Helianthus annuus as a natural host for Stemphylium vesicarium in Iran

Abstract

Sunflower leaf spot is one of the most common as well as important foliar diseases of this host in northern Iran. Stemphylium vesicarium was revealed to be one of the causal agents of sunflower leaf spot based on morphological and molecular characteristics. The identity of the species was confirmed using sequence data from the ITS rDNA region and glyceraldehyde-3-phosphate dehydrogenase (gpd) gene sequences. Pathogenicity of the fungus was proven by inoculation of four-week-old sunflower plants (cv. Euroflor) under controlled conditions. This is the first report on the incidence of S. vesicarium on H. annuus anywhere in the world.

Management of Purple Blotch Complex of Onion in Indian Punjab

“…Mature conidia were oblong to broadly ellipsoid, densely verrucose, golden brown to olive brown rounded at the ends and were 24.18-38.43 μm x 12.61-21.18 μm in size with length to width ratios ranging from 1.64-2.43 with 1-3 transverse and 1-4 longitudinal or oblique septa and often constricted at one or more of the septa. These findings are in close conformity with those of Simmons (1969), Ellis (1971), Basallote et al (1999) and Arzanlou et al (2012) who reported that mature conidia are produced singly on the swollen apex of the conidiophores and are light to dark brown, densely verrucose, oval to ellipsoidal with transverse and longitudinal septa, and measured 25-42 μm x 12-22 μm.…”

“…Chowdhury (2013) reported that the colony colour of S. vesicarium varied from greenish brown to dirty white, deep grey to whitish, light grey to whitish, deep greenish white, light grey and dirty white to greenish with elevation varying from umbonate, raised to flat and texture varying from cottony, fluffy to velvety. Arzanlou et al (2012) reported that the colonies of S. vesicarium on potato carrot agar medium were grey to brownish grey, flat, attaining a diameter of 50 mm after 7 days with sparse aerial mycelium.…”

A Comparative Analysis of Culture Media for Optimizing the Mycelial Growth and Sporulation of Stemphylium vesicarium Cause of White Blotch of Onion

“…The length of conidia varied from 14.6 µm to 30.6 µm, and the breadth of conidia ranged from 4.7 µm to 15.7 µm. The present findings agreed with the report of Arzanlou et al [16] and Ellis [18], who measured 25-40 μm  13-21 μm and 20-24 (-30) μm × 12-15 μm conidial length and breadth of S. vesicarium. Hosen et al [14,15], Koike et al [19] and Simmons [22] also observed 33-35 μm  24-26 μm, 17-28 μm  13-19 μm, 10-25 μm  5-15 μm and 12.35-23.45 μm  10.5-15 μm onidia of Stemphylium botryosum.…”

“…Umbonate, raised and flat type colony elevation were found among all the isolates with cottony, fluffy and velvety texture on PDA. Arzanlou et al [16] found flat type colony elevation of S. vesicarium grown on potato carrot agar (PCA) media. The results of textural growth of S. vesicarium are in agreement with Mehta [17], who found that the mycelium of Stemphylium solani isolated from cotton was velvety, cottony or immersed.…”

Stemphylium Blight of Onion: A Review

“…Variability studies are important to document the changes occurring in the population and individuals with variability in morphological, cultural and pathogenic characteristics. Under natural epiphytotics, S. vesicarium has been found to express a wide range of Stemphylium Blight of Onion: A Review variability in disease symptoms expression depending upon the onion cultivars, environmental conditions etc as observed by various workers (Hosen et al, 2009;Arzanlou et al, 2012;Nisha, 2013).…”