Cytogenetic evaluation of anther source IR43, its doubled haploid lines and their F1 hybrids.

Date

4-1993

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Edwin L. Javier

Abstract

A study was conducted to determine the cytogenetic behavior of pureline IR 43, its anther culture-derived doubled haploid lines (DH1) and their Fl hybrids. The chromosome number for all materials was 2n=24. Chromosome pairing was limited to bivalent formation indicating that no gross chromosomal aberrations had taken place during the anther culture. However, occasional unpaired terminal regions of 1-2 paired homologues at pachytene were observed in DH1-2 (4.2%), IR43 x DH1-2 (2.4%) and IR43 x DH1-3 (4.0%). Unstable pairing could be due to the presence of small structural aberrations induced during the anther culture in one of the homologues. Early disjunction of 1-2 bivalents was observed at diakinesis in all mterials. The frequency of cells with early disjoining bivalents increased from diakinesis to metaphase L. Cells at anaphase I had a high frequency of normal chromosome distribution of 12 I each at opposite poles. Lagging bivalents or even-numberes univalents at anaphase I were present at low frequency (IR43 x DH1-5) or absent (other materials evaluated) at telophase I. In general, there was no chromosome behavior noted that would significantly affect the production of functional gametes.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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