Dr A.G.B. Aruggoda

Species concepts in Phomopsis are based primarily on host association because morphological and cultural characters are generally insufficient for species diagnosis. Increasingly, there are reports that some species of Phomopsis are not host restricted but are capable of infecting several or more taxonomically unrelated host genera. Phylogenetic analysis of nuclear ribosomal DNA internal transcribed spacer sequences (ITS1 and ITS2) for 43 North American and Caribbean strains of Phomopsis isolated from diverse plant hosts and geographic origins resolved three clades, provisionally termed groups A, B, and C. Group A consists of isolates from shrubs and trees originating primarily from eastern North America. Group B includes isolates from woody and herbaceous plants that originate from tropical to subtropical regions and produce paraphyses among their conidiogenous cells. Group C occurs primarily on herbaceous plant hosts, including agricultural field crops, and is widely distributed t...

Soil fertility and productivity depend on soil chemical, physical and biological properties. Sri Lanka is an agricultural country and extensive use of inorganic fertilizers by the farmers has harmful impact on human and the environment. Therefore, promoting application of organic fertilizer is a need. Legumes are not only grown as human food but also improve soil fertility through biological nitrogen fixation. Rhizobium, a soil borne bacteria living in nodules of legume plants, fixes aerial nitrogen on a symbiotic association. Thus it reduces nitrogen requirement of legume and make the legume based cropping system sustainable. The response of cowpea variety Waruni to seed inoculated Rhizobium, cattle manure, and inorganic nitrogen fertilizer was investigated conducting field experiments. The results indicate that the seed inoculated rhizobia increased number of nodules and nodules dry weight per plant, 100 seed weight, number of pods per plant, yield, hydration coefficient and cooka...

ABSTRACT. Although ladybird beetles (Coccinellidae: Coleoptera) are charismatic and have great ecological and economic significance, understanding of the evolutionary history of Coccinellidae remains poor. Many hypothesis of evolutionary relationships based on morphological features have been proposed, but none have been verified using a formal phylogenetic analysis. The objectives of this study was to apply molecular evidence of 16S rDNA to construct a molecular phylogeny for ladybird beetles, examining the monophyly of the tribes and several lower-level taxa within the group, and to establish basic phylogenetic patterns. 16S rDNA fragments were sequenced from 47 species of in-group and two species of out-group taxa. DNA data showed evidences of rapid evolution and saturation, having AT and transition at a higher level. 16S rDNA gene region indicated the availability of phylogenetic signals with the presence of skewness with significant hierarchical structure as well as having high...

The compositional characteristics of Corn leaves, Corn Husks, Bagasse, Guinea Grass and Sugarcane leaves were established in terms of lignin, cellulose and hemicellulose contents, to assess the suitability of agricultural wastes for the extraction of cellulose. The objective of the present study was to evaluate the performances of the alkaline hydrogen peroxide method by applying three different concentrations of pretreatment solutions on five selected plant biomasses; Corn leaves, Corn husks, Bagasse, Guinea grass and Sugar cane leaves. In addition the best pretreatment solution was evaluated based on the extraction of maximum cellulose percentages with minimum weight losses of Plant biomaterials. For the experiment, three prepared pretreatment solutions named as S1 (prepared by mixing10ml of 1.25 mol/L and1 ml of 99% hydrogen peroxide), S2 (prepared by mixing10ml of 2.5 mol/L and 0.75 ml of 99% hydrogen peroxide) and S3 (prepared by mixing10ml of 5 mol/L and 0.5 ml of 99% hydrogen...

Although ladybird beetles (Coccinellidae: Coleoptera) are charismatic and have great ecological and economic significance, understanding of the evolutionary history of Coccinellidae remains poor. Many hypothesis of evolutionary relationships based on morphological features have been proposed, but none have been verified using a formal phylogenetic analysis. The objectives of this study was to apply molecular evidence of 16S rDNA to construct a molecular phylogeny for ladybird beetles, examining the monophyly of the tribes and several lower-level taxa within the group, and to establish basic phylogenetic patterns. 16S rDNA fragments were sequenced from 47 species of in-group and two species of out-group taxa. DNA data showed evidences of rapid evolution and saturation, having AT and transition at a higher level. 16S rDNA gene region indicated the availability of phylogenetic signals with the presence of skewness with significant hierarchical structure as well as having higher number ...

Supper Absorbent Polymers (SAPs) have been used as water retaining materials in agricultural fields. It can slowly release stored water and nutrients as required by the plants. The aim of the present study was to evaluate the effect of SAP named GAM-sorb, on growth of tomatoes. Two factor factorial experiments were carried out in Completely Randomized Design with three replicates. Water capacities in three levels; 75% of Filed Capacity (FC), 50% of FC and 25% of FC and SAPs in four levels, Low level (L) 2.625g, High level (H) 5.25g, Intermediate High level (M) 7.875g, Double High level (DH) 10.5g were applied as treatments. Control was carried out without SAP. The analysis data indicated that number of flowers/plant, Moisture Content of soil (MC), Relative Water Content (RWC) of plant leaves and % of dry weight/ fresh weight revealed significant different among different rates of SAPs. Plant height, yield and amount of chlorophyll present in plant leaves (SPAD values) were not signi...