Karyotype of some species of <i>Chara</i> and <i>Nitella</i> (Charophyta) from Bangladesh

Abstract

Karyotypic analysis of Chara corallina Linn., C. vulgaris Linn., C. gymnopitys Linn. and Nitella translucens Ag. collected from natural habitats revealed that C. corallina has n=42, C. vulgaris and Chara gymnopitys have n=14 while Nitella translucens has n=18 chromosomes. All the species had differences in individual chromosome length, total chromatin length, total frequency between the complements of their chromosomes. Cytological investigation on the chromosome number in members of charophyta from India have been made in the last several decades (Noor 1969, Noor and Mukherjee 1977, Khan and Sarma 1967, Sinha and Verma 1970.It has been reported that the chromosomes of algae are predominatly like that of the higher plants and most of the green algae possess localized centromeres as do most of the higher plants (Nagl and Furening 1979). In the present study, an attempt has been made to report the chromosome number and their morphology because so far no such work has been done in Bangladesh.Chara corallina Linn., Chara vulgaris Linn., Chara gymnopitys Linn. and Nitella translucens Ag. were collected from different places in Rajshahi district, Bangladesh. These species were identified based on monographs by Paul et al. (1960) and the British Charophyta by Groves and Webster (1920). Antheridial filaments were the most favourable material for cytological study. Green tips with prominent sex organs were collected and fixed in 1:1 aceto-alcohol solution for 24-48 hours and then transferred to 70% ethanol. During cytological investigation Godward's (1948) iron-alum acetocarmine method was applied with slight modification. Sometimes for clear staining 1% haematoxylin was used instead of acetocarmine. Squashing and light tapping were carried out for better spreading of metaphase chromosomes in one plane. The number of chromosomes for each of algal species were counted and length of chromosomes with respect to the centromeric position were measured from camera lucida drawings. From the total chromatin length (TCL), TF% and coefficient of variation (CV) among the chromosome complement were computed statistically by conventional methods to characterize each of four karyotypes of the Charophytes.

Karyotype analysis in someCharaspecies (Charales, Charophyceae) in Iran

“…The karyotype within the genus Chara is considered to be symmetrical and the majority of taxa have a dominance of metacentric and sub-metacentric chromosomes (Singh and Chaudhary 2010;Khatun et al 2009). In present study, four Chara species showed high values of TF% (> 40) and contained a symmetrical karyotype.…”

“…ANOVA and LSD tests revealed significant differences in the total size of chromosomes, size of the long arms, size of the short arms and the arm ratio among the populations of each species and varieties studied, 1967a, 1967bMirasidov 1971;Grant and Proctor 1972;Khatun et al 2009) reported the occurrence of n =14, 18, 28, and 42, but n = 14 and 28 are the most frequent chromosome counts for this species (Singh and Chaudhary 2010).…”