ABSTRACT Cassava (Manihot esculenta Crantz) black stem and root rot (BSRR) caused by complex fungi is one of the most serious fungal disease of cassava in Thailand. The objective of this study was to identify the causal agent of BSRR disease of cassava in Nakhon Ratchasima province, Thailand. From June 2015 to May 2018, the outbreak areas in three districts of Nakhon Ratchasima province were surveyed for cassava plants with the characteristic symptoms. From 1800 diseased samples, 139 fungal pathogens were isolated and separated by morphological traits. Among them, 33 fungal isolates were subsequently tested for pathogenicity on detached stems and roots of CMR 43-08-89, a susceptible cassava cultivar, and proved to be pathogenic with different levels of aggressiveness. Next, PCR amplification of DNA of eight pathogenic isolates with high aggressiveness using two sets of universal primers ITS1/ITS4 and Ef1-688F/Ef1-1251R, revealed that the TEF1-α gene region could be used for the identification and classification at the species level. The analysis results fit well with that of the morphological studies on growth and colonial characteristics of the eight isolates. Based on the GenBank database, they were identified as Lasiodiplodia theobromae, L. euphorbiaceicola and Neoscytalidium dimidiatum.

Abstract Psoriasis is a common chronic, immune-mediated inflammatory disease of the skin. PSORS1C3 is a non-protein coding gene, of which the RNA transcript is found in psoriatic patients. CARD14 is mainly expressed in epidermal keratinocytes. TLR4 is a transmembrane protein to recognize microbial antigens. Our study aimed to assess the relationship among PSORS1C3, CARD14 and TLR4 polymorphisms, inflammatory expression and psoriasis susceptibility. To the end, 71 patients with psoriasis and 46 healthy individuals with the well-characterized clinical profiles were enrolled. Gene polymorphisms were determined by Sanger DNA sequencing and secretion of cytokines by ELISA. As a result, genetic analysis of PSORS1C3 gene identified nine SNPs and three haplotype blocks. Sequencing of the CARD14 gene determined eight SNPs and one haplotype block. Sequencing of TLR4 gene identified nine SNPs, in which a SNP rs1018673641 was found to exert deleterious effect. The linkage disequilibrium analysis showed that seven variants in PSORS1C3 gene and three SNPs in CARD14 gene were in tightly linked. More importantly, a significant association between IL-6 level and rs1018673641 AT genotype in TLR4 gene was detected in psoriatic patients. In conclusion, the PSORS1C3, CARD14 and TLR4 polymorphisms and haplotypes may be correlated with risk of suffering psoriasis and the IL-6-mediated chronic inflammation in psoriasis could be partially regulated by the TLR4 functional variant.