Water managed properties of apple and pear trees based on lysimeters

A significant proportion of the aboveground green and dry weight of the plant is constituted by foliage. The canopy is an important factor of plant growth. On the one hand, the canopy absorbs solar energy, which is necessary for photosynthesis; on the other hand, it accumulates the nutrients absorbed by the roots, and most of the water-loss occurs through the foliage. The determination of the full canopy is not an easy target. In our research, we developed a measurement method to determine the leaf area. With the parameters of the examined tree (leaf length and maximum width) and the data of the ADC AM 100 leaf area scanner, we determined the k-value, with which we can easily and fast evaluate the leaf surface. Furthermore, we defined from the water balance of compensation lysimeters the cumulative transpiration of fruit trees and the efficiency of water use of trees. From the examined trees were made a 3D depiction, which show the shape, branching and the location of trees

Timely removal of exogenous cytokinin and the prevention of auxin transport from the shoot to the root affect the regeneration potential of Arabidopsis roots

In vitro regeneration of Arabidopsis from roots is generally achieved via indirect organogenesis. First, transdifferentiation of lateral root primordia to calli is achieved by a balanced auxin-to-cytokinin ratio that is followed by the induction of shoot meristem formation using a high cytokinin level. Here we demonstrate that if the root explants were transferred onto a hormone-free medium after a transient (4-days) cytokinin treatment, embryogenic marker genes (LEC1, LEC2, FUS3) started to be expressed. App. 50% of the regeneration foci developed into plantlets with trichome-less cotyledon-like leaves. Moreover, the somatic embryogenesis defective lec1 mutant could regenerate only shoots with trichome-bearing leaves under this condition. Based on these observations, the mixed accomplishment of shoot organogenesis and somatic embryogenesis is hypothesized in the Arabidopsis root explants cultured under hormone-free conditions following cytokinin induction. Using whole seedlings instead of root explants in the same experimental set up, no regenerates were formed on the roots. Applying the auxin transport inhibitor TIBA to the root-to-shoot junction of the seedlings, the regeneration ability of the root could be restored. The observations indicate that shoot-derived endogenous auxin blocks the cytokinin-induced regeneration process in the roots of whole seedlings. The expression of the wound-induced transcription factor WIND1 could be detected in the roots of unwounded seedlings if the shoot-to-root auxin transport was inhibited. Manipulating the exogenous cytokinin level together with the endogenous shoot-to-root auxin transport therefore could mimic the effect of wounding (removal of shoot) on plant regeneration from roots. Key message Transferring root explants from high cytokinin to hormone-free conditions resulted in the expression of embryogenic markers. Inhibiting the shoot-to-root auxin transport had similar effect on regeneration as wounding

Timely removal of exogenous cytokinin and the prevention of auxin transport from the shoot to the root affect the regeneration potential of Arabidopsis roots

In vitro regeneration of Arabidopsis from roots is generally achieved via indirect organogenesis. First, transdifferentiation of lateral root primordia to calli is achieved by a balanced auxin-to-cytokinin ratio that is followed by the induction of shoot meristem formation using a high cytokinin level. Here we demonstrate that if the root explants were transferred onto a hormone-free medium after a transient (4-days) cytokinin treatment, embryogenic marker genes (LEC1, LEC2, FUS3) started to be expressed. App. 50% of the regeneration foci developed into plantlets with trichome-less cotyledon-like leaves. Moreover, the somatic embryogenesis defective lec1 mutant could regenerate only shoots with trichome-bearing leaves under this condition. Based on these observations, the mixed accomplishment of shoot organogenesis and somatic embryogenesis is hypothesized in the Arabidopsis root explants cultured under hormone-free conditions following cytokinin induction. Using whole seedlings instead of root explants in the same experimental set up, no regenerates were formed on the roots. Applying the auxin transport inhibitor TIBA to the root-to-shoot junction of the seedlings, the regeneration ability of the root could be restored. The observations indicate that shoot-derived endogenous auxin blocks the cytokinin-induced regeneration process in the roots of whole seedlings. The expression of the wound-induced transcription factor WIND1 could be detected in the roots of unwounded seedlings if the shoot-to-root auxin transport was inhibited. Manipulating the exogenous cytokinin level together with the endogenous shoot-to-root auxin transport therefore could mimic the effect of wounding (removal of shoot) on plant regeneration from roots. Key message Transferring root explants from high cytokinin to hormone-free conditions resulted in the expression of embryogenic markers. Inhibiting the shoot-to-root auxin transport had similar effect on regeneration as wounding

Environmental impact assessment based on soil indicators

A mezőgazdaság, mint természeti rendszer közvetlen kölcsönhatásban van a környezettel, így jelentős hatást gyakorol arra, ugyanakkor a környezet összetevői, illetve azok állapota is alapvetően meghatározza a mezőgazdasági tevékenységet, annak jellegét, eredményességét. A mezőgazdasági növénytermesztés igen széles körben jelentkezik szennyezőként, azonban az agrár-környezetgazdálkodás révén a környezet megóvásához is hozzájárulhat. Ezen hatások kimutatatásához jelzőszámokra van szükség. Az OECD 1994-ben készítette el a DPSIR jelzőszám rendszer (Driving forces-Pressure-State-Impact-Response), ami a Hatótényezők – Terhelés – Állapot – Hatás – Válasz rendszerben vizsgálja az antropogén eredetű környezetre ható ok-okozati összefüggéseket. Dolgozatomban agrár-környezeti indikátorok segítségével meghatároztam a vizsgált növénytermesztési rendszerek hatótényezőit a DPRIS modell szerint, majd feltártam a hatásfolyamatokat. Megvizsgáltam a növénytermesztés várható környezeti hatásait a környezeti elemekre, környezeti elemek rendszereire és a vizsgált tájra. Az agrár-környezeti indikátorokra alapozott kutatásaimat Debrecenben és Karcag térségében végeztem. Mindezeket a laboratóriumi vizsgálatokból kiindulva, a táj szintű modellezéssel bezárólag terjesztettem ki. A DPSIR keret indikátor rendszert figyelembe véve, erre alapozva összeállítottam egy agrár-környezeti indikátor rendszert. Az agrár-környezeti terhelések közé soroltam egyrészt a makro- és mikrogazdasági szabályozókat, földhasználat változást, szakértelem esetleges hiányát. Másrészt értékeltem: a gépi munka felhasználás okozta levegőszennyezés és talajdegradációs folyamatokat, káros vízbőség okozta talaj-víz rendszer terheléseit, a talajvíz mozgásából eredő agrár-környezeti hatásokat, illetve kimutattam a különböző évjáratok biomassza termelésre gyakorolt hatásait is. Agrár-környezeti állapot indikátorok révén tudtam számszerűsíteni és értékelni az agrár-környezeti pozitív és/vagy negatív hatásokat. Az agár-környezeti hatásindikátorokon keresztül szolgáltattam agrár-környezeti szempontból pozitív megoldásokat, jövőre vonatkozó predikciót. Az agrár-környezeti válasz indikátorok megnevezésén keresztül tettem javaslatot az elkövetkező EU-s költségvetés ciklusra. Összességében elmondható, hogy az általam összeállított agrár-környezeti indikátor rendszer alkalmasnak bizonyult több léptékváltásban az agrár-környezet értékelésére talaj indikátorok alapján.Agriculture is in direct interaction with environment as part of natural system. So it has strong effects on nature. However, the characteristic and efficiency of agricultural activities are entirely determined by elements and state of nature. Agricultural plant production has plenty of environmental pollution and at the same time, it could contribute to agriculture environmental protection. Agri-environmental schemes has key role in agriculture related environmental activities by the motivation of farmers to implement sustainable and good agricultural practice. To detect these effects, use of indicators and indices are required. In 1994 OECD set up DPSIR model (Driving forces-Pressure-State-Impact-Response) which helps to analyse and highlight anthropogenic originated environmental cause-and-effect relationships. In my thesis I estimated the environmental effects of plant production – as Driving force of DPSIR – by subjected agri-environmental relationships. My agriculture-environment indicator oriented researches were carried out in Debrecen and in Karcag region. My research work covers lab measurements, field experiment analyses in Karcag, GIS evaluation works and predictions based on IPCC method in Karcag area. Based on DPSIR model, I compiled a new agri-environmental indicator system adapted to my researches. Group of Agricultural-environmental pollutions involve macro- and microeconomics regulations, land use changes, lack of professional skills and decrease of wildlife. Moreover, the following indicators were evaluated: air pollution and soil degradation processes by agricultural machinery, inland water and ponds, changeable soil water regime, year effects on yield (drought, high precipitation, average year). Agricultural-environmental state indicators were used to get information about positive or negative effects. I made agri-environmental friendly solution and prediction on agricultural practice and how to change land use. Agricultural-Environmental Response indicators were used to make recommendations on next EU budget period. On the whole, the new and specified agricultural-environmental indicator system is seems to be suitable in spatial and in time to make agri-environmental evaluation based on soil indicators