Fenotipska varijabilnost korijenovog sustava pšenice (Triticum aesitivum L.)

master's thesis

• Title (english): Phenotypic variability of wheat root system (Triticum aestivum L.)
• Author: Bernardica Jelčić
• Mentor: Boris Lazarević (mentor)
• Committee member: Boris Lazarević (predsjednik povjerenstva)
• Committee member: Toni Safner (član povjerenstva)
• Committee member: Hrvoje Šarčević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Department of Plant Nutrition); Zagreb
• Defense date and country: 2018-12-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Fenotipske karakteristike korijenovog sustava imaju važnu ulogu u adaptaciji biljaka na nepovoljne okolišne uvjete. Istraživanje fenotipskih karakteristika omogućuje opis ideotipova korijena za poboljšano usvajanje vode i hranjiva, dok se primjenom molekularnih biljega stvara mogućnost lociranja gena koji kontroliraju određene fenotipske karakteristike korijena.
Cilj rada bio je analizirati fenotipske karakteristike korijenovog sustava pšenice te analizom polimorfizma jednog nukleotida (single nucleotide polymorphism; SNP) provesti kartiranje pridruživanjem kako bi se pronašle regije u genomu pšenice koje kontroliraju određene fenotipske karakteristike korijena.
Pokus je postavljen u pouch sustavima. Klijanci 56 genotipova i oplemenjivačkih linija pšenice uzgajani su u Magnavaca hranjivoj otopini (pH = 4,0) tijekom pet dana. Fenotipske karakteristike korijenovog sustava određivane su pomoću WinRhizo Pro softvera analizom fotografija korijenovog sustava nastalih petog dana nakon presađivanja. Analizirane su sljedeće fenotipske karakteristike: širina i dubina korijena, kut grananja korijena, ukupna duljina te ukupna površina korijena. DNA je ekstrahirana iz osušenog i usitnjenog lisnog materijala uz pomoć komercijalnog kita “peqGOLD plant DNA mini kit”. Analiza polimorfizma jednog nukleotida provedena je novorazvijenim 15k SNP-čipom koji sadrži 13 006 funkcionalnih SNP biljega. Za potrebe analize genoma pšenice korišteno je ukupno 10 649 biljega za koje je postojala informacija o poziciji unutar genoma (kromosom i pozicija lokusa).
Utvrđena je značajna fenotipska varijabilnost između korijena klijanaca korištenih genotipova pšenice. Također, pronađeni su potencijalni ideotipovi korijena za poboljšano usvajanje vode i dušika, odnosno fosfora. Nadalje, pomoću analize polimorfizma jednog nukleotida (SNP) detektirani su signifikantni QTL-ovi za sve četiri analizirane karakteristike korijena. Sukladno tome, na području genoma pšenice pronađene su potencijalne regije koje sadrže jedan ili više gena jakog efekta koji kontroliraju mjerene fenotipske karakteristike korijena.

Abstract (english)

Root phenes play an important role in plant adaptation to unfavourable environmental conditions. In fact, investigation of root traits gives an opportunity to describe root system ideotypes for enhanced water and nutrient acquisition. What is more, usage of molecular markers gives the opportunity to identify genetic loci associated with the respective root phenes.
The main aim of this study was to analyse wheat seedlings root phenes and, by performing single nucleotide polymorphism (SNP) analysis, to conduct an association mapping in order to identify wheat genome regions which control expression of particular root phenes.
Seedlings of 56 wheat genotypes and inbred lines were grown in Magnavaca’s nutrient solution (pH = 4,0) for five days. Plants were grown in pouch systems. Root phenes were analysed five days after planting using WinRhizo Pro software. Analysed root phenes included: root system width and depth, root growth angle, total root lenght and total root area. DNA was extracted from dried-mashed leaf material of respective genotypes and inbred lines using “peqGOLD plant DNA mini kit” commercial kit. Single nucleotide polymorphism analysis was assisted by a newly developed 15k SNP chip containing 13 006 functional SNP markers. Regarding the wheat genome-wide analysis, 10 649 SNP markers (with determined position) were used.
Wheat seedlings root system showed significant phenotypic variability among genotypes. Moreover, potential root ideotypes for enhanced water and nitrogen, as well as phosphorus acquisition, were identified. What is more, significant QTLs for all analysed root phenes were identified by single nucleotide polymorphism analysis. In this regard, potential wheat genome regions containing one or few genes controlling particular root phenes were identified.

• Keywords: pšenica (Triticum aestivum L.); fenotipske karakteristike korijena; fenotipska varijabilnost; polimorfizam jednog nukleotida (SNP); lokusi kvantitativnih svojstava (QTL)
• Keywords (english): wheat (Triticum aestivum L.); root phenes; phenotypic variability; single nucleotide polymorphism (SNP); quantitative trait loci (QTL)
• Language: croatian
• URN:NBN: urn:nbn:hr:204:202209
• Study programme: Title: Agroecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka agroekologija (magistar/ magistra inženjer/inženjerka agroekologija)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Repository: Repository Faculty of Agriculture University of Zagreb
• Created on: 2019-01-10 09:23:09