Leaf blight of coconut (Cocos nucifera L.) caused by Fusarium proliferatum (Matsush.) Nirenberg, a new disease record in the Philippines

Date

6-2015

Degree

Bachelor of Science in Agriculture

Major Course

Major in Plant Pathology

College

College of Agriculture and Food Science (CAFS)

Adviser/Committee Chair

Teresita U. Dalisay

Abstract

Leaf blight disease on coconut was observed in different growing areas in Batangas and Laguna provinces. A study was conducted primarily to establish the fungal pathogen(s) responsible for the disease and to determine their identity to species level based on morphological characterization and molecular work. A total of 40 fungal isolates were obtained from disinfected diseased leaf sections. Out of these isolates, ten were confirmed causing the disease by satisfying the pathogenicity test on coconut seedlings. Morphological characterization of the fruit bodies namely macro- and microconidia, chlamydospores, conidiophores, and phialides were done, however, sizes were taken only for the different spore forms. Macroconidia are hyaline, lunate, smooth, multiseptated (3-4 septa) while microconidia are constantly ellipsoidal, unicellular to bicelled, occasionally constricted at the septum. The conidia originate from long, hyaline, branched conidiophores with round apices of phialides. Average size range for macroconidia is 24.89-41.27 x 1.70-3.02 μm while that of microconidia is 5.76-7.52 x 1.54-1.85 μm. Moreover, the mean size range of 8.62-11.40 x 5.54-8.31 μm were recorded on chlamydospores. Comparing the descriptions and sizes of the above structures with the published taxonomic descriptions warrant the genus of the causal organism as Fusarium. Molecular methods were done to further identify the fungal pathogens to its species level. All isolates formed a 650-bp product when subjected to agarose gel electrophoresis. Sequences of these, resembled the database of Fusarium proliferatum (Matsush.) Nirenberg at National Centre for Biotechnology Information?s (NCBI) Blast Tool.

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2015 A3 /D44

Document Type

Thesis

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