Influence of edapho-climatic factors on the sporulation and colonization of arbuscular mycorrhizal fungi in two Amazonian native fruit species

Abstract

Arbuscular mycorrhizal fungi (AMF) colonization and spore numbers in the rhizosphere

Arbuscular mycorrhizal and dark septate fungal associations in shallot (Allium cepa L. var. aggregatum) under conventional agriculture

“…Such a lack of correlation between AMF colonization and spore numbers indicate that the factors influencing these variables are totally different. In this study AMF spore numbers were negatively correlated to soil N and K. This contradicts the suggestions that soil K could stimulate the production of AMF spores (OLIVEIRA and OLIVEIRA 2010). This influence of soil N and K on AMF spore numbers can be attributed to their influence on soil pH as soil N (r = 0.463) and soil K (r = 0.464) were correlated (p<0.05) to soil pH.…”

“…The positive correlation between soil Fe and AMF variables indicate that Fe could stimulate colonization by AMF. A similar correlation has been reported in Paullinia cupana during the rainy season by OLIVEIRA and OLIVEIRA (2010). MICHELINI et al (1993) indicated that Fe interacts with other soil nutrients like Ca, Mn or P to influence AMF colonization and can greatly be influenced by soil pH.…”

“…The average AMF spore number (11 spores per 100g soil) recorded in the present study is lower than the range of 54-3920 spores per 100g soil reported for tropical soils (VALSALA-KUMAR et al 2007, KHANAM et al 2006, KHADE and RODRIGUES 2008, OLIVEIRA and OLIVEIRA 2010, ANANTHAKRISHNAN et al 2004, DAS and KAYANG 2010b. Major portions of AMF spores occurring in field soils are either dead or spore cases (MUTHUKUMAR and UDAIYAN 1999) and the spore numbers presented in this study are only for intact spores.…”

“…Soil pH has a great relevance for plant growth as it influences nutrient mobilization as well as availability (MARSCHNER 1995). Many studies reporting the influence of soil factors on AMF colonization have failed to find any relationship between soil pH and colonization (ZAHKA et al 1995, KHADE and RODRIGUES 2008, VALSALAKUMAR et al 2007, OLIVEIRA and OLIVEIRA 2010, KHANAM et al 2006. In the present study pH of the soil was positively correlated to all AMF colonization parameters except %RLV.…”

Diversity of cultivable fungal endophytes in Paullinia cupana (Mart.) Ducke and bioactivity of their secondary metabolites

“…The literature reports the association between P . cupana and mycorrhizal fungi [ 173 , 174 ]. Colonization and sporulation are seasonal events strongly influenced by increased rainfall [ 173 ], favored by increased soil acidity and manganese concentration, and inhibited by high iron content [ 174 ].…”