Seasonal variation in the elemental composition of Gracilaria species of the Gulf of Mannar, Tamil Nadu coast

Seasonal variation of the different cations such as Sodium (Na+) , Potassium (K+), Magnesium (Mg++), Calcium (Ca++) and Iron (Fe++) was analysed in three species of Gracilaria of Gulf of Mannar from August, 1994 to July, 1995. Significant interspecific variation in the elemental composition was observed. G.crassa showed higher concentration of Magnesium, Calcium and Iron whereas Sodium and Potassium dominated in G.edulis. Accumulation of cation content was high during March in G.crassa

Nutrient Dynamics and Inventory in Tropical Grassland Ecosystem in Southern India

The present study was to ascertain the distribution of calcium (Ca), magnesium (Mg) and sodium (Na) in the different plant components and in the soil top 30 cm at Kalikesam in Western Ghats region of southern India. Magnesium concentration increased in the order: dead shoots \u3e belowground \u3e litter \u3e aboveground live. Sodium concentration in live shoots was maximum in February (0.51%) and minimum in August (0.05%). Annually 8.94 g/m2 Ca, 2.41g/ m2 Mg and 2.30g/ m2 Na was taken up by plants. The distribution of the three nutrients in plant/soil system indicated that the major portion of the nutrients in the system was retained in the soil, while small fraction of it stayed in plant components. Less than 0.4% of Mg entered the vegetation. Ca and Na entered 16% and 6% respectively

Nutrient Cycling in a Tropical Grazing Land Ecosystem of Southern India

The nutrient component of any ecosystem operates in a dynamic state through a series of inputs and outputs of the essential elements. Nutrients from plants are continuously transferred to soil via litter formation, which act as a reservoir for the plants in an ecosystem. Most of the studies on nutrient budgets and flux rates have been reported in forest communities and to a lesser degree in grassland. The present study was, therefore, aims to understand the variation of calcium (Ca) and magnesium (Mg) in the vegetation compartments and to quantify annual budget by estimating the annual uptake from soil and its release to soil

In vitro plant regeneration of red sanders (Pterocarpus santalinus L.f.) from cotyledonary nodes

541-546A reliable and efficient micropropagation protocol was developed through axillary shoot proliferation from cotyledonary nodes of Pterocarpus santalinus. Cotyledonary nodes showed significantly (P<0.05) higher shoot multiplication rate and shoot length than leaf nodes on MS medium with 2.5 μM BAP and 2 μM 2-iP after first subculture (i.e. in the second harvest). For rooting, dipping of microshoots in 5 μM IAA solution proved superior to other in vitro methods. Of the various hardening media used for the acclimatization of rooted plants, a mixture of coarse sand, clay and farmyard manure (1:1:1) (v/v) supported the maximum percentage of survival (95%). There were no significant differences between the in vitro regenerated plants and seedlings of the same age for all the growth parameters measured (i.e. mean plant height, number of leaves per plant, fresh weight and dry weight of leaves, shoot and root per plant) four months after transfer to ex vitro conditions