Four Oxalis L. species namely O. corymbosa, O. corniculata, O. latifolia, and O. triangularis were investigated cytogenetically and at the molecular level for proper characterization. Different 2n chromosome numbers were found in four species, such as 2n=44 in O. corniculata, 2n=28 in O. latifolia, 2n=30 in O. corymbosa, and 2n=30 in O. triangularis. The diploid chromosome number 2n= 30 is the first report for O. triangularis. The four species differed with respect to centromeric formulae, such as 30m in O. corymbosa, 44m in O. corniculata, 24m+4sm in O. latifolia, 26m+4sm in O. triangularis. The four species of Oxalis have distinct CMA-and DAPI banding patterns based on the number, location, intensity, and percentage of GC-and AT-rich repeats. With the help of CMA and DAPI staining, it was possible to mark certain chromosomes specific for each species. Moreover, the four species possess distinct RAPD fingerprinting patterns with species-specific unique marker fragments. RAPD fingerprinting analysis placed O. corymbosa in a different cluster whereas the rest three in another cluster. Therefore, the compilation of the cytological and molecular information will be useful for authentic identification and characterization of the four Oxalis species found in Bangladesh.

Acalypha indica L. was cytogenetically characterized after staining with orcein, CMA and DAPI. In this species "Simple Chromocenter Type" of interphase nuclei was observed with a few small heterochromatin blocks following orcein staining. Prophase chromosomes showed “Interstitial Type” of staining pattern with orcein which indicated the tendency of aggregation of heterochromatin in interstitial regions of chromosome. This plant was found to possess 2n = 20 metacentric chromosomes. The total length of 2n chromosome complement was 55.33 μm. Individual chromosome length ranged from 1.84 to 3.50 μm. The relative length of each chromosome ranged from 0.03 to 0.06. After staining with CMA, three bright bands were observed at different locations of chromosomes. A total of four DAPI-positive bands were also found of which two bands were centromeric and other two were entirely fluoresced with DAPI. The results of the cytological investigation may be useful for future characterization of this plant species. Dhaka Univ. J. Biol. Sci. 27(2): 183-189, 2018 (July)

Comparative chromosome analysis by conventional staining with orcein and differential staining with CMA and DAPI was carried out in three Amaranthus species viz. A. viridis, A. tricolor, and A. lividus. Although, the three species were found to possess 2n=34 chromosomes, differed in respect of total length of chromosome complement. Each Amaranthus species showed a characteristic fluorescent banding pattern based on distribution and amount of CMA-and DAPI-bands. In the three species, out of 22 CMA-banded and 27 DAPIbanded chromosomes, seven and eight were entirely fluoresced with CMA and DAPI, respectively. The compiled data gathered from comparative chromosome analysis on orcein, CMA-and DAPI-banding will be useful for cytogenetical characterization of Amaranthus species.

Three Curcuma L. species were investigated cytogenetically which represent diversed staining pattern of heterochromatins in interphase nuclei and prophase chromosomes with orcein staining. Curcuma longa and C. caesia were found to possess 2n = 3x = 63 somatic chromosomes whereas 2n = 2x = 42 chromosome number in C. zedoaria is reported for the first time from Bangladesh. Total chromosome length recorded in C. longa, C. caesia and C. zedoaria were 145.08 ± 2.85 μm, 164.93 ± 4.29 μm and 97.78 ± 2.41 μm, respectively. This was the first attempt to measure the length of the chromosomes for these species. The experiment confirmed the basic chromosome number x = 21 with triploid (C. longa, C. caesia) and diploid (C. zedoaria) Curcuma plants. Polyploidy could be employed in the evolution and diversification of the genus Curcuma, which is an essential factor to characterize the species of this genus. Dhaka Univ. J. Biol. Sci. 30(2): 133-140, 2021 (July)

Karyotypes of three Piper species viz. P. betle L., P. longum L., and P. retrofractum Vahl were studied with a conventional staining and a fluorescent banding. P. betle, P. longum, and P. retrofractum possessed 2n=68, 2n=48 and 2n= 72 chromosomes in root tip cells, respectively. Chromosome number of P. retrofractum (2n=6x= 72) is the first report. The three species of Piper showed distinct chromomycin A 3 (CMA)-and 4′,6-diamidino-2-phenylindole (DAPI)-band patterns based on the number, location, and size of CMA-and DAPI-bands. The several chromosomes fluoresced overall by CMA or DAPI and these fluorescent bands will be a good marker for chromosome study. The three species were different in respect of conventional karyotype and fluorescent banding pattern. In three Piper species, the comparative karyotype analysis of fluorescent banded chromosomes might suggest that chromosome diversity occurs in aneuploidy and polyploidy.