scholarly journals Role of Antibiosis in Control of Cabbage Black Rot Caused by Xanthomonas campestris pv. campestris

2017 ◽  
Vol 45 (2) ◽  
pp. 165-181
Author(s):  
Ahmed Elsisi
2005 ◽  
Vol 48 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Leila Monteiro ◽  
Rosa de Lima Ramos Mariano ◽  
Ana Maria Souto-Maior

The antagonism of eight Bacillus isolates was investigated against nine strains of Xanthomonas campestris pv. campestris (causal agent of crucifers black rot) to assess the role of lipopeptides in this process. Antimicrobial and hemolytic (surfactant) activity tests were performed in vitro using agar diffusion methods. Antibiosis and hemolysis were positive for four Bacillus isolates against all X. campestris pv. campestris strains. The correlation observed between antimicrobial and hemolytic activities indicated that lipopeptides were involved in the antibiosis mechanism of the studied antagonists. Fermentation studies were carried out with the isolates that showed highest antimicrobial and hemolytic activities, to follow up growth and production of bioactive and surfactant compounds. Production of bioactive and surfactant compounds was observed during the late growth phase of the Bacillus isolates.


2017 ◽  
Vol 83 (6) ◽  
pp. 373-381 ◽  
Author(s):  
Hirofumi Nagai ◽  
Noriyuki Miyake ◽  
Shinro Kato ◽  
Daisuke Maekawa ◽  
Yasuhiro Inoue ◽  
...  

1999 ◽  
Vol 30 (3) ◽  
pp. 191-195 ◽  
Author(s):  
Sayonara M.P. Assis ◽  
Rosa L.R. Mariano ◽  
Sami J. Michereff ◽  
Gil Silva ◽  
Elizabeth A.A. Maranhão

Twenty yeast isolates, obtained from cabbage phylloplane, were evaluated for antagonistic activity against Xanthomonas campestris pv. campestris, in field. Plants of cabbage cv. Midori were pulverized simultaneously with suspensions of antagonists and pathogen. After 10 days, plants were evaluated through percentage of foliar area with lesions. Percentage of disease severity reduction (DSR%) was also calculated. Yeast isolates LR32, LR42 and LR19 showed, respectively, 72, 75 and 79% of DSR. These antagonists were tested in seven different application periods in relation to pathogen inoculation (T1=4 d before; T2=simultaneously; T3=4 d after; T4=4 d before + simultaneously; T5=4 d after + simultaneously; T6=4 d before + 4 d after; T7=4 d before + simultaneously + 4 d after). The highest DSRs were showed by LR42 (71%), LR42 (67%), LR35 (69%) and LR19 (68%) in the treatments T7, T4, T5 and T6, which significantly differed from the others. The same yeast antagonists were also tested for black rot control using different cabbage cultivars (Fuyutoyo, Master-325, Matsukaze, Midori, Sekai I and Red Winner). The DSRs varied from 58 to 61%, and there was no significant difference among cultivars.


2021 ◽  
Vol 60 (1) ◽  
pp. 51-62
Author(s):  
Samia LAALA ◽  
Sophie CESBRON ◽  
Mohamed KERKOUD ◽  
Franco VALENTINI ◽  
Zouaoui BOUZNAD ◽  
...  

Xanthomonas campestris pv. campestris (Xcc) causes the black rot of cruciferous plants. This seed-borne bacterium is considered as the most destructive disease to cruciferous crops. Although sources of contamination are various, seeds are the main source of transmission. Typical symptoms of black rot were first observed in 2011 on cabbage and cauliflower fields in the main production areas of Algeria. Leaf samples displaying typical symptoms were collected during 2011 to 2014, and 170 strains were isolated from 45 commercial fields. Xcc isolates were very homogeneous in morphological, physiological and biochemical characteristics similar to reference strains, and gave positive pathogenicity and molecular test results (multiplex PCR with specific primers). This is the first record of Xcc in Algeria. Genetic diversity within the isolates was assessed in comparison with strains isolated elsewhere. A multilocus sequence analysis based on two housekeeping genes (gyrB and rpoD) was carried out on 77 strains representative isolates. The isolates grouped into 20 haplotypes defined with 68 polymorphic sites. The phylogenetic tree obtained showed that Xcc is in two groups, and all Algerian strains clustered in group 1 in three subgroups. No relationships were detected between haplotypes and the origins of the seed lots, the varieties of host cabbage, the years of isolation and agroclimatic regions.


2000 ◽  
Vol 78 (9) ◽  
pp. 1144-1149 ◽  
Author(s):  
P A Gay ◽  
S Tuzun

The physiological mechanisms associated with resistance of cabbage to black rot disease seem to be associated with the hydathodes. To investigate the role of hydathodes in disease resistance, total peroxidase activities, anionic peroxidase isozyme expression, and lignin deposition were determined in hydathodes of resistant (Hancock and Green Cup), partially resistant (Cheers), and susceptible (Strukton and Perfect Ball) cabbage varieties (Brassica oleracea L.) during pathogenesis with Xanthomonas campestris pv. campestris. Four-week-old plants were petiole-inoculated with a highly virulent strain of X. campestris pv. campestris (FD91L). Hydathodal fluids were collected daily over a 14-day period from infected plants as well as noninfected, mock-inoculated control plants. Hydathodal fluids of resistant varieties had greater peroxidase activity when compared to susceptible ones, with infected plants having higher peroxidase levels than noninfected plants. Isoelectric focusing revealed the presence of four anionic peroxidase isozymes in hydathodal fluids, with the most anionic one (pI of 3.6) accumulating only upon infection. Lignin deposition in and around the hydathodes was associated with the accumulation of this particular isozyme in hydathodal fluids. The evidence suggests that a rapid, systemic response is associated with resistance to the bacterial pathogen.Key words: peroxidases, hydathodes, isozymes, black rot disease, cabbage, Xanthomonas campestris pv. campestris.


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