Effect of arbuscular mycorrhizal inoculation on growth, mineral nutrient uptake, photosynthesis and antioxidant activities of black pepper cuttings

Abstract

Arbuscular mycorrhizal (AM) fungi are one of most important soil microor-ganisms that can form mycorrhizal symbiosis with most of the terrestrialplants. In the present study, the effect of arbuscular mycorrhizal fungiinoculation on root colonization, growth, nutrition, photosynthetic gasexchange and antioxidant activities of black pepper cuttings were eval-uated under polyhouse conditions. The single node cuttings of black pep-per were grown in the presence and absence of AM combinations for150 days under poly house. AM inoculated plants showed significantlyhigher mycorrhizal root colonization (95%) and spore numbers (312/50 g ofsample). The effect of AM fungi was more prominent in improving rootbiomass than above ground biomass. Nutrient accumulations were higherin AM inoculated plants rather than uninoculated black pepper plants.Amount of acid phosphatase and dehydrogenase activity were significantlyhigher in AM inoculated soils. Net photosynthetic rate and stomatal con-ductance of AM colonized black pepper leaves were found to be signifi-cantly greater than uninoculated plants. The influence of AM was moreprominent on poly phenol oxidase and b-glucanase activity in leaves thanroots. In principal component analysis the scatter plot revealed variationsof the effects of arbuscular mycorrhizal fungi on growth of black peppercuttings. Based on these results, AM inoculation at the earlier stage ofplant development could improve symbiosis, and increased plant growthin the nursery which may improve the performance after planting inthe field