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

NH

O

O

OH

HO OHO

O

O O OH

O

O

(45)

N+

O

O

OCH 3

OCH 3

(46)

N+

O

O

(47)

N

N

O

O

OH O

(48)

9.7 Factors Influencing the Production of Secondary

Metabolites of Endophytic Fungi

In the natural setting, the climatic conditions, soil, season, location, age and tissue

of the host plant, all affect the endophytes’biology, and consequently considerable

variations in the production of secondary metabolites (Strobel and Daisy 2003 ).

Therefore, the chemical substances isolated from two endophytic fungi of the same

species may differ from each other. At the same time, the differences also in the

isolation methods and in vitro cultivation conditions can impact the kind and range

of secondary metabolites (Gunatilaka 2006 ). It has been reported that the size of the

plant tissue fragments used for the isolation, time since harvesting of the tissue,

composition of the culture media and culture conditions such as aeration, temper-
ature, pH, incubation period, agitation, shape of the culturingflask (with respect to

liquid media), all affect the production of secondary metabolites in laboratory (Aly

et al. 2011 ; Kusari et al. 2012 ). Even, the production of six new secondary

metabolites by the plant associated fungusParaphaeosphaeria quadriseptata, only

when the water used to make the media changed from tap water to distilled water is

a good example to prove this fact (Paranagama et al. 2007 ).

206 P.B. Ratnaweera and E.D. de Silva

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