Molecular and Morphological Characterization of Rhizoctonia Isolates Collected in Florida and Screening of St. Augustinegrass Germplasm for Brown Patch and Large Patch Resistance

Download or read book Molecular and Morphological Characterization of Rhizoctonia Isolates Collected in Florida and Screening of St. Augustinegrass Germplasm for Brown Patch and Large Patch Resistance written by Norma Cristina Flor and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Fungi in the genus Rhizoctonia make up a complex taxonomical group of plant pathogens. Multinucleate species such as Rhizoctonia solani (Thanatephorus cucumeris), Rhizoctonia zeae, Rhizoctonia oryzae (Waitea circinata var. zeae and var. oryzae), Rhizoctonia circinata (not defined anamorph) and binucleate species such as Rhizoctonia cerealis (Ceratobasidium cerealis) are known for causing major and minor diseases on cool and warm season turfgrasses. Rhizoctonia solani causes brown patch and large patch diseases. Brown patch is a disease of cool season grasses caused by the AG 2-2 III B during summer. Large patch on warm season grasses caused by AG 2-2 LP is the most economically important disease that affects turf quality and development in fall and spring seasons. The present study was focused on describing the isolates present on the University of Florida collection that are associated mainly with warm season grasses. The description was based on the most important morphological features of the fungus and supported by molecular data obtained from amplification of Internal Transcribed Spacer regions, a gene phylogenetically informative. Screening of twenty St. Augustinegrass genotypes also was performed in order to evaluate the possible effect that ploidy level of the plants and morphotypes had on disease response.