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2009–2011 metais Lietuvos Žemės ūkio universiteto Bandymų stotyje, karbonatingame sekliai glėjiškame išplautžemyje (Calc(ar)i-Epihypogleyic Luvisols) IDg8-k (LVg-p-w-cc) atlikti tyrimai, siekiant įvertinti skirtingų žieminių kviečių veislių žiemkentiškumą. Fotosintezės pigmentų didžiausias kiekis nustatytas rudens-žiemos periodu, o pavasario pradžioje fotosintezės produktyvumas buvo mažiausias. Nustatyta, kad labai gerų kepimo sąvybių ’Ada’ linkusi kaupti didesnius fotosintezės pigmentų kiekius, lyginant su gerų kepimo savybių ’Tauras DS’. Didžiausias sacharidų kiekis (447,2 mg g-1) nustatytas lapkričio mėn. žieminiuose kviečiuose ’Tauras DS’ ir ’Ada’ (443,2 mg g-1), o nuo sausio mėn., nukritus lauko temperatūrai - sumažėjo iki 37,3–61,1 mg g-1 ’Tauras DS’ ir 128–80 mg g-1 ’Ada’ želmenyse. Ilgai trukę šalčiai sumažino tirpiųjų sacharidų kaupimąsi, jų kiekis padidėjo tik sumažėjus šalčiui. Tyrimo duomenys rodo, kad esant pastoviems žiemos šalčiams, sacharidų kiekis augaluose keitėsi nežymiai. Kadangi klimatinės sąlygos buvo vienodos, galima teigti, kad ’Ada’ veislės kviečiai kaupia didesnį kiekį sacharidų dėl veislės genetinių ypatumų. Tyrimo metu didesnius fenolinių junginių kiekius kaupė ’Tauras DS’ žieminiai kviečiai, todėl galime teigti, kad tai nulėmė veislės genetinės savybės. Nustatyta, kad ’Tauras DS’ kaupė didesnius prolino kiekius žemų temperatūrų poveikyje (gruodžio ir vasario mėnesiais – 1,65 μM g-1 ir 2,61 μM g-1 ) palyginus su žieminiais kviečiais ’Ada’... [toliau žr. visą tekstą] / The research was carried out in the Experimental Station of LUA. The aim of the research was to investigate and evaluate the frost resistence of different varieties of wheat. The soil ot the experimental site was (carbonaceous shallow Luvisols (Calc (or) i Epihypogleyic Luvisols) IDg8 k (LVD-pw-cc). The study revealed the maximum amount of photosyntthetic pigments in the autumn – winter period whereas in spring the photosyntthetic productivity was the lowest. It was found that ‚Ada‘ variety, having very good baking quality, tends to accumulate higher levels of photosyntthetic pigments than ‘Tauras DS‘ wheats with good baking properties. The highest amount of sugars was recorded in November in winter wheat ‘Tauras DS’ and ‘Ada’ (443,2 mg g-1), but the amount of sugars decreased significantly by 37,3–61,1 mg g-1 in ‘Tauras DS’ wheat and by 128–80 mg g-1 in ‘Ada’ wheat in January, as a result of a drop in temperature. The prolonged frosts reduced the accumulation of soluble sugars, moreover the amount of sugars increased only after the rise of temperature. The study shows the amount of sugars in plants is rather stable if there is no fluctuation in temperatures. Since the climatic conditions were stable we can state that the ‘Ada’ variety wheat accumulate bigger amounts of sugars because of its genetic characteristics. ‘Tauras DS’ variety demonstrated largers phenolic compounds due to its genetic characteristics. It was found that the ‘Tauras DS’ accumulated higher... [to full text]

Magistrantūros studijų baigiamajame darbe pateikiami tyrimų duomenys apie piktžolių dygimą, sunykimą ir bendrą jų skaičių žieminių kviečių spelta pasėlyje nuo sėjos iki derliaus nuėmimo. Apie žieminių spelta kviečių piktžolėtumą, piktžolių sausųjų medžiagų masę g m‾², jų rūšinę sudėtį ir dirvos piktžolių sėklų banką 0-10 ir 10-20 cm armens sluoksnyje: Darbo objektas –žieminių kviečių spelta veislės 'Franckenkorn' agrofitocenozės piktžolėtumo dinamika kintančio klimato sąlygomis, sėjos laiko fonuose. Darbo metodai: Piktžolių dygimo ir sunykimo dinamika spelta žieminiuose kviečiuose nustatyta visuose laukeliuose, atsitiktine tvarka įrengus po 3 pastovias piktžolių išdygimo ir sunykimo stebėjimų aikšteles (viso 24 stacionarios piktžolių apskaitos aikštelės). Piktžolėtumo vertinimas nustatytas kiekiniu svoriniu metodu. Piktžolės buvo suskirstytos į rūšis pagal biologinę- agronominę klasifikaciją (Montsvilaitė, 1996). Darbo rezultatai. Piktžolių sudygimas, sunykimas ir bendras jų skaičius esmingai priklausė nuo eksperimento tiriamųjų veiksnių – spelta žieminių kviečių sėjos laiko, piktžolėtumo apskaitos laiko ir jų sąveikos. Vėlyvesnės sėjos pasėlyje nustatytas intensyvesnis piktžolių sudygimas, galimai dėl vėlyvesnio kviečių sudygimo ir lėtesnio pasėlio vystymosi. Tik gegužės mėnesį intensyvėjant piktžolių sudygimui, ankstyvesnės sėjos pasėlyje nustatyta piktžolių sudygimo didėjimo tendencija lyginant su vėlyvesnės sėjos pasėliu. Piktžolių sunykimas nustatytas tik sausio – kovo... [toliau žr. visą tekstą] / Master's thesis presented research data on the germination of weed, the decline and the total number of winter wheat spelta crop from sowing to harvesting. The weediness of winter wheat spelta, weed dry weight g m -², their species composition and soil weed seed bank of 0-10 and 10-20 cm soil layer: Object of the work – weediness dynamics of the winter wheat spelta 'Franckenkorn' agrophytocenoses of different sowing time in a changing climate conditions. Method of the work weed germination and death dynamics of the winter wheat spelta in arranged stacionary plots (total 24 stacionary observation plot side). Assessment of the weed quantitatively weighted method. Crop weedines were assesedby the quantitative-weighing method. Weeds were grouped according to the biologic-agronomic classification of weeds (Mostvilaitė, 1996). The results of work. Weed germination, death and the total number essentialy depende on the experimental factors - winter wheat spelta sowing time, weed ccounting time and interaction of the factors. The more intensive crop weed germination was established in the latersowe drop, possibly due to later wheat germination and slower crop development. In earlier sowed winter wheat spelta crop only in May with increase of weed germination was established intensivification of weed germination comparing it with the crop of later sowing time. Decline of weed number was found in January - March. The higher total weediness of the winter wheat spelta crop was... [to full text]

Fusarium graminearum, the causative agent of Fusarium head blight, is an economically important pathogen of wheat (Triticum aestivum). Breeding Fusarium head blight (FHB) resistant wheat requires knowledge of the underlying genetic control of FHB resistance. Genetic parameters for FHB resistance and five related traits were estimated in three populations at two locations and in two years. Moderate broad sense heritabilities for FHB severity and Fusarium damaged kernels (FDK) were observed. Incidence of FHB and the toxin deoxynivalenol (DON) accumulation had low to moderate broad sense heritabilities. Correlations between FDK and severity and FDK and DON were moderate to high in the three populations and do support indirect selection for FHB severity or DON based on FDK data alone, but it is important to be cautious in years with a high disease pressure when FHB resistance could be masked. A cycle of among-family and within-family selection cycle was conducted in 2003. Actual selection gain was higher than predicted gain based on variance components in 2003 in the within-family selection study. One population had also a strong response for low DON in the among-family selection study. The observed results suggest that selection for FHB resistant genotypes could be achieved with a recurrent selection scheme. Along with conventional breeding, molecular techniques are being used in breeding for FHB resistance. A first genotypic screening of the three populations showed Population 2 had the presence of a resistance allele form the resistant Chinese cultivar Sumai 3. Although Populations 1 and 3 did not have the resistance allele, the results suggest other sources of resistance might be present in these two populations.

Fusarium graminearum, the causative agent of Fusarium head blight, is an economically important pathogen of wheat (Triticum aestivum). Breeding Fusarium head blight (FHB) resistant wheat requires knowledge of the underlying genetic control of FHB resistance. Two nine-parent diallel analyses were completed in greenhouse and field environments. Combining abilities, variance component ratios, and narrow sense heritabilities for FHB resistance and deoxynivalenol levels were calculated. Significant general and specific combining ability effects were observed. Resistance to FHB seems to be mostly controlled by additive genetic effects with some dominance noted in the field. Resistance noted in the greenhouse environment may not hold up in the field. Genetic parameters for FHB resistance and four related traits were estimated in three populations. Moderate to high broad sense heritabilities for FHB severity and Fusarium damaged kernels (FDK) were observed. Incidence of FHB had low to moderate broad sense heritabilities. Correlations between FDK and severity and FDK and incidence were moderate and low, respectively, and do not support indirect selection for FHB severity or incidence based on FDK data alone. Substantial predicted gains from family selection were observed and therefore selection of FHB resistant wheat lines should be based on family means and not individual selection.

Fusarium head blight (FHB) or head scab, caused by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)], is one of the most destructive diseases of wheat (Triticum aestivum L.) worldwide. Numerous strategies for scab resistance breeding are in use, including phenotypic selection for low severity and marker-assisted selection for resistance QTL. The most destructive consequences of scab are evidenced through a reduction in grain quality, and the presence of mycotoxins, the most common of which is deoxynivalenol (DON). Thus, there is great interest among breeders in selecting for resistance to both of these traits. To this end, a study was devised as follows. In 2010, 20 bulk F3 SRW wheat populations with scab resistant parents in their pedigrees were harvested by population from unreplicated plots near Lexington, KY. The plots were affected by a naturally occurring mild-moderate scab epidemic. The grain was sorted on a USDA/ARS and National Manufacturing Seed Sorter System with color camera according to a calibration that reflected visual differences between asymptomatic grain and grain showing FHB symptoms. This process was repeated in 2011 using grain from plots that had conidial suspension applied at anthesis. In 2012, an unreplicated plot study of the C0, C1 and C2 cycles of selection, inoculated with grain spawn and conidial suspension, was evaluated for Fusarium damaged kernels (FDK) and DON concentration. An additional cycle of selection was conducted by running the bulk grain through the sorter. In October 2012, 4 selection cycles of the 20 populations were planted in a RCB experiment at Lexington and Princeton, KY. Bulk populations were planted in both scab nursery and plots, and C3 accepted and rejected of all populations and derived lines of 2 populations were planted in the scab nursery in Lexington, KY. Some populations had FDK and DON reduction with selection, and some derived lines had either numerical or significant reduction with selection. Although the accepted fraction had non-significant reduction compared with the rejected fraction over the populations, FDK and DON means were obviously lower in accepted than in rejected fractions.

Tyrimų tikslas. Identifikuoti naujus žieminių kviečių genus, aktyvuojamus žemose temperatūrose bei atlikti šių genų sekų ir genetinės raiškos analizę. Tyrimų uždaviniai: 1. Ištirti žieminių kviečių genotipų tolerantiškumą žemoms neigiamoms temperatūroms natūraliomis ir dirbtinėmis sąlygomis. 2. Nustatyti skirtingose grūdinimosi stadijose diferenciškai ekspresuojamus genus (kDNR-AFLP analizė) ir atlikti DNR sekų analizę. 3. Optimizuoti mutagenezės metodą ir sukurti dviejų perspektyvių žieminių kviečių linijų mutagenines populiacijas. 4. Nustatyti skirtingu intensyvumu ekspresuojamų genų mutacijas HRM metodu, įvertinti nustatytų mutacijų įtaką genų ekspresijai grūdinimosi metu ir žemų neigiamų temperatūrų tolerancijai. / Research objective: To identify new genes of winter wheat induced at low temperatures, to perform sequence analysis of these genes and to quantify their expression. Experimental tasks: 1. To evaluate freezing tolerance of various winter wheat genotypes under field and controlled conditions. 2. To identify differentially expressed genes at subsequent time points of cold acclimation and to perform analysis of their DNA sequences. 3. To optimize mutagenesis method and to create Targeting Induced Local Lesions in Genomes (TILLING) population of two winter wheat lines. 4. To identify mutations in differentially expressed genes by High Resolution melting (HRM) method, to estimate the impact of mutations on the gene expression during cold acclimation and tolerance to freezing.

Research objective: To identify new genes of winter wheat induced at low temperatures, to perform sequence analysis of these genes and to quantify their expression. Experimental tasks: 1. To evaluate freezing tolerance of various winter wheat genotypes under field and controlled conditions. 2. To identify differentially expressed genes at subsequent time points of cold acclimation and to perform analysis of their DNA sequences. 3. To optimize mutagenesis method and to create Targeting Induced Local Lesions in Genomes (TILLING) population of two winter wheat lines. 4. To identify mutations in differentially expressed genes by High Resolution melting (HRM) method, to estimate the impact of mutations on the gene expression during cold acclimation and tolerance to freezing. / Tyrimų tikslas. Identifikuoti naujus žieminių kviečių genus, aktyvuojamus žemose temperatūrose bei atlikti šių genų sekų ir genetinės raiškos analizę. Tyrimų uždaviniai: 1. Ištirti žieminių kviečių genotipų tolerantiškumą žemoms neigiamoms temperatūroms natūraliomis ir dirbtinėmis sąlygomis. 2. Nustatyti skirtingose grūdinimosi stadijose diferenciškai ekspresuojamus genus (kDNR-AFLP analizė) ir atlikti DNR sekų analizę. 3. Optimizuoti mutagenezės metodą ir sukurti dviejų perspektyvių žieminių kviečių linijų mutagenines populiacijas. 4. Nustatyti skirtingu intensyvumu ekspresuojamų genų mutacijas HRM metodu, įvertinti nustatytų mutacijų įtaką genų ekspresijai grūdinimosi metu ir žemų neigiamų temperatūrų tolerancijai.

This research project gauges producer demand on the Canadian Prairies for the attributes of new hypothetical varieties of winter wheat. Data collected from a survey of producers in Western Canada is used to determine the values and attitudes of producers regarding new winter wheat variety traits with a focus on increased winter survival rates and increased waterfowl nesting habitat. Increased nesting habitat was found to have a small negative but significant impact on the decision to adopt hypothetical winter wheat varieties; however winter kill rates and gross profit had a large positive effect on its adoption and expansion. Other important drivers of the decision to adopt hypothetical winter wheat varieties are also analyzed. Policy implications include potential guidance of incentives for environmentally friendly farming practices, and the provision of information to winter wheat breeding programs about the needs of producers.