Garden geranium ( genus Pelargonium × hortorum L.H. Bailey , Geraniaceae ) is a pop cosmetic industrial plant cultivate worldwide , whose extracts are used in cosmetics and medicinal drug ( Jugulam et al . 2001 ) . On the University of Electronic Science and Technology of China campus ( Chengdu , China ) , leaf blight on the garden geranium was observed in April - September 2021 . The average disease incidence was around 40%–50 % , which caused severe deprivation of ornamental value . ab initio , circular , brown necrotic areas appear on the margin of the foliage . In the ripe stagecoach of contagion , lesions may enlarge speedily and become irregular in conformation , with the fundamental portion of the lesion fall down out and defoliation . To isolate the pathogen , symptomatic tissues obtain from pathologic leaves were airfoil - sterilized for 1 min with 0.3 % NaClO , rinsed in sterile distilled weewee , and plate onto potato dextrose agar ( PDA ) .
The inoculated plate were hatch for 7 days at 25 ° C . Successively , pure culture were prevail by shift hyphal tips to Modern PDA plate . A total of 20 isolates were obtained across 25 garden geranium plants investigated . The colonies on the PDA plates reached a diam of 60–70 mm after 10 days at 25 ° degree centigrade , spreading with a regular margin , aerial mycelium whitened and smuggled mycelium on the undersides cottony and nonsocial and globose pycnidium were produced after ten day . Conidia were either cylindrical or soon cylindrical , hyalin 4˗11 μm × 2˗5 μm . These morphology corresponded to those of Stagonosporopsis coinage . Sequence data point for the 28S nrDNA , the internal canned spacer , β - tubulin , and RNA polymerase II fractional monetary unit ( White et al . 1990 , Liu et al . 1999 , Aveskamp et al . 2009 ) were obtained randomly for one of the sodding isolates ( P1 - L4 - 1 - L1 - 1 ) , which lead in the GenBank accession number ON667723 , ON667722 , ON677462 , and ON677463 , severally . The RAxML analytic thinking ( Stamatakis 2014 ) of the combined episode data of the isolate P1 - L4 - 1 - L1 - 1 and the reference sequence obtained from GenBank establish that the isolate P1 - L4 - 1 - L1 - 1 formed a powerfully supported clade with the type isolates ( C5 - 5 ) of Stagonosporopsis citrulli M.T. Brewer & J.E. Stewart , which has been found on cucurbit ( Stewart et al . 2015 ) .
The procedure for Koch ’s postulate was followed to affirm fungal pathogenicity using 4 - day - sure-enough mycelial saucer . A total of 15 same - older hefty leave were divided into three groups , and each mathematical group received a different handling . contrived wound were create on one group of leaves using a sterile pin , and a 5 - mm mycelial plug of the fungus was placed on the injured tissue . Mycelial plugs were also placed on the surface of the sets of unwounded leaves . The remaining leave-taking were maintained as control and immunize with sterile PDA plugs . The test was repeated three time . Both the wounded and non - wounded leaves exhibited symptom after 4–9 Clarence Shepard Day Jr. selfsame to those observe in the field . The control group remain symptomless , and the geomorphology of the fungus reisolated from the inoculated leaves was similar to that of S. citrulli . The phylogenesis , together with structural identification and vaccination results , affirm the identity of the pathogen on garden geranium as S. citrulli .
Read the gross enquiry at : www.researchgate.net
Zeng , Xianyu & Maharachchikumbura , Sajeewa . ( 2022 ) . First Report of Leaf blight triggered by Stagonosporopsis citrulli on Garden Geranium in China . Plant Disease . 10.1094 / PDIS-06 - 22 - 1302 - PDN .
