Oogenetic cell and chromosomes of the rice- infesting brown planthopper Nilaparvata lugens (Stal) (Homoptera : Delphacidae)

Date

5-1987

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Adelina A. Barrion

Abstract

Oogenetic cells of Nilaparvata lugens (Stal) involving mitosis and melosis were investigated. Early mitotic division was observed on the primary and secondary oogonia, first and second meiotic divisions were observed in the primary secondary oocytes, respectively. The meiotic division was reductional at oocytes I and equational at oocytes II stages. The karyotype of female N. lugens was 2n=30 (14IIA + XX), yielding only one type of ovum or an egg cell - 141 + 14I + X. Homologous chromosomes possessed diffused centromeres. Pachytene autosomes had relative lengths ranging from 0.011 to 0.084, while XX chromosomes measured 0.005. Meiotic pre-pachytene chromosomes, on the other hand relative lengths ranging from 0.011 to 0.066, while XX chromosomes measured 0.007. AT metaphase I, anaphase I and telophase I the heterochromatic sex chromosome isolated themselves from the autosomal grouping. At late telophase I. they join themselves with the autosomes and reached either on of the poles. Cell having the sex chromosomes undergo the second meiotic divisions. Spontaneous chromosomal aberration includes stickiness of chromosomes. Among all the dividing cells observed, 2 percent (%) of all the dividing cells exhibits stickiness of chromosome.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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