The influence of mycorrhiza on the adsorption of plant nutrition and grape, must and wine quality on Graševina variety (Vitis vinifera L.)

Termin mikoriza (od grčke riječi Mykes: gljiva i Rhiza: korijen) podrazumijeva asocijaciju gljiva i korijena biljka koji su uključeni u apsorpciju hraniva iz tla. Oko 80% zabilježenih kopnenih biljnih vrsta posjeduje neki od oblika mikorize. Učinkovitost mikoriznih hifa u usvajanju minerala posebno je značajna za slabo topiva anorganska hraniva, kao što su fosfor, cink i bakar. Cilj istraživanja bio je, analizom biljnog materijala utvrditi razlike u sadržaju pojedinih biljnih hraniva (dušika, fosfora, kalija, magnezija, kalcija, mangana, bakra i cinka) među tretmanima, zatim razlike u prinosu grožđa, sadržaju šećera i kiselina u grožđu, koncentraciji pojedinih aromatskih spojeva u grožđu, moštu i vinu kao i razlike u senzornim svojstvima vina različitih tretmana. Istraživanje je provedeno tijekom 2014. i 2015. godine na kultivaru 'Graševina', na loznoj podlozi Vitis berlandieri x Vitis riparia SO4. 'Graševina' je najzastupljeniji kultivar u Hrvatskoj. Pokusni nasad na kojem je provedeno istraživanje dio je pokušališta Veleučilišta u Požegi, a nalazi se u vinogradarskoj regiji Slavonija i hrvatsko Podunavlje, podregiji Slavonija u vinogorju Kutjevo na položaju Vražjak (općina Kaptol). Uzgojni oblik je Guyot s jednim reznikom s dva pupa i jednim lucnjem s osam pupova. Visina stabla je 80 cm. Pokus je postavljen po slučajnom bloknom rasporedu u četiri repeticije, a sastoji se od dva tretmana: kontrole bez inokulacije trsova mikorizom (NOMYC) i inokulacije trsova mješavinom mikoriznih gljiva (MYC). Svaka repeticija sastoji se od 18 trsova u nizu. Inokulacija mikoriznim gljivama provedena je u proljeće, 2013. godine. U neposrednu blizinu korjenovog sustava inokulirano je 20 mL mikorizne suspenzije „Mykoflor“ koja sadrži oko 2000 propagacijskih jedinica mikoriznih gljiva. Kontrolni, netretirani trsovi Graševine udaljeni su oko 100 metara od mikoriziranih trsova, kako bi se izbjegla potencijalna kontaminacija mikorizom. Za kontrolne i inokulirane trsove izračunat je postotak kolonizacije. Uzorkovanje biljnog materijala obavljeno je u četiri navrata od završetka cvatnje do nastupa tehnološke zrelosti grožđa. Analize lišća obuhvatile su određivanje ukupnog dušika metodom po Kjeldahlu, ukupnog fosfora spektrofotometrijom, ukupnog kalija plamenofotometrijom, ukupnog kalcija, magnezija, ukupnih mikroelemenata te teških metala atomskom apsorpcijskom spektrometrijom. U berbi su prikupljeni podatci o prinosu. U uzorcima mošta uzetima netom nakon muljanja i runjenja grožđa te bistrenja određen je sadržaj šećera i ukupnih kiselina. Analiza aromatskih spojeva u grožđu i vinu provedena je primjenom ekstrakcije na čvrstoj fazi i plinske kromatografije. Vina su ocjenjena organoleptički, metodom 100 pozitivnih bodova. Podaci su statistički obrađeni analizom varijance (ANOVA), a razlike između razina signifikantnih faktora Fisherovim LSD testom. Nakon obrađenih podataka nije utvrđen pozitivan utjecaj mikorize na dinamiku kretanja ukupne kiselosti i koncentracije šećera u grožđu tijekom dozrijevanja. Utvrđen je pozitivan utjecaj na prosječni sadržaj dušika u listu 'Graševine' tijekom vegetacije 2014. godine, dok u 2015. godini nisu utvrđene statistički opravdane razlike. Utvrđen je pozitivan utjecaj mikorize na sadržaj fosfora (P), u biljci lako pristupačnom obliku (P2O5) i sadržaj kalija (K) i kalijevog oksida (K2O) u suhoj tvari lista tijekom obje godine istraživanja. Mikoriza je utjecala na veći sadržaj 1-heksanola u grožđu 'Graševine' u 2014. godini. Konačnom organoleptičkom ocjenom vina 'Graševine' berbi 2014. i 2015 godine nije utvrđena statistički opravdana razlika između tretmana.The term mycorrhiza (from the Greek word Mykes: fungi and Rhiza: root ) implies the association of fungi and plant roots that are involved in the absorption of nutrients from the soil. About 80% of the recorded terrestrial plant species, ie 92% of plant families possess some form of mycorrhiza. Because of their smaller diameter compared to the root hairs, hyphae of mycorrhizal fungi permeate a larger volume of soil and penetrate smaller pores, thus enabling the plant to absorb and translocate water and minerals much easier than root hairs. The mobilization and uptake of minerals is further aided by the release of hydroxyamate, oxalate, citrate, and malate by hyphae. The efficiency of mycorrhizal hyphae in mineral uptake is particularly significant for poorly soluble inorganic nutrients, such as phosphorus, zinc, and copper. The aim of the study was: Analysis of plant material to determine differences in the content of certain plant nutrients (nitrogen, phosphorus, potassium, magnesium, calcium, manganese, copper and zinc) between treatments, to determine differences in grape yield, sugar and acid content in grapes, and differences in the content of individual aromatic compounds in grapes, must and wine between treatments and to determine differences in the sensory characteristics of wine of different treatments. The research was conducted during 2014 and 2015 on the 'Graševina' cultivar on the vine rootstock Vitis berlandieri x Vitis riparia SO4. 'Graševina' is the most represented variety in Croatia, and the area of the Danube basin is probably the place of origin of the variety. In the Republic of Croatia, 'Graševina' is grown predominantly in the continental areas in the wine-growing regions of Slavonia and Croatian Danube region and Croatian uplands region, but cultivation is also possible in the regions of Croatia Istria and Kvarner and Dalmatia. In Požega-Slavonia County in 2018, the share of 'Graševina' wines is 95.04% of the total amount of wine with a variety designation. The experimental plantation on which the experiment was conducted is part of the experimental campus of the Polytechnic of Požega, and is located in the wine region of Slavonia and the Croatian Danube region, subregion of Slavonia in the Kutjevo vineyards in the municipality of Kaptol at Vražjak. The plantation is located on the southern slope of Papuk Mountain as part of the Papuk Nature Park and the UNESCO World Geopark. The vineyard has a southern exposure, a slight drop in terrain from north to south, and the same direction is followed by rows. The plot is rectangular in training system with a total size of 4.35 ha on a plateau with an average altitude of 270 m. The cultivation shape is Guyot with one spur with two buds and one cane with eight buds. The height of the tree is 80 cm. The experiment was set up according to a randomized block design in four repetitions and consisted of two treatments: Control, without inoculation of vines with mycorrhiza (NOMYC) and inoculation of vines with a mixture of mycorrhizal fungi (MYC). Each repetition consists of 18 vines in a row, and each treatment is represented by 72 vines. The experiment consists of 8 experimental blocks. Inoculation with mycorrhizal fungi was carried out in the spring, before the beginning of grapevine flowering in 2013. In the immediate vicinity of the root system, 20 mL of mycorrhizal suspension "Mykoflor" containing about 2000 propagation units of mycorrhizal fungi was inoculated. Control, untreated 'Graševina' vines were about 100 meters away from mycorrhizal vines, to avoid potential mycorrhizal contamination. For control and inoculated vines, the percentage of colonization was calculated. Sampling of plant material was performed on four occasions from the end of flowering to the onset of technological maturity of the grapes. The dried leaves were dried at 105 °C, ground and homogenized to form prepared samples of plant material for further processing. Leaf analyzes were performed according to the methods: total nitrogen was determined by Kjeldahl method, total phosphorus by spectrophotometry, total potassium by flame photometry, total calcium, magnesium, total trace elements and heavy metals by atomic absorption spectrometry. During the harvest, data were collected on the number of bunches per vine, yield per vine and the average weight of the grapes in such a way that each vine was harvested and weighed separately, and the bunches on each vine were counted individually. For vinification purposes, each repetition was harvested and processed separately. In the samples of must taken immediately after mulching and crushing the grapes and clarification, the content of sugar and total acids was determined, for each repetition separately. The average sugar content was determined by reftactometer and Oechsle must scale and was expressed in degrees Oechsle (˚Oe). Total grapes and wine acidity, pH, alcohol, reducing sugars and total dry extract were determined according to OIV standards (2013). Analysis of aromatic compounds in grapes and wines was performed using solid phase extraction and gas chromatography. The wines were evaluated organoleptically, by the method of 100 positive points. Data were statistically processed by analysis of variance (ANOVA), and differences between levels of significant factors by Fisher’s LSD test. After the processed data, no positive effect of the mycorrhizal vaccine Mykoflor on the dynamics of the movement of total acidity and accumulation of sugar in grapes during ripening was determined. Mycorrhiza had a positive effect on the average nitrogen content in 'Graševina' leaves during the vegetation in 2014, while in 2015. no statistically significant differences were found. The positive effect of mycorrhiza on the content of phosphorus, plant easily accessible form (P2O5) and the content of potassium and potassium oxide (K2O) in the dry matter of the leaves during both years of research was determined. Mycorrhiza affected the higher content of 1-Hexenol in 'Graševina' grapes in 2014. The final organoleptic evaluation of the wine did not determine significant difference between treatments