Introduction Directory UMM :Data Elmu:jurnal:A:Applied Soil Ecology:Vol15.Issue2.Oct2000:

Applied Soil Ecology 15 2000 145–152 Response of micropropagated potatoes transplanted to peat media to post-vitro inoculation with arbuscular mycorrhizal fungi and soil bacteria Miroslav Vosátka a,∗ , Milan Gryndler b a Institute of Botany, Academy of Sciences of the Czech Republic, 25243 Pruhonice, Czech Republic b Institute of Microbiology, Academy of Sciences of the Czech Republic, V´ıdenská 1083, 14220 Prague 4, Czech Republic Received 31 May 1999; received in revised form 13 January 2000; accepted 23 March 2000 Abstract Positive effects of dual inoculation with some combinations of arbuscular mycorrhizal fungi AMF and bacteria on the growth of micropropagated potato Solanum tuberosum transplanted to a peat-based substrate were found in three different cultivation systems — pots, greenhouse or shadowhouse beds. Some inoculation treatments, e.g. with Glomus etunicatum, Glomus fistulosum together with bacterial isolate B1 Bacillus subtilis in pots, or with Glomus fistulosum plus bacteria B1 in greenhouse beds or with a mixture of Glomus manihotis and two bacteria in shadowhouse beds resulted in higher number of minitubers NT, higher weight per minituber or in higher total weight of minitubers per plant. However, the effects of mycorrhization varied for two different potato varieties and the synergistic effects of coinoculation with different bacteria isolated from rhizosphere or hyphosphere was not significant in most cases. There were no significant effects of Zeolite clinoptinolite clay amendment on the mycorrhization and aboveground growth of potato plants, while slight stimulation was observed for minituber weight. The inoculation into peat-based substrate might be successful regarding plant growth response; however, to increase the potential of the inoculation in practical production of potato minitubers, it is necessary to consider possible differences of various potato varieties and to select appropriate combination of bacteria and AMF symbionts. © 2000 Elsevier Science B.V. All rights reserved. Keywords: Agrobacterium; Arbuscular mycorrhizal fungi AMF; Bacillus; Dual inoculation; Potato minitubers; Rhizosphere bacteria; Zeolite

1. Introduction

Commercial importance of in vitro propagated potato plants for the production of minitubers is high enough to look for a way to reduce the cost of the final product by reducing the inputs of the large-scale cultivation systems. It could be possible to reduce the use of phosphate fertilizers and shorten the cultivation ∗ Corresponding author. Tel.fax: +42-2-6775-0022. E-mail address: vosatkaibot.cas.cz M. Vos´atka time to achieve valuable and marketable plant mate- rial by the introduction of beneficial microbial pop- ulation into the cultivation substrate. Regarding the plant mineral nutrition, arbuscular mycorrhizal fungi AMF represent one of the most important group of soil microflora which can be potentially used for practical inoculations in horticulture and agriculture Holevas, 1966; Kiernan et al., 1984; Chang, 1994. Inoculation of micropropagated potato plants with AMF during the transfer from in vitro conditions may improve the viability of potato and their physiological 0929-139300 – see front matter © 2000 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 9 - 1 3 9 3 0 0 0 0 0 9 0 - 1 146 M. Vos´atka, M. Gryndler Applied Soil Ecology 15 2000 145–152 state McArthur and Knowles, 1992, 1993; Niemira et al., 1995. Micropropagated plants form the rhizo- sphere during post-vitro establishment and there is a free niche and space for interaction with introduced soil microflora. During the step of post-vitro trans- plantation, there is a unique possibility to influence the composition of newly formed rhizosphere by preinoc- ulation of the cultivation substrate with selected mi- croorganisms Vestberg, 1992. After dual inoculation with AMF and an appropriate bacterial partner, a syn- ergistic effect on plant growth and nutrition can be observed Meyer and Lindermann, 1984; Barea and Azcón-Aguilar, 1986; Vosatka et al., 1992. The aim of this study was to investigate the effects of dual inoculation with different AMF and bacteria on two varieties of micropropagated potatoes Solanum tuberosum transplanted to a peat-based substrate in three different cultivation systems. In addition, the ef- fect of Zeolite clinoptinolite clay used as substrate conditioner amendment on the mycorrhization and growth response of potato plants was tested.

2. Materials and methods