Philippine Science Letters
vol. 5 | no. 2 | 2012
published online October 25, 2012


ARTICLE


Disease Identification and In situ Screening of Gumamela (Hibiscus rosa-sinensis Linn) Germplasm and Hybrids to Leaf Anthracnose for Disease Resistance Breeding


by Cecilia B. Pascual* and Pablito M. Magdalita*


Crop Science Cluster and Institute of Plant Breeding,
College of Agriculture, University of the Philippines
Los Baños, 4031 College, Laguna, Philippines




FULL PDF VERSION

 



Hibiscus germplasm and hybrids planted at the Crop Science Cluster - Institute of Plant Breeding (CSC-IPB) breeding blocks have been observed to be affected by a few diseases. The identification of these diseases and their causal organism plus the identification of natural sources of resistance is crucial for the breeding program. The diseases that were identified included the following: a) anthracnose, commonly known as the leaf spot disease caused by Colletotrichum gloeosporoides Penz., b) early wilt and die-back attributed to Fusarium oxysporum Schlect, c) stem rot at the base of the plant, wilting and blighting of the plant caused by Rhizoctonia solani Kuhn. All fungal isolates demonstrated pathogenicity to hibiscus. Out of the 36 hibiscus genotypes evaluated in situ, 12 showed less than 10% average of the leaf area infected for leaf anthracnose. In contrast, two Hibiscus species namely: Hibiscus cooperri and H. schizopetalus, two hybrids namely: H. rosasinensis ‘Perla Santos Ocampo’ x H. rosa-sinensis ‘Loren B. Legarda’ and H. rosa-sinensis ‘Gelia T. Castillo’x H. rosasinensis ‘Betty Go-Belmonte’ including three other varieties like ‘Reddy or Not’, ‘Wilcox’ and ‘Petite Peach’ were not infected by the leafspot disease or anthracnose under field conditions, which suggests that they could have some form of resistance to this disease. This further suggests that the resistant related species especially H. cooperri having red and white variegated leaves could be used for hybridization with the susceptible varieties to develop a variety with a dual purpose trait, i.e. resistant to the fungus and leaves with variegations as another ornamental trait of the hybrid variety.

*Corresponding author
Email Address:
cbpascual22@yahoo.com,
magdalitapm@yahoo.com
Submitted: January 17, 2012
Revised: June 25, 2012
Accepted:July 22, 2012
Published: October 25, 2012
Editor-in-charge: Gisela P. Padilla-Concepcion
Reviewers:
Rex Sadaba
Thomas Edison de la Cruz