1. Arbuscular mycorrhiza activity into Prunus sp. roots
33rd New Phytologist Symposium
Networks of Power and Influence: ecology and evolution of symbioses between plants and mycorrhizal fungi
Zürich, Switzerland 14–16 May 2014
Arbuscular mycorrhiza activity into Prunus sp. roots
Ieva Druva-Lūsīte, Daina Feldmane, Valentīna Pole, Imants Missa, Edgars Rubauskis, Edīte Kaufmane
Latvia State Institute of Fruit-Growing, Dobele, Graudu Street 1, LV-3701, Latvia
Introduction
Prunus sp. plants – cherries and plums – are one of important trees in fruit-growing. Fruits are used fresh or processed to make different foodstuff, for example, juice or jam. There is demand for local fruits of cherries and plums in market of Latvia.
The rootstocks of Prunus cerasifera seedlings are used in plum orchards in Latvia. The rootstocks of Prunus mahaleb dominate for cherries. The restrictions for rootstocks are low cold tolerance during winters with thaws, low compatibility with cultivars. The most popular plum rootstocks of West Europe origin are not suitable in Latvia, due to low winterhardiness.
For rootstocks of P. cerasifera and P. mahaleb seedlings are used mostly. As it is known, the seedlings have not uniformity. The vegatative propogation have very low output of them. Only 30% of Prunus sp. cuttings develops root primordia. Therefore we looking for other forms of rootstocks and applicable for vegetative cuttings.
Mycorrhiza symbiosis is useful tool in organic and integrated farming as well as in plant propagation. Therefore we will investigate comprehensive research about arbuscular mycorrhizal fungal symbiosis with Prunus sp. plants in three experiments.
The First Experiment
The aim is to find out a most suitable orchard management system (drip irrigation, woodchip mulch and black fallow in row) for mycorrhiza symbiosis with sour cherries. Objectives will be to collect and analysis root samples in orchard from April till August in years 2014 and First root samples are already collected.
During this experiment we will be able to observe arbuscular mycorrhiza dynamic during vegetation season. That will show, which management system will be suitable for better mycorrhiza activity in organic and integrated farming.
The Second Experiment
In this experiment we will found out the composition of mycorrhizal fungal species, what make symbiosis with cherries and plums. Objectives will be to collect root samples in late June or in first decade of July and to determine species by molecular method.
Results of this experiment we plant to use in inoculation experiment of green cuttings with mycorrhiza spores in These results also will be reason for next project to isolate mycorrhiza spores from local fruit-growing orchards to make inoculum for green cuttings. It is generally known, that better for each country is to use its native microorganims.
The Third Experiment
The aim of the experiment will be to improve the growth of green cuttings of cherry and plum rootstocks by inoculation with two arbuscular mycorrhizal fungal species from Glomeromycota. Objective will be to inoculate green cuttings with mycorrhizal fungal spores after development of first root primordia.
We plan to compare Glomus intraradices and Gigaspora margarita influence on root system development of green cuttings during the second half of 2014.
Preliminary Study
Before beginning of this project, we made preliminary study of mycorrhiza into sour cherries roots. Samples of two rootstocks P. mahaleb and Gisela 5 (P. cerasus) collected at institute garden in October, 2013.
Roots were heated into 10% KOH for 40 min, washed with tap water, then stained with 0.05% trypan blue for 5 min, then washed with tap water, stored into lactoglicerol. Roots were analysed in 200x magnification. For one repeat was 100 eyeshots. Total were 3 repeats for each rootstocks. After root preparation we observed too red sour cherries roots in microscope, what were approximately 1mm in diameter. These samples were too dark for analysis. Therefore for P. mahaleb were two repeats. Roots, what were less than 1mm, were useful. We observed inner and external hyphae and vesicules, but no arbuscules into all useful root samples. Mycorrhiza calculation made with “Mycocalc” computer program (Trouvelot et al, 1986).
Results are shown in table. Roots of rootstock Gisela 5 were better colonised with arbuscular mycorrhiza than Prunus mahaleb. The same results obtained, if compered two repeats of Gisela 5 with Prunus mahaleb.
Literature
Trouvelot A., Kough J., Gianinazzi-Pearson V  Evaluation of VA infection levels in root systems. Research for estimation methods having a functional significance, in Physiological and Genetical Aspects of Mycorrhizae, eds Gianinazzi-Pearson V., Gianinazzi S., editors. (France: INRA Press;), 217–221. C
Location of Latvia State Institute of Fruit-Growing and orchards of cherries and plums
(56°37′N 23°16′E).
Arbuscular mycorrhiza structures – hyphae and vesicules – into root samples of Prunus mahaleb. Magnification 200x.
Results of arbuscular mycorrhiza into roots of two cherries rootstocks.
Unit
Prunus mahaleb
Gisela 5
Frequency of mycorrhiza in the root system (F%)
54.5
74.3
Intensity of the mycorrhizal colonisation in the root system (M%)
10.0
14.2
Intensity of the mycorrhizal colonisation in the root fragments (m%)
13.4
18.1
This research is supported by European Social Fund project "Creation of a researcher group to investigate the possibilities of stone fruit trees propagation, quality improvement of generative processes and fruit usage”. Project Nr. 2013/0048/1DP/ /13/APIA/VIAA/008.