Molecular Characterization of a Leaf Curl Disease Infecting Zucchini Squash in Iraq

Abstract

Leaf curl diseases symptoms were observed in a zucchini squash field west Baghdad. Total DNA was extracted from leaves collected from three symptomatic plants using a commercial plant DNA extraction kit. Polymerase chain reaction (PCR) using genus specific primers were used to amplify the viral DNA fragments. PCR products were visualized by gel electrophoresis and directly sequenced. Sequence analysis using MEGA6 software confirmed the detection of Squash leaf curl virus (SLCV) when shared 99% maximum nucleotide sequence identity with equivalent GenBank sequence from Israel (KT099131) and (KM595115), Jordan (JX444577) and (KM595211), Lebanon (KM595136) and Palestine (KM595230). The high nucleotide sequence identity suggests the virus could be introduced to Iraq from neighboring countries through infected plant materials. Restriction site similarity was tested to show sequence variability. In silico restriction digestion was applied to SLCV sequences to compare restriction sites similarities in partial CP region amplified. Both obtained and equivalent GenBank sequences were digested virtually using NEBcutter V2 software and compared on the basis of restriction enzyme and restriction site incidence. When compared to equivalent sequences, SLCV from Iraq shared 96% maximum restriction site (RS) similarity with SLCV from Israel (KM595115). While it scored 56% maximum RS similarity to TYLCV sequences from Iraq (JQ025990), (JQ025991) and (JQ025993). In silico restriction digestion showed to be a useful approach to differentiate among SLCV sequences.

Whole genome characterization, recombination, variation, satellites and phylogeny analyses of Tomato leaf curl Palampur virus infecting courgetti squash (Cucurbita pepo L.) in Iraq

“…ToLCPalV virus was first recorded in the Indian city of Palmpur in 2008 [30], then it was recorded in Pakistan [31]. In Iraq, it was reported on squash and Datura [32] cucumber and tomato [18,20] in many Iraqi governorates, which indicates the wide range of hosts and spread. So far, the full genome and phylogenetic analysis of the present Iraqi ToLCPalV isolates confirmed the evidence for existing only the bipartite genome of this virus in Iraq.…”

Molecular characterization of viruses associated to leaf curl disease complex on zucchini squash in Iraq reveals Deng primer set could distinguish between New and Old World Begomoviruses

“…Total DNA was extracted using commercial DNA extraction kit (Bioneer, South Korea) following the manufacturer`s instructions. PCR amplification was performed using AccuPower PCR PreMix commercial kit (Bioneer, South Korea) using a bigomovirus specific primer set (Deng et al 1994) and following the protocol described by Al-Kuwaiti (2017). PCR products were visualized by ethidium bromide agarose gel electrophoresis following Sambrook & Russell (2006) Sequence comparison confirmed the detection of two begomoviruses when the obtained sequences shared 99.51 and 98.59 % maximum nucleotide (nt) identity percent with the equivalent SLCuV and ToLCPMV GenBank sequences, respectively, in partial CP gene (Table I).…”

“…It originated from and was domesticated in Mexico and North America about 7000 years ago (Paris 1989, Hirst 2020. In Iraq, zucchini is grown both in protected (greenhouse) and open fi elds, throughout the year (Al-Kuwaiti 2017). Based on local statistical data released by the Iraqi Central Statistical Organization (CSO) in 2020, zucchini production decreased up to 79.6 %, in the past few years, from 126,000 tons in 2014 to 25,700 tons; this decline in zucchini production may be attributed to factors including viral diseases (CSO 2020).…”