Key words: Cassia alata, flavonoids, fungicidal activities. DOI:10.3329/jbs.v16i0.3759 J. bio-sci. 16: 139-142, 2008

Context: The essential oils are being tried as potential candidates for pest and disease management. Several essential oils of botanical origin have been reported for their repellant, toxic and developmental inhibitory activities. The ovicidal effect of essential oil is probably the major factor in the suppression of the development of adults from treated eggs.Objectives: To investigate the ovicidal effect of vapours of five essential oils viz., cardamom (Elletaria cardamomum L.), cinnamon (Cinnamomum zeylanicum Blume), clove (Sygium aromaticum L. Merrill. et. Perry), Eucalyptus spp. and neem (Azadirectica indica A. juss) against the eggs of red flour beetle, Tribolium castaneum (Herbst).Materials and Methods: Ten eggs (24 h old) of T. castaneum were placed in each petridish with wheat flour as food medium and without flour medium and then the petridish were kept inside 650 ml jars with screwed lids. Aliquots of 0.5 ml of each dose of essential oils were applied on filter paper attached to the lower side of the lids. The exposure periods were 24, 48, 72 and 96 h, respectively. After treatment periods, petridishes were taken out of the jars and the final mortality counts were made after 11 days. Mortality data were subjected to probit analysis. Results: The oils had high-fumigant activity against eggs and toxicity progressively increased with increase in exposure time and concentration. At the highest concentration of 5.769 mg/l air and exposure period of 24 h, cinnamon oil achieved 100% mortality in flour and without flour media. The vapours of essential oils from cardamom and clove resulted in 100% mortality of the eggs. Neem oil achieved mortalities as high as 51.66 and 50% mortality at the highest concentration and exposure period in with-flour and without flour medium respectively. At a concentration of 5.769 mg/ l air cardamom oil, the LT90 values were 50.80 and 62.78 h for with-flour and without flour medium respectively.Conclusion: The essential oils of cinnamon and clove, proved to be promising as control agents against stored-product insects, especially T. castaneum.Key words: Essential oil; Fumigant toxicity; Ovicidal activity; Tribolium castaneumDOI: 10.3329/jbs.v17i0.7102J. bio-sci. 17: 57-62, 2009

The exotic barb Puntius gonionotus was introduced into Bangladesh in 1987. Its faster growth rate, nice taste and compatibility with our culturable species have made it very popular food fish in Bangladesh. With a view to providing some basic information towards development of sustainable seed production of the species, a study was undertaken to determine the fecundity and ovary characteristics of the fish. The mean fecundity of 55 gravid females (of 11 length group) of Puntius gonionotus was obtained as 14321 with a range of 2254.67 to 6964.73 from fishes having a mean total length and mean body weight of 200.13±20.58 mm and 196±34.379 g respectively. The relationship between the fecundity (F) and total length (TL), total body weight (TW), ovary length (OL) and ovary weight (OW) were established. Regression analysis was made and the co-efficient of correlation (r) was calculated for each of the following F-TL, F-TW, F-OL and F-OW and the values of r were obtained to be 0.84, 0.84, 0.95 and 0.96 respectively. In all the cases linear relationships obtained were highly significant. Key words: Fecundity, Puntius gonionotus, ovarian characteristics. J. bio-sci. 14: 99-102, 2006

Nuclear phenotype and chromosome characteristics of eight types of Impatiens balsamina L. were studied. The diploid chromosome number was found to be 2n=14 in all types of Impatiens balsamina. Interphase chromosome volume was found to range from 0.1665μ3 (violet type) to 0.3904 μ3 (red type). The maximum total chromatin length (24.73μm) was observed in pink type and minimum (11.70μm) in violet type. Maximum total frequency percent (50.00%) was found in both foreign types (red and violet) and minimum (48.03%) in violet type. The karyotype analysis revealed that there was no secondary constriction and sub-terminal chromosome in any of the seven types belonging to Impatiens balsamina. So, on the basis of karyotypic analysis the present findings indicated that all the types of Impatiens balsamina were of primitive nature. Key words: Karyotype, Nuclear phenotype, Impatiens balsamina L.  doi: 10.3329/jbs.v15i0.2155   J. bio-sci. 15: 147-152, 2007

A field trial was conducted during the winter season of 2001-2002 to find out the effect of planting method and nitrogen levels on wheat. Effects of two planting methods viz. bed planting and conventional planting were studied on three nitrogen levels viz. 50, 100 & 150 kg /ha on wheat (var. Protiva). Planting methods exhibited significant variation in respect of all the characters studied. The maximum grain yield (3.60 t/ha) was obtained from bed planting. Different levels of nitrogen significantly influenced on yield and yield attributing parameters of wheat. The highest grain yield (3.70 t/ha) was recorded from 150 kg N per hectare. The interaction effects of planting methods and nitrogen levels showed the significant difference in respect of spike/m2, spike length and grain yield. Highest grain yield (4.04 t/ha) was obtained at bed planting using 150 kg N per hectare. Though higher rate of N are used but lodging of plant height was not noticed. The correlation analyses showed that the rate of change of grain yield was highly dependent upon the rate of change of yield contributing characters of wheat. 
 
 Key words: Planting methods, Nitrogen, Wheat, Cropping system. 
 
 J. bio-sci. 14: 127-130, 2006

The effect of gamma radiation on the shelf life extension of Bananas was studied. Bananas were treated with three gamma radiation doses of 0.30k Gy; 0.40k Gy and 0.50k Gy for 5 mins respectively and stored in a dry place under room conditions (25±2°C/ 80± 5% RH). The physical conditions of the radiation treated and control bananas were observed at every 2 days interval for their organoleptic properties till spoilage. The control bananas ripened within 6 days while the gamma irradiated bananas ripened within 26 days, indicating that the shelf life of banana was extended by 20 days thereby delaying banana ripening. The nutrient contents as well as some important physico-chemical parameters of the irradiated Bananas and the control Bananas were analyzed quantitatively at an interval of 2-4 days throughout the experimental period. A minor decrease in the ascorbic acid content was the only adverse effects observed in irradiated bananas and no other major changes occured in nutritional and organoleptic qualities and the chemical constituents of banana is maintained. A taste-testing panel of 16 panelists determined the acceptability of the fruit. The scores given by the panelists were statistically analyzed and the treated bananas were found to be acceptable up to 26 days at room temperature whereas in the case of control the fruits were spoiled within 6 days. Thus, radiation can be used for the shelf life extension of Bananas and is not harmful to health.  Key words: Banana, gamma-irradiation, shelf life extension.  doi: 10.3329/jbs.v15i0.2202 J. bio-sci. 15: 47-53, 2007

Context: Kranz anatomy of locally developed sugarcane cultivars were studied in relation to C4 vascular arrangement. Objective: The objective of this study was to make gross cross-sectional anatomy and quantitative assessment of the anatomic traits of the leaf-blade and midrib of the sugarcane cultivars. Materials and Methods: Leaf blade and leaf sheath of two sugarcane cultivars Ishurdi 20 and Ishurdi 32 were used as the materials. Free hand section with appropriate stain were used. Sections were studied using an advanced biological system microscope fitted with motic camera. Anatomic traits were studied through motic image plus J 1.0 software using Macintosh computer. Results: Three sized vascular bundles and significant differences in distance between those vascular bundles were noted. Ishurdi 32 possessed two sized vascular bundles. Large vascular bundles characters by two large metaxylem vessels on either side of protoxylem. Phloem well developed. Intermediate and small bundles lack metaxylem vessels and protoxylem, but have metaphloem with thick and thin walled sieve tubes. Bundle sheaths have extended to upper and lower epidermis but for small bundle it is extended to abaxial epidermis. Vascular bundles are almost completely surrounded by chlorenchymatous bundle sheath and associated with hypodermal sclerenchyma on both abaxially and adaxially except small blade bundles which associated with the abaxial sclerenchyma. Bundle sheath cells were smaller in large and larger in other two types of vascular bundle. An inner mestome sheath with thickened walls is always present round the phloem and metaxylem around all or part of the xylem in large and intermediate bundles. In small bundles mestome sheath is altogether absent. Bulliform cells with varied area were present on the adaxial epidermis opposite to small vascular bundles. Midrib anatomy consists of central large vascular bundles lacking bundle sheath cells pushed deep inside parenchymatous hypodermis from abaxial hypodermal sclerenchyma girders. Lack of Kranz traits, and bundle sheath cells have transformed into sclerenchymatous bundle cover. Central mid-rib large bundle flanked by 3-10 small bundles on either side of midrib which have Kranz system of anatomy. Midrib region have continuous hypodermis consists of sclerenchyma cells and it is few layer (Ishurdi 32) to multilayer (Ishurdi 20). Conclusion: Kranz system with well developed bundle sheath associated with Kranz mesophil in the leaf blade were observed but Kranz tissue absent in midrib region. Large and small vascular bundles alternate all alone the leaf blade. Bulliform cell well develop indicates zeric adaptation. Two cultivars differ in respect of quantitative expression of Kranz tissue. Keywords: Sugarcane cultivar; Kranz tissue; bulliform cells; mestome sheath. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8778 JBS 2010; 18(0): 66-73

Context: In the last few decades an ample array of molecular techniques has been introduced to obtain new disposition for the classification of Trichoderma species. Today the concern of scientists is either in the direction of gene targeting or ribotyping, the newest fingerprinting tool for genomic DNA that contain all or part of the genes coding for 18S rRNA in eukaryotes.Objectives: To take advantage of advanced molecular techniques for phylogenetic analysis of indigenous isolates of Trichoderma to comprehend our knowledge of this genus by supplementing the phenotypic identification.Materials and Methods: Genomic DNA of twenty four isolates of Trichoderma species (T. harzianum, T. hamatum, T. koningii and T. pseudokoningii) were extracted by CTAB method and indicated band of ~15Kb on 0.8% agarose gel. Quality of DNA was determined by obtaining absorbance ratio (260/280) in the range of 1.7-1.9. Restriction fragment length polymorphism (RFLP) analyses were performed by using two restriction endonulease enzymes i.e., BamHI and HindIII. The BamHI represented results in the range of 500bp-750bp. 18S rRNA gene targeting was further carried out through optimization in ribotyping analysis.Results: The DNA bands of 24 isolates of Trichoderma species were compared with marker DNA bands and indicated the presence of genomic DNA intact band of ~15Kb. The ratio of absorbance 260/280nm (1.8-1.9 for pure DNA preparations) provided an estimate of the purity of the DNA RFLP analysis, along with the negative control of twenty four different isolates of Trichoderma species subjected to restriction using BamHI enzyme. The rRNA gene amplified band was observed at 600bp in the case of T. hamatum isolate (S. cumini stem bark, FCBP accession number 769) while in remaining isolates bands were in slightly smeared form. Furthermore, rRNA gene amplification conditions were optimized by altering different Tm and MgCl2 concentrations. Conclusion: The genomic DNA can serve as long term storage of information. Therefore advance molecular techniques can be used to study the variability in the genome of organism. RFLP are the initial steps for screening the genome of any organism.Key words: Trichoderma; DNA; RFLP; restriction endonuleases; 18S rRNA.DOI: 10.3329/jbs.v17i0.7117J. bio-sci. 17: 117-122, 2009

Context: Carbon plays a vital role in plant cell growth and regeneration in artificial media but the source of carbon deserves scientific investigation to analysis their comparative performance. Objectives: To analyze the comparative performance of different carbon sources (glucose, sucrose and sorbitol) in cell growth and regeneration efficiency of banana (Musa spp) cultivars. Materials and Methods: Male flowers of banana cultivars cv. Sabri, Gine and Ranginsagar were used in this experiment. Male flowers were cut into small pieces and they were transferred in petri dishes containing Murashige and Skoog media supplemented with 2 mg/l 2,4-D + 1mg/l NAA + 1mg/l IAA + 1mg/l Biotin + 1mg/l glutamine and 3% (w/v) different sugars: sucrose, glucose, and sorbitol singly or in combinations autoclaved in 121ºC temperature for 20 min. The pH of the medium was adjusted to 5.8. Results: Glucose showed the highest performance in callus induction and cell growth and 3% glucose proved as the optimal dose in media formulation for callus induction and cell growth. Sucrose and sorbitol behaves differently in embryo formation and they produced the highest and lowest number of embryos respectively in regeneration medium. In respect of overall performance the highest percentages of shoot and root formation was obtained in the media containing 3% sucrose. Conclusion: Glucose proved to be the best carbon source in callus induction and cell growth media. Key words: Banana; Musa; callus; single cell; regenerationDOI: 10.3329/jbs.v17i0.7111J. bio-sci. 17: 83-88, 2009

Context: Lamda cyhalothrin and neem seed extract can protect chickpea by controlling pod borer Helicoverpa armigera (Hubner). Objective: To find out the effect of neem seed extract and lambda-cyhalothrin application schedule for the effective and economic management of pod borer attacking chickpea. Materials and Methods: The experiments were conducted in High Barind Tract of northern Bangladesh with the application of neem seed extract @ 50 g-l (two and three spraying) and lambda-cyhalothrin. (Karate 2.5 EC) @ 2 ml-l (two and three spraying) and untreated control. The seeds of BARI-Chola 5 chickpea were sown in rows with the spacing of 40 cm. At maturity, all the pods were collected from 10 randomly selected plants from middle rows of each plot. The damaged (bored) and total numbers of pod were counted. The grain yield loss (kg-ha) and percent pod damage were determined. The seed yield of each treatment was converted to kg-ha. Results: The lowest pod damage (2.55%) as well as grain yield loss (34.90 kg-ha) were observed in the treatment where lamda cyhalothrin applied three times at 7 days interval from flowering stage. Chickpea seed yield was maximum (1338 kg-ha) with lamda cyhalothrin sprayed thrice which was identical to sprayed twice (1280 kg-ha). Neem seed extract showed a marginal performance to control chickpea pod borer. The highest marginal benefit cost ratio (3.19) was recorded from lamda cyhalothrin sprayed twice. Conclusion: Lamda cyhalothrin double sprayed with 7 days interval from pod formation stage is the best package in managing pod borer in chickpea considering efficacy and profitability. Keywords: Chickpea; pod borer; pod damage; pesticides; yield. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8774 JBS 2010; 18(0): 44-48