Disinfected mature seed embryos of Picralima nitida, were cultured in MS medium supplemented with different concentrations and combinations of 2,4-D, BAP and NAA to determine an efficient protocol for in vitro propagation. Nine culture media made of combination of different components were used in a factorial design with three replications. Results showed up to 80 ± 4% disinfection rate with combination of triton x- 100 (0.2%) and sodium hypochlorite (30%). Embryo germination was highest on control medium. Rooting was higher (2±1 roots per embryo) after 4 weeks on control medium and on BAP supplemented medium at 0.8 μM while the longest root (1.5±0.5 cm) was observed on 2,4-D supplemented medium at 1.8 μM. Black soil was suitable for leaf formation (4 ± 2 leaves) and shoot elongation (2±1 cm) after 8 weeks in acclimatisation. These results show efficient disinfection, regeneration and acclimatisation of Picralima nitida.
Plant Tissue Cult. & Biotech. 31(2): 143-151, 2021 (December)
Considering the vegetable and medicinal values, a micropropagation protocol has been established for Japanese Burdock (Arctium lappa L.) by culturing the explants of cotyledon and leaf obtained from in vitro grown seedlings. Direct shoot regeneration was achieved from cotyledon and leaf explants on MS fortified with 4.0 μM BAP and 2.0 μM IBA or NAA after 5 weeks of culture. In addition, both the explants also formed callus from their cut margins within 6 weeks of cultivation on medium complemented with 6.0 μM BAP and 4.0 μM IBA or NAA. Adventitious shoots were also redeveloped through indirect organogenesis from the cotyledon and leaf-derived callus within 10 weeks of culture on MS containing 4.0 μM BAP and 2.0 μM IBA or NAA. The highest rate of shoot reproduction was attained at the third subculture, and more than 12.6 shoots were formed per callus clump. Within 4 weeks of transfer to the rooting medium on MS containing 6.0 μM IBA, the cultured micro-shoots produced highest 5.3 roots per cultured shoot. Rooted plantlets were successfully established on a soil-composed-sand mixture under natural condition with 93.3% survival rate
Plant Tissue Cult. & Biotech. 31(2): 123-134, 2021 (December)
This study was undertaken to evaluate the removal of lipid-rich organic matter from wastewater by lipase producing bacteria. Ten potential lipase producing bacteria were isolated from lipid-rich environments in and around Dhaka Metropolitan city. Three of them produced lipase higher than 10 U/ml. These three isolates and their consortium were used for synthetic wastewater treatment in the laboratory. The initial COD value of synthetic wastewater was 1,200 mg/l. COD removal efficiencies in the synthetic wastewater were 74.75, 73.33 and 66.67% by the Stenotrophomonas maltophilia e-a22, Pseudomonas aeruginosa 12 and Bacillus subtilis 20B, respectively. Stenotrophomonas maltophilia showed better COD removal performance (74.75%) in case of monoculture. But consortium showed better COD removal (83.33%) than that of monoculture. Therefore, it could be concluded that consortium of three isolates will be more useful for wastewater treatment as seed cultures in the wastewater treatment plant associated with the lipid-rich wastewater.
Plant Tissue Cult. & Biotech. 31(2): 135-142, 2021 (December)
The present study was planned to enable in vitro conservation of Vanda testacea, a highly medicinal orchid species through in vitro asymbiotic seed germination technique in Mitra orchid medium supplemented with cytokinins (Kn - 4.65 μM, BAP - 4.44 μM), and auxin (NAA- 5.37 μM). The germination frequency and initiation of germination was higher in NAA augmented medium and seedlings developed in 12.50 ± 0.50 weeks. Coconut water (20%) proved optimum for the multiplication of protocorm like bodies. Activated charcoal successfully checked the release of brownish exudates in the cultures.
Plant Tissue Cult. & Biotech. 31(2): 153-160, 2021 (December)
An efficient and rapid in vitro regeneration protocol was developed for chrysanthemum (Chrysanthemum morifolium Ramat) using two local varieties of Bangladesh namely, BARI Chrysanthemum-2 (BARI Chry-2) and local yellow (Y). MS medium supplemented with nine different concentrations and combinations of BAP and IAA was employed to optimize regeneration protocol using young in vitro derived leaf explants. Direct organogenesis was observed from the leaf explants on MS medium supplemented with 0.5 mg/l BAP and 2.0 mg/l IAA (T6) for both the varieties. This treatment (T6) induced shoot buds directly on the adaxial surface of the leaf providing the highest regeneration percentage (90% for BARI Chry-2 and 94.73% for Y), the highest number of shoot/explant (7.6 for BARI Chry-2 and 8.6 for Y) and maximum length of the shoot after six weeks (3 cm for BARI Chry-2 and 2.9 cm for Y) of culture. Explants with initially regenerated shoots were subculture on hormone free MS medium for shoot elongation after 4 weeks of their inoculation. During elongation of shoots, 90-95% of the regenerated shoots produced roots spontaneously in hormone free MS medium within 7-8 weeks of their inoculation. Rooted plantlets were transplanted to the field following hardening where 100% plantlets were survived and produced flower without any variation.
Plant Tissue Cult. & Biotech. 31(2): 161-171, 2021 (December)
Biramsundari is a rice germplasm from Bangladesh showing one to four grain in a single seed. Comparative study of morphological traits revealed that BS is a taller rice variety compared to modern rice varieties with longer and wider flag leaves, longer panicle length and higher thousand seed weight (TSW) than transplanted aman rice variety BRRI dhan 49. Flower morphological analysis unveil that multiple grains of Biramsundari are originating from multiple number of carpels in each floret. About 40.1% flower contains three carpels. Fluorescent microscopic study also confirms the zygotic origin of multiple grain formation in Biramsundari. Molecular characterisation of Biramsundari was performed by using TeaCpSSR27 and TeaCpSSR28 chloroplast microsatellite markers. The results of this investigation reveal that atpF and rsp14-psaB intergenic spacer regions of Biramsundari have variation compared to sequences of with O. sativa ssp. indica, O. sativa ssp. japonica and O. rufipogon.
Plant Tissue Cult. & Biotech. 31(2): 115-122, 2021 (December)
Nauclea diderrichii is a tree species of economic importance. However, its plantation establishment is limited by inadequate seedling production. Hence, there is ample scope of tissue culture for its mass propagation. Its in vitro plantlets development as affected by media strengths indicated that 100 % seed germination was obtained in full MS basal medium while the least (3.35 %) was from quarter-strength at 8 Weeks after inoculation (WAI). The effects of BAP and NAA assessed on the growth of its sub-cultured plantlets showed that highest number of leaves (17) and adventitious shoots (3) were obtained from MS basal medium supplemented with 0.1 mg/l BAP only. Whereas, highest shoot length (3.61 cm) and average number of roots (5/plantlet) were obtained from the same medium without hormone(s) at 8 WAI. Further sub-culturing into MS with 0.05 mg/l NAA resulted into plantlets having optimum shoot and massive root growth ready for acclimatization in 6 WAI. The plantlets were successfully acclimatized using coconuthusk/ topsoil mixture with 90 % survival.
Plant Tissue Cult. & Biotech. 31(1): 51-60, 2021 (June)
In general, antimicrobial agents are often used in micropropagation techniques to obtain contaminant free clones. The objective of the present study was to evaluate the effects of bavistin and cefotaxime on producing contaminant free plants of Ruellia tuberosa cultured on MS supplemented with phytohormones. Field grown nodal explants of Ruellia tuberosa was used to regenerate entire plants via direct organogenesis. Among the decontaminants tested, the fungicide bavistin along with higher concentration of BAP (2.0 mg/l) and lower concentration of NAA (1.0 mg/l) was the most effective in regeneration and producing contaminant free shoots from cultured explants. This fungicide at 300 mg/l minimised fungal contamination with survival rate of 54%. While the addition of decontaminant cefotaxime at low concentration (200 mg/l) along with same concentration of BAP and NAA stimulated the bud formation and controlled the bacterial contamination. However, its increasing concentration adversely affected the survival rate of Ruellia tuberosa. These findings clearly showed that low concentrations of bavistin and cefotaxime were not only non-toxic but also facilitated bud regeneration. The results achieved showed the decisive role not only of the use of successful fungicides and antibiotics, but also of their sufficient doses were very important in reducing contamination and helping multiple shoot proliferation.
Plant Tissue Cult. & Biotech. 31(1): 1-12, 2021 (June)
Agrobacterium mediated genetic transformation of BRRI Dhan 58 was conducted by using immature embryos following indirect regeneration. High percentage of callus induction at 96.5% was obtained when seeds of BRRI dhan 58 were cultured on modified MS medium supplemented with 2.5 mg/l 2, 4-D under dark condition. The maximum regeneration response was rerecorded when MS was supplemented with 3 mg/l BAP + 0.5 mg/l NAA and 1.0 mg/l Kn. Genetic transformation was performed using A. tumefaciens strain LBA4404 harboring pCAMBIA1301 plasmid carrying the marker genes for β-glucuronidase (GUS) and hygromycin resistance (hptII). Integration of the GUS gene into the genome of the rice plants was confirmed by PCR. The leaf segments of the PCR positive transformed plants showed the expression of GUS. The results of this study would be an effective tool for crop improvement and functional studies of gene on rice plant.
Plant Tissue Cult. & Biotech. 31(1): 71-80, 2021 (June)