Bases genéticas da deiscência natural de grãos de trigo: estimativa artificial envolvendo o caráter vigor de glumas e lemas

Grain yield losses from natural shattering require the development of shatter resistant genotypes, and breeding methods depend on the type of variability and genetic conditioning the trait under study. Shatter tolerance was measured in wheat (Triticum aestivum L.) as the force required to free a glume and lemma from the raquis. Measurements were made on single, random plants of six generations (P1, P3, F1, F2, RC1F1 and RC2F1) from crosses among four parental lines. All populations were grown at the Experimental Agronomic Station/UFRGS, Guaíba, RS, in 1978. High genetic variability was detected. Additive for glume and lemma vigor susceptibility as well as epistatic effects separating the parents were observed. In general, the results suggest that the inheritance of shattering resistance is not too complex and the expression of gene effects appears not to be sensitive to environmental conditions. However, because glume and lemma vigor is recessive and because genes with large effects were present in these crosses, direct selection for shattering resistance in early generations should be effective.A perda do rendimento de grãos através de debulha natural merece uma atenção especial por parte dos melhoristas para o desenvolvimento de genótipos resistentes à deiscência. A tolerância à debulha em trigo (Ttiticum aestivum L.) foi estimada através de uma força requerida para livrar glumas e lemas do raquis. Medidas foram feitas em plantas individuais nas seis gerações (P1, P2, F1, F2, RC1F1 e RC2F1), provenientes dos cruzamentos envolvendo quatro diferentes genótipos. Foi observada a existência de uma alta variabilidade genética. Aditividade para suscetibilidade do vigor de glumas e lemas, como também efeitos de epistasia foram observados nos genótipos em estudo. Em geral, os resultados sugerem que não há muita complexidade na herança da resistência à debulha e a expressão do efeito dos genes parece ser pouco afetado pelas condições ambientais. Contudo, visto que o vigor das glumas e lemas é recessivo e que genes com grande efeito estão presentes nestes cruzamentos, a orientação de seleção para a resistência à debulha em gerações segregantes poderá ser efetiva

Wheat plant stature components

A estatura da planta do trigo (Triticum aestivum L.) e seus componentes foram medidos em populações não segregantes (P1, P2 e F1) e segregantes (F2, RC1F1 e RC2F1), derivadas de cruzamentos entre diferentes genótipos de trigo em experimentos conduzidos a campo na Estação Experimental Agronômica da Universidade Federal do Rio Grande do Sul, Guaíba, RS, em 1979. Amostragens de entrenós de ambos os genitores, semi-anões e altos, revelaram que: 1. O comprimento médio dos entrenós foi crescente da base ao ápice da planta; 2. Uma expressiva porção da variabilidade fenotípica do caráter "número de entrenós" era de natureza ambiental; 3. O pedúnculo contribuiu com, aproximadamente, 40% da estatura total dos genótipos.Wheat plant stature and its components were measured in non-segregated (P1, P2 and F1) and segregated (F2, RC1F1 and RC2F1) populations derived from crosses among different genotypes of wheat in field experiments carried out at the Agronomic Experimental Station/UFRGS, Guaíba, RS, in 1979. Internode patterns of both semi-dwarf and tall parents showed that: 1. Average internode lengths were progressively longer from the culm base to the spike; 2. A high portion of the phenotypic variation of the internode number was environmental in origin, and 3. The peduncle contributed with approximately 40% of the total stature of the genotypes

Mecanismos de indução à reprodução sexual em trigo

The paper presents the response to vernalization requirement of 98 varieties and lines of common wheat from Tenth and Eleventh International Winter Wheat Perforrnance Nursery (IWWPN) during grown season of 1979 and 1980. Sexual reproduction can be greatly accelerated in winter wheats by first subjecting the slightly applied seeds to alcohol, HgCl2, water and low temperatures (near freezing) in the dank for 20 days before sowing. When so treated, winter wheats sown in the field at higher growing temperatures in long day will behave as spring wheats.Este trabalho apresenta a resposta à vernalização requerida em 98 variedades e linhagens de trigo panificável proveniente da 10.a e 11.a International Winter Wheat Performance Nursey (IWWPN) durante a estação fria de 1979 e 1980. A reprodução sexual pode ser altamente acelerada em trigos de inverno com a aplicação de álcool, HgCl2 , água e baixa temperatura (perto do ponto de congelamento) em condições úmidas por 20 dias antes da semeadura. Quando tratados e semeados em áreas com altas temperaturas e dias longos, os trigos de inverno reagem como trigo de primavera

Plant stature heritability in wheat: estimate through the regression coefficient

O estudo desenvolvido neste trabalho foi estabelecido para determinar a relação entre o desempenho do caráter estatura de planta, entre linhas F3 ou F4 ou RC1 F2, derivadas de F2 ou F3 ou RC1 F1, de diversos cruzamentos de trigo hexaplóide. Resultados superiores à unidade, para a herdabilidade, foram estimados através dó método de desvio padrão, calculando-se a regressão pela codificação dos dados originais, em termos de unidades de desvio padrão. Uma comparação entre o método convencional e o de unidades de desvio padrão foi realizada para as estimativas de herdabilidade. Em programas de melhoramento fitogenético, muitas questões poderão ser respondidas através da estimativa da herdabilidade de um determinado caráter.  The study reported herein was designed to determine the relationship between the plant stature trait performance of F3 or F4 or RC1 F2 derived lines from F2 or F3 or RC1 F1 in several hexaploid wheat crosses, respectively. The heritability results greater than one were computed through the standard unit method by calculating the regression on data coded in terms of standard deviation units. A comparison was made between heritability estimated by these two methods, conventional and standard units. Heritability estimates provides useful guidelines of answering many questions which arise in a plant breeding program

Concentration of apricot juice using complex membrane technology

In this study, pressed apricot (Prunus armeniaca L.) juice was concentrated using complex membrane technology with different module combinations: UF-RO-OD, UF-RO-MD, UF-NF-OD and UF-NF-MD. In case of the best combination a cross-flow polyethylene ultrafiltration membrane (UF) was applied for clarification, after which preconcentration was done using reverse osmosis (RO) with a polyamide membrane, and the final concentration was completed by osmotic distillation (OD) using a polypropylene module. The UF-RO-OD procedure resulted in a final concentrate with a 65-70 °Brix dry solid content and an excellent quality juice with high polyphenol content and high antioxidant capacity.Nanofiltration (NF) and membrane distillation (MD) were not proper economic solutions.The influence of certain operation parameters was examined experimentally. Temperatures of UF and RO were: 25, 30, and 35 °C, and of OD 25 °C. Recycle flow rates were: UF: 1, 1.5, and 2 m3 h−1; RO: 200, 400, and 600 l h−1; OD: 20, 30 and 40 l h−1. The flow rates in the module were expressed by the Reynolds number, as well. Based on preliminary experiments, the transmembrane pressures of UF and RO filtration were 4 bar and 50 bar, respectively. Each experimental run was performed three times. The following optimal operation parameters provided the lowest total cost: UF: 35 °C, 2 m3 h−1, 4 bar; RO: 35 °C, 600 l h−1, 50 bar; OD: 20, 30 and 40 l h−1; temperature 25 °C.In addition, experiments were performed for apricot juice concentration by evaporation, which technique is widely applied in the industry using vacuum and low temperature.For description the UF filtration, a dynamic model and regression by SPSS 14.0 statistics software were applied

Baseline gene signatures of reactogenicity to Ebola vaccination: a machine learning approach across multiple cohorts

Introduction: The rVSVDG-ZEBOV-GP (Ervebo®) vaccine is both immunogenic and protective against Ebola. However, the vaccine can cause a broad range of transient adverse reactions, from headache to arthritis. Identifying baseline reactogenicity signatures can advance personalized vaccinology and increase our understanding of the molecular factors associated with such adverse events.Methods: In this study, we developed a machine learning approach to integrate prevaccination gene expression data with adverse events that occurred within 14 days post-vaccination.Results and Discussion: We analyzed the expression of 144 genes across 343 blood samples collected from participants of 4 phase I clinical trial cohorts: Switzerland, USA, Gabon, and Kenya. Our machine learning approach revealed 22 key genes associated with adverse events such as local reactions, fatigue, headache, myalgia, fever, chills, arthralgia, nausea, and arthritis, providing insights into potential biological mechanisms linked to vaccine reactogenicity.Immunogenetics and cellular immunology of bacterial infectious disease