Volume 61, Issue 3
March 1965, pages 125-179
pp 125-128 March 1965
pp 129-134 March 1965
pp 135-141 March 1965
“Gibberellic acid (GA3) solutions (10–200 p.p.m.) when sprayed onMentha arvensis Linn. var.piperascens at preflowering stage induces 30–50 per cent. increase in the yield of total herb. Apart from the elongation of internode, the leaf area was also increased. The stage of development of the plant at the time of treatment, appeared to be a significant factor in obtaining favourable Gibberellin effects. Pre-soaking of the suckers in GA solution induced early sprouting. Essential oil obtained from the treated leaves, however, decreased by 5–15 per cent. but had no deleterious effect on menthol contents.”Mentha arvensis Linn. var.piperascens (Japanese mint) which has been introduced in India by the Regional Research Laboratory, Jammu, is now fairly well established for commercial exploitation of natural Menthol. During the course of investigation on the influence of Gibberellic Acid (GA) on various aromatic plants, the authors studied its effect on the growth, volatile oil and Menthol contents of this mint.
pp 142-146 March 1965
pp 147-159 March 1965
In this paper vegetative anatomy and vascular anatomy of the flower of three species ofAponogeton, A. natans, A. crispum, andA. distachyon, have been described.
Although the flowers ofAponogeton are trimerous, there are present only two perianth segments placed anterolaterally inA. natans andA. crispum and only one spathaceous bract-like perianth segment subtending the flower ofA. distachyon. It has been presumed that the two and one perianth segments have been produced about by reduction. Sometimes the perianth ofA. distachyon shows bifacial anatomy which appears to indicate its phyllodic nature.
The carpels of all the three species ofAponogeton investigated are basally and adaxially connate for some distance. In the basal region of the ovary the placentation is anatomically axile, however, in the upper region individual carpels show marginal placentation. The carpels are open in young condition and thus they show some resemblance with the primitive ranalian carpels.
The vascular supply of each carpel consists of a carpellary dorsal and two ventral bundles, inA. distachyon some additional lateral bundles are also seen.
The present study also substantiates the placing of Aponogetonaceae close to Scheuchzeriaceae.
pp 160-163 March 1965
pp 164-169 March 1965
An account of the nitrogen-fixing capacity, extra-cellular N liberated and total organic matter produced by the blue-green algaAnabaena circinalis Rabh. is given. Studies indicate that N fixed as well as organic matter produced are more under conditions as near to nature as possible. It is suggested that the blue-green algae could be best exploited for enrichment of the soil by conditioning the soil for the manifestation ofthe indigenous flora and/or for knownintroduced forms. Owing to the action of these algae in the building up of the fertility of the soil, the possibility of an economic schedule of growing crops in succession is indicated leading to beneficial results.
pp 170-179 March 1965
A review of the literature on the fossil records of Musaceae shows that many fossil fragments of leaves have been referred to this family asMusophyllum spp. and some asHeliconia spp. It has been shown that there is little justification for naming the American banana-like fossil leaves asHeliconia spp.
As regardsMusa andEnsete, their only definite fossil records areMusa cardiosperma Jain andEnsete enseteformis (Berry) Jain respectively. In the light of the fossil records, the maintenance ofEnsete as a genus distinct fromMusa L. has been supported. Further, a study of the past and present-day distributingMusa L. has shown that the Central India must have been a part of the native home of this genus. In the light of fossil evidence the problem of nativity ofEnsete has also been discussed.