US EPA

4601926 

Journal Article 

Effects of Glomus aggregatum on lethal yellowing disease of Java citronella caused by Pythium aphanidermatum 

Ratti, N; Alam, M; Sharma, S; Janardhanan, KK 

1998 

1 

Symbiosis
ISSN: 0334-5114 

24 

1 

115-126 

WOS:000072074000006 

Effects of the vesicular-arbuscular mycorrhiza (VAM), Glomus aggregatum Schenck and Smith emend Koske on the lethal yellowing disease of Java citronella (Cymbopogon winterianus Jowitt) caused by Pythium aphanidermatum (Edson) Fitzp. and its interaction with the pathogen affecting plant growth, biomass production, N, P and K concentrations and acid phosphatase activity were investigated under glasshouse conditions. Citronella plants infected by P. aphanidermatum (Pa treatment) were chlorotic and showed a reduction in biomass production from 39.8 to 18.2 g plant(-1), N, P and K concentrations in shoot from 14.7, 3.51 and 12.7 to 13.3, 1.74 and 5.4 mg g(-1) dry weight, respectively, and acid phosphatase activity from 17.52 to 11.08 mu m p-nitrophenol min(-1) mg(-1) fresh weight over untreated healthy control plants. Treatments of 15dGa+Pa and simGa+Pa reduced lethal yellowing by 80% and 60%, respectively as compared with Pa treatment. Further, 15dGa+Pa treatment increased the biomass by 163.74%, N, P and K concentrations in shoot by 51.88%, 152.29% and 157.41% and acid phosphatase activity in root by 80.96%, respectively, as compared with Pa treatment. Colonization by the VAM fungus (Ga treatment) also enhanced biomass, N, P and K concentrations and acid phosphatase activity over the non VAM control. It is concluded that G. aggregatum improves the biomass production and reduces the damaging effect of P. aphanidermatum on Java citronella. 

Glomus aggregatum; Cymbopogon winterianus; Java citronella; Pythium aphanidermatum; lethal yellowing; N, P and K concentration; phosphatase activity