Kinetics of Oxidation of Methyl Orange & Methyl Red by V(V)*

16-1

Seaweed resources of the Tuticorin-Tiruchendur coast, Tamil Nadu, India

The southern coast of Tamil Nadu (Mandapam to Kanyakumari) supports luxuriant growth of economic seaweeds. The entire indigenous phycocoUoid industry of the country gets the raw material from this region and during the last two decades, due to indiscriminate harvesting, there has been over-exploitation of the resource. The present paper deals with survey conducted in the first sector from Tuticorin to Tiruchendur during December 1986—March 1987. In this study 58 species of marine algae were recorded of which 7 belong to Chlorophyta, 12 to Phaeophyta and 39 to Rhodophyta besides 3 species of seagrasses namely Cymodocea seiriilata, Halophila ovalis and //. ovata within 650 sq. km area surveyed. The total standing crop of the seaweeds was estimated at 9,100 tonnes (wt.). The estimates for the dominant species are Dictyota maxima 530 t, Sargassum tenerrium 640 t, D. bartayresiana 8601, Selieria rebusta 2,0901 and Hypnea valemiae 2,4301. The seaweed potential for commercial exploitation has been briefly discussed

Genetic Resistance of Pearl Millet Male-Sterile Lines to Diverse Indian Pathotypes of Sclerospora graminicola

Single-cross F1 hybrid cultivars based on cytoplasmic-nuclear male-sterility (CMS) system have contributed significantly to increasing productivity of pearl millet (Pennisetum glaucum). Genetic resistance to downy mildew (Sclerospora graminicola) in parental lines is critical for successful commercial cultivation of a hybrid cultivar. In this study, 46 genetically diverse male-sterile lines (A-lines), including 42 test A-lines, four control A-lines, a commercial hybrid, and a highly susceptible line, were evaluated in disease nurseries at four diverse locations in India and compared with pathotype isolates from the same locations under greenhouse environments. Variability in downy mildew incidence (0 to 100%) due to genetic differences among lines, among pathotypes, and that due to line × pathotype interaction were all highly significant (P < 0.001). In the field experiment, eight of the 42 test A-lines, including 841A (control), that recorded ≤10% disease incidence, were identified as resistant compared with 84 to 100% incidence on the control susceptible line 7042S. Resistance in eight of these test A-lines (863A, ICMA 88004, -94333, -98222, -98111, -92777, and -96666) and 841A was confirmed against the four pathotypes in greenhouse experiments. Cluster analysis of downy mildew incidence data from field and greenhouse experiments, using the Euclidian distance, classified the 48 lines into four distinct groups with the above eight A-lines in the resistant group. These resistant A-lines would be useful in the development of F1 hybrids with stable resistance to diverse pathotypes of downy mildew in India

Distribution of sea weeds off Kattapadu - Tiruchendur coast, Tamil nadu

The present paper deals with the distribution of seaweeds and seagrasses during the deep sea survey conducted in the first sector from Kattapadu to Tiruchendur in Tamil Nadu coast between December 1986 and March 1987 covering an area of 650 sq.km. In thiS survey. 58 species of marine algae \\ere recorded. of which 7 belong to Chlorophyta. 12 to Phaeophyta and 39 to Rhodophyta. Three species of seagrasses vi z. Cymodocea serrl/lata. Halophila ovails and H. ovala were also recorded at the depths ranging from 5.5 to 21.5 III Halim eda macroloba, D,ClyOIO barlayresiana, D. Maxima, Gracliaria corl/cala var. corlicala, G. edulis, Sarcodia indica, Sarconema filiform e, Soliena rob"sla, flypnea esperi and H. "alenliae were found to be dominant and widely distributed. Hydrological data were also collected from area surveyed. The atmospheric and bottom water temperature varied from 25.0 to 36.8'C and 26.0 to 31.8'C respectively. The pH ranged from 8.3 to 8.6 and the salinity from 26.39 to 33.430/00 . The dissolved oxygen ranged from 3A2 to 6.47 mill. The phosphate content varied from 0.05 to 0. 15 I'g atm/ l, silicate from 4.00 to 12.00 I'g atmll, nitrate from 0.25 to 1.00 I'g at mil and nitrite from 1.05 to 3.99 I'g atml l

Geographic distribution of basic and intermediate races in the world collection of sorghum germplasm

The sorghum germplasm collection at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) is reviewed. The characteristics of the five basic races of sorghum, (bicolor, guinea, caudatum, kafir and durra) are described, and their usage discussed. The geographical distribution of the five basic races and ten intermediate races is tabulated by country. This shows that racial divergence in sorghum is related to geographic origin. The genebank at ICRISAT currently conserves 36?774 accessions from ninety countries with the basic races durra, caudatum and guinea representing 21.8, 20.9 and 13.4% of the collection, respectively

Seaweed resources off Tamil Nadu coast: Sector II. Alanthali - Manapad and Vembar – Nallathanni Thivu

The seaweeds are used for the production of polysaccharides such as agar, algin, carragennan and they are harvested from intertidal regions along the southeast shores of India. The resource potential from intertidal regions was estimated (Anon 1978

BOBMEX: the Bay of Bengal monsoon experiment

The first observational experiment under the Indian Climate Research Programme, called the Bay of Bengal Monsoon Experiment (BOBMEX), was carried out during July-August 1999. BOBMEX was aimed at measurements of important variables of the atmosphere, ocean, and their interface to gain deeper insight into some of the processes that govern the variability of organized convection over the bay. Simultaneous time series observations were carried out in the northern and southern Bay of Bengal from ships and moored buoys. About 80 scientists from 15 different institutions in India collaborated during BOBMEX to make observations in most-hostile conditions of the raging monsoon. In this paper, the objectives and the design of BOBMEX are described and some initial results presented. During the BOBMEX field phase there were several active spells of convection over the bay, separated by weak spells. Observation with high-resolution radiosondes, launched for the first time over the northern bay, showed that the magnitudes of the convective available potential energy (CAPE) and the convective inhibition energy were comparable to those for the atmosphere over the west Pacific warm pool. CAPE decreased by 2-3 kJ kg-1 following convection, and recovered in a time period of 1-2 days. The surface wind speed was generally higher than 8 m s-1. The thermohaline structure as well as its time evolution during the BOBMEX field phase were found to be different in the northern bay than in the southern bay. Over both the regions, the SST decreased during rain events and increased in cloud-free conditions. Over the season as a whole, the upper-layer salinity decreased for the north bay and increased for the south bay. The variation in SST during 1999 was found to be of smaller amplitude than in 1998. Further analysis of the surface fluxes and currents is expected to give insight into the nature of coupling