A. RajaSekhar Reddy , C. V. Naidu

Abstract

Azadirachta indica is a typical tropical/sub-tropical plant were used for micropropagation and generation of plantlets from callus cultures. Induction of somaclonal variability in the existing germplasm was another aim. Callus was initiated from young leaves on MS medium supplemented with different concentrations of BA (2 mg/l) and 2,4-D (0.5 mg/l). Organogenesis was achieved by transferring callus on MS medium supplemented with TDZ (3.0 mg/l) and adenine (1.0 mg/l) getting a very high frequency of shoot regeneration 81.3 per cent. Well-grown shoots ischolar_mained easily on MS-half supplemented with IBA +IAA (2.0+0.5 mg/l) and 80-90% ischolar_maining was achieved. Plantlets got hardened by keeping them in hardening unit for few days. Hardened plants established very well in the nursery. Though originated from callus, these plants did not show any morphological variations and were similar to their parent donar plant. Histological study revealed that regeneration took place through denovo merestemoid formation.

Keywords

Callus Induction, Regeneration, In-vitro, Azadirachta indica

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G. Rajendrudu , C. V. Naidu

Abstract

Teak (Tectona grandis L.f.) is the most important timber yielding tree of the Indian Peninsula and has got world wide reputation due to its high grade timber quality. With ever increasing demand for its timber, it has become the need to expand Teak plantations even in regions outside its natural occurrence. Thus in recent times, Teak is being planted on commercial scale both in agricultural and marginal lands. The success of Teak cultivation greatly depends on the productivity of Teak trees which in turn is determined by the magnitude of their annual growth. Teak is a tropical deciduous tree and apparently exhibits seasonal variations in growth. Generally Teak trees remain leafless in winter and become dormant in their growth. Further, they also become leafless or exhibit dry nature of foliage during dry spells in summer and show apparent decrease in growth. Such seasonal variation in growth often observed in Teak is a result of interaction of its physiological processes with the environmental factors. Knowledge of shoot growth in Teak and the mechanism of its regulation by internal and environmental factors is most important to understand key factors underlying seasonal variations in their shoot growth. Therefore, this paper is intended to explain briefly the regulation of shoot growth by internal and environmental factors and further, to explain possibilities to induce shoot growth during dormancy periods for the benefit of those growing Teak and also for the expansion of forestry and agroforestry.

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C. V. Naidu , P. M. Swamy

Abstract

Leaf Relative Water Content (LRWC) and biomass production were estimated at monthly intervals in seven deciduous forest tree species for a period of one year starting from June, 1990 to May, 1991. The leaves of all the seven tree species showed significantly higher leaf relative water content during winter than in summer. Leaf relative water content showed marked seasonal variations and these differed from one plant species to the other. A significant positive correlation (r² = 0.79) was found between leaf relative water content and biomass production in all the seven deciduous forest tree species studied. The results of the present study indicate that measurement of leaf relative water content could be used as simple screening method for selecting the right type of tree species for energy plantations.

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C. V. Naidu , P. M. Swamy

Abstract

Seasonal changes in the growth rates of seven tree saplings were studied for a period of one year. Maximum leaf area, number of branches, stem girth, shoot and ischolar_main length were observed in the winter season in all the seven tree species. The growth rates showed month to month and species to species variations.

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C. V. Naidu , P. M. Swamy

Abstract

Deoiled seed cakes of B. latifoila, P. glabra, A. indica and R. communis were applied as fertiliser to the saplings of Terminalia bellerica. The treatment of all the four deoiled seed cakes caused better growth response compared to that of control. Among the four deoiled seed cakes the best growth and biomass production was observed with B. latifolia seed oil cake.

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