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Browsing by study line "Plant production sciences"

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  • Haavisto, Minna (2022)
    Weed management is a challenge in organic agriculture and consequently investigation for developing mechanical weed control methods is needed. The aim is to decrease competition between weeds and crop to prevent reduction of the crop yield. Weed control aims at preventing seedbank of the weeds increasing in the fields and weed pressure in the future as well. The effect of the different weed harrowing methods for crop yield and controlling annual weeds in the spring cereal fields were examined in the Mustiala farm as a part of the project “Luomussa vara parempi” for three years. The weed harrowing methods were single post emergence harrowing and combination of pre-emergence and post emergence harrowing. Different weed harrowing treatments were compared with each other and the untreated control treatment. Pre-emergence harrowing was carried out after sowing before emerging of the crop and post emergence harrowing at 2–4 leaf stage of the crop. The most abundant annual weed species was fat hen (Chenopodium album L.) and number of other weed species were proved to be minor during the years of the field experiment. Therefore, the effects of the weed harrowing treatments were concentrated to examine for fat hen. The occurence of fat hen was assessed three times from the experimental plots: before post emergence weed harrowing treatments, after weed harrowing treatments and before harvest. Biomasses of fat hen and yields of the crop were determined in August. Combination of pre-emergence and post emergence harrowing was proved to be the most effective and reliable treatment. Fat hen was controlled substantially by single post emergence harrowing as well. None of the weed harrowing treatments affected significantly crop yield. The smallest crop yield was in the experimental plots of the combination treatment where soil compaction was the greatest due to the weed harrowing. The infestation of fat hen was most effectively decreased by a combination of pre-emergence and post emergence harrowing as well as single post emergence treatment during the next successive years of cereals. Annual reductions in the number of weeds could reduce the yield of the crop in the long term.
  • Bhadhury, Suzan Kumer (2022)
    Plant vascular cambium development involves dynamic changes in transcriptional profiles, which are mediated by key transcription factors. Understanding secondary growth through complex molecular processes of vascular cambium development has remarkable significance in maximizing carbon storage in trees and is crucial for the genetic improvement of trees for wood production. Here, we studied the functions of NO TRANSMITTING TRACT (NTT)/WIP DOMAIN PROTEIN2 (WIP2) zinc-finger transcription factor in regulating vascular cambium activity and xylem formation using Arabidopsis roots and tree stems as model organisms. Reporter lines carrying red fluorescent protein driven by the promoter of NTT/WIP2 showed cambium specific expression in Arabidopsis roots under confocal microscope. Inducible overexpression of NTT/WIP2 after cambium activation reduced vascular diameter, primary phloem pole distance and secondary vessel number in Arabidopsis roots. In loss of function ntt mutants, significant reductions of vascular diameter, phloem pole distance and number of secondary vessels were also evident. Our data suggests that, both increased expression and loss of function of NTT/WIP2 gene significantly reduce secondary growth in Arabidopsis roots. Simultaneous to our Arabidopsis experiments we also tested the possibility of increasing wood formation amounts through manipulation of PttNTT (putative Populus ortholog of Arabidopsis NTT/WIP2 gene) expression in hybrid aspen trees. But increased expression of NTT/WIP2 in Poplar significantly reduced plant height, stem girth and internode numbers. Altogether, we hypothesize that, appropriate spatiotemporal expression pattern and levels of NTT/WIP2 is required for cambial activity to proceed properly in plants. These findings represent a new foundation toward a more comprehensive understanding of the molecular mechanisms of NTT/WIP2 gene in regulation of cambium development and secondary growth in plants.
  • Uusitupa, Jenni (2021)
    Tiivistelmä  Referat  Abstract Lettuce (Lactuca sativa L.) may accumulate high amounts of nitrate in the hydroponic NFT-cultivation system. Accumulation is known to increase under low light conditions, and thus high nitrate content causes problems in year-round lettuce production in Finland. Nitrate is classified as a harmful food additive, and the regulation (194/97) of the European Commission requires the Member States to monitor the nitrate content of commercial lettuce. Hence, to control the nitrate content, farmers have requested an efficient method that does not shorten the shelf-life or negatively affect the quality of lettuce. In the earlier studies, root-applied glycinebetaine (GB) was shown to reduce lettuce nitrate content and increase the contents of amino acids and minerals. The present study aimed to investigate, whether glycinebetaine can serve as a precise method to control lettuce nitrate content in commercial-scale greenhouse production. Glycinebetaine 10 mM was applied into the nutrient solution twice at three days intervals, and lettuce was exposed to treatment during the last six growing days before the harvest. Plant samples were collected every second day for 14 days after the first GB application, and samples from nutrient solution were collected simultaneously. The reduction of GB from the nutrient solution was monitored. The fresh weight of the plants was weighed during the harvest, and contents of nitrate, dry matter, minerals, amino acids, and GB in the plant samples were analyzed. Root-applied GB reduced lettuce nitrate content by over 29 % in comparison to control plants. The total contents of hydrolyzed- and free amino acids were increased. The total content of essential amino acids was increased up to 14 % following the GB treatment. Also, the contents of minerals in the lettuce leaves were altered. The potassium (K+) content in lettuce was reduced by over 40 % after GB application. Lettuce accumulated the applied GB and leaf GB content was 7 mg kg-1 fresh lettuce at the highest. Root-applied GB reduced the fresh weight of the harvested lettuce, but all plants reached the commercial size (>100 g) during the typical commercial growing period of 41–43 days. The result of the present study proved that GB is a practical method to control nitrate content and the quality of lettuce on commercial-scale lettuce production. Glycinebetaine was detectable in the nutrient solution for three days after application and thus, continuously maintained lower nitrate content in plants requires continuous GB application in the commercial lettuce production. The reduction of the nitrate content was significant six days after the first GB application, which indicates that a six-day treatment period is required.
  • Zhanybekova, Zhanargul (2022)
    Abstract Background. Faba bean (Vicia faba L.,) is a protein-rich grain crop and a good source of many nutrients. However, the productivity and composition of this crop can be limited by several biotic and abiotic stresses. Acid soil leads to a reduction in water uptake, and influences on major biological and chemical processes. However, some plants can manage stress. Mostly, low pH reduces plant vegetative organs and a has a negative effect on physiological processes such as gas exchange, photosynthesis, chlorophyll concentration, and transpiration. The aim of this study was to find homolog genes in close spp. and o test selected gene response as a factor in resilience to rootzone acidity in Vicia faba L. Methods. Four faba bean genotypes were selected for our experiment based on germplasm screening in aquaponic conditions from a previous study. According to obtained results of morpho-physiological measures from a previous experiment, IG11204 and Bourdon showed tolerance to acid only. DULUC is tolerant to acid and Al treatments. In contrast, Nora38 demonstrated susceptibility to both stresses. Selected genotypes were grown under the same experimental conditions in order to proceed with samples for further analysis (total RNA extraction, cDNA synthesis, RT-PCR, gel-electrophoresis, validation of selected gene by RT-qPCR). Results. Selected genes have been identified as hub genes in A. thaliana (alternative oxidase 1A, glutamate dehydrogenase 1, zinc fingers superfamily protein), which demonstrated an increase in expression levels under acidic pH stress. We have found homolog genes in the Hedin cultivar. Selected homolog gene were used to check its expression in four genotypes under Al3+ and acidic stresses using RT-qPCR. Finally, up-regulation of the GDH1 was detected by acid and also occurred by Al3+ treatments. Discussion. Our analysis of gene expression revealed that GDH1 was expressed differently between control and treated groups. However, its activity was detected for both stresses. The expression of GDH1 transcripts in this study, also concurs with findings where GDH1 in A. thaliana were expressed under Al3+ stress. Furthermore, it was confirmed that they are novel Al3+ resistance genes, which are regulated by the transcription factor STOP1 (sensitive-to-proton-rhizotoxicity1). GDHs are involved in stress tolerance, and pH-regulated metabolic pathways – GABA shunt. It participates in the regulation of cytosolic pH, carbon fluxes into the TCA cycle, nitrogen metabolism, deterrence of insects, protection against oxidative stress, osmoregulation and signaling in plant cells under different stress conditions. The GABA shunt is enhanced by stresses, which cause cytosol acidification. Genes expressed in conditions of low pH partly overlap with those expressed in plants exposed to Al3+ stress. Generally, acidic soil is associated with the co-occurrence of Al3+ and H+ rhizotoxicities.
  • Kukkola, Annukka (2022)
    Biochars are produced from organic materials using pyrolysis and are used as a soil amendment to improve soil fertility and plant growth. Biochars are particularly beneficial to soils with high acidity, low carbon (C) content, nitrogen (N) content and other nutrient contents. However, it is not well-studied whether the beneficial effects of a biochar exist for the long-term. The aim of this study was to examine the effects of one-time application of spruce biochar on soil and barley (Hordeum vulgare L.) properties in the long-term. For this purpose, soil and plant properties were measured from the biochar field experiment in a boreal nutrient deficient Umbrisol where spruce biochar was applied eight years earlier. The experiment had a split-plot design with biochar application rates (0, 5, 10, 20 and 30 t ha-1) as the main-plot factor. The effects of fertilisers alone and their interaction with biochar were studied with three treatments (control, mineral fertiliser and meat bone meal (MBM)) as the sub-plot factor. Soil moisture content at 0–15 cm depth, as well as pH, plant available nutrients, total C and N content and C/N ratio of the soil were measured. Barley growth was assessed indirectly by measuring leaf chlorophyll content (SPAD), leaf area index (LAI), plant stand density, biomass, C and N content, C/N ratio, grain yield and weight of 1000 grains (TGW). No consistent significant effects of biochar on soil moisture content or soil chemical properties were observed. Biochar application did not have significant effects on leaf chlorophyll, leaf area index, plant density or biomass of barley. The highest biochar application rate of 30 t ha-1 tended to increase grain yield and TGW but the increases were not statistically significant. Mineral and MBM fertilisers produced similar grain yields although N was likely less available from MBM earlier in the growing season. Biochar and fertiliser interaction did not have significant effects on any of the measured properties. The lack of effects of biochar may be explained by the high amount of initial soil organic matter as well as low liming effect and low nutrient content of the used biochar. In addition, the lack of significant effects of biochar also suggests loss of biochar from topsoil due to weathering and downward displacement of biochar over the period of eight years. In this study, biochar application did not have negative consequences on the measured soil and crop properties. Therefore, it should be safe to use. Biochars may provide a viable option to sequester carbon in boreal agriculture. Further research on this is still needed to investigate the long-term effects of different types of biochars on different types of soils.
  • Pandey, Kailash (2022)
    A well-adjusted regulation of vascular development is crucial for plant growth and development. CLASS III HOMEODOMAIN LEUCINE ZIPPER (HD-ZIP III) genes play a decisive role in cambial stem-cell maintenance, xylem cell fate determination, and ensuring proper patterning of vasculature. LITTLE ZIPPER (ZPR) microproteins are involved in the post-translational regulation of HD-ZIP III via a negative feedback mechanism. The protein-protein docking has predicted that HD-ZIP III and ZPR interact at the b-ZIP domain, which is an evolutionarily conserved region. The expression and mutant phenotype of ZPR in root vasculature haven’t been previously described. In this study, we developed the reporter lines and checked the expression in the Arabidopsis root. ZPR1 and ZPR3 showed a distinct and continuous expression from root tip to elongation and differentiation zone. In the cross-section, the expression was detected in cambium and xylem cells. Unlike ZPR1, ZPR3 showed a stronger expression towards the phloem side. Although ZPR2 didn’t show any endogenous expression, expression was detected in the primary root tip and lateral root initiation site upon xylemin treatment. Exogenous auxin application increased the expression of ZPR3, but it required a longer response time. The expression results suggest that ZPR follows the HD-ZIP III expression pattern, however, each ZPR shows some variation from the others. In the mutant analysis, zpr1 showed increased cellular proliferation in the vasculature, but zpr2 had no difference compared to the wild type. The results suggest that ZPR and HD-ZIP III have their function in a similar region in the root vasculature. However, further empirical evidence is necessary to elucidate the interaction of HD-ZIP III and ZPR, and its role in the regulation of root vascular development.
  • Vigelius, Liisa (2022)
    Tutkimuksen tavoitteena oli selvittää, voisiko tomaatin (Solanum lycopersicum) typpilannoitusta vähentämällä hidastaa ansarijauhiaisen (Trialeurodes vaporariorum) populaation kasvunopeutta ja siten parantaa biologisen torjunnan tehokkuutta. Ansarijauhiainen on merkittävä kasvihuonetuholainen, jota torjutaan yleisesti jauhiaiskiilukaisella (Encarsia formosa), mutta torjunnan tehokkuus ei aina ole riittävä, jos ansarijauhiaisen populaation kasvunopeus on suurempi kuin jauhiaiskiilukaisella. Aiemmissa tutkimuksissa ansarijauhiaisen on havaittu hyötyvän tomaatin typpilannoituksesta. Tutkimuksessa jauhiaisia munitettiin vuorokauden ajan klipsihäkeissä tomaateilla, joille annettiin typpipitoisuudeltaan neljää erilaista lannoiteliuosta. Lannoiteliuosten typpipitoisuus muuttui tomaatin kehitysvaiheen perusteella kaupallisten viljelmien käytäntöjen mukaisesti. Jauhiaisten kuolleisuus ja kehitysaika munasta aikuiseksi määritettiin. Kehitysaika laskettiin kummallekin sukupuolelle erikseen. Kuoriutuneista naaraista osa munitettiin kahden viikon ajan gelatiinikapseleista valmistetuissa häkeissä muninnan määrän selvittämiseksi. Typpilannoituksen vaikutusta tomaatin typpipitoisuuteen arvioitiin jauhiaislehtien klorofylli-indeksien perusteella. Tulosten perusteella typpilannoituksella ei ollut merkitsevää vaikutusta jauhiaisten kuolleisuuteen ja kehitysaikaan eikä jauhiaislehtien klorofyllipitoisuuksiin. Yllättävänä havaintona naaraat kuoriutuivat koiraita aikaisemmin kaikilla typpitasoilla: hyönteisillä on yleisempää, että pienikokoisemmat koiraat kuoriutuvat ensin. Kokeen toinen vaihe epäonnistui, eikä muninnan määrää per naaras saatu analysoitua. Näyttäisi siltä, että typpilannoituksen tulisi olla huomattavasti nykykäytäntöä vähäisempi, jotta sillä voisi hillitä jauhiaispopulaation kasvunopeutta. Tämä tulisi kuitenkin varmistaa lisäkokein, ja samalla selvittää vähennetyn typpilannoituksen vaikutukset jauhiaiskiilukaisen torjuntatehoon sekä mahdolliset satovaikutukset. Myös sukupuolten välistä kehitysaikojen eroa olisi tutkittava lisää, jotta saataisiin selville taustalla vaikuttavat syyt tai mekanismit.
  • Kurunsaari, Jani (2022)
    Amerikankarpalo (Vaccinium macrocarpon) on hapan punainen marja, joka on kotoisin Pohjois-Amerikasta. Karpalon suosio on lisääntynyt viime aikoina sen tutkittujen terveysvaikutusten johdosta. Karpalon terveysvaikutukset ovat herättäneet halun viljellä niitä myös Suomessa. Suomen kasvukausi on kuitenkin lyhyt, eivätkä karpalot ehdi kypsyä täällä riittävästi. Siksi karpalon tunneliviljelyä on ryhdytty kokeilemaan. Tästäkin huolimatta marjat saatetaan joutua keräämään raakoina. Valon tiedetään vaikuttavan etyleenin ja antosyaanien muodostumiseen, joten karpaloiden jälkikypsytys valojen alla pitäisi olla mahdollista. Tutkimuksen tavoitteena oli selvittää miten valospektrit vaikuttavat eri kypsyysasteissa kerättyjen amerikankarpaloiden etyleenin, antosyaanien ja värin muodostukseen. Amerikankarpalolajikkeen Pilgrim- marjoja kerättiin kolmella eri kypsyysasteella vihreinä, valkoisina ja punertuvina. Käsittelyinä käytettiin sinistä, punaista ja laajaa (AP673L Valoya) valospektriä. Kontrollina toimi pimeys. Jokainen kypsyysaste sai 0 vrk:n, 7 vrk:n ja 14 vrk:n käsittelyn. Käsittelyiden jälkeen karpaloista mitattiin etyleenin muodostumisnopeus, kokonaisantosyaanipitoisuus ja väri. Valokäsittelyllä, kypsyysasteella ja näiden yhdysvaikutuksella oli merkitsevä vaikutus karpalon etyleenin, värin ja antosyaanien muodostumiseen sadonkorjuun jälkeen. Erityisesti sininen valo vaikutti merkittävästi värin muodostumiseen vihreinä kerätyillä karpaloilla. Käsittelyiden väliset erot tasaantuivat valkoisina kerätyissä karpaloissa. Punertuvina kerätyissä karpaloissa värin muodostumisessa ei ollut eroja käsittelyiden välillä. Kaikki valokäsittelyt kiihdyttivät etyleenin muodostumista vihreinä kerätyissä karpaloissa. Valkoisina kerätyissä etyleeniä muodostui enää sinisen valon alla. Punertuvina kerätyissä karpaloissa etyleenin muodostumisessa ei ollut eroja käsittelyiden välillä. Antosyaaneja muodostui vihreinä ja valkoisina kerätyissä karpaloissa eniten sinisen valon alla. Punertuvina kerätyissä antosyaaneja kertyi eniten laajan spektrin alla. Tutkimus osoitti, että raakoina kerättyjä karpaloita voidaan kypsyttää valon avulla. Tämä saattaisi mahdollistaa karpaloiden kypsyttämisen varastoinnin aikana. Sinisen valon vaikutuksesta karpalon viljelyssä kannattaisi tehdä jatkotutkimuksia.
  • Grönroos, Sanna (2021)
    Organic agriculture is growing steadily in Europe. Demand for organic products and pressure from policy changes in the EU have created a need for organic seed material. One of the limiting factors is the lack of organic variety testing. Currently no official organic Value of Cultivation and Use (VCU) trials or standards for organic variety testing excist in the EU. Plant breeding companies like Boreal Plant Breeding want to offer varieties for organic farmers but they lack information on the performance of their varieties in organic conditions. The main objective of this experiment was to determine the most important variety traits in organic agriculture in Finland and which of the Boreal Plant Breeding oat varieties exhibit the most favourable traits for organic growing conditions. Relationships between observed traits were also examined. A wide range of observations and measurements were performed from the trial throughout the growing season. Quality analysis of the yield were performed after harvest. The objects of examination during growing season included growth development, leaf area index (LAI), nutrient status with SPAD (Soil and Plant Analysis Development) measurements, plant height and yield components. Plant height and LAI appeared to be the best indicators for evaluation of performance potential of oat in organic conditions. SPAD value wasn’t found to have a connection to oat yield nor was it an indicator for oat LAI. High LAI increased oat height, yield and yield component shoots/m2 but effected negatively on the yield component panicles/m2 during the end of stem elongation. Plant height was a good indicator of yield level. The number of weeds and LAI value didn’t have a connection in this experiment and neither did weed number and yield. The early and late varieties varied in their reaction to the low-input growing conditions. Early varieties had generally lower yield but better yield quality than the late varieties. ‘Nella’ showed potential to be a variety with good yield quality and high yield in low-input conditions in Southern Finland. Area of cultivation and the end use of the oat are important factors in variety selection.