Cytogenetic analysis of Oryza sativa L., Oryza australiensis Domin., and their derived progenies

Date

4-2007

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Celia B. Dela Viña

Co-adviser

Darshan S. Brar

Abstract

Somatic chromosome number, meiotic behavior, and pollen fertility were determined in Oryza saliva L. (AA), 0. ausiraliensis Domin. (EE), their Fi hybrid, and backcross progeny. Somatic chromosome analysis revealed that the chromosome number of the parents and the F, hybrid is 2n=24 while the BC1Fi and BC, F2 is 2n=48. Normal chromosome pairing at diakinesis and metaphase I and regular chromosome distribution at anaphase 1 were observed in the parents. The F, hybrid showed predominantly 24 I and highly irregular meiosis. Anaphase I showed unequal distribution of chromosomes and there was complete pollen sterility. Normal meiosis was observed in BC,F, and BC, F2 at diakinesis showing 20-24 II instead of the predicted 12 11 + 12 1 configuration. There is possibility that the obtained BC,F, may not actually be backcross progenies but doubled F, hybrid resulting through spontaneous chromosome doubling or through unreduced F, where male and female gametes, both containing 12 A and 12 E chromosomes combined to produce plants with 2n=48. Regular chromosome distribution (24/24) was recorded at anaphase I in 62% and 78% cells of BC,F, and BC,F2, respectively. However, pollen fertility was very low in the BC,F, (0.004%) and BC, F2 (5.1%).

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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