Effect of arbuscular mycorrhizal fungi on survival and growth of micropropagated Comanthera mucugensis spp. mucugensis (Eriocaulaceae)

Abstract

The use of micropropagation technique has been an alternative to conservation of endangered species, Comanthera mucugensis subsp. mucugensis (popular namely sempre viva de Mucuge); however, there is no information on the effect of arbuscular mycorrhizal fungi (AMF) on the acclimation process of micropropagated plants. This study evaluated the survival, growth and nutritional aspects of the species, C. mucugensis subsp. mucugensis inoculated with native AMFs in greenhouse condition. The design of the experiment consisted initially of 80 sampling units divided into four treatments: plants inoculated with native AMF, with microbiota filtrate from soil, with AMF plus filtrate and control (non-inoculated plants). At three and eleven-month-old, the plants were collected for evaluation of growth, nutrition and mycorrhizal colonization. After eleven months of experiment, survival rate of AMF and AMF plus filtrate plants were 62.5 and 87.5%, respectively, and only one microbiota filtrate and one control plants survived. AMF inoculation also provided increase in n dry matter of rosettes and permitted obtaining flowering ten-month-growth plants. Rates of mycorrhizal colonization were high at three (aproximately 64.9%) and eleven (aproximately 94.5%) months for AMF and AMF plus filtrate plants. Number of spores in rhizosphere soil of mycorrhizal plants was also high (1599 per 100 dm3 of soil) and seven diferent species of AMF were identified at the end of experiment. Data set evidenced mycortrophic character of C. mucugensis subsp. mucugensis and the importance of AMF inoculation for acclimation and survival of microprogagated plants which is essential for conservation of this endangered plant.   Key words: Micropropagation, nutrition, arbuscular mycorrhiza fungi, sempre viva de Mucuge, aclimatation