Morphological characterization and isozyme analysis of 16 cashew (Anacardium occidentale Linn.) accessions

Date

4-2005

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Merlyn S. Mendioro

Abstract

MARANAN, FAITH SANTIAGO. April 2005. Morphological Characterization and Isozyme Analysis of 16 Cashew (Anacardium occidentals Linn.) Accessions. University of the Philippines Los Balms. B.S. Biology, major in Genetics.

Adviser: Merlyn S. Mendioro

ABSTRACT

Sixteen cashew (Anacardium occidentale Linn.) accessions, namely, B1T3, Mitra, unk3, Caliwag, CIG, unk6, Guevarra, B2T6, Pizarro 4, Pizarro 8, Pizarro, Pizarro 9, IR6, 1R174, Dela Liana 5 and Pizarro 13 were characterized using morphological evaluation and isozyme analysis. Morphological evaluation revealed that there were five invariant characters namely: internode length, leaf shape, presence and absence of cracks on trunk barks, ease of peeling bark from twigs and leaf shape apex. IR174, PIZ, PIZ4, PIZ8, UNK3, Mitra, C1G and B2T6 manifested the spreading tree habit while the others showed the upright and open tree habit. Caliwag, CIG and Guevarra exhibited red color of young leaves while the rest showed the brownish color. Majority of the accessions also expressed low heights of the main branch. The crotch angle of the main branch was either obtuse or acute. Majority showed the cymose elaboration of inflorescence and the inflorescence shape ranged from pyramidal, narrow pyramidal to broad pyramidal. Isozyme analysis revealed similarities in the banding patterns of the collections. Alkaline phosphatase (ALP), acid phosphatase (ACP), esterase (EST), shikimate dehydrogenase (SKDH), isocitrate dehydrogenase (IDH), phosphoglucomutase (PGM) and 6-phosphogluconate dehydrogenase (PGD) were the enzyme systems used. Five of the isozyme systems used (ALP, 1DH, PGM, SKDH and PGD) were found to be monomorphic for all the cashew collections. Fourteen presumptive loci were also observed. A dendrogram was constructed showing the relationship among the accessions based on the similarities in their banding patterns. Genotypes designated to the loci further confirmed the similarities observed. Some cashew accessions collected from Zambales showed similarities in the banding pattern and genotypes while cashew accessions from Palawan were found to be distinct from one another. Unknown 6, which was the only accession from Los Banos, expressed a distinct genotype from the rest of the accessions studied. Similarities among the accessions collected from the same location could imply that those accessions were derived from a common plant. Likewise, similarities in accessions collected from different locations could imply that these were derived from the same plant then transferred to a new location. Little genetic variation was observed due to the fact that cashew can be propagated asexually.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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