doktorska disertacija
Tanja Guček (Avtor), Sebastjan Radišek (Mentor), Stanislav Trdan (Član komisije za zagovor), Maja Ravnikar (Član komisije za zagovor), Dunja Bandelj Mavsar (Član komisije za zagovor), Jernej Jakše (Komentor)

Povzetek

Huda viroidna zakrnelost, ki jo povzročata viroida CBCVd in HLVd, je ena izmed najhujših bolezni hmelja. V okviru disertacije smo analizirali gostiteljsko specifičnost viroida CBCVd, stabilnost, širjenje in vpliv bolezni na hmelj ter razvili metode za umetno okuževanje, sočasno določanje in kvantifikacijo viroidov. Med gostitelji smo s CBCVd okužili grenkoslad (Solanum dulcamara) in s HLVd navadno konopljo (Cannabis sativa). Z analizo stabilnosti CBCVd smo viroid v ostankih in tleh zaznali do enega leta po uničenju in zakopu okuženih rastlin. Z analizo širjenja bolezni smo v sedmih letih določili 8,5 % hitrost širjenja (št. obolelih rastlin/leto) in več kot 50 % povečanje števila obolelih rastlin. Vpliv bolezni na pridelek hmelja je bil negativen z izrazitimi bolezenskimi znamenji, z 10-kratnim zmanjšanjem hitrosti rasti, do 70 % padcem α-kislin, do 55 % padcem β-kislin, do 85 % nižjimi eteričnimi olji, do 40 % krajšo dolžino in do 70 % nižjo težo storžkov. Za učinkovito določanje viroidov smo razvili metodi za sočasno analizo viroidov: mRT-PCR za določanje vseh 4 viroidov iz hmelja in endogene kontrole ter mRT-qPCR za določanje CBCVd, HLVd in HSVd. Z uporabo razvitih metod smo določili sezonsko dinamiko in tkivno kolonizacijo viroidov CBCVd in HLVd v hmelju. Med viroidoma smo potrdili sinergijo in pozitivno korelacijo, glede na tkivo sta se akumulirala v podobnih vzorcih lokalizacije. V listih in generativnih organih je bil največji titer viroidov julija in avgusta, v koreninah maja. Z raziskavo smo določili biologijo viroida CBCVd, razvili metode za umetno okuževanje in določanje viroidov ter kot prvi analizirali sezonsko dinamiko viroidov na hmelju.

Ključne besede

hmelj;viroid;viroid razpokanosti skorje agrumov (CBCVd);huda viroidna zakrnelost hmelja;umetna okužba;gostiteljska specifičnost;metode za določanje viroidov;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.08 - Doktorska disertacija
Organizacija: UL BF - Biotehniška fakulteta
Založnik: [T. Guček]
UDK: 606:632:633.791:57.083.24(043.3)
COBISS: 35706883 Povezava se bo odprla v novem oknu
Št. ogledov: 474
Št. prenosov: 159
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Biology of citrus bark cracking viroid (CBCVd) and development of methods for detection of viroids in hop
Sekundarni povzetek: Severe hop stunt disease caused by CBCVd and HLVd viroids is one of the worst diseases in hop. In this dissertation, we analyzed the host specificity of CBCVd, tohether with stability, spread and impact of the disease on hop. We developed methods for artificial infection, simultaneous detection and quantification of viroids. Woody nightshade (Solanum dulcamara) was infected with CBCVd and cannabis (Cannabis sativa) with HLVd. Analyzing the stability of CBCVd, the viroid was detected in residues and soil up to one year after the destruction and burial of infected plants. Analyzing the spread of the disease, we determined an 8.5 % rate of spread (no. of symptomatic pants/year) and a 50 % increase in the number of diseased plants in seven years. The impact of the disease on hop yields was negative with pronounced disease symptoms: 10-fold decrease in growth rate, 70 % drop in α-acids, 55 % drop in β-acids, 85 % lower essential oils, 40 % shorter length and up to 70 % lower cone weight. For efficient viroid detection, we developed multiplex methods: mRT-PCR for detection of all 4 hop viroids and endogenous control, and mRT-qPCR for detection of CBCVd, HLVd and HSVd. We next determined the seasonal dynamics and tissue colonization of CBCVd and HLVd in hop. Synergy and a positive correlation were confirmed between the viroids, they accumulated in similar localization patterns with respect to tissue. In leaves and generative organs, the highest titer of viroids was in July and August, in the roots in May. The research determined the biology of the CBCVd, developed methods for artificial infection and detection of viroids, and was the first to analyze the seasonal dynamics of viroids in hop.
Sekundarne ključne besede: hop;viroid;citrus bark cracking viroid (CBCVd);severe hop stunt disease;artificial infection;host range;methods for detection of viroids;
Vrsta dela (COBISS): Doktorsko delo/naloga
Študijski program: 0
Konec prepovedi (OpenAIRE): 1970-01-01
Komentar na gradivo: Univ. v Ljubljani, Biotehniška fak.
Strani: XIV f., 139, [32] str.
ID: 12082197