Cytology of Zea perennis, Zea mays and their F1 hybrid.

Date

3-1992

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Dolores A. Ramirez

Abstract

The chromosome number of Sea perennis was 2n=40, in Zea mays 2n=20 and their F1 2n=30. At diakinesis, Z. mays showed 100% normal pairing (10II) and it showed high frequency of normal behavior in other meiotic stages, accounting for its high pollen fertility . Z. perennis also exhibited high frequency (72%) of normal pairing (20II). However, it showed higher frequency of abnormalities in other meiotic stages such as laggards and bridges in metaphase I and anaphase I which may account for its low pollen fertility (38.25%). The lowest frequency of normal pairing (10II 10I) was observed in F1 hybrid (52.8%). In other meoitic stages, the F1 hybrid showed a significantly higher frequency of abnormalities which explains its low pollen fertility as compared to its parents. Quadrivalents and univalents were also observed in F 1 . In pachytene analysis, chromosome lengths determined on the camera lucida drawings were measured from the interpretative drawing and expressed in millimeter units. Chromosome lengths in Z. perennis range from 26.6 to 10.6 mm while that in Z. mays range from 57 to 128.3 mm. Pachytene analysis was not performed on F1 due to lack of available sporocytes.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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