Fungi causing fruit rot of roseleaf raspberry (Rubus rosifolius Sm.) 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

Eight fungal genera were proved to be the causal organisms of roseleaf raspberry fruit rot upon conduct of the pathogenicity test. The degree of rot in relation to the absence or presence of scanty to profuse mycelial growth determined the virulence of the fungal isolates. The above criteria for evaluation utilized the Visual Quality Rating Scale (VQRS). Among the isolates, sterile mycelia obtained the highest VQRS of 2.22 which caused moderate rotted tissues and dense mycelial growth followed by Fusarium sp. AFAB7 (1.89) and Fusarium sp. AFAB 8 (1.78). A little over and mid-way between 1 and 2 VQRS was manifested by Pestalotiopsis sp. AFAB 2 (1.44), Fusarium sp. AFAB 4 and AFAB 9 (both with VQRS of 1.22), and Phoma sp. AFAB 6 (1.11). Least capacity to cause infection was coelomycete sp. AFAB 5 with VQRS of 0.89. Cultural characterization revealed that Pestalotiopsis sp. AFAB 2 grew best on MEA and PDA; sterile mycelia AFAB 3 on PDA; Fusarium sp. AFAB 4 on MEA, RLDA and PDA; coelomycete sp. AFAB 5 on PDA, RLDA and RSDA; Phoma sp. AFAB 6 on RLDA and PDA,; Fusarium sp. AFAB 7 on PDA, MEA and RLDA,; Fusarium sp. AFAB 8 on all the media and Fusarium sp. AFAB 9 on PDA, MEA, RLDA and RSDA. Different light and dark conditions gave unpredictable patterns of growth on the isolates but generally, all the isolates gained their highest peak of growth on the first day after mycelial disc transfer. The growth rate and colony growth of each isolate were almost statistically the same. Moreover, the effect of different light and dark conditions was evident on coelomycete AFAB 5 which had the best growth upon exposure to total darkness. Results showed that the optimum temperature that favored the growth of the fungal isolates ranges from 24°C to 27°C. Higher temperatures 30°C to 37°C had consistently inhibited the growth of the isolates.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2015 A3 /J35

Document Type

Thesis

This document is currently not available here.

Share

COinS