"Cytological effects of Neem oil (Azadirarchta indica, A. Juss) on the spermatocytes of red flour beetle, Tribolium castaneum (Herbst) (Coleoptra : Tenebrionidae)."

Date

5-1988

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Adelina A. Barrion

Abstract

Lacto-aceto-orcein squashes of testicular cells of T. castaneum revealed the following: mitotic index, 92%; meiotic index, 90%; diploid (2n) chromosome number, 20; sex determining mechanism, XX (o) : Xy (o'); karyotype formulae of T. castaneum, 911A + XX and (0'1) = 911A + Xy; relative length of chromosomes ranged from 0.019 to 0.129; unique 'parachute-like' association of sex chromosomes at diakinesis; and three differentiation stages of prophase nuclei and spermatids. Cells of T. castaneum treated with 200, 400, 800 and 1600 ppm neem oil were examined and compared with the untreated. All treated samples exhibited significantly lower mean meiotic indices. As neem oil concentrations increase, the frequencies of occurrence of chromosome fusions and aneuploids increase. Bivalent diakinetic chromosomes of treated individuals increased in length, width and area. Extensive chromosome clumpings were observed in 800 and 1600 ppm neem oil-treated samples. Chromosome elongation, chromo-some stickiness and non-differentiation of spermatids were distinctly exhibited by 1600 ppm neem oil-treated T. castaneum.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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