• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 4
  • 2
  • 1
  • 1
  • Tagged with
  • 22
  • 22
  • 8
  • 7
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Fenologia, desenvolvimento e produtividade de cultivares de soja em função de épocas de semeadura e densidades de plantas /

Oliveira, Arnold Barbosa de. January 2010 (has links)
Orientadora: Maria Aparecida Pessôa da Cruz Centurion / Banca: Paulo Henrique Caramori / Banca: Pedro Luís da Costa Aguiar Alves / Resumo: O objetivo do trabalho foi avaliar fenologia, crescimento, desenvolvimento, acamamento e produtividade de soja, conforme cultivar, época de semeadura e densidade de plantas, em Londrina - PR. Dez cultivares de soja foram semeadas em 18/10 e 28/11/2008, e conduzidas nas densidades de 250 e 400 mil plantas por hectare. Utilizou-se o delineamento em blocos ao acaso, com quatro repetições, e parcelas de quatro linhas de 8 m de comprimento. Quantificaram-se: (i) os dias, crescimento da haste e nós formados da emergência ao início do florescimento (VE-R1) e até a colheita (VE-R8); (ii) os dias até o início de enchimento de grãos (VE-R5); além de (iii) vagens e grãos por planta, massa de 100 sementes, ramificação, acamamento e produtividade na colheita (R8). A menor densidade de plantas promoveu maior formação de nós e ramos na haste principal. A primeira época condicionou maior crescimento das plantas no período reprodutivo e maior número de ramos. A segunda condicionou maior crescimento no período vegetativo. Períodos juvenis, na primeira, e fotoperíodos críticos, na segunda, influenciaram florescimentos, interagindo com os fotoperíodos, para a maioria das cultivares. O fator genético exerceu maior influência sobre as variáveis relacionadas ao desenvolvimento, produtividade e componentes da produção / Abstract: The objective of this research work was to evaluate phenology, plant growth, development, lodging and grain yield of soybean, according to cultivar, sowing date and plant density in Londrina, PR. Ten soybean cultivars were sown on Oct/18 and Nov/28/2008, and cropped under 250 and 400 thousand plants per hectare. A randomized block design with four replicates was applied with plots consisting of four rows of 8 m long. The following evaluations were determined: (i) number of days, stem growth and nodes formed from seedling emergence to beginning flowering (VE-R1) and also up to harvesting (VE-R8); (ii) number of days to beginning of seed filling (VE-R5); and (iii) number of pods and grains per plant, mass of 100 seeds, branching, lodging and grain yield at harvest (R8). The lowest plant population resulted in the largest number of branches and nodes on the main stem. The first sowing date promoted the largest plant growth on the reproductive stage and largest number of branches. The second resulted in the largest plant growth in the vegetative period. Juvenile period in the first planting date and critical photoperiods in the second influenced flowering, which interacted with photoperiods for the majority of the cultivars. Genetic factors had the greatest influence on the variables related to plant development, grain productivity and yield components / Mestre
12

Fenologia, desenvolvimento e produtividade de cultivares de soja em função de épocas de semeadura e densidades de plantas

Oliveira, Arnold Barbosa de [UNESP] 15 July 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-15Bitstream added on 2014-06-13T19:37:08Z : No. of bitstreams: 1 oliveira_ab_me_jabo.pdf: 857304 bytes, checksum: 4083f8e58550245f349a14c7d74f0a7b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo do trabalho foi avaliar fenologia, crescimento, desenvolvimento, acamamento e produtividade de soja, conforme cultivar, época de semeadura e densidade de plantas, em Londrina - PR. Dez cultivares de soja foram semeadas em 18/10 e 28/11/2008, e conduzidas nas densidades de 250 e 400 mil plantas por hectare. Utilizou-se o delineamento em blocos ao acaso, com quatro repetições, e parcelas de quatro linhas de 8 m de comprimento. Quantificaram-se: (i) os dias, crescimento da haste e nós formados da emergência ao início do florescimento (VE-R1) e até a colheita (VE-R8); (ii) os dias até o início de enchimento de grãos (VE-R5); além de (iii) vagens e grãos por planta, massa de 100 sementes, ramificação, acamamento e produtividade na colheita (R8). A menor densidade de plantas promoveu maior formação de nós e ramos na haste principal. A primeira época condicionou maior crescimento das plantas no período reprodutivo e maior número de ramos. A segunda condicionou maior crescimento no período vegetativo. Períodos juvenis, na primeira, e fotoperíodos críticos, na segunda, influenciaram florescimentos, interagindo com os fotoperíodos, para a maioria das cultivares. O fator genético exerceu maior influência sobre as variáveis relacionadas ao desenvolvimento, produtividade e componentes da produção / The objective of this research work was to evaluate phenology, plant growth, development, lodging and grain yield of soybean, according to cultivar, sowing date and plant density in Londrina, PR. Ten soybean cultivars were sown on Oct/18 and Nov/28/2008, and cropped under 250 and 400 thousand plants per hectare. A randomized block design with four replicates was applied with plots consisting of four rows of 8 m long. The following evaluations were determined: (i) number of days, stem growth and nodes formed from seedling emergence to beginning flowering (VE-R1) and also up to harvesting (VE-R8); (ii) number of days to beginning of seed filling (VE-R5); and (iii) number of pods and grains per plant, mass of 100 seeds, branching, lodging and grain yield at harvest (R8). The lowest plant population resulted in the largest number of branches and nodes on the main stem. The first sowing date promoted the largest plant growth on the reproductive stage and largest number of branches. The second resulted in the largest plant growth in the vegetative period. Juvenile period in the first planting date and critical photoperiods in the second influenced flowering, which interacted with photoperiods for the majority of the cultivars. Genetic factors had the greatest influence on the variables related to plant development, grain productivity and yield components
13

Uso do regulador de crescimento etil trinexapac como alternativa para aumentar a resposta do milho à adubação nitrogenada em cobertura / Use of the growth regulator ethil trinexapac as an alternative to increase maize response to nitrogen side-dress

Durli, Murilo Miguel 18 February 2016 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-21T15:07:06Z No. of bitstreams: 1 PGPV16MA189.pdf: 1182946 bytes, checksum: cdac92d859fc3431d9c622f433fc3ae9 (MD5) / Made available in DSpace on 2018-02-21T15:07:06Z (GMT). No. of bitstreams: 1 PGPV16MA189.pdf: 1182946 bytes, checksum: cdac92d859fc3431d9c622f433fc3ae9 (MD5) Previous issue date: 2016-02-18 / FUMDES / Uniedu / Nitrogen is the mineral nutrient taken up in highest amounts by maize (Zea mays) and the one that has the largest impact on its grain yield. Maize requires great nitrogen rates and high plant densities to achieve elevated grain yield. However, these two management practices favor stem lodging which may decrease grain yield and quality. An alternative to avoid this problem is the use of growth regulators that restrict theinternode expansion, preventing the excessive increase of plant height. This study was carried out aiming to evaluate the use of ethyl trinexapac growth regulator as an alternative to increase the response to nitrogen side-dress fertilization of maize hybrids with contrasting cycles. The experiment was set in Lages, SC, during the 2014/2015 growing season. A randomized block experimental designarranged in split-split plots was used. Two hybrids were tested in the main plots: P1630 (hipper early cycle) and 30F53 (early cycle). Four nitrogen (N) rates were evaluated in the split plots, equivalent to 0; 0.5; 1 and 1.5 times the amount of N required to achieve a grain productivity of 21,000 kg ha-1. Thepresence and absence of the growth regulator ethy trinexapac l was assessed in the split-split plots. The plant density of 90,000 pl ha-1 and the row spacing of 0.7 m were used. The application of the growth regulatorethy trinexapac decreased 12% plant height, at the average of four N rates and two hybrids. The percentage of broken and lodged stems was lower than 1% and was not affected by the evaluated treatments. The application ofethyl trinexapac reduced 3% the 16 17 weight of 1000 grains. This contributed to the decrease of 815 kg ha-1 of maize hybrids grain yield when the growth regulator was applied, at the average of four N rates. The nitrogen efficiency use decreased linearly with the increase in N rate, both in presence and absence of the growth regulator. The application of the growth regulator ethyl trinexapac was not an effective managementstrategy to increase grain yield and nitrogen efficiencyuse of maize hybrids P1630 and P30F533 / O nitrogênio é o nutriente mineral mais absorvido pelo milho (Zea mays) e o que mais interfere no rendimento de grãos. Para alcançar altas produtividades, é necessário utilizar altas doses de N e densidades de plantas elevadas na lavoura. Contudo, estas duas práticas de manejo favorecem o acamamento, podendo causar perdas significativas no rendimento e na qualidade de grãos. Uma estratégia para evitar este problema é o uso de reguladores de crescimento que restrinjam a expansão dos entrenós e o incremento excessivo na estatura da planta. Este trabalho objetivou avaliar o uso do regulador de crescimento etil trinexapac como alternativa para aumentar a resposta do milho à adubação nitrogenada em cobertura de híbridos de milho com ciclos contrastantes. O experimento foi implantado em Lages, SC, na safra 2014/2015. O delineamento experimental utilizado foi de blocos casualizados dispostos em parcelas sub-subdivididas. Na parcela principal foram testados dois híbridos: P1630 (ciclo hiperprecoce) e 30F53 (ciclo precoce). Nas subparcelas foram testadas quatro doses de nitrogênio (N), equivalentes a 0; 0,5; 1 e 1,5 vezes a dose necessária para atingir produtividade de 21.000 kg ha-1. Nas sub-subparcelas foram testadas a ausência e presença do 12 13 regulador de crescimento etil trinexapac. A densidade utilizada foi de 90.000 plantas ha-1 e o espaçamento entre fileiras de 0,7m. A aplicação do regulador de crescimentoetil trinexapac diminuiu em 12% a estatura de plantas, na média das quatro doses de N e dois híbridos usados. A percentagem de plantas acamadas e quebradas foi inferior a 1º e não foi afetada pelos tratamentos testados no trabalho. A aplicação de etil trinexapac reduziu em 3% a massa de 1000 grãos. Isto contribuiu para o decréscimo de 815 kg ha1 do rendimento de grãos dos híbridos avaliados quando se aplicou o produto, na média das doses de N. A eficiência do uso do nitrogênio diminuiu linearmente com o incremento na dose de N aplicada em cobertura, tanto na presença quanto na ausência do regulador de crescimento. A aplicação do regulador de crescimento etil trinexapac não foi uma estratégia efetiva para aumentar para aumentar o rendimento de grãos e a eficiência de uso do nitrogênio dos híbridos P1630 e P30F533
14

Respostas morfo-agronômicas do milho à aplicação de trinexapac-ethyl em diferentes estádios fenológicos e doses de nitrogênio / Morpho agronomic response of maize to trinexapac-ethyl application on distinct phenologic stages and levels of nitrogen

Fagherazzi, Mariana Mendes 13 March 2015 (has links)
Made available in DSpace on 2016-12-08T16:44:50Z (GMT). No. of bitstreams: 1 PGPV15MA175.pdf: 1026831 bytes, checksum: 4d2c804c6222d9a4af12939527ac64e4 (MD5) Previous issue date: 2015-03-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The increased maize production and yield in recent years has been driven by global demand for food and the prices paid to the farmers. To maximize the yield of maize are used different production technologies, including the use of high doses of nitrogen and management plant arrangement, which make the plants more susceptible to lodging. The growth regulators has been used in many crops in Brazilian agriculture aimed at the management of plant shoot and indirectly the lowest lodging. However, in maize there are few reports on the effects of these regulators, specifically the trinexapac-ethyl (TE), which are a growth regulator with its action in arrest of cell elongation. Given the above, the objective of this research was to evaluate the effect of TE sprayed at different concentrations and to in different phenological maize stages. The product were sprayed on maize plants conducted in the greenhouse and in the field conditions, both at the Santa Catarina State University in Centro de Ciências Agroveterinárias, located in Lages, in the 2013/2014 growing season. Was used three cultivars: SCS 154 Fortuna, P30F53HR and P30R50H. The experimental design and procedures are presented as chapter: I, II and III. The chapter I was developed in greenhouse, with treatments consisting of a control and sequential doses of TE applied from V2 to V7, plus a treatment with a single dose applied at stage V5. The chapter II, consisted of an experiment carried out in the field, and with TE sequential doses applied from V4 to V7 stages. The chapter III, describe the effects of increasing nitrogen rates in sidedress associated with the use of TE. The main results indicate that plant height is changed for all cultivars as a function of the dose of TE and phenological stage of maize plant. The split dose applied as a sequential manner is more effective than single application of TE, particularly in decreased plant height and ear insertion height of SCS 154 Fortuna and P30F53HR. The plant seven fully developed leaves stage (V7) treated with 800 g a.i. ha-1 of TE provided the more shortest the plant height. About the nitrogen sidedressing, there was no positive response on yield with the highest dose of N fertilizer. There is a direct relationship between plant height with reduced lodging, but severe reductions in height adversely affect the grain yield / O aumento da produção e produtividade no cultivo do milho nos últimos anos foi impulsionado pela demanda mundial em alimentos e pelos preços pagos ao agricultor. Para maximizar a produtividade do milho, adotam-se diferentes tecnologias de produção, entre elas o uso de elevadas doses de nitrogênio e o manejo do arranjo de plantas, as quais podem, em determinadas condições de cultivo, deixar as plantas mais suscetíveis ao acamamento. O uso de reguladores de crescimento vem sendo utilizado em diversas culturas na agricultura brasileira visando o manejo da altura de plantas e indiretamente o menor acamamento. Entretanto, na cultura do milho há poucos relatos sobre os efeitos desses reguladores, mais especificamente do ingrediente ativo trinexapac-ethyl (TE), um regulador de crescimento com ação na inibição da elongação celular. Diante do exposto, o objetivo da pesquisa foi avaliar o efeito de diferentes concentrações do regulador de crescimento TE, em diferentes estádios fenológico na cultura do milho. As pulverizações foram realizadas em cultivos de milho conduzidos em casa de vegetação e a campo, ambos na Universidade do Estado de Santa Catarina no Centro de Ciências Agroveterinárias, localizado em Lages, no ano agrícola de 2013/2014. As cultivares avaliadas foram SCS 154 Fortuna, P30F53HR e P30R50H. O delineamento experimental e as variáveis analisadas estão divididas e apresentadas como capítulo: I, II e III. Sendo o capítulo I desenvolvido em casa-de-vegetação, com os tratamentos compostos por uma testemunha e doses sequenciais de TE aplicados de V2 a V7 e mais um tratamento com dose única do mesmo ingrediente ativo. O capítulo II, consistiu de um experimento conduzido em campo e, com doses sequenciais de TE aplicadas nos estádios V4 a V7. E o capítulo III, com tratamentos compostos por aumento de doses de nitrogênio em cobertura associado ao uso de TE. Os principais resultados indicam que a altura de planta é alterada para todas cultivares avaliadas em função da dose de TE e de estádios fenológicos de milho. Há diferença de resposta entre a aplicação de dose única de TE com sua respectiva divisão e aplicação sequencial para as variáveis, altura de planta e altura de inserção de espiga nas cultivares SCS 154 Fortuna e para a cv. P30F53HR. A maior dose de TE aplicado no estádio fenológico de sete folhas completamente desenvolvidas, proporcionou a menor altura de planta. Quando avaliado doses de nitrogênio, não houve resposta positiva sobre produtividade com a maior dose do adubo aplicado em cobertura. Há relação direta entre altura de plantas com a redução do acamamento, mas reduções severas de altura afetam negativamente o potencial produtivo
15

Comparative Mapping of QTLs Affecting Oil Content, Oil Composition, and other Agronomically Important Traits in Oat (Avena sativa L.)

Hizbai, Biniam T. January 2012 (has links)
Groat oil content and composition are important quality traits in oats (Avena sativa L). These traits are controlled by many genes with additive effects. The chromosomal regions containing these genes, known as quantitative trait loci (QTL), can be discovered through their close association with markers. This study investigated total oil content and fatty acid components in an oat breeding population derived from a cross between high oil ('Dal') and low oil ('Exeter') parents. A genetic map consisting of 475 DArT (Diversity Array Technology) markers spanning 1271.8 cM across 40 linkage groups was constructed. QTL analysis for groat oil content and composition was conducted using grain samples grown at Aberdeen, ID in 1997. QTL analysis for multiple agronomic traits was also conducted using data collected from hill plots and field plots in Ottawa, ON in 2010. QTLs for oil content, palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3) were identified. Two of the QTLs associated with oil content were also associated with all of the fatty acids examined in this study, and most oil-related QTL showed similar patterns of effect on the fatty acid profile. These results suggest the presence of pleiotropic effects on oil-related traits through influences at specific nodes of the oil synthesis pathway. In addition, 12 QTL-associated markers (likely representing nine unique regions) were associated with plant height, heading date, lodging, and protein content. The results of this study will provide information for molecular breeding as well as insight into the genetic mechanisms controlling oil biosynthesis in oat.
16

Multitrophic interactions along a plant size gradient in Brassicaceae

Schlinkert, Hella 18 March 2014 (has links)
Das Wissen über Mechanismen, die einen Einfluss auf Muster der Artenvielfalt und biotische Interaktionen haben, ist grundlegend für den Schutz von Biodiversität. Darüber hinaus kann es von direktem ökonomischem Nutzen sein, zum Beispiel im biologischen Pflanzenschutz oder bei Bestäubungsdienstleistungen. Die Größe eines Organismus kann ein solcher Faktor sein, der die Artenzahl und Interaktionen der assoziierten Organismen beeinflusst, denn große Organismen sind auffälliger als kleine und ihr Angebot an Ressourcen und Nischen für mit ihnen assoziierte Organismen ist oft reicher. Bezogen auf Pflanzen könnte daher die Größe einer Pflanze einen erheblichen Einfluss auf die Artenzahl der mit ihr assoziierten Arthropoden und ihre biotischen Interaktionen wie Herbivorie oder Bestäubung haben. Trotzdem ist der Einfluss der Pflanzengröße auf mutualistische und antagonistische Interaktionspartner der Pflanze und der sich daraus ergebende Einfluss auf die reproduktive Fitness der Pflanze bisher nicht umfassend und unter standardisierten Bedingungen untersucht worden. In der vorliegenden Studie wurden die Auswirkungen der Pflanzengröße auf die Artenzahl von Herbivoren, deren Gegenspielern und Bestäubern untersucht, sowie die Auswirkungen dieser Interaktionspartner auf die Pflanzenfitness. Dabei wurde zusätzlich zwischen endophagen und ektophagen Herbivoren und deren Gegenspielern unterschieden. Außerdem wurden die Herbivoren einzelner Pflanzenkompartimente und deren Gegenspieler separat analysiert. Des Weiteren wurde der Einfluss der Pflanzengröße auf den Herbivorieschaden an den verschiedenen Pflanzenkompartimenten und deren Einfluss auf die reproduktive Fitness der Pflanze, d.h. auf ihre Samenzahl, Tausendkorngewicht und Samengesamtgewicht, untersucht. Zuletzt wurde besonderes Augenmerk auf den Einfluss der Pflanzengröße auf mutualistische und antagonistische Blütenbesucher und deren Einfluss auf die reproduktive Fitness gelegt und untersucht, ob und inwiefern die reproduktive Fitness letztendlich von der Pflanzengröße abhängig ist. Zur Untersuchung dieser Fragen wurde ein „Common Garden“-Experiment angelegt. Um einen interspezifischen Pflanzengrößengradienten zu erzeugen, wurden 21 annuelle Pflanzenarten aus der Familie der Kreuzblütler (Brassicaceae) ausgewählt, deren Größe von 10 bis 130 cm reichte (gemessen als Pflanzenhöhe vom Boden bis zur Spitze). So konnten die Einflüsse des Habitats und der umgebenden Landschaft für alle Pflanzenarten standardisiert und trotzdem ein breiter Gradient realisiert werden. Dadurch hebt sich diese Studie von den bisherigen ab, die den Effekt von meist intraspezifischer Pflanzengröße auf die assoziierten Tiere anhand wild wachsender Pflanzen untersucht haben. Pflanzengröße sowie Zahl, Biomasse und Größe der unterschiedlichen überirdischen Pflanzenkompartimente (Blüten, Schoten, Blätter, Stängel) sowie Blütendeckung und -farbe wurden aufgenommen. Der Herbivorieschaden an diesen Pflanzenkompartimenten und die reproduktive Fitness (Samenzahl, Tausendkorngewicht und Gesamtsamengewicht) wurden gemessen. An und in Blüten, Schoten, Blättern und Stängeln wurden herbivore, räuberische, parasitäre und bestäubende Arthropoden gezählt. Die Pflanzengröße hatte einen positiven Einfluss auf die Artenzahl von Herbivoren, deren Gegenspielern und Bestäubern. Das traf ebenso auf endophage und ektophage sowie auf mit Blättern und Schoten assoziierte Herbivore und deren Gegenspieler zu. Des Weiteren konnte ein Anstieg des Herbivorieschadens an Blüten und Schoten mit zunehmender Pflanzengröße festgestellt werden, wohingegen der Schaden an Blättern und Stängeln von der Biomasse des entsprechenden Kompartiments positiv beeinflusst wurde. Der Schaden an Blüten hatte den stärksten Einfluss auf die reproduktive Fitness und reduzierte neben der Samenzahl auch das Tausendkorngewicht und das Gesamtsamengewicht der Pflanze. Die genaue Analyse der blütenbesuchenden Insekten ergab einen positiven Einfluss der Pflanzengröße auf die Abundanz und Artenzahl von Bestäubern (allerdings nicht bei extrem großem Blütenangebot), wie auch auf die Abundanz der adulten und juvenilen Rapsglanzkäfer und deren Parasitierungsrate. Steigende Rapsglanzkäferzahlen verringerten die Samenzahl sowie das Tausendkorngewicht, während die Bestäuber sich lediglich auf die Samenzahl positiv auswirkten. Insgesamt führte ein Anstieg der Pflanzenhöhe zu einer Abnahme des Tausendkorngewichts, aber nicht zu einer Veränderung der Samenzahl oder des Gesamtsamengewichts, was auf einen Ausgleich der Effekte von zunehmender Antagonistenzahl und zunehmender Mutualistenzahl hindeutet. Großen Pflanzen entstehen also durch ihre Auffälligkeit und Attraktivität für Herbivore hohe Fitnesskosten, wobei insbesondere der Blütenschaden durch Rapsglanzkäfer einen starken negativen Einfluss auf Samenzahl, Tausendkorngewicht und Gesamtsamengewicht hat. Diesen Fitnesskosten großer Pflanzen wirkt der Nutzen durch ihre Auffälligkeit und Attraktivität für Bestäuber entgegen, die die Samenzahl positiv beeinflussen. Hinsichtlich der Samenzahl sollten also große Pflanzen gegenüber kleineren im Vorteil sein, wenn die Insektengemeinschaft des Habitats von Bestäubern dominiert wird. Wird sie aber von herbivoren Blütenbesuchern dominiert, sollten kleine Pflanzen gegenüber großen einen Vorteil haben. Im Gegensatz dazu sollten große Pflanzen immer einen Nachteil bezüglich des Tausendkorngewichts haben, das von Antagonisten, nicht aber von Mutualisten beeinflusst wurde. Der Einfluss der Pflanzengröße auf biotische Interaktionen wurde bisher oft unterschätzt, obwohl er sich auf komplexe Weise über die mutualistischen und antagonistischen Insekten auf die reproduktive Fitness der Pflanze auswirkt.
17

Uticaj kvaliteta semena na dinamiku razvoja, prinosi kvalitet suncokreta / The effect of seed quality on the developmentaldynamics, yield and quality of sunflower

Mrđa Jelena 30 December 2015 (has links)
<p>Izvod<br />IZ<br />Pet hibrida suncokreta (Sremac, Oliva, Cepko, NS-H-111 i Sumo 2 OR) gajena su tokom<br />vegetacionih sezona 2010. i 2011. godine na oglednom polju Instituta za ratarstvo i<br />povrtarstvo, Novi Sad, na Rimskim &scaron;ančevima i na oglednom polju Poljoprivredne stručne<br />službe Zrenjanin. Laboratorijski deo ogleda izveden je u Laboratoriji za ispitivanje semena<br />Instituta za ratarstvo i povrtarstvo iz Novog Sada i Biohemijskoj laboratoriji<br />Poljoprivrednog fakulteta u Novom Sadu. Cilj istraživanja je bio da se utvrdi da li semenski<br />materijal, poreklom sa istog lokaliteta i iste parcele, u procesu dorade semena tj. odvajanja<br />semena po frakcijama menja kvalitet, kao i da li ovakav način dorade semenskog materijala<br />utiče na prinos i komponente prinosa semena, kao i na sadržaj i prinos ulja odabranih<br />hibrida suncokreta. Takođe, cilj je bio i da se utvrdi da li nedostatak primarnog korena kod<br />ponika suncokreta dovodi do statistički značajnog smanjenja prinosa semena i ulja, kao i<br />kakav uticaj ima na komponente prinosa suncokreta. Analizirane su sledeće osobine:<br />klijavost i vigor semena, enzimska aktivnost, nicanje u polju, nakupljanje suve materije (po<br />biljnim organima i ukupno po biljci), visina stabla, prečnik glave, prinos semena, masa 1000<br />semena, sadržaj ulja i prinos ulja. Statistička obrada podataka izvr&scaron;ena je primenom analize<br />varijanse trofaktorijalnog ogleda, prema modelu podeljenih parcela. Iz tabele analize<br />varijanse je prikazana verovatnoća značajnosti razlika po F-testu, a na osnovu uče&scaron;ća u<br />sumi kvadrata tretmana određen je procentualni udeo svakog faktora u ukupnoj<br />varijabilnosti. Takođe su izračunate i LSD vrednosti za poređenje razlika između tretmana<br />posmatranog faktora, na pragovima značajnosti od 1 i 5%. Utvrđena je i korelaciona<br />zavisnost posmatranih osobina. Rezultati analize varijanse pokazali su visoko značajno<br />uče&scaron;će glavnih faktora (godine, lokaliteta, frakcije semena, tipa ponika), kao i njihovih<br />međusobnih interakcija za većinu ispitivanih osobina. Na vrednosti ispitivanih osobina<br />najveći uticaj imala je godina istraživanja, a zatim lokalitet. Frakcija semena je imala visoko<br />značajan uticaj na klijavost semena, nicanje u polju, nakupljanje suve materije, prinos<br />semena i prinos ulja. Tip ponika je imao visoko značajan uticaj na enzimsku aktivnost</p> / <p>Five sunflower hybrids (Sremac, Oliva, Cepko, NS-H-111, and Sumo 2 OR) were grown in<br />2010 and 2011, on experimental fields of the Institute of Field and Vegetable Crops Novi<br />Sad - Rimski &Scaron;ančevi, and experimental fields of the Agricultural Service Zrenjanin.<br />Laboratory tests were conducted at Laboratory for Seed Testing of the Institute of Field<br />and Vegetable Crops Novi Sad, and Biochemical Laboratory of the Faculty of Agriculture,<br />University of Novi Sad. The aim of this research was to determine whether seed material<br />from the same locality and the same field lot changes quality during seed processing, i.e.<br />dividing seed lot into fractions, and additionally whether this type of seed processing<br />affects seed yield, seed yield components, oil yield, and oil content of the selected<br />sunflower hybrids. The aim was also to determine if missing primary root in sunflower<br />seedlings results in statistically significant decrease of seed and oil yield, and establish how<br />it influences sunflower yield components. The following traits were examined: seed<br />germination and vigour, enzymatic activity, field emergence, dry matter accumulation (in<br />plant organs and in the whole plant), stem height, head diameter, seed yield, 1000 seed<br />mass, oil content and oil yield. Statistical analysis of data was performed by analysis of<br />variance of the trifactorial trial using the split-plot design model. Table of analysis of<br />variance shows the probability of significance of differences by F-test, and based on the<br />participation in the treatment sum of squares, percentage ratio of each factor was<br />calculated in the total variability. LSD values at 1 and 5% were computed to compare<br />differences between treatments of the observed factor. Correlation dependence between<br />the observed traits was determined. Results of the analysis of variance showed a highly<br />significant participation of the main factors (year, locality, seed fraction, type of seedling),<br />and their mutual interactions for the majority of the examined traits. Year and locality had<br />the highest effect on the value of the examined traits. Seed fraction had highly significant<br />effect on seed germination, emergence, dry matter accumulation, seed yield, and oil yield.<br />Type of seedling had a highly significant effect on the enzymatic activity, seed yield, oil<br />content, and oil yield.</p>
18

A Novel Maize Dwarf Resulting From a Gain-of-Function Mutation In a Glutamate Receptor Gene

Amanpreet Kaur (9183557) 30 July 2020 (has links)
<p>Plant height is an important agronomic trait and a major target for crop improvement. Owing to the ease of detection and measurement of plant stature, as well as its high heritability, several height-related mutants have been reported in maize. The genes underlying a few of those mutants have also been identified, with a majority of them related to the biosynthesis or signaling of two key phytohormones - gibberellins (GAs) and brassinosteroids (BRs). However, most other maize dwarfing mutants, and especially those that result from gain-of-function mutations, remain uncharacterized. The present study was undertaken to characterize a novel dominant dwarfing mutant, named <i>D13</i>. This mutant appeared in the M1 population of the inbred B73 that was generated by mutagenesis with ethyl methanesulfonate (EMS). Like most other maize dwarfing mutants, the reduction in <i>D13</i> height was largely due to the compression of the internodes. However, unlike the GA or BR mutants, <i>D13</i> had no defects in the female or male inflorescences. Further, in contrast to the GA and BR mutants, the mesocotyl elongation during etiolation was not impacted in <i>D13</i>. <i>D13</i> seedlings developed red coloration in two to three lowermost leaves. In addition, <i>D13</i> also showed enhanced tillering when the phenotype was very severe. The size of the shoot apical meristem of <i>D13</i> was reduced slightly, and significant aberrations in the structure of vascular bundles in the mutant were observed. All anatomical and phenotypic features of <i>D13</i> were highly exaggerated in homozygous state, indicating the partially dominant nature of the <i>D13</i> mutation. Interestingly, the heterozygous mutants showed remarkable variation in their phenotype, which was maintained across generations. Moreover, the <i>D13</i> phenotype was found to be sensitive to the genetic background, being completely suppressed in Mo17, Oh7B, enhanced in CML322, P39 and changed to different degrees in others. To identify the genetic defect responsible for the <i>D13</i> mutant phenotype, a map-based cloning approach was used, which identified a single base-pair change from G to A (G2976A) in the coding region of a glutamate receptor gene (Zm00001d015007). The G2976A missense mutation resulted in the replacement of alanine with threonine at the location 670. The replaced alanine is highly conserved in glutamate receptors across all domains of life from cyanobacteria to plants to mammals, suggesting a causal relationship between the G2976A substitution and the <i>D13</i> phenotype. To validate this relationship, a targeted EMS-based mutagenesis approach was used to knock-out (inactivate) the <i>D13</i> mutant allele. A suppressor mutant was found in which the <i>D13</i> mutant phenotype reverted to the normal tall phenotype. The sequence of the revertant allele, designated <i>D13</i>*, revealed that the original <i>D13</i> mutant allele underwent a second G to A mutation (G1520A) to change glycine into aspartic acid at position 473. This intragenic second-site mutation in the <i>D13</i> allele suppressed the function of the <i>D13</i> allele, thereby preventing it from interfering with the function of the wild type allele. To further unveil the genes and underlying mechanisms that enable the <i>D13</i> mutant to confer a dwarf phenotype, transcriptomic and metabolomic analyses of <i>D13</i> mutants were conducted and compared to the wild type sibs. While the omics analysis confirmed that stress responses were upregulated and genes related to shoot system development were downregulated in the mutant, the data did not allow us to pinpoint the underlying mechanisms that connect the <i>D13</i> mutation with its dwarfing phenotype. Furthermore, it remains unclear whether these stress and shoot system-related changes result in the manifestation of <i>D13</i> phenotype, or the dwarf phenotype due to <i>D13</i> mutation activates the stress-related mechanisms. This is the first study that signifies the importance of a glutamate receptor gene in controlling plant height.</p>
19

Genetic analysis of resistance to Fusarium head blight in wheat (Triticum spp.) using phenotypic characters and molecular markers

Malihipour, Ali 26 October 2010 (has links)
Fusarium head blight (FHB), caused mainly by Fusarium graminearum (teleomorph: Gibberella zeae), is one of the most damaging diseases of wheat. A ‘Brio’/‘TC 67’ spring wheat population was used to map quantitative trait loci (QTLs) for resistance to FHB, and to study the association of morphological and developmental characteristics with FHB resistance. Interval mapping (IM) detected a major QTL on chromosome 5AL for resistance to disease severity (type II resistance) and Fusarium-damaged kernels (FDK) under greenhouse and field conditions, respectively. Inconsistent QTL(s) was also detected on chromosome 5BS for disease severity and index using field data. The associations of plant height and number of days to anthesis were negative with disease incidence, severity, index, and deoxynivalenol (DON) accumulation data under field conditions. However, number of days to anthesis was positively correlated with disease severity (greenhouse) and FDK (field). Awnedness had a negative effect on FHB, namely the presence of awns resulted in less disease in the population. Spike threshability also affected FHB so that the hard threshable genotypes represented lower disease. Phylogenetic relationships of putative F. graminearum isolates from different sources were characterized using Tri101 gene sequencing data. Canadian and Iranian isolates clustered in F. graminearum lineage 7 (=F. graminearum sensu stricto) within the F. graminearum clade while the isolates received from CIMMYT, Mexico were placed in F. graminearum lineage 3 (=Fusarium boothii) within the Fg clade or Fusarium cerealis. The PCR assay based on the Tri12 gene revealed the presence of the NIV, 3-ADON, and 15-ADON chemotypes with 15-ADON being the predominant chemotype. While we did not find the NIV chemotype among the Canadian isolates, it was the predominant chemotype among the Iranian isolates. High variation in aggressiveness was observed among and within Fusarium species tested, with the isolates of F. graminearum sensu stricto being the most aggressive and the NIV chemotype being the least aggressive. The interactions between Fusarium isolates and wheat genotypes from different sources were investigated by inoculating isolates of F. graminearum sensu stricto and F. boothii on wheat genotypes. Significant differences were observed among the genotypes inoculated by single isolates. Results also showed significant interactions between Fusarium isolates and wheat genotypes. The F. boothii isolates from CIMMYT produced low disease symptom and infection on wheat genotypes regardless of the origin of the genotypes while F. graminearum sensu stricto isolates from Canada and Iran resulted in higher FHB scores.
20

Genetic analysis of resistance to Fusarium head blight in wheat (Triticum spp.) using phenotypic characters and molecular markers

Malihipour, Ali 26 October 2010 (has links)
Fusarium head blight (FHB), caused mainly by Fusarium graminearum (teleomorph: Gibberella zeae), is one of the most damaging diseases of wheat. A ‘Brio’/‘TC 67’ spring wheat population was used to map quantitative trait loci (QTLs) for resistance to FHB, and to study the association of morphological and developmental characteristics with FHB resistance. Interval mapping (IM) detected a major QTL on chromosome 5AL for resistance to disease severity (type II resistance) and Fusarium-damaged kernels (FDK) under greenhouse and field conditions, respectively. Inconsistent QTL(s) was also detected on chromosome 5BS for disease severity and index using field data. The associations of plant height and number of days to anthesis were negative with disease incidence, severity, index, and deoxynivalenol (DON) accumulation data under field conditions. However, number of days to anthesis was positively correlated with disease severity (greenhouse) and FDK (field). Awnedness had a negative effect on FHB, namely the presence of awns resulted in less disease in the population. Spike threshability also affected FHB so that the hard threshable genotypes represented lower disease. Phylogenetic relationships of putative F. graminearum isolates from different sources were characterized using Tri101 gene sequencing data. Canadian and Iranian isolates clustered in F. graminearum lineage 7 (=F. graminearum sensu stricto) within the F. graminearum clade while the isolates received from CIMMYT, Mexico were placed in F. graminearum lineage 3 (=Fusarium boothii) within the Fg clade or Fusarium cerealis. The PCR assay based on the Tri12 gene revealed the presence of the NIV, 3-ADON, and 15-ADON chemotypes with 15-ADON being the predominant chemotype. While we did not find the NIV chemotype among the Canadian isolates, it was the predominant chemotype among the Iranian isolates. High variation in aggressiveness was observed among and within Fusarium species tested, with the isolates of F. graminearum sensu stricto being the most aggressive and the NIV chemotype being the least aggressive. The interactions between Fusarium isolates and wheat genotypes from different sources were investigated by inoculating isolates of F. graminearum sensu stricto and F. boothii on wheat genotypes. Significant differences were observed among the genotypes inoculated by single isolates. Results also showed significant interactions between Fusarium isolates and wheat genotypes. The F. boothii isolates from CIMMYT produced low disease symptom and infection on wheat genotypes regardless of the origin of the genotypes while F. graminearum sensu stricto isolates from Canada and Iran resulted in higher FHB scores.

Page generated in 0.0341 seconds