Viruses (2022) 14 (10 - 2165)

Rudolph Rufini Shirima, Everlyne Nafula Wosula, Abdou Azali Hamza, Nobataine Ali Mohammed, Hadji Mouigni, Salima Nouhou, Naima Mmadi Mchinda, Gloria Ceasar, Massoud Amour, Emmanuel Njukwe and James Peter Legg (2022)
Epidemiological analysis of cassava mosaic and brown streak diseases, and Bemisia tabaci in the Comoros Islands
Viruses 14 (10 - 2165)
Abstract: A comprehensive assessment of cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) was carried out in Comoros where cassava yield (5.7 t/ha) is significantly below the African average (8.6 t/ha) largely due to virus diseases. Observations from 66 sites across the Comoros Islands of Mwali, Ngazidja, and Ndzwani revealed that 83.3% of cassava fields had foliar symptoms of CBSD compared with 95.5% for CMD. Molecular diagnostics confirmed the presence of both cassava brown streak ipomoviruses (CBSIs) and cassava mosaic begomoviruses (CMBs). Although real-time RT-PCR only detected the presence of one CBSI species (Cassava brown streak virus, CBSV) the second species (Ugandan cassava brown streak virus, UCBSV) was identified using next-generation high-throughput sequencing. Both PCR and HTS detected the presence of East African cassava mosaic virus (EACMV). African cassava mosaic virus was not detected in any of the samples. Four whitefly species were identified from a sample of 131 specimens: Bemisia tabaci, B. afer, Aleurodicus dispersus, and Paraleyrodes bondari. Cassava B. tabaci comprised two mitotypes: SSA1-SG2 (89%) and SSA1-SG3 (11%). KASP SNP genotyping categorized 82% of cassava B. tabaci as haplogroup SSA-ESA. This knowledge will provide an important base for developing and deploying effective management strategies for cassava viruses and their vectors.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): James P. Legg

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
transmission/dispersal of plant diseases

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cassava brown streak virus	Cassava (Manihot esculenta)	Comoros Islands
	Ugandan cassava brown streak virus	Cassava (Manihot esculenta)	Comoros Islands
	Bemisia tabaci biotype Sub Saharan Africa 1	Cassava (Manihot esculenta)	Comoros Islands