Evaluation of somaclones in the field of three potato varieties (Diamant, Multa and Cardinal) were examined through callus culture using node, internode and leaf segments. Multiple shoot regeneration from callus at various frequencies was observed using different concentrations and combinations of growth regulators. The highest percentage of callus induction from internode was observed in MS medium containing 3.0 mg l-1 of 2,4-D + 150 mg l-1 of L-asparagine. In this combination, the percentage of callusing was 90% for Diamant, 80% for Multa and 70% for Cardinal. The best response for multiple shoot formation was observed in MS medium supplemented with 4.0 mg l-1 of KIN + 0.5 mg l-1 of NAA. Diamant responded better than Multa and Cardinal for shoot regeneration from callus. Best rooting was observed from node or internode derived plantlets of primary calliclone in MS medium supplemented with IBA. Rooted calliclones were transplanted in the field and evaluated somaclones variation using parameters viz. plant height, number of leaves/plant, number of tuber/plant and tuber weight/plant. The result of statistical analysis on individual character supports existence of significant variation among the different somaclones.

The released three varieties of bush bean (BARI Jhar Shim-1, 2 and 3) were grown in both Sclerotium rolfsii inoculated and un-inoculated plots to assess the yield loss in the field of Plant Pathology Division, Bangladesh Agricultural Research Institute (BARI), Gazipur during 2013. Sclerotium rolfsii infected the bush bean plant in every growth stage and reduced the germination capacity and lessened plant vigor. The yield loss ranged from 55.43 to 64.94%. A screening study was conducted to observe the resistant level of released varieties and local lines collected from On Farm Research Division (OFRD), BARI, Sylhet during 2013. B0124 and BARI Jhar Shim-3 showed susceptible and the others showed highly susceptible reaction. The antagonistic potential of the local isolates of Trichoderma harzianum against the phytopathogenic S. rolfsii was investigated in dual culture and bioassay on bean plants. Isolated T. harzianum showed antagonism effect against S. rolfsii and restricted around 80% mycelial growth in-vitro. A field experiment was carried out in Plant Pathology Division, BARI, Gazipur during 2014 to observe the efficacy of T. harzianum in controlling foot rot disease induced by S.rolfsii of bush bean in the field. Soil treated with T. harzianum mass plus seed treated with Provax 200 WP showed the lowest disease incidence (28.47%) and the highest germination (98.61%) and yield (873.33 kg/ha) in compared to other treatments with pathogen inoculated soil.Bangladesh J. Agril. Res. 43(2): 289-299, June 2018

Strawberry is a valuable, nutritious, and economically important fruit all over the world including Bangladesh. Therefore, there is a demand to develop a suitable variety of strawberry. For this purpose, leaf explants from in vitro grown strawberry plantlets were cultured onto MS medium supplemented with different concentrations and combinations of 2,4-D, NAA and BA for callus induction. The most effective combination was 2.0 mg/L NAA with 0.5 mg/L BA. Then, the calli proliferated in this medium were cultured in MS medium containing different concentrations and combinations of BA, BA + NAA and BA + KIN + NAA for shoot regeneration. The best media combination was 1.5 mg/L BA + 0.75 mg/L NAA + 0.5 mg/L KIN. The regenerated shoots were cultured onto MS medium with different combinations of auxins or in MS and ½ MS medium without plant growth regulators (PGRs). The highest rooting performance was recorded in MS medium without PGRs. The plantlets were then gradually acclimated and successfully transferred to the field for evaluation. Somaclonal variations in different morphological characters such as plant height, no. of leaves/plant, petiole length, no. of stolon/plant, stolon length, no. of nodes/stolon, canopy size, no. of clusters/plant, fruit shape, no. of fruits/plant, average fruit wt. (g), fruit wt/plant (g), were noticed. Some of the somaclones exhibited better performances of the above mentioned characteristics than those of micropropagated mother plants and were well adapted to Bangladesh agro-climatic condition and were cultivated commercially in the winter season by many farmers.

Dose-mortality and repellent activity tests of the chloroform extracts of fruit, leaf, root and stem of Solanum ferox L. against the red flour beetle Tribolium castaneum (Herbst) adults have been done. The fruit, leaf and stem extracts offered promising toxicity to the beetles within 30 min. of exposure. The LD50 values for 30 min., 12, 24, 36 and 48h of exposures were 0.440, 0.247, 0.211, 0.207 and 0.164mg cm-2 respectively for the fruit extract; 2.394, 1.712, 1.540, 1.239 and 0.993mg cm-2 respectively for the leaf extract; and 4.918, 0.871, 0.546, 0.472 and 0.522mg cm-2 respectively for the stem extract. However, the root extract did not offer any mortality for 30 min. and 12h of exposure; and thus the LD50 values for 24, 36 and 48h of exposure were 6.667, 5.086 and 3.357mg cm-2 respectively. While the dose-mortality activity can be arranged in the order of fruit> leaf> stem> root extracts. The fruit and stem extracts showed repellent activity against T. castaneum adults at P<0.01 and the leaf extract at P<0.05 level of significance, while the root extract did not show any repellency. DOI: http://dx.doi.org/10.3329/jles.v7i0.20118 J. Life Earth Sci., Vol. 7: 29-32, 2012

The present study was conducted to determine the effects of Jasmonic acid (JA) and light periods on performance of microtuber growth response in five potato cultivars (Diamant, Atlanta, All Blue, Shepody and Shilbilaty). Microtubers were produced from in vitro grown plantlets treated with or without 5µM JA on micropropagation and microtuberization media under 0 and 8 h light periods. Microtuberization was established in MS liquid media having 8% sucrose along with the above treatments. Among the investigated cultivars, the highest number of microtubers (12.97 microtubers per vessel) was obtained in All Blue. On the other hand, Diamant microtubers gave maximum fresh weight (106.7 mg) and Shilbilaty yielded the highest percentage (57.72%) and number of larger microtubers (8.25 larger microtubers out of total 12.78 microtubers per vessel) followed by Diamant and All Blue. Atlanta showed lower values at all investigated microtuber growth traits. Microtuber growth was better in 5µM JA supplemented microtuberization media with 8 h photoperiodic incubation than those were in micropropagation media with the same treatment. The 0 h period was found significantly inferior than 8 h at all growth traits.

With a view to select divergent parents genetic diversity was estimated among twenty genotypes. Thirty F1 progenies developed by line-tester mating were studied from seedling generation to first clonal generation for five important agronomic traits. Cluster analysis reveals that the parents could be grouped into seven different clusters. Cluster means showed wide range of variation for several traits among singles as well as multi genotypic clusters. Considering diversity pattern, parents should select from cluster I, III, IV and V for the improvement of potato. Analysis of variance revealed that all most all the sources of variation were highly significant for all the studied traits in both generations. Parents Challisha, Lalpakri, Patnai, Chamak, Sadagoti, TPS-67 and TPS-364 were found to be good general combiners for tuber yield and yield contribution traits due to their gca effects. The sca effects showed that out of 30 hybrids 12 were found to have specific combining ability for tuber yield and those hybrids also exhibited considerable heterosis for tuber yield and yield contributing traits.

Leaf sheath explants of an indigenous variety Isd-16 of sugarcane (Saccharum officinarum L.) produced light yellow friable callus after culturing on to MS with 2,4-D (2 - 4 mg/l) and NAA (3 - 5 mg/l) singly. Callus formation was the maximum on MS + 3 mg/l 2,4-D. Callus underwent embryogenesis producing huge number of somatic embryos when subcultured on MS with 15 - 30 mg/l L-proline, 3 mg/l 2,4-D + 5 - 10% coconut water (v/v) and 3 mg/l 2,4-D + 10% CW (v/v) + 300 - 500 mg/l CH. L-proline significantly enhanced somatic embryo-genesis and 25 mg/l L-proline in MS was the best culture medium formulation. Most of the somatic embryos germinated and developed plantlets after 1 - 2 weeks of incubation in proline-supplimented medium. On the other hand, maturation and germination of embryos were achieved on half-strength MS with or without 0.25 - 1.0 mg/l L-proline, and 5% coconut water (v/v). Somatic embryos derived plantlets were then successfully transferred to natural condition through successive phages of acclimation. Key words: Plant regeneration, Leaf sheath, Somatic embryogenesis, Sugarcane D. O. I. 10.3329/ptcb.v21i2.10237 Plant Tissue Cult. & Biotech. 21(2): 143-149, 2011 (December)

Strawberry cultivation is not popular in Bangladesh due to the unpredictable climatic conditions and lack of proper cultivars. Using somaclonal variation, several new promising selections were generated and evaluated for their flowering and fruiting ability, adaptability and sustainability. To induce variation, plants were regenerated using various tissue culture techniques. Our results suggested that a high concentration of BAP in culture medium successfully resulted in the induction of somaclonal variation. Among the tissue culture techniques adopted in this study, meristem culture was most effective for induction of somaclonal variation. Twenty five putative somaclones with better horticultural features were subsequently selected and field evaluated for three clonal generations. Several of the selections reverted back to their original phenotype within 2–3 vegetative propagations. Three of the stable selections were distinct from each other in terms of fruit and other horticultural characters, and have potential for commercial cultivation in Bangladesh.

The in vitro multiple shoot regeneration was tried from runner tip explants of three strawberry clones. Different concentrations and combinations of BA, Kin and NAA were used in MS media for the above purpose. Best response towards multiple shoot regeneration was obtained on MS medium having 0.5 mg/l BA. Among the tested clones no significant differences were found shoot number and harvestable shoots. To enhance shoot multiplication low concentration of BA was recommended. Mean were significantly different for the traits NL, NC, NF and AFW among the tissue culture and runner derived plants. Analysis of variance showed that the strawberry clones under study were highly significant for most of the traits except PH and CZ. Our results reveal that phenotypic variance and phenotypic coefficient of variance were higher than the corresponding genotypic variance, environmental variance, genotypic coefficient of variance and environmental coefficient of variance.

2 Abstract: Genetic diversity and heterosis was estimated for six important yield contributing quantitative traits in thirteen parents and their thirty hybrids. Hybrids were derived from line-tester mating design. According to diversity analysis thirteen parents were grouped in six clusters and superior male and female parents were distributed in relatively distance cluster. Among the thirteen parents TPS-13, TPS-67, lalpakri, patnai and ausha were selected to produce hybrids with considerable hybrid vigor. In the present investigation degree of heterosis varied from trait to trait. Highest average mid-, better- and standard- parent heterosis was recorded in the tuber number, yield and average tuber weight traits, respectively. Correlation coefficient of geneti c distance with F performance, mid-, better- and standard- parent heterosis for six studied traits were statistically 1 non significant and most of the cases were negative.

A study was conducted on a 10×10 diallel set of tomato excluding reciprocals to find out the extent of heterosis, combining ability and nature of gene action for yield with two important quality traits: brix% and days to first fruit ripening (DFFR). Significant differences among genotypes were obtained for all three traits. Positive high significant heterosis was found for yield (211.00, 232.00 and 298.00), for brix% (61.04, 106.70 and 37.76) and for DFFR (8.92, 9.33 and 6.07) over the mid, the better and standard parent respectively. The magnitudes of variance due to general as well as specific combining ability were highly significant indicating the importance of both additive and non-additive gene action. However degree of dominance (o g/o s) 22 revealed the prevalence of a non-additive gene effect. Cross combinations P ×P (0.66), P ×P (7.85) and 97 5 2 P ×P (1.22) were best specific combiners for brix%, DFFR and yield/plant. Predominance of non-additive gene 96 action plays a greater role in the inheritance of brix% and DFFR in tomato.

Effects of colour illumination on multiple shoot regeneration from runner tip explants of strawberry were studied. Six colour (mixed, white, red, yellow, blue and green) illuminations were used in this study and among them mixed colour illumination showed the high percentage of shoot proliferation. Fresh and dry weights were also significantly higher under the mixed colour condition. Proliferated shoots showed 100% rooting in half strength of MS media. Plantlets were established successfully in soil.

2 Abstract: Lactuca sativa is widely used leafy vegetable belonging to the asteraceae family, which is adopted as a model plant for transgenic research. We established an Agrobacterium tumifaciens- mediated transformation procedure for L. sativa. Leaf discs of L. sativa were incubated with A. tumefaciens strain LBA4404 containing pBIPTA plasmid with the npt gene as a selectable marker for kanamycin resistance and intron containing pta gene as an aphicidal gene. Following co-cultivation, leaf discs were cultured on selective medium containing 50 mg l kanamycin + 50 mg l cefotaxime. Kanamycin resistant shoots were induced 11

A field experiment was conducted at the Agronomy Field of Bangladesh Agricultural University (BAU), Mymensingh during the period from November 2001 to March 2002 to investigate the effect of Chenopodium album competition on growth and yield of wheat and to determine the critical period of weed ( C. album ) competition in wheat. The experiment was consisted of 7 treatments viz., weed free for whole crop life, weed competition (WC) for 20, 40, 60, and 80 days after emergence (DAE), WC for 110 DAE (no weed control) and weed monoculture. The highest grain yield (3.95 t/ha) was obtained from weed free and that of the lowest from weedy (2.65 t/ha) condition. Grain yield decreased gradually with the increase in weed competition duration. Wheat yield reductions due to C. album competition for 20, 40, 60, 80, and 110 DAE were 12.65, 28.10, 29.11, 31.64, and 32.9 %, respectively. The highest rate of yield decrease was in between 20 and 40 DAE. The highest reduction of wheat yields under weedy check treatment (32.91% grain and 33.75% straw) were the results of 31.0 % reduction of total tillers/plant, 43.34% reduction of effective tillers/plant, 14.57% reduction of grains/spike, 34.5% reduction of total dry weight of wheat. The plant height of C. album was reduced due to wheat competition by 32.3% and that of total dry matter by 34.2 %. The critical period of weed competition lies between 20 and 40 DAE. Bangladesh J. Agril. Res. 32(2) 2007: 191-203.

Shootlets were regenerated from nodal explants of Stevia rebaudiana Bertoni through axillary shoot proliferation. The induction of multiple shoots from nodal segments was the highest in MS medium supplemented with 1.5 mg l̄ BA + 0.5 mg l̄ Kn. For rooting different concentrations of IBA, NAA and IAA 1 1 were used and highest rooting percentage (97.66%) was recorded on MS medium with 0.1 mg l̄ IAA. The 1

2 Abstract: Nodal segments of strawberry gave rise to multiple shoots when cultured on MS medium supplemented with different concentration of BA with KIN or GA The highest response of shoot multiplication 3. was obtained in MS containing 1.5 mg l BA + 0.5-0.1 mg l KIN. The regenerated shootlets were rooted on 11 MS basal medium with different concentrations IBA and IAA. The maximum frequency of rooting and highest number of roots was produced on medium containing 1.0 mg l IBA. The plantlets, thus developed were 1 hardened and successfully established in soil. The plants raised through tissue culture exhibited normal growth, flowering and fruit setting.

2 Abstract: The present investigation was carried out with a view to standardize an in vitro culture technique for mass propagation of important medicinal plant species, Acorus calamus L. Naturally grown rhizome tip was used as explants for initial culture. The explants were cultured on standard MS (Murashige and Skoog, 1962) medium supplemented with different concentration and combination of cytokinines and auxines for primary shoot proliferation. The best shoot proliferation was observed in MS medium containing 2.0 mg l̄ KIN and 1

2 Abstract: The present investigation was carried out with a view to standardize an in vitro culture technique for mass propagation of important medicinal plant species, Acorus calamus L. Naturally grown rhizome tip was used as explants for initial culture. The explants were cultured on standard MS (Murashige and Skoog, 1962) medium supplemented with different concentration and combination of cytokinines and auxines for primary shoot proliferation. The best shoot proliferation was observed in MS medium containing 2.0 mg l KIN and 1