Ivan Tsvetkov 1 , Evlogi Markov 2 , Teodora Dzhambazova 1 , Rossitza Batchvarova 1 ,

1. Mineral uptake and dry matter accumulation of biotised GF677/Royal Glory nursery plants Ivan Tsvetkov1, Evlogi Markov2, Teodora Dzhambazova1, Rossitza Batchvarova1, Stavrou Efstratios3, Giuseppe Tataranni4, Cristos Xiloyannis4 1AgroBioInstitute, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria, e-mail: ivantsvetkov@abi.bg ; ivantsvetkov@hotmail.com 2Institute of Soil Science “Nikola Poushkarov”, 7 Shousee Bankya Str., 1080 Sofia, Bulgaria, e-mail: evlogi2005@abv.bg 3Bulgarian Plant LTD, 8800 Sliven, Bulgaria, e-mail: stratos_stavrou@yahoo.gr 4Universita della Basilicata, Via dell’Ateneo Lucano n.10., 85100 Potenza, Italy, e-mail: cristos.xiloyannis@unibas.it INTRODUCTION The beneficial effects of mycorrhiza fungi symbiotic association on the growth of plants are well known, and they may be involved in improving uptake of macro- and micronutrient, increasing plant resistance against biotic and abiotic stress, and beneficial alternations of plant growth regulators (Kung’u et al., 2008; Smith and Smith, 2011). Increased growth rates in mycorrhizal plants have most often been attributed to increased nutrient uptake. Mycorrhizas appear to increase nutrient acquisition, especially for elements that are immobile in soils, either because inorganic ions diffuse slowly (such as P, Cu, Zn, and Ca) or when (like both N and P) they are present in complex organic forms (Tinker and Nye, 2000). Mycorrhizal stimulation of nutrient uptake is attributed to (i) uptake by fungi from soil beyond the depletion zones that can develop around roots, (ii) production of degradative extracellular enzymes or organic acids by the fungi, and (or) (iii) the ability of fungi to translocate nutrients faster than they could diffuse through soil (Simard et al., 2002; Jones and Smith, 2004). Nowadays, mycorrhizal fungi have been widely used in agriculture, horticulture, and forestry programs, as well as for environmental reclamation, to increase crop yield and health and to limit the application of agrochemicals (Jiang et al., 2013). While the artificial infection is effective in the nurseries, some problems have not yet been solved, such as the difficulty to produce a large amount of commercial pathogen-free product, the scarce knowledge on the host-fungus interactions, the likely competition with the soil borne fungi, the impossibility to sterilize the nursery soil (Lindermann and Davis, 2001; Bavaresco et al., 2011). The aim of the paper is to study the influence of different mycorhizal fungi and their additional treatment in the nursery on mineral uptake and dry matter accumulation of GF677/Royal Glory nursery plants. MATERIALS AND METHODS In vitro obtained and biotizated GF 677 rootstocks were obtained from SME Fitotechniki- Greece. It was planted in the Bulgarian project experimental field (Sliven region). The rootstocks were grafted 5 months after planting with certified buds from peach variety “Royal Glory” by T-budding (10 cm from the soil level, with one- bud scions) (Hartman et al., 1997). Additional biotizations were done inside of the relevant experimental plots (Table 1). Analysis of fresh/dry matter accumulation and mineral elements uptake were done at the start and at the end of plant vegetation. It was destroyed and analyzed tree individual plants (replications) per each experimental variant. Every plant is separated to four parts (samples): rootstock root, rootstock upper part, variety shoot, variety leaves (A, B, C, D). Fresh/dry matter accumulation analyses have done for each plant part (sample). Average values of the plant fresh/dry matter accumulation were calculated as aggregate amount of average values of each plant parts (samples) (A+B+C+D). FW/DW ratios were present as coefficients (average plant fresh weight divided to average plant dry weight). Each sample was performed for mineral uptake analyzing at six basic macro and microelements (N, P, K, Ca, Mg, Fe) by the methods described by Penkov et al. (1981). RESULTS AND DISCUSSION Concerning the dry matter accumulation (Table 2; Table 3), it could be seen that all additional treatments has a positive effect than non-treated variants. In case of Trichoderma experimental plots highest increase are observed in Trichoderma (BS)(TG) and Trichoderma (SL)(TG) variants which shows more than 55% dry matter accumulation rates. For comparison, Trichoderma non-treated variant increase rate are less than 10%. Similar results are obtained in Glomus and Glomus+Agrobacterium variants where additional treated plots overrun non treated ones with 21,06% and 82,69% respectively. In generous, best results about dry matter accumulation demonstrated Glomus+Agrobacterium (AG) with increase rates of 44,77% for the rootstock part, and 53,39% for the scion part. Summarized results of mineral uptake analyses are presented in Table 4. Nitrogen (N) uptake rates shows advantage of Glomus+Agrobacterium (AG) variant, that susceptible ahead the all others with the values between 15,31% (Trichoderma (SL)(TG)) and 59,88% (Control SITINPLANT). Despite of highest final values of phosphorus (P), obtained in Glomus (AG) variant, the percentages of quantity increasing in Glomus+Agrobacterium (AG) is better- 46,73% for the rootstock part and 48,46%- for the scion part. The same calculations for Glomus (AG) are 43,28% and 45,45%. In this aspect, Control Nurcery shows 26,92% and 32,96% quantity increasing, meanwhile Control Sitinplant- 29,62% and 20,00% respectively. With regard to potassium (K), Glomus+Agrobacterium (AG) variant also demonstrated the best rates of quantity increasing overrun the Control Sitinplant and the Control Nursery totally with 47,29% and 41,83%. Other experimental variants have not too high-distinguished differences compared with the controls. Calcium (Ca) is one of most important macroelements especially for peaches. Concerning calcium accumulation, Glomus+Agrobacterium (AG) shows 52,18% quantity increasing for rootstock part and 60,54%-for scion part which are approximately double rates compared with non-treated variant and the controls. In case of Trichoderma treatments, impressive positive effect shows the combination of additional mycorrhizal treatments with bioagents Baccilus subtilis and Streptomyces lydicus. These variants demonstrated significantly better quantity increasing rates compared with non-treated Trichoderma (0) as well as with the treated ones Trichoderma (TP) and Trichoderma (TG). Magnesium (Mg) uptake rates showed that Glomus (AG) variant occupied the first place with 57,85% quantity increasing for rootstock part and 50,12%- for scion part. Immediately after it is ordered Glomus+Trichoderma (AG) experimental plants with a rates of 40,91% and 56,17% respectively. The same results for Control SITINPLANT are 11,66%/21,73% and for the Control Nursery 29,09%/42,47%. There are not statistically distinguished differences between the experimental variants and the controls in case of iron (Fe) uptake. CONCLUSIONS In summary, our results suggested that additional mycorrhiza treatments have a remarkable positive effect on mineral uptake and dry matter accumulation of GF677/Royal Glory nursery plants. These fungal inoculations can promote plant growth, biomass accumulation and mineral nutrients absorption and could make an important contribution to fruit plants production. The utilization of additional biotizations in the nurseries seems to be a promising technique, but further studies are necessary in order to have better understanding of plant- soil- microorganisms (natural soil- borne and supplied) interactions and how to keep effective the artificial inoculums along the plant life cycle. Table 1.Biotizations in GF 677/Royal Glory experimental plots Table 2. GF 677 / Royal Glory fresh/dry matter accumulation (start of vegetation) Table 3. GF 677 / Royal Glory fresh/dry matter accumulation (end of vegetation) LEGEND: A-ROOTSTOCK ROOT; B-ROOSTOCK UPPER PART (up to grafting point); C-VARIETY SHOOT; D-VARIETY LEAVES; PLANT=A+B+C+D Table 4.Analysis of mineral elements uptake of GF 677/Royal Glory REFERENCES Bavaresco, L., Gatti, M., Zamboni, M., Fogher, C. and Ferrarri F. 2011. Role of artificial mycorrhization on iron uptake in calcareus soils, on stilbene root synthesis and in other physiological processes in grapevine. 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(in Bulgarian): 60-143. Simard, S.W., Jones, M.D. and Durall, D.M. 2002. Carbon and nutrient fluxes within and between mycorrhizal plants. In: Mycorrhizal ecology. (Edited by M.G.A. van der Heijden and I. Sanders, Springer-Verlag, Berlin): 33–74. Smith, S.E. and Smith, F.A. 2011. Roles of arbuscularmycorrhizas in plant nutrition and growth: new paradigms from cellular to ecosystem scales. Annu. Rev. Plant Biol. 62: 227-250. Tinker, P.B. and Nye, P.H. 2000. Solute movement in the rhizosphere. Oxford University Press, New York. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7-SME-2007-1) under grant agreement n. 222048 - Sitinplant Project. Poster - Ref. 158. ------------------------------------------------------------------------------------------------------------------------------ VIII International Peach Symposium -Matera, ITALY, 17-20 June, 2013