Publications by authors named "Jack Comstock"

is an obligate biotrophic fungal pathogen that causes orange rust of sugarcane, which is prevalent in many countries around the globe. In the United States, orange rust was first detected in sugarcane in Florida in 2007 and poses a persistent and economically damaging threat to the sugarcane industry in this region. Here, we generated the first genome assemblies for two isolates of (1040 and 2143) collected in Florida in 2017 from two sugarcane cultivars, CL85-1040 and CP89-2143, respectively.

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An Axiom Sugarcane100K SNP array has been designed and successfully utilized to construct the sugarcane genetic map and to identify the QTLs associated with SCYLV resistance. To accelerate genetic studies in sugarcane, an Axiom Sugarcane100K single-nucleotide polymorphism (SNP) array was designed and customized in this study. Target enrichment sequencing 300 sugarcane accessions selected from the world collection of sugarcane and related grass species yielded more than four million SNPs, from which a total of 31,449 single-dose (SD) SNPs and 68,648 low-dosage (33,277 SD and 35,371 double dose) SNPs from two datasets, respectively, were selected and tiled on Affymetrix Axiom SNP array.

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Brown rust (caused by ) and orange rust (caused by ) are two major diseases of sugarcane in Florida. To better understand the epidemiology of these two rusts, disease severity and weather variables were monitored for two seasons in cultivars CL90-4725 (susceptible to brown rust and resistant to orange rust) and CL85-1040 (susceptible to orange rust and resistant to brown rust). Brown rust was most severe during mid-May to mid-July, whereas orange rust severity peaked during two periods: mid-May to early August and then November to December.

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Sugarcane ( spp.) is an important economic crop, contributing up to 80% of table sugar used in the world and has become a promising feedstock for biofuel production. Sugarcane production has been threatened by many diseases, and fungicide applications for disease control have been opted out for sustainable agriculture.

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Background: In Africa and Asia, sugarcane is the host of at least seven different virus species in the genus Mastrevirus of the family Geminiviridae. However, with the exception of Sugarcane white streak virus in Barbados, no other sugarcane-infecting mastrevirus has been reported in the New World. Conservation and exchange of sugarcane germplasm using stalk cuttings facilitates the spread of sugarcane-infecting viruses.

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Ratoon stunt, caused by the bacterium Leifsonia xyli subsp. xyli, is one of the major sugarcane diseases worldwide. The objectives of this study were to determine the variation in morphology and DNA sequence of L.

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Sugarcane (Saccharum spp.) is an important sugar and biofuel crop with high polyploid and complex genomes. The Saccharum complex, comprised of Saccharum genus and a few related genera, are important genetic resources for sugarcane breeding.

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Background: Pokkah boeng disease caused by the Fusarium species complex results in significant yield losses in sugarcane. Thus, the rapid and accurate detection and identification of the pathogen is urgently required to manage and prevent the spreading of sugarcane pokkah boeng.

Methods: A total of 101 isolates were recovered from the pokkah boeng samples collected from five major sugarcane production areas in China throughout 2012 and 2013.

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Orange rust of sugarcane (Saccharum spp. hybrids), caused by Puccinia kuehnii, is a relatively new disease in the Western Hemisphere that substantially reduces yields in susceptible sugarcane genotypes. The objective of this study was to determine the physiological mechanisms of orange rust-induced reductions in sugarcane growth and yield by quantifying effects of the disease on leaf SPAD index (an indication of leaf chlorophyll content), net photosynthetic rate, dark respiration, maximum quantum yield of CO assimilation, carbon fixation efficiency, and the relationships between these leaf photosynthetic components and rust disease ratings.

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Brown rust, caused by Puccinia melanocephala, and orange rust, caused by P. kuehnii, are agronomically important diseases of sugarcane in Florida. Cultivar resistance is the best means of controlling these diseases.

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Background: Resistance gene analogues (RGAs) have been isolated from many crops and offer potential in breeding for disease resistance through marker-assisted selection, either as closely linked or as perfect markers. Many R-gene sequences contain kinase domains, and indeed kinase genes have been reported as being proximal to R-genes, making kinase analogues an additionally promising target. The first step towards utilizing RGAs as markers for disease resistance is isolation and characterization of the sequences.

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