Karyotype Variation in Eight Cultivars of Indian Dessert Banana (Musa acuminata L.) of Section Eumusa From Odisha, India

Banana (Musa spp.) cultivars especially dessert banana are important cash crop with high market demand all over the world as an integral part of the diet. The need for assessment of cytogenetic characters in Musa cultivars is inevitable as out of thousands of cultivars, cytogenetic characterization of most of them remains unresolved due to difficulties like small chromosome size, diversity in ploidy levels and high cultivar diversity which behave differently to standardized cytogenetic protocols. In this report, somatic chromosome number, detailed karyotype analysis including total chromosome length, volume, form percentage, Interphase Nuclear Volume (INV) were accessed on eight dessert type of Musa accessions from different places of Odisha. All the cultivars studied were found triploid (2n = 33) with a basic chromosome number of x=11. The karyotype formulae were assigned to each cultivar by grouping the chromosome according to their shared characteristics. The total chromosome length ranged from 54.95 µm in cv. Robusta to 81.5 µm in cv. Kathia with symmetric karyotype in all the studied cultivar. Karyotype formula revealed structural alteration of chromosome with Total Form percentage (TF%) variation from 35.65% in cv. Amritapani to 41.68% in cv. Patakpura that confirms more number of nearly median constricted chromosome as compared to sub-median chromosome. The total chromosome volume recorded from 10.78 µm3 in cv. Robusta to 15.99 µm3 in cv. Khatia and the INV varied from 1336.44 µm3 in cv. Dwarf Cavendish to 2048.37 µm3 in cv. Patakpura. The recorded structural variation might be due to differential genome specific condensation of chromosome. Chromosome length and volume found statistically significant among the cultivars.

Comparison of different cytological parameters of three species of Ocimum

Karyomorphological analysis of three species of the genus Ocimum (O. basilicum L., O. americanum L. and O. tenuiflorum L.) was carried out. Gross chromosome morphology of these species are nearly sub metacentric (Sm), nearly metacentric (m) and metacentric (M) in nature. The high values of mean chromosome length, total chromosome length of O. americanum followed by O. basilicum show their primitiveness. Whereas, lower values of these parameters in O. tenuiflorum denotes evolved nature of the species. All the three species of Ocimum showed high values of total forma percentage (TF%) in conjunction with low coefficient of variation (CV), which corresponds to the primitive status in the evolution of flowering plants and was placed in 3A class of Stebbins’ system, indicating the presence of symmetrical karyotype in them. Karyotyping along with UPGMA based dendrogram analysis clearly separated O. basilicum L. and O. americanum L. in one cluster and O. tenuiflorum L. in a separate cluster with greater Euclidian distance.

Cytotaxonomy of four Floral Variants of Impatiens Balsamina L.

Karyomorphological characters were investigated in four floral variants of Impatiens balsamina L. viz. white, pink, violet and red for proper characterization and inferring relationships among them. All four floral variants of I. balsamina were found to possess 2n = 14 chromosomes, and ‘Simple Chromocenter Type’ of interphase nuclei was observed in all variants with many small heterochromatin blocks after orcein staining. ‘Continuous Type’ of prophase chromosomes was found in red variant, whereas both ‘Continuous and Gradient Type’ were found in other three variants. The red variant could easily be distinguished from the remaining three variants by total chromosome length, centromeric formula, average chromosome length, total form value, and karyotype asymmetry plus symmetry index. Based on karyomorphology, the white, pink and violet variants of I. balsamina were found very closely related and constituted with similar genome, whereas red variant was found to possess slightly modified genome and distinct from other three floral variants. Journal of Bangladesh Academy of Sciences, Vol. 43, No. 1, 1-9, 2019

Karyological Characteristics of Some Endemic Onobrychis Taxa Belonging to Onobrychis Section Naturally Grown in Turkey

Karyotype properties of of six endemic Onobrychis taxa (O. beata, O. cilicica, O. fallax, O. podperae, O. sulphurea and O. lasistanica) naturally grown in Turkey were determined using squash preparation method and similarity of these endemics with cultivated taxon (O. viciifolia) were revealed. Ploidy levels of Onobrychis taxa were diploid (2n=14) except O. lasistanica and O. viciifolia (2n=28). Basic chromosome number is x=7 and chromosomes ranged from median to sub median with regard to centromere position. While the longest total chromosome length was measured in O. cilicica (28.21 µm), the shortest total chromosome length was in O. beata (21.47 µm). O. cilicica and O. sulphurea have satellite on chromosome 1 and chromosome 2, respectively. Hierarchical cluster analysis was performed to determine the relationships among the Onobrychis taxa and they were separated into three groups. O. fallax, and O. podperae were in the first group while O. sulphurea and O. cilicica were in the second group. O. beata, O. lasistanica, and O. viciifolia were assigned to the third group.

Variation in actual relationship among descendants of inbred individuals

SummaryIn previous analyses, the variation in actual, or realized, relationship has been derived as a function of map length of chromosomes and type of relationship, the variation being greater the shorter the total chromosome length and the coefficient of variation being greater the more distant the relationship. Here, the results are extended to allow for the relatives’ ancestor being inbred. Inbreeding of a parent reduces variation in actual relationship among its offspring, by an amount that depends on the inbreeding level and the type of mating that led to that level. For descendants of full-sibs, the variation is reduced in later generations, but for descendants of half-sibs, it is increased.

Comparative Analysis of Karyotypes from the Strezelecki Ranges Race of the Complex Eucalyptus globulus Labill. ssp. globulus (Myrtaceae) and a Population in Central-Southern Chile

Summary This study presents information on karyotypes of the Strezelecki Ranges race, referred to in previous studies as Jeerelangs (Victoria, Australia), of the complex Eucalyptus globulus. ssp globulus and another from Central- Southern Chile (Contulmo). The chromosomes counted (2n = 22) are fairly small-sized and found within the size ranges reported by other authors. The chromosome measurements, done with the Micromeasure program, indicate that the Strezelecki Ranges lineage has a relatively large genome (Total Chromosome Length = 8.94%) as compared to measurements of local lineages (Chile). This could be explained by genetic recombinations resulting from the successive hybridizations reported for this race. The data obtained for both lineages reveal a set of markedly metacentric chromosomes with a centromeric index between 0.44 and 0.46.

Observations on chromosomes and gametogenesis ofTransversotrema patialense(Trematoda)

SUMMARYThe karyotype ofTransversotrema patia1enconsists of 10 pairs of chromosomes (2n= 20) of which 5 pairs are metacentrics and 5 pairs are submetacentrics. The chromosomes are large and range in size from 5 to 12 μm. The total chromosome length of the diploid complement is 16783 μm. Stages of spermatogenesis including the two gonial divisions and two reduction divisions leading to production of spermatozoa occur in cercarial embryos inside snail tissue, while the maturation divisions of the ovum occur in eggs freshly liberated by the fluke. The chiasma frequency is high, being 3888/cell and 388/bivalent. Cytological data indicate an independent phylogenetic status for the family Transversotrematidae.