ABSTRACT
In 2018,
mosaic symptoms were observed on sugarcane plantations of the commercial
variety G.T. 54-9 that grown at Qena governorate, Egypt. The initial serological
diagnosis confirmed that the Sugarcane mosaic virus (SCMV) was the
causative agent of mosaic disease on sugarcane. Mosaic correlation with the
altered photosynthetic activity caused a significant reduction for chlorophyll
content by 56%, and 40% through the tested experimental seasons 2018/2019 and
2019/2020, respectively. The decrease in
chlorophyll content led to a reduction in various growth parameters in
sugarcane variety G.T. 54-9, such as stalk length and diameter, the number of
internodes per plant, cane yield, and cane stalk juice quality through both
experimental seasons. Concerning the reducing sugars (Rs), the concentration
increased in infected sugarcane plants with SCMV in both tested seasons by 9.7%
and 4.7%, respectively. Leaves from Sugarcane plants tested positive in a
reverse transcription-PCR using SCMV-specific primers for coat protein gene. All
tested plants are from vegetative cuttings of the original infected plant which
show mosaic symptoms with different severity. All samples showed an expected band at about 900
bp. The PCR amplicon of the CP gene was analyzed by nucleotide sequence
analysis. The coat protein sequence comparison revealed that the current SCMV
isolate (HaF isolate) shared the highest nucleotide identity (97.9-100%) with
the Egyptian isolate EGY7-1 and with all Iranian GenBank reference isolates. The
phylogenetic analysis showed that the HaF isolate grouped together in a clade
with the EGY7-1 and KhuzM isolates and it closely related to KhuzM isolate from
Iran. The coat protein core region (CP-CR) of the Egyptian SCMV (HaF) isolate
shared 98% sequence homology with SCMV-E serotype strain from the USA and the
current HaF Egyptian isolate contains a conserved DAG motif in its N-terminal
region in CP sequence which is associated with aphid transmissibility. An
SCMV-infected Sugarcane crop could pose a threat to established crops of Sorghum,
Maize, and many susceptible sugarcane varieties in Upper Egypt since the virus
can spread non-persistently by aphid species as well as by planting infected
cane cuttings.
Amin, H.A., Osman, M.A.M., and Mokbel, S.A. (2021). Molecular Characterization of Sugarcane Mosaic Virus and its Influence on Sugarcane Yield and Juice Quality. Curr. Sci. Int., 10(4):644-657.
