Search

Manipulacija izražanja spola pri navadni konoplji (Cannabis sativa L.) je povezana s hermafroditizmom, ki je genetsko in okoljsko pogojen. To lastnost lahko uporabimo pri križanju rastlin in pri pridelavi feminiziranih semen, kjer s stresnimi dejavniki na genetsko ženskih rastlinah sprožimo nastanek moških cvetov oziroma maskuliniziramo ženske rastline. Cilj magistrske naloge je bil preveriti delovanje koloidnega srebra in srebrovega tiosulfata (STS) na nastanek ženskih in moških cvetov na šestih populacijah genetsko različnih ženskih konopelj ter preveriti kalivost nastalega peloda. Izkazalo se je, da smo največji odstotek (90 %) moških cvetov na rastlino inducirali s tretiranjem z dnevnim nanosom 90 ml koloidnega srebra. Drugi največji odstotek moških cvetov je induciralo tretiranje z 0,3 mM STS (77 %). Najbolj odzivna je bila žlahtnjiteljska populacija MX-CBD-707, ki je skoraj edina tvorila kalivi pelod. Najboljši sredstvi za tvorbo kalivega peloda, ki sta pri žlahtnjiteljski populaciji MX-CBD-707 razvili kalivi pelod, sta bili 0,3 mM STS (4,8 %) in dnevno nanešeno 30 ppm koloidno srebro (2 %). Povprečni odstotek nastalih moških cvetov pri populaciji MX-CBD-707, sproženih z 0,3 mM STS, je bil 51 %. V zaključku ugotavljamo, da je za razvoj moških cvetov na genetsko ženskih rastlinah in za razvoj kalivega peloda bilo najbolj uspešno tretiranje z 0,3 mM STS, kjer je bil za uspeh predvsem ključen optimalen genotip. Manipulation of gender expression in cannabis (Cannabis sativa L.) is connected with hermaphroditism that is conditioned genetically and environmentally. This trait can be used in cannabis breeding and in the production of feminized seeds where stress factors are applied on genetically female plants to induce male flowers or so called masculinization of female plants. The goal of this thesis was to check the effect of colloidal silver and silver thiosulfate (STS) on the formation of female and male flowers on six genetically different cannabis female populations and on the germination of the developed pollen. As it turned out, the highest share (90%) of male flowers per plant was induced by treatment with daily application of 90 ml of colloidal silver. The second highest share of male flowers was induced by an application of 0,3 mM STS (77%). Almost the only and most responsive genetically female population that has produced germinative pollen was MX-CBD-707. The two most effective treatments that have produced germinative pollen on MX-CBD-707 were an application of 0,3 mM STS (4,8%) and a daily application of colloidal silver (2%). The average share of induced male flowers on population MX-CBD-707 (induced by a one time application of 0,3 mM STS) was 51%. In conclusion, we have found that the most effective treatment for induction of male flowers on genetically female plants and production of germinative pollen was an application of 0,3 mM STS, in which the optimal genotype was crucial for success.

The experiments showing the effect of drip irrigation on yield and evapotranspiration of fibre hemp (Cannabis sativa L.) were conducted at the experimental field of the Alternative Crops Department, Institute of Field and Vegetable Crops, Novi Sad, Serbia. Irrigation was based on the water balance method. Daily evapotranspiration (ETd) was computed from the reference evapotranspiration (ETo) and crop coefficient (kc) 0.5, 0.9 and 1.1 from sowing to 3-4 pair of leaves, from 3-4 pair of leaves to appearance of male flowers and from appearance of male flowers to the end of the season, respectively. ETo was calculated using Hargreaves equation. The irrigation depth was restricted to the soil depth of 0.4 m. In other words, irrigation started when readily available water in the soil layer of 0.4 m was completely depleted by plants. The irrigation rate was 30 mm at the beginning of the season, 40 mm in the middle of the season, and the amount of water added by irrigation was 320 mm during the entire season. Irrigation significantly affected the yield of fresh stems, fresh leaves, flowers and plant height, but not stem diameter and fibre content. Water used on evapotranspiration in irrigation conditions (ETm) was 470 mm, while in non-irrigated control variant it amounted to 129 mm (ETa). These preliminary results could be used as a good platform for hemp growers in the region, in terms of optimizing the use of irrigation water. Eksperimentalna istraživanja o uticaju navodnjavanja kapanjem na prinos i evapotranspiraciju konoplje za vlakno (Cannabis sativa L.) su obavljena na oglednom polju Instituta za ratarstvo i povrtarstvo iz Novog Sada u Odeljenju za alternativne biljne vrste u Bačkom Petrovcu. Vreme zalivanja je određivano obračunom vodnog bilansa. Dnevne vrednosti utroška vode na evapotranspiraciju biljaka (ETd) su obračunate korišćenjem referentne evapotranspiracije (ETo) i koeficijenata useva (kc) čije su vrednosti 0,5, 0,9 i 1,1 za potperiode vegetacije konoplje od setve do porasta 3-4 lista, od 3-4 lista do pojave muških cvetova i od pojave muških cvetova do žetve. Referentna evapotranspiracija (ETo) računata je formulom Hargreaves-a. Zalivanje je obavljano kada su rezerve lakopristupačne vode u sloju zemljišta dubine 0,4 m bile iskorišćene. Zalivna norma je na početku vegetacije iznosila 30 mm, a od sredine vegetacije 40 mm. Navodnjavanjem je ukupno dodato 320 mm vode. Navodnjavanje je signifikantno uticalo na prinos sveže stabljike, svežih listova i cvetova i visinu biljaka, ali ne i na dijametar stabla i sadržaj vlakna. Utrošak vode na evapotranspiraciju biljaka u uslovima navodnjavanja (ETm) iznosio je 470 mm, a u uslovima bez navodnjavanja (ETa) 129 mm. Preliminarni rezultati istraživanja mogu biti korišćeni kao dobra osnova za proizvođače konoplje u regionu, u smislu racionalnog korišćenja vode za navodnjavanje.

The most critical aspect of plant survival and reproduction is seed germination. Considering the specificity of the Cannabis sativa production, obtaining high-quality hemp seed is not an easy task. Germination testing is often the most reliable way of assessing viability, but the selection of appropriate methods is complex. This study aimed to evaluate the effect of different conditions (i.e. various methods of germination testing) on the successful process of hemp seed germination, achieving maximum germination potential. Our results showed that C. sativa seeds germinated well in different methods, such as between filter papers, top of filter papers and sand, but there were significant differences between the applied methods. This means that the hemp seeds may have different requirements for germination than conditions covered by the Rules recommended methods. Further, the results show that hemp seed may have certain residual dormancy that needs to be investigated in detail. Najkritičnija faza preživljavanja i razmnožavanja biljaka je klijanje semena. S obzirom na specifičnost proizvodnje industrijske konoplje (Cannabis sativa), dobijanje visokokvalitetnog semena konoplje nije jednostavno. Ispitivanje klijavosti je često najpouzdaniji način procene vitalnosti, ali je odabir odgovarajućih metoda složen. Ovo istraživanje je sprovedeno kako bi se procenio efekat različitih uslova tj. različitih metoda testiranja klijavosti, na proces klijanja semena konoplje uz postizanje maksimalnog potencijala za klijanje. Dobijeni rezultati pokazuju da seme C. sativa dobro klija primenom različitih metoda (između filter papira, na filter papiru, pesak), ali postoje značajne razlike između primenjenih metoda. Ovo praktično znači da seme konoplje može imati zahteve za klijavost različite od onih koje su obuhvaćene preporučenim metodama. Takođe, rezultati pokazuju da kod semena konoplje možda postoji neki vid zaostale dormantnosti što je potrebno dodatno istražiti.

Zaradi široke uporabe in vse večje prepoznavnosti konoplje (Cannabis sativa L.) se potreba po žlahtnjenju in iskanju novih sort povečuje. Konoplja je zaradi fizioloških in morfoloških značilnosti zelo zanimiva rastlina za pridelovanje. Te lastnosti pa vplivajo tudi na potencialne pristope za pridobivanje novih sort. Mnoge žlahtniteljske tehnike se pri konoplji že uporabljajo. Ena izmed tehnik je tudi induciranje haploidov, ki so rastline z gametnim številom kromosomov. Če bi uspeli pridobiti haploidno linijo in nato podvojene haploide, bi to olajšalo možnost za pridobitev F1 hibridnih linij, ki jih pri konoplji še ni. Hibridne linije so genetopisko in fenotipsko izenačene, na račun izražene heteroze pa imajo boljše lastnosti, kot starševske linije. Tehnik indukcije haploidov je več, npr. ginogeneza in situ in in vitro ter androgeneza . V nalogi smo te tehnike opisali in se naslonili na postopke, ki so jih razvili pri drugih rastlinskih vrstah, ter na raziskave na konoplji, ki bi lahko igrale vlogo v teh postopkih. Due to the wide use and increasing recognition of cannabis (Cannabis sativa L.), search for new varieties and the need for breeding is increasing. Cannabis is a very interesting plant for cultivation because of its physiological and morphological characteristics. These aspects also affect potential approaches to obtain new varieties. Many breeding techniques are already in use for cannabis. One of the techniques is to induce haploids, which are plants with gametic number of chromosomes. Successfully acquiring a haploid line and then doubled haploids, would make it easier to obtain F1 hybrid lines that currently do not exist in cannabis. Hybrid lines are genetically and phenotypically uniform. Expressed heterosis would induce better traits in hybrids than in parental lines. There are several techniques for haploid induction like gynogenesis in situ and in vitro and androgenesis. We described these techniques and leaned on processes developed on other plant species, as well as on researches on cannabis that could play a role in these processes.