Damage and Control Suggestions for the Emerging Disease Coffee Root Rot

[Objectives]The paper was to elucidate the symptoms,morphological characteristics,etiological factors,and current extent of damage associated with coffee root rot disease.[Methods]The symptoms,morphological characteristics,and etiological factors associated with coffee root rot disease were systematically observed,described,and analyzed.The assessment of damage was carried out using a specialized investigative methodology.[Results]The application of bottom fertilizer containing Fusarium incarnatum facilitated the pathogen's entry through root wounds during transplantation,resulting in the development of water-soaked depression lesions in the affected areas.This infection significantly reduced the number of lateral roots in coffee plants,leading to symptoms such as wilting,withering,and ultimately,the death of the aboveground foliage.F.incarnatum exhibited three distinct types of spore morphology:macroconidia,which were sickle-shaped;mesoconidia,which were spindle-shaped;and microconidia,which were oval-shaped.The incidence rate of the disease in the affected region reached 100%,with a disease index exceeding 91,indicating severe damage.[Conclusions]This study serves as a valuable reference for the prevention and management of the emerging disease known as coffee root rot.

Transcriptome and carotenoid profiling of different varieties of Coffea arabica provides insights into fruit color formation

The processability and ultimate quality of coffee(Coffea arabica)are determined by the composition of the matured fruits.The basis of genetic variation in coffee fruit quality could be explained by studying color formation during fruit maturation.Transcriptome profiling was conducted on matured fruits of four C.arabica varieties(orange colored fruits(ORF);purple colored fruits(PF);red colored fruits(RF)and yellow colored fruits(YF))to identify key color-regulating genes,biosynthesis pathways and transcription factors implicated in fruit color formation.A total of 39,938 genes were identified in the transcriptomes of the four C.arabica varieties.In all,2745,781 and 1224 differentially expressed genes(DEGs)were detected in YF_vs_PF,YF_vs_RF and YF_vs_ORF,respectively,with 1732 DEGs conserved among the three pairwise groups.Functional annotation of the DEGs led to the detection of 28 and 82 key genes involved in the biosynthesis of carotenoids and anthocyanins,respectively.Key transcription factors bHLH,MYB,NAC,MADS,and WRKY implicated in fruit color regulation were detected.The high expression levels of gene-LOC113688784(PSY),gene-LOC113730013(b-CHY),gene-LOC113728842(CCD7),gene-LOC113689681(NCED)and gene-LOC113729473(ABA2)in YF may have accounted for the yellow coloration.The differential expression of several anthocyanin and carotenoid-specific genes in the fruits substantially account for the purple(PF),red(RF),and orange(ORF)colorations.This study provides important insights into fruit color formation and variations in C.arabica and will help to develop coffee varieties with specific color and quality traits.

Identification of Hyperparasitic Fungal Species Associated with Coffee Leaf Rust

[Objectives]The paper was to elucidate the specific hyperparasitic fungal species that are associated with coffee leaf rust.[Methods]Tissue isolation,sample humidification,and three-point inoculation techniques were employed to isolate,culture,and purify the hyperparasitic fungi responsible for coffee leaf rust.The purified strains were identified using traditional morphological techniques and molecular biology methods.[Results]Four strains were isolated,specifically BS21(Cladosporium cladosporioides),BS34(C.tenuissimum),BS62(C.cladosporioides),and BS75(C.colombiae).[Conclusions]The findings of this research will contribute novel insights into the biological control of coffee leaf rust.