TY - JOUR AU - Karna, Pushpa PY - 2017/03/25 Y2 - 2024/03/28 TI - Cytological Studies on Two Species, Xanthium strumarium Linn. and Bidens pilosa Linn. Var. minor (Blume) Sherff (Asteraceae-Heliantheae) from Nepal JF - International Journal of Applied Sciences and Biotechnology JA - Int J Appl Sci Biotechnol VL - 5 IS - 1 SE - Research Articles: Biological Sciences DO - 10.3126/ijasbt.v5i1.17010 UR - https://www.nepjol.info/index.php/IJASBT/article/view/17010 SP - 66-71 AB - <p>Karyotype, meiosis and pollen stainability of the taxa <em>Bidens pilosa </em>L. var. <em>minor</em> (Blume) Sherff<strong> </strong>and <em>Xanthium strumarium</em> L. collected from central part of Nepal was cytologically carried out. Results obtained from this investigation showed that chromosome number in somatic cells were recorded to be 2n=36 in <em>Bidens pilosa </em>and 2n=32 in <em>Xanthium strumarium</em> using aceto-orceine squash technique. Likewise haploid chromosome number in reproductive cells were recorded to be n=18 in <em>Bidens pilosa</em><strong> </strong>and n=16 in <em>Xanthium strumarium </em>using aceto-carmine squash technique. The range of chromosome length found to be 0.4 to 2.1 µm<em> </em>in<em> Bidens pilosa</em> and 0.4 to 1.6 µm in <em>Xanthium strumarium.</em> Karyotype formula was M<sub>16</sub>+m<sub>2</sub>+sm<sub>14</sub>+st<sub>4</sub> for <em>Bidens pilosa </em>and<em> </em>M<sub>18</sub>+ sm<sub>12+</sub>st<sub>2</sub> for <em>Xanthium strumarium</em>.<strong> </strong>Based on the position of the centromeres, the chromosomes were categorized into four types with centromere at median point, median region, sub median region and terminal region in <em>Bidens </em>pilosa whereas three types, namely chromosomes with centromere at median point, sub median region and sub terminal region in<em> Xanthium strumarium</em> . In <em>Bidens pilosa</em> karyotype is asymmetrical and slightly asymmetrical karyotype is found in<em> Xanthium strumarium.</em> Absolute length recorded in<em> Bidens pilosa </em>were<em> </em>19.2µm and<em> </em>15.8. µm in<em> Xanthium strumarium </em>. Pollen stainability is found to be 94.0 percent in <em>Bidens pilosa </em>and 92.7 percent in <em>Xanthium strumarium.</em></p><p><em><em>Int. J. Appl. Sci. Biotechnol. Vol 5(1): 66-71</em></em></p> ER -