Bio-accumulation and metabolic effects of zinc on marine fouling dreissinid bivalve,Mytilopsis sallei (Recluz)

Zinc (Zn) toxicity to a marine fouling dreissinid bivalveMytilopsis sallei was investigated and the safe concentration of Zn was determined for this bivalve. In acute toxicity tests onM. sallei the 96 h LC₅₀ value for Zn is found to be 8.364 mg 1^?1. The results suggest that Zn has the lowest toxic effect onM. sallei when compared to copper and mercury. Effect of Zn on the oxygen consumption ofM. sallei was studied. Sub-lethal concentrations of Zn functioned as respiratory depressants. Accumulation of Zn was investigated in relation to exposure period and concentration inM. sallei. Zn accumulation was found to be sensitive to both concentration of Zn and exposure time. The effect of exposure time and concentration on body biochemical components was also studied inM. sallei. This accumulated Zn has resulted in impairment of carbohydrate metabolism and protein utilisation.     

Effect of cadmium,lead and nickel on three freshwater green algae

Effects of Cd, Pb, and Ni on three freshwater green algae, Ankistrodesmus falcatus, Scenedesmus obliquus, and Chlorococcum spp., were studied. Cadmium and Pb had slight stimulatory effects on growth at lower concentrations (0.1 to 1.0 ppm) while they were lethal at higher concentrations (> 5 ppm). Nickel was not lethal between 0.1 and 10.0 ppm. When combined, both Cd and Ni and Cd and Pb showed interaction on A. falcatus. No interaction was noted between Pb and Ni.     

Effect of nitrogen fertilization on the nutritional quality of wheat variety,Yecora Rojo

The effects of N-fertilization on the nutritional quality of short-straw wheat variety, Yecora Rojo, was studied under sprinkler irrigation system. The fertilizers applied were the conventional N-fertilizer, urea (U) applied as single dose or in three split applications (U-S), and the slow release N-fertilizers, ureaform (UF) (38% N and 20 N), osmocote (OC) with 9 or 14 months longevity and sulphur-coated urea (SCU) with either 17% or 37% dissolution rates in 7 days. These fertilizers were applied at 0 (control), 75, 125, and 175 kg/ha during the 1982–1983 season. Results indicated that at 75 kg/ha there was no significant change in the protein content. At 125 kg/ha, the protein content increased (P<0.05) with urea (applied in three split applications) and OC. At 175 kg/ha, all the fertilizers increased the protein content with the exception of urea (applied as single dose) and UF. Ash content tended to decrease with increasing levels of N, while fat and crude fiber were unaffected. All the fertilizers increased the protein yield (kg/ha), the maximum increase occurring with the slow-release N fertilizers, OC and SCU. Except UF, all the fertilizers decreased the lysine content significantly (P<0.05) in the protein moeity at 175 kg/ha level but lysine percentage in the grain was not reduced. The yield (kg/ha) of individual amino acids including lysine was increased several times at the 175 kg/ha level. P content tended to decrease while Fe and Zn increased with fertilization. Slow-release N-fertilizers, OC and SCU as well as urea (in 3 split applications) appear to have a significant positive effect on the nutritional quality of the grains of wheat variety, Yecora Rojo.     

New report of Citrus indica Yu. Tanaka,a wild progenitor species of citrus from Dailong Forest,Manipur, and recommendation for its conservation

Genetic Resources and Crop Evolution - Citrus indica Yu. Tanaka is a wild and endangered progenitor species of citrus endemic to North East (NE) India. It is reported to be restricted to Nokrek...     

Quantitative trait loci for stay-greenness and agronomic traits provide new insights into chlorophyll homeostasis and nitrogen use in rice

Functional stay-green (FSG) is characterized by delayed senescence during the reproductive stage in rice. A recombinant inbred line (RIL) population derived from ‘Pusa 677’/‘PSG16’ was used to study the genetics of FSG in a rice mutant, ‘PSG16’. The RILs exhibited significant variation under two N regimes for agro-morphological traits, leaf chlorophyll content, flowering time, yield components and nitrogen (N) use. Using a genome wide linkage map spanning 1910.8 cM with 104 polymorphic markers, we have mapped six major quantitative trait loci (QTLs). One robust QTL on chromosome 1 was associated consistently across different N regimes with chlorophyll content and flowering time. The QTL on chromosome 7 was associated with grain number, whereas the QTL on chromosome 6 was found related to N harvest index and spikelet fertility. Although ‘PSG16’ showed a clear advantage in grain yield as well as having better N assimilation, we could not establish a direct genetic relationship SG trait and N use. Based on the QTL information, FSG trait of ‘PSG16’ could be useful in deciphering multiple stress responses in rice.