Endophytes Crop Productivity and Protection Volume 2 (Sustainable Development and Biodiversity)

(Tina Meador) #1

7.7.2 Blights and Leaf Spot


Foliar application withPseudomonasspp. induced disease resistance in rice against


sheath blight pathogen. In spite of the absence of this bacterium on plant surfaces,


its presence in the internal stem led to suppression of disease (Krishnamurthy and


Gnanamanickam 1997 ). Endobacteria bacteriumB. subtilis, isolated from xylem


fluid of chestnuts, suppressed the growth of chestnut blight pathogen,
Cryphonectria parasiticain vitro. The same bacteria reduced the lesion areas on


stems, when applied 3 days prior to challenge inoculation (Wilhelm et al. 1998 ).


The endophytes, viz.,Bacillus circulanceand Serratia marcescensesupple-


mented with chitin inhibited the conidial germination of early and late tikka leaf


spot in groundnut (Kishore et al. 2005 ). Four endophytic bacteria (OS-9, OS-10,


OS-11 and OS-12) were isolated from healthy leaves ofOcimum sanctumand


tested againstfive plant pathogens namelyR. solani, S. rolfsii, F. solani, A. solani


andC. lindemuthianum. Of these, the bacterial strain OS-9 was highly inhibitory to


the growth ofR. solani, A. solani, F. solaniandC. lindemuthianumwhile OS-11


alone was found antagonistic totA. solani(Kalraa et al. 2010 ). The culturefiltrate


of endophytic bacteria CE-6 exhibited the highest inhibition on the mycelia growth


of (61.3%) ofCercosporain vitro (Hima et al. 2013 ).


7.7.3 Powdery Mildew


The endophyticB. subtilisstrain E1R-j exhibited high antifungal activity against


wheat take all disease both in glasshouse andfield conditions (Liu et al. 2009 ).


Recently (Gao et al. 2015 ), who isolated 14 endophytic bacterial strains from wheat


leaves and tested againstBlumeria graminisf.sp.triticicausing wheat powdery


mildew disease. The results revealed thatB. subtilisstrain (E1R-j) significantly
reduced per cent disease index by 90.97% in pot culture under greenhouse


conditions.


7.7.4 Rust


The endophytic bacteria was isolated from leaves and branches ofCoffea arabica


andCoffea robustaand were tested against leaf rust pathogenHemileia vastatrixby


detached leaf and leaf disc method. Of these, the bacterial isolates TG4-Ia (Bacillus


lentimorbusDutky) and TF9-Ia (Bacillus cereusFrank & Frank) exhibited highest


growth inhibition against coffee rust pathogen (Shiomi et al. 2006 ). An endophytic


bacteria E1R-j was isolated from wheat leaves showed strong inhibitory effect on


wheat stripe rust in both greenhouse andfield conditions (Li et al. 2013 ).


7 Role of Bacterial Endophytes in Plant Disease Control 145

Free download pdf