, and identified using well known manuals. Study of the isolates revealed differential behaviour of the same isolate and identical behaviour of dissimilar isolates in different environments (culture conditions). A revision of the genus is suggested.
pp 83-92 May 1978
The gynoecial development inEnicostemma littorale Blume (Gentianaceae) has been studied. The bicarpellary, syncarpous gynoecium begins its development in an apocarpous fashion. The free carpels of the young gynoecium remain open and resemble those ofMichelia champaca, Polyalthia longifolia andCananga odorata studied earlier. The young carpel exhibits initial abaxial overgrowth followed by expansion of the adaxial surface while the laminai part develops. The marginal meristem continues to be active and proliferates into a much folded structure (the placenta) on which numerous ovules arise. The two carpels fuse by their margins and form the unilocular syncarpous gynoecium with parietal placentation. This postgenital fusion is initiated by the contact of the abaxial protodermal layers of the adjacent margins. The homologies of the carpel and gynoecium are discussed in the light of recent views on the nature of the gynoecium.
pp 93-98 May 1978
The fungusPestalotia palmarum Cooke required light for formation of acervuli in culture. Best fruiting was obtained on Czapek’s agar with yeast extract and under black light. Fruiting could also be induced by daylight fluorescent and incandescent lamps. When cultures were exposed to light for 12 hr fruiting was similar under blue, green, yellow and red filters.
pp 99-104 May 1978
A synnematous hyphomycetePutagraivam sundaram gen. et sp. nov. collected on dead twigs ofMacaranga indica Wight from India is described and illustrated. It is the conidial state of a hypocreaceous fungus.
pp 105-107 May 1978
Lobelia courtallensis K K N Nair sp. nov.(Campanulaceae) is described from Kuttalam, Tamil Nadu state, India with illustrations. The description of the genus is amended to accommodate the new species.
pp 109-112 May 1978
Stomatal chloroplast count technique as a tool to identify the ploidy status was evaluated in species, hybrids and polyploids (natural and induced) involving the A, B and D genomes inGossypium. The differences between group means were significant. Intra group differences were significant for diploids and hexaploids but this was not due to the genomes involved. Thus some varieties of diploids,G. arboreum (A2) were on par withG. raimondii (D5). The percentage increase in chloroplast number per stoma was 25 for triploids, 72 for tetraploids and 102 for hexaploids taking the diploid number as the base. Ploidyper se had great impact on chloroplast number. It appears that stomatal chloroplast count technique can be used as a rapid method to identify polyploids in the genusGossypium.
pp 113-118 May 1978
Twenty species of rust fungi are reported in this paper. Of thesePuccinia fimbristylidis-ferrugineae andUredo setariae-tomentosae are described as new species.Puccinia conclusa Thum.,P. cyperi-tagetiformis (P. Henn.) Kenn, andP. pseudocesatii Cumm. have been recorded for the first time from India.
pp 119-124 May 1978
The paper gives an illustrated account of two new species of the orchid genusCoelogyne Lindl., namely,C. raizadae andC. schultesii.
pp 125-127 May 1978
Clearing can be successfully attained by soaking portions of leaves in a mixture of trichloroacetic acid and phenol (2:1) for 10–15 min at 60° C. These can be stained with writing ink (Chelpark make). The intensity of staining does not change even in permanent preparations. The preparations made as outlined above have been found specially beneficial for studying the morphology of fungi parasitic on leaves.
pp 129-133 May 1978
The variations induced by x-irradiation of seeds ofAbelmoschus esculentus in X1 generation have been studied. Percentage of germination showed a slight increase in treatments at 1 to 3 kR, while at the higher doses there was a gradual decrease in germination. Seedling growth measured at regular intervals of 6 hr up to 96 hr, showed that growth rate was reduced and germination delayed at doses of 8 to 10 kR. Lateral root number and length were not significantly effected by the dosage rate. Total chlorophyll content of leaves was reduced by 50% at 8 kR treatment, while an increased chlorophyll metabolism was observed at doses of 4 and 7 kR. Increasing dose rate caused a gradual decrease in plant height. Early flowering was induced in 8, 9 and 10 kR treatments, while flowering was delayed in the 5 and 6 kR treated samples. Average pod length did not show significant variations between the different dose rates as was also the stomatal index. Increased seed weight was observed in samples treated above 8 kR.
pp 135-139 May 1978
Cellulolytic activity of six fruit-rot fungiH. hawaiiense Bougn,A. tenuis Nees isolated from tomato fruits,H. spiciferum (Bain.) Nicot causing fruit-rot of snake gourd,Curvularia lunata (Wakker) Boed. inciting black rot of banana,Hendersonula toruloidea Nattrass isolated from decaying fruits of apples andPhomopsis mangiferae Ahmad from diseased fruits of mango are investigated for the activity of Cx and c1 enzymes. The fungi differ significantly in their enzyme activity. In general CMC supplemented media are more conducive for enzymatic activity, exceptP. mangiferae which shows maximum activity on Asthana and Hawker’s medium A. None of the organisms under study shows c1 activity.
pp 141-148 May 1978
NaCl induced salinity altered the characteristics of stomata in young safflower plants. The salt treatment affected the cell enlargement resulting in the reduction of the initially high stomatal frequency. The favourable effect of sodium salt was perceptible with 100 mM salt treatment only, with concomitant increase in the succulence of leaf. 50 mM NaCl concentration was not found to be that effective to reduce stomatal density over the control. The pore width decreased with salinity treatment, and rhythm also altered.
pp 149-156 May 1978
The embryology ofFelicia bergeriana O. Hoffm,Conyza stricta Willd. andErigeron bonariensis L. has been studied. The anthers are tetrasporangiate inC. stricta andF. bergeriana and bisporangiate inE. bonariensis. The anther wall consists of epidermis, endothecium, middle layer and tapetum. Binucleate, tetranucleate and 12 nucleate tapetal cells have been observed respectively inE. bonariensis,C. stricta andF. bergeriana. The tapetum forms periplasmodium and endothecial thickenings are formed in all the species studied. Pollen grains are shed at 3 celled stage. The ovule is anatropous, unitegmic and tenuinucellate. The mature embryo sac is 8 nucleate polygonum type in all the species studied. As many as 6 antipodal cells inErigeron bonariensis and 12 inC. stricta are observed due to secondary multiplication. InF. bergeriana the antipodal cells become 2–4 nucleate. The persistence of antipodal tissue and its penetration into chalazal region confirm haustorial nature. The endosperm is nuclear inE. bonariensis andC. stricta and cellular inF. bergeriana. The outer cells of endosperm form jacket layer which persists surrounding the mature embryo. The embryo development is of the Asterad type and resembles the Senecio variation.
pp 157-160 May 1978
The effects of variation in planting times and spacings on the growth behaviour, yield of green herbage and essential oil formation inMentha citrata in the Burdwan District of West Bengal is reported.