PhD Thesis
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Item Effect of Plant Extracts on the Growth and Development of the Mulberry Silkworm Bombyx Mori L(University of Rajshahi, 2014) Banu, Hosna Ara; Rahman, Sowdagar Mahfuzar; Ahsan, Md. KamrulAn attempt was initiated for the utilization of different plant materials as food supplement for the improvement of different economic traits of Bombyx mori L. For this purpose initially an experiment was conducted to screen out different parts of Abroma Augusta, Centella asiatica, Neolamarckia cadamba, Solanum tuberosum, Persicaria acuminata and Andrographis paniculate plant with respect to their toxic effect on silkworm, Bombyx mori L. Relative toxicity by probity analysis for different parts of six plants extracts at different feeding schedules against silkworm larvae have been found out. Results on the mean mortality percentage of the larvae indicated that all the parts of P. acuminata and A. paniculata extracts showed toxic effect. With the increase of the dose of the extracts of the plant materials mortality of the larvae were increased. The LD50 values for different parts extracts at different feeding schedules also implied that different parts of those plant extracts produced higher mortality so that fruitful results could not be achieved with the supplementation in the feeding of silkworm larvae. On the other hand, results on the mean mortality percentage of the larvae indicated that all the parts of A. Augusta, C. asiatica, N. cadamba, S. tuberosum plant extracts were not toxic. The LD50 values also reported the same effect. After screening, the effects of the supplementation of different parts, viz. leaf, stem, root extracts of A. Augusta, C. asiatica, N. cadamba, S. tuberosum on growth and development of B. mori at different feeding schedules, viz. fed only in 1st feeding of 3rd to 5th instar larvae (FS-1), fed every day in 1st feeding of 3rd to 5th instar larvae (FS-2), fed every day in 1st and 3rd feeding of 3rd to 5th instar larvae (FS-3) were conducted. Leaf extract of A. Augusta increased the WML, LML, BML at different doses compare to control while fed in FS-1, FS-2 and FS-3. The highest and the lowest results for these parameters were observed at 500 ppm and control respectively………………………………Item Effect of vitamins on the growth and development of the mulberry silkworm, Bombyx mori L.(University of Rajshahi, 2016) Ferdous, Tasnima; Ahsan, Md. KamrulThe effect of the supplementation of mulberry leaves with vitamin B2 and C at different concentrations (e.g. 60, 150, 240, 330 and 420ppm for vitamin B2 and 10000, 15000, 20000, 25000 and 30000ppm for vitamin C) throughout different seasons, e.g. S-1, S-2, S-3 and S-4, at different feeding schedules, e.g. fed every day in 1st feeding of 3rd to 5th instar larvae (FS-1), fed in 1st to 5th feeding of 3rd to 5th instar larvae (FS-2), fed only in 1st feeding of 3rd to 5th instar larvae (FS-3) on the growth and development of B. mori were assessed in this investigation. The supplementation of vitamin B2 increased the WML, LML and BML under different concentrations (except 420ppm) compared to the control while fed according to FS-1, FS-2 and FS-3 in S-1. The highest and the lowest results of these parameters were observed at 240ppm and 420ppm respectively. Similar results were also found in S-2, S-3 and S-4. At FS-1, FS-2 and FS-3 while the supplementation of vitamin B2 slightly increased the PW under different concentration, e.g. at 60ppm, 150ppm, 240ppm and 330ppm in comparison to the control in S-1, S-2, S-3 and S-4. Vitamin B2 significantly increased the CW, CL, CB, SW, SP, TEL and EHP of B. mori at different feeding schedules under different seasons. Generally, the highest and the lowest results for these parameters were recorded at 240ppm and 420ppm respectively. In case of SR% the most effective concentration of vitamin B2 was not followed the normal trend as found in other parameters. On the other hand, vitamin B2 slightly decreased the larval period, pupal period and mortality percent at different concentrations except 420ppm compared to the control. The results of physiological parameters like food consumption, food utilization, food digestibility, food consumption index and co-efficient of food utilization were significantly increased in different concentrations (e.g. 60ppm, 150ppm, 240ppm and 330ppm.) under different feeding schedules and seasons. The results of ANOVA indicated that the items of feeding schedules, seasons and doses showed highly significant differences for all the parameters at 1% level of significance. But the item dose × season showed insignificant results in majority of the cases. The effectiveness of vitamin B2 with respect to different seasons on different characters under study followed the order S-2 > S-1 > S-3 > S-4, while in respect of different feeding schedules this trend has been in the order of FS-2 > FS-3 > FS-1. The most effective dose of vitamin B2 followed the order 240ppm > 150ppm > 60ppm > 330ppm. In case of vitamin C supplementation, WML, LML and BML were increased at different concentrations except 30000ppm compared to the control while fed in FS-1, FS-2 and FS-3 during different seasons. The mean values of PW were also increased at different concentrations, e.g. at 10000ppm, 15000ppm, 20000ppm and 25000ppm in comparison to the control. Similar results were also recorded for CW, CL, CB, SW, AE%, TEL and EHP of B. mori at different feeding schedules and seasons. In these cases the highest and lowest results were observed at 15000ppm and 30000ppm respectively. Vitamin C supplementation reduced the developmental periods in B. mori at majority concentrations except 30000ppm. It was also found that the mortality percent of B. mori was significantly decreased in these concentrations. The physiological traits like FC, FU, AD%, FCI and CFU of B. mori were enhanced against all the concentrations except 30000ppm compared to the control. In most of the cases the result of ANOVA indicated that the items of feeding schedules, seasons and doses showed highly significant differences at 1% level of significance. In majority of the cases it was observed that the effective dose of vitamin C on different characters followed in the order of 15000ppm>20000ppm>10000ppm> 25000ppm and in respect of feeding schedules it was in the order of FS-2> FS-1>FS-3. The most effective season was found in the following order S-2> S-1> S-3> S-4. Finally, the results depicted that the supplementation of vitamin B2 and C at some concentrations e.g. 60ppm, 150ppm, 240ppm, 330ppm of B2 and 10000ppm, 15000ppm, 20000ppm, 25000ppm of vitamin C may have beneficial effects on the physiological parameters, larval growth, cocoon characters and survival percentage by stimulating metabolic processes of the silkworm B. mori. Although it was observed that the growth and development of B. mori took place upto a particular dose 240ppm of vitamin B2 and 15000ppm of vitamin C at FS-2. So, this supplementation could be prescribed to the farmers to get more quantity of silk. On the contrary, higher concentrations, e.g. 420ppm of B2 and 30000ppm of C reduced the growth parameters and increased the developmental period and mortality percent. It may be due to hypervitaminosis.Item Isolation and Molecular Characterization of Bacteria from Diseased Farm Fish(University of Rajshahi, 2015) Ahsan, Md. Kamrul; Parween, Selina; Saha, Ananda Kumar; Hossain, Md. MosharrofPresent study was carried out for three years duration from March 2012 to February 2015 to isolate and characterize the bacteria collected from diseased farmed carp fishes and pond water. From the collected diseased carps (Puntius sarana, Labeo rohita, L. bata, Catla catla, Cirrhinus mrigala, Hypophthalmichthys molitrix) and water samples total nine isolates were differentiated and sub-cultured at 30-37C in the laboratory. The bacteria were identified on the basis of their morphological, physiological and biochemical characteristics and confirmed by sequencing of 16S rRNA gene sequence analysis. Among the nine isolates six were Gram-negative rods and three were Grampositive. Gram-negative six isolates can utilize citrate, and two isolates can ferment lactose. Four isolates were found as catalase positive, while two were weak positive; three were oxidase positive. All the nine isolates were found as fermentative type of bacteria. None of the isolates reduce sulphur, five produced indole; three were motile on motility indole urea media and showed flagellar movement on hanging-drop method. Six isolates showed positive results for methyl red test, while four of them were Voges- Proskauer positive. Sucrose was utilized by all the isolates where one of the isolate could only ferment sucrose. Among the nine isolates six showed resistance against bacitracin. All the isolates are more or less sensitive to gentamicin, neomycin, cephradine, doxycycline, tetracycline, ceftriaxone, ciprofloxacin, pefloxacin, mecillinam and nitrofurantoin. The highest colony forming units/ml was calculated as 65-71×1010 and lowest was 11-16×108. Two isolates were found ampicillin resistant, and MIC for this antibiotic ranged from 320-640 μg/ml and MBC was in the range of 320-1280 μg/ml for the rest of the isolates. The MIC and MBC were ranged from 320-640 μg/ml and 320-1280 μg/ml respectively for the antibiotic tetracycline as all the isolates were sensitive to this antibiotic. Isolates showed their optimum growth in the range of temperature 28–30C, pH 6.8–7.5 and salinity 1%. Five different primers were used and the combination of 8F–806R and 8F–1492R gave the more contrast single band in between 700–800 bp in comparison to 1kb plus DNA ladder. NCBI BLAST nucleotide sequence first matching revealed the nine isolates as Klebsiella oxytoca strain KB (98%), Klebsiella oxytoca strain SHD-1 (99%), Klebsiella oxytoca strain AIMST 8.Cp.16 (99%), Pantoea sp. strain F6-PCAi-T3P21 (84%), Aeromonas sp. strain OS6 (97%), Aeromonas veronii biovar sobria strain ER.1.24 (99%), Brevibacillus borstelensis strain 1CK49 (99%), Brevibacillus borstelensis strain 1CK49 (91%) and Bacillus sp. BVC99 (99%). Among the identified isolates six belongs to the family Enterobacteriaceae, two from the family Paenibacillaceae and one from the family Bacillaceae.