Pathogenic and morphological variability among Fusarium oxysporum f. sp. ciceri isolates causing wilt in chickpea

Author(s):  
H. R. Chaithra ◽  
H. Manjunath ◽  
M. Saifulla ◽  
Pagala Deepthi

Twelve Fusarium oxysporum f. sp. ciceri isolates were isolated from chickpea infected samples collected across different states of India. Pathogenic variability of twelve isolates was observed on seven chickpea cultivars viz., JG 62, Annigeri-1, Chaffa, CPS-1, K 850, L 550 and DCP 92-3. Among the twelve isolates APFOC-1 showed lowest wilt incidence 71.43 per cent and the isolate MPFOC-9 showed 100 per cent wilt incidence in all cultivars. The variability in morphological characters like size, shape, color of conidia and size, shape, color of chlamydospore were observed in all the isolates. The size of macroconidia varied from 9.23X2.53 ìm (WBFOC-12) to 19.3X5.52 ìm (MHFOC-8) with 2-4 septation. The size of microconidia varied from 4.4X2.93 ìm (MPFOC-9) to 8.26X4.2 ìm (MHFOC-8) with 0-1 septation. Macroconidia were sickle shaped and blunt ends with hyaline color. Microconidia were round to oval with hyaline color. Size of chlamydospore varied from 2.67 (UPFOC-11) to 8.24 (JKFOC-5). Chlamydospores did not show much variation with respect to shape and color. Based on the total number of spores observed per microscopic field, the twelve isolates categorized into four groups viz., poor sporulants, moderate sporulants, good sporulants and very good sporulants.

2021 ◽  
Vol 13 (4) ◽  
pp. 1305-1309
Author(s):  
Sanjeev Kumar ◽  
Shambhu Roy ◽  
J. P. Upadhyay

Wilt is the most serious disease causing irreversible losses and lethal damage to the crop in Bihar, Jharkhand, Orissa and the West Bengal states of Eastern India. Because of the existence of high pathogen variability, management of the disease using resistant cultivars will be a challenging task. For breeding resistant varieties, knowledge of pathogen variability in the particular crop area is essential.  In present study, fifteen isolates viz., Fu-9, Fu-10, Fu-27,Fu-32, Fu-42, Fu-49, Fu-63, Fu-72, Fu-73, Fu-74,Fu-75,Fu-84, Fu-86, Fu-87, Fu-97of Fusarium udum  obtained from wilt infected pigeonpea plants of Bihar, Jharkhand, Orissa and West Bengal of Eastern India were assessed for the phenotypic variation.  The isolates exhibited considerable variations in cultural and morphological characters viz., radial growth, mycelial color, sporulation, size and shape of macroconidia. Pathogenic variability on soil inoculated pot grown plants of pigeonpea resulted in 12.0 to 57.1 percent wilt incidence. The isolates also exhibited significant variations in symptoms like drooping of shoots, latent period, timing of fungal invasion, vascular clogging, drooping of shoots, and wilt establishment etc.  Based on the wilt incidence, the fifteen isolates were distinguished into pathogenic groups. Fu- 10, Fu-27, Fu-32 and Fu-49  were found highly pathogenic and predominantly causing the typical wilt symptoms of more than one 31% wilt incidence. The present study indicates the existence of variability among isolates of vascular wilt pathogen collected from Eastern region of India.  


Author(s):  
Jitendra Sharma ◽  
G.S. Rathore ◽  
S.L. Yadav ◽  
S.K. Goyal ◽  
Suresh Meena

Background: Alternaria cyamopsidis (Rang. and Rao) causes Alternaria blight of clusterbean and it is one of the significant disease of clusterbean. Studies were conducted to compare the Cultural, morphological and pathogenic variability among ten isolates of Alternaria cyamopsidis from clusterbean, in five districts of Rajasthan viz., Bikaner, Barmer, Churu, Hanumangarh and Jaipur. Methods: During 2016-17 exhaustive survey was conducted in clusterbean growing areas of Rajasthan and collected diseased samples of clusterbean caused by Alternaria. All the samples were processed for isolation, purification and their pathogenicity was proved in cagehouse and laboratory and standard methods were adopted for cultural and morphological variability study. Result: All the isolates showed variation in their morphological characters, i.e., colony color and shape; conidial number, size, width, length, shape and septation on PDA. Out of ten isolates two isolate, viz., AlcyJp1 and AlcyJp2 showed maximum colony diameter 89.50 and 86.30 mm, respectively. All the isolates varied in their spore length and width and virulent on the tested variety of clusterbean for virulence. AlcyJp1 was the most virulent and produced maximum (65.50%) disease intensity, followed by AlcyJp2 isolate (61.22%).


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Umer Iqbal ◽  
Tariq Mukhtar

Macrophomina phaseolinais a serious pathogen of many crops. In the present studies, 65 isolates ofMacrophomina phaseolinafrom different agroecological regions of Punjab and Khyber Pakhtunkhwa provinces of Pakistan were analyzed for morphological and pathogenic variability. Regardless of their geographic origins, significant differences were detected among 65 isolates in their radial growth, sclerotial size, and weight as well as in pathogenicity. Sixteen isolates were rated as fast growing, 11 as slow growing, and the rest of the isolates as medium growing. Nine isolates were classified as large sized, 26 as small sized, and the remaining 30 isolates as medium sized. Thirty five isolates were ranked as heavy weight, 12 as low weight, and the rest of isolates were grouped as medium weight. Ten fungal isolates appeared to be least virulent, whereas eight isolates of diverse origin proved to be highly virulent against mungbean cultivars. The remaining isolates were regarded as moderately virulent. No relationship was found among the morphological characters and pathogenicity of the isolates. These morphological and pathogenic variations in various isolates ofM. phaseolinamay be considered important in disease management systems and will be useful in breeding programmes of mungbean cultivars resistant to charcoal rot.


1963 ◽  
Vol 9 (2) ◽  
pp. 237-249 ◽  
Author(s):  
R. N. Wensley ◽  
C. D. McKeen

The relation of soil populations of the muskmelon wilt fungus, Fusarium oxysporum f. melonis, to the wilt potentials of a yellow Fox sandy loam soil (Fsl) and a dark Colwood loam (Cl) was investigated. In either soil a direct relationship existed between the size of the population of the fungus and wilt incidence. Notwithstanding this relationship, with the same population the greater incidence of wilt in Fsl than in Cl showed that a factor or factors other than population affect the wilt potential. Whereas mean populations of field soils obtained at the site of wilted plants ranged upward to 3300 per gram, they declined steadily during the 9-month interval between crops. During this interval random samples of field soils yielded mean populations of 228 and 268 per gram of Fsl and Cl, respectively. Of the F. oxysporum colonies isolated at the end of harvest, about 70% from plant sites and approximately 21% from intersites were pathogenic. Two to eight months later only 12 to 15% of F. oxysporum isolates obtained by random sampling of infested field soils were pathogenic.


2021 ◽  
Vol 58 (5) ◽  
pp. 913-916
Author(s):  
Gurjot Singh ◽  
Daljeet Singh Buttar ◽  
Sukhman Kaur Aulakh

Genetika ◽  
2017 ◽  
Vol 49 (2) ◽  
pp. 529-541
Author(s):  
Branislava Batos ◽  
Danijela Miljkovic ◽  
Marko Perovic ◽  
Sasa Orlovic

This paper presents the results of a study dealing with leaf morphological variability of Quercus robur L. 148 trees were sampled from 5 population across Serbia and 17 morphological traits were assessed. Interpopulation variability was confirmed by the results of the analysis of variance (ANOVA). A statistically significant (p <0.05) effect of population was obtained for most of the studied morphological characters. Intrapopulation variability was confirmed by statistically significant tree effects for all of the studied leaf characters (all p < 0.05). The results of the multivariate analysis of variance (MANOVA) confirmed a significant population and tree share in the total phenotypic variability (all p <0.05). By applying the canonical discriminant analysis (CDA), the first discriminant function accounted for 63% of the variability between populations and the second accounted for 20% of the population variability. The leaf area (AREA), specific leaf area (SLA) and surface area to perimeter ratio (ARPE) had the greatest effect on population differentiation (CDA). It is assumed that different environmental conditions affect population differentiation and that high intrapopulation variability is due to intraspecific variability.


2020 ◽  
Vol 131 (3) ◽  
pp. 505-520
Author(s):  
Janet Nolasco-Soto ◽  
Mario E Favila ◽  
Alejandro Espinosa De Los Monteros ◽  
Jorge González-Astorga ◽  
Gonzalo Halffter ◽  
...  

Abstract We analysed the genetic divergence and morphology of the aedeagus (i.e. phallobase and parameres) in Canthon cyanellus at different geographical levels. The results from both approaches were compared with the current taxonomic assignment of the C. cyanellus complex, which includes three subspecies. We found a high variation in all the morphological characters of the aedeagus in the populations analysed; the morphometric variation was not geographically structured, either by population or by region. The genealogical analysis indicates a significant genetic structure that does not match either the morphological variation in the male genitalia or the previous subspecific taxonomic classification. Our results suggest that the morphological variation of the aedeagus is seemingly not an isolating reproductive barrier and that the intra- and interpopulation morphological variability of the aedeagus in the C. cyanellus complex does not permit the division into several species. We suggest that other evolutionary forces, such as genetic drift and sexual selection, have influenced the evolution of the male genitalia and the incipient differentiation of this species complex.


2011 ◽  
Vol 39 (No. 2) ◽  
pp. 59-67 ◽  
Author(s):  
I. Doležalová ◽  
A. Lebeda ◽  
M. Dziechciarková ◽  
E. Křístková ◽  
D. Astley ◽  
...  

Fifty one accessions of nineteen Lactuca species, the hybrid L. serriola &times; L. sativa and the related species Mycelis muralis were evaluated for morphological variability, esterase (EST) polymorphism, Amplified Fragment Length Polymorphism (AFLP) and relative DNA content. Sixteen Lactuca accessions were classified taxonomically on the basis of morphology, isozyme analysis and AFLP. Twenty-eight bands (isoforms) of EST were recorded allowing 82% of accessions to be distinguished. The relative DNA content, measured using flow-cytometry (DAPI staining), ranged from 2.02 pg in L. capensis to 17.96 pg in L. canadensis. The results from AFLP analysis and the relative DNA content measurement corresponded well with recent taxonomic classification of the genus Lactuca. &nbsp;


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