ESTIMATION OF HETEROSIS FOR YIELD AND YIELD RELATED COMPONENTS USING DIVERSE TESTERS IN PEARL MILLET [PENNISETUM GLAUCUM (L.) R. BR.]

Experiment comprised of twenty six female type parents and seven restorer parents of pearl millet and their 182 hybrids was conducted at two locations viz., ICRISAT, Patancheru (Latitude 17.52° N; Longitude 78.26° E and Altitude 522 m) and research farm of Super seeds Pvt Ltd., Hisar (Latitude 29.15° N; Longitude 75.72° E and Altitude 215 m) during rainy 2018, for studying the extent of hybrid vigour in F1 for grain yield and its components. For days to 50% owering, top cross hybrid MBL-5 X MOPT-31 (-13.37**) showed highest signicant and positive heterosis over check 86M86. The top cross hybrid MBL-17 X MOPT-33 (45.21**) highest, signicant standard heterosis in positive direction over check 86M86 for panicle length (cm). The single cross hybrid MBL-3 X MIT-29 (14.12*) exhibited signicant and positive standard heterosis over 86M86 for panicle girth (cm). for productive tillers, single cross hybrid MBL-8 X MIT-28 (98.34**) showed highest signicant positive standard heterosis over check 86M86 and the single cross hybrid MBL-24 X MIT-28 (18.42) showed positive standard heterosis over check 86M86

Mutagénesis inducida en plantas de Solanum betaceum Cav. mediante el uso de dietil sulfato (DES) / Induced mutagenesis in Solanum betaceum Cav. plants by the use of diethyl sulphate (DES)

RESUMEN La materia prima del fitomejoramiento es la variabilidad genética, que se presenta baja, en especies en proceso de domesticación, que no han sido sometidas a selección, como en Solanum betaceum. Una de las tecnologías para incrementar la variabilidad genética es la inducción de mutagénesis. El objetivo del estudio fue evaluar, a través de marcadores RAMs, las variaciones moleculares presentes en plántulas de S. betaceum, provenientes de semillas sometidas a diferentes concentraciones del agente mutante dietil sulfato (DES). Los loci polimórficos oscilaron entre 87,5 y 100 % y el número de alelos efectivos (Ne), entre 1,0 y 1,99. Los loci más polimórficos se observaron en TG, AG, ACA y CGA, que mostraron una heterosis media insesgada entre 0,34 y 0,51, que permite establecer que estos marcadores sean útiles para obtener mayor discriminación entre mutantes en S. betaceum. Las distancias genéticas oscilaron entre 0,30 y 1,0. El 81,28 % de estos registros se dieron entre 0,60 y 0,90; esto revela bajo nivel de cambios, debido al DES. Estos pequeños cambios contribuyeron a enriquecer la variabilidad genética de la muestra tratada con DES. Los marcadores RAMs fueron útiles para detectar cambios entre plantas provenientes de semillas tratadas con DES y plantas normales. La variabilidad genética entre tratamientos con DES fueron más altos que tratamientos sin DES. Las similitudes genéticas fueron bajas entre plantas tratadas y no tratadas y fueron altas, entre no tratadas. Los cambios producidos por DES fueron de baja magnitud; sin embargo, produjeron cambios en los niveles de variabilidad genética.

ABSTRACT The raw material for plant breeding is genetic variability, which is low in species in the process of domestication that have not been subjected to selection, as is the case with Solanum betaceum. One of the technologies to increase genetic variability is mutagenesis induction. The objective was to evaluate, through RAMs markers, the molecular variations present in S. betaceum seedlings from seeds previously subjected to different concentrations of the mutant agent diethyl sulfate (DES). The polymorphic loci ranged from 87.5 to 100%, number of effective alleles (Ne) between 1.0 and 1.99. The most polymorphic loci were observed in TG, AG, ACA, and CGA, which showed a mean unbiased heterosis between 0.34 and 0.51 with an average of 0.44, which allows establishing that these markers are useful to obtain greater discrimination between mutants in S. betaceum. Genetic distances ranged from 0.30 to 1.0. The 81.28% of these records were between 0.60 and 0.90. This reveals a low level of changes due to DES. These small changes contribute to enriching the genetic variability of the DES-treated sample. The RAMs markers were useful for detecting changes between plants from DES treated seeds and normal plants. Genetic variability between DES treatments was higher than non-DES treatments. Genetic similarities were low between treated and untreated plants and were high among untreated plants. The changes produced by DES were of low magnitude, however, they produced changes in the levels of genetic variability.

Exploitation of Heterosis among Phenotypically Diverse Capsicum Parents for Important Fruit Traits

Abstract One nuclear male sterile (NMS) line of chilli pepper and eight elite inbred lines of bell pepper were evaluated in a line × tester mating design to project heterotic F1's through studying plant growth and yield performance of developed hybrids in relation to phenotypic distance between their parental lines. Hybrids and their parental lines were grown and evaluated under poly-net house conditions at the Punjab Agricultural University, Ludhiana, India during the years 2017-2019. Pooled over the year, mean squares (MS) due to genotypes was recorded significant (p=0.05) for all the traits studied, suggesting that there existed significant differences among the genotypic means that included nine parental lines and their eight F1 hybrids. The MS due to the G × Y interaction effects were also significantly different for plant growth and fruit traits, indicating differential response of each genotype in the year. On the basis of heterotic performance, the hybrids namely MS-12 × PAU SM-31 had positive significant mid-parent heterosis (MPH) for total fruit yield plant-1 (96.68**), number of fruits plant-1 (51.98**), pericarp thickness (47.91**), fruit length (25.77**), and plant height (63.35**). Apart from this cross-combination, the hybrids MS-12 × PAU SM-3 and MS-12 × PAU SM-9 also depicted MPH for total fruit yield plant-1 (71.22** and 50.64**), fruit length (41.98** and 68.09**) and number of fruits plant-1 (27.60** and 44.73**). Based on better parent heterosis (BPH), the hybrid MS-12 × PAU SM-31 was found to be superior in respect of total fruit yield plant-1 (36.37**) and pericarp thickness (11.27**). These hybrids seem to be the utmost valuable materials for the future breeding program of bell pepper.

Genetic Similarity Among Accessions of Paspalum notatum Flügge (Poaceae): a Potential to Parental Selection

HIGHLIGHTS Low genetic similarity in Paspalum notatum accessions. High genetic distance among diploid accessions. The accessions have good potential to breeding program.

Abstract Paspalum notatum is an important forage grass contributing significantly to the coverage of the natural fields of Southern Brazil. Simple sequence repeat (SSR) markers were used to evaluate the genetic similarity of strains within a P. notatum collection. Genomic DNA was extracted in bulk from young leaves of five plants from each accession obtained from the USDA. In the molecular analysis, the eight SSR markers evaluated formed seven distinct groups, and two isolated genotypes, with an average similarity index of 0.29, ranging from zero to 0.83. All the loci were polymorphic and the polymorphism information content ranging from 0.41 to 0.69. The results evidenced a low genetic similarity, which can be explored via parental selection in a breeding program.

Habilidad combinatoria general y específica relacionada con los componentes del rendimiento en cinco líneas endogámicas de maíz (Zea mays L.) / General and specific combinatorial ability related to yield components in five inbred lines of maize (Zea mays L.) / Capacidade combinatória geral e específica relacionada aos componentes de produção em cinco linhagens consanguíneas de milho (Zea mays L.)

Resumen Con el fin de obtener información teórica de los efectos genéticos que gobiernan los componentes del rendimiento y poder tener mayor información que permitiera elegir los mejores progenitores para la formación de híbridos con interés comercial, se estimaron los efectos y la capacidad combinatoria general (H.C.G) y específica (H.C.E) en cinco líneas endocríadas de maíz tropical de endospermo amarillo pertenecientes al programa de mejoramiento genético de maíz tropical de la empresa Sem Latam S.A. Se encontró que los efectos de habilidad combinatoria específica para los caracteres relacionados con el componente rendimiento presentaron valores positivos, no obstante, estos no fueron significativamente distintos de cero, lo que se traduce en la no existencia de un patrón heterótico en las líneas evaluadas. De igual modo, las líneas evaluadas presentaron una escasa capitalización de los efectos genéticos no aditivos o dominantes en el proceso de selección genealógica, permitiendo interpretar la baja manifestación de la heterosis como expresión del vigor hibrido de los cruzamientos F1 comparados con los genotipos parentales.

Abstract The general (GCA) and specific (SCA) combining ability and effects of five inbred lines of tropical endosperm maize from Sem Latam SA's tropical maize breeding programme were estimated for obtaining theoretical information concerning the genetic effects governing yield components and to have more information available for selecting the best progenitors for developing and producing commercially interesting hybrids. Positive SCA effect values were found regarding specific combinatorial ability for yield-related characters; however, they were not significantly different from zero, resulting in the lack of a heterotic pattern concerning the lines evaluated here. Little capitalisation regarding such lines' non-additive or dominant genetic effects concerning genealogical selection was seen here, thereby leading to interpreting the low manifestation of heterosis as an expression of the F1 crosses' hybrid vigour compared to that of the parental genotypes.

Resumo Com o objetivo de obter informações teóricas sobre os efeitos genéticos que regem os componentes de desempenho para escolher os melhores genitores de híbridos com interesse comercial, foram estimados os efeitos e a capacidade combinatória geral (HCG) e específica (HCE) em cinco linhagens de endosperma amarelo tropical perten­centes ao programa de melhoramento genético de milho tropical da empresa Sem Latam S.A. Encontrou-se que os efeitos da habilidade combinatória específica para os caracteres relacionados ao componente desempenho apresentaram valores positivos, porém, estes não foram significativamente diferentes de zero, o que se traduz na ausência de um padrão hete­rótico nas linhas avaliadas. Da mesma forma, as linhagens avaliadas apresentaram pouca capitalização dos efeitos genéticos não aditivos ou dominantes no processo de seleção genealógica, permitindo interpretar a baixa manifestação de heterose como expressão do vigor híbrido dos cruzamentos F1 em comparação com os genótipos parentais.

Potential of parents and hybrids experimental of the yellow melon / Potencial de parentais e híbridos experimentais de melão amarelo

ABSTRACT: Melon or muskmelon (Cucumis melo L.) is of considerable economic importance in Brazil. Nearly all the cultivars currently grown are hybrids. Heterosis has been used to advantage in the melon plant, and the use of uniform hybrids is one of the reasons for successful cultivation. The aim of the present study was to evaluate the agronomic potential of yellow melon lines and hybrids. An experiment was conducted in randomized blocks with three replications to evaluate 24 hybrids generated by crosses among three elite lines used as female parents (AF-01, AF-02, and AF-03) and eight lines used as male parents (LAM-01, LAM-02, LAM-03, LAM-04, LAM-05, LAM-06, LAM-07, and LAM-08). Yield and fruit quality traits were evaluated. Partial diallel analysis was carried out to estimate general combining ability and specific combining ability. Additive and non-additive effects were observed for the yield, mean fruit weight, and pulp thickness traits. The lines AF-02, LAM-02, and LAM-03 are the most promising as parents as they more frequently have favorable alleles. The most prominent hybrids in diallel analysis were AF-02 x LAM-02, AF-02 x LAM-03, AF-02 x LAM-04, and AF-03 x LAM-06.

RESUMO: O melão amarelo (Cucumis melo L.) é uma hortaliça de grande importância econômica. Atualmente as cultivares plantadas, em quase sua totalidade, são híbridos. A heterose tem sido explorada no meloeiro, sendo o emprego de híbridos uniformes uma das razões do sucesso da cultura. O objetivo do presente trabalho foi avaliar o potencial agronômico de linhagens e híbridos de melão amarelo. Foi conduzido um ensaio em blocos casualizados com três repetições para avaliar 24 híbridos gerados pelos cruzamentos entre três linhagens elites utilizadas como genitores femininos (AF-01, AF-02 e AF-03), e oito linhagens utilizadas como genitores masculinos (LAM-01; LAM-02; LAM-03; LAM-04; LAM-05; LAM-06; LAM-07 e LAM-08). Foram avaliados caracteres a produção e a qualidade do fruto. Realizou-se a análise dialélica parcial para estimação das capacidades geral e específica de combinação. Observou-se efeitos aditivos e não aditivos para os caracteres produtividade, peso médio do fruto e espessura da polpa. As linhagens AF-02, LAM-02 e LAM03 são as mais promissoras por possuir maior frequência de alelos favoráveis. Os híbridos de maior destaque foram AF-02 x LAM-02, AF-02 x LAM-03, AF-02 x LAM-04 e AF-03 x LAM-06.

MIME-Mitosis instead of meiosis and its application in crop apomixis / 生物工程学报

Apomixis has been widely concerned because of its great potential in heterosis fixation. Artificial apomixis is an important direction of current apomixis research. Mitosis instead of Meiosis (MIME) produces diploid gametes that is identical with the maternal genetic composition and is a key step in the artificial creation of apomixes. This paper reviews the occurrence of MIME and its application in crop apomixis and the problems encountered, in an aim to provide reference for expanding the application of MIME in crop apomixis.

Association of SSR based genetic distances with heterosis in sunflower

Aim: Development of commercial hybrid of sunflower on basis of best inbred combination remains a key challenge to sunflower breeders. In the current investigation, heterosis of F1 hybrids, parental genetic diversity and correlation between genetic distance and level of heterosis were estimated. Methodology: Thirty five parental genotypes (3 CMS A lines and 32 R lines) and their hybrids were assessed for physio-morphological, yield and quality traits. Heterosis was measured as mid-parent and better parent heterosis. Among parents, SSR marker based genetic distances were calculated using DARwin software. Correlation between heterosis and genetic distances was carried out by Karl Pearson’s simple correlation method. Results: Range of genetic distances, based on SSR marker analysis, varied from 0.32-0.73. Genetic distance had significant positive correlation with the heterosis for oil content (r = 0.22 p<0.05) and linoleic acid (r = 0.32 p<0.05), but negative correlation was observed for days to maturity, test weight, volume weight, stearic acid and oleic acid. There was no significant correlation between genetic distance and heterosis for seed yield and other agronomic traits. Interpretation: Although, genetic distance is poor predictor of heterosis, dependence of oil content on genetic distance among parental lines may be used for designing an effective breeding program for sunflower.

Agronomic characters and genomic markers based assessment of genetic divergence and its relation to heterotic performance in maize

Aim: The present study was undertaken to examine the relation between genetic divergence of some tropical inbred lines of maize and extent of heterosis manifestation in their single cross hybrids. Methodology: Fifteen inbred lines and three inbred testers along with 45 single cross hybrids were evaluated by adopting randomized complete block design during two seasons. The observations recorded on eight metric traits of the entries in each of three replications were utilized during statistical analysis across the seasons. Relative importance of classification variables was determined by principal component analysis and the phenogram was generated using average taxonomic distance. Molecular profiling of inbred lines was carried out by employing 28 SSR primer pairs covering all the chromosomes. Principal coordinate analysis was performed and similarity indices based dendrogram was constructed. Relationship between parental genetic divergence and heterosis was statistically tested. Results: Significant differences due to parents, hybrids and parent vs. hybrids were observed for all metric characters. Principal component analysis based diagram and average taxonomic distance based phenogram separated the inbred lines into five clusters. Amplification profiles based principal coordinate analysis and hierarchical cluster analysis differentiated the inbred lines into four major clusters. Statistically non-significant correlation of genomic data based genetic similarity or phenotypic data based genetic dissimilarity of inbreds was revealed with grain yield and heterosis of hybrid combinations. Significantly positive correlation was found between heterosis over mid parent or better parent and grain yield of hybrids. Interpretation: Parental genetic divergence was not linearly or additively related to heterosis manifestation in hybrid. Moderate genetic divergence together with high per se performance of inbreds seemed to be a better criterion than consideration of merely extreme genetic diversity as the basis for the choice of parental inbreds during heterotic single cross hybrid development in maize

A brief note on genes that trigger components of apomixis

Apomixis or asexual reproduction through seeds occurs in about 400 species of flowering plants producing geneticallyuniform progeny. During apomixis, meiosis is bypassed and embryos develop by parthenogenesis. However, the endospermcould form either autonomously without fertilization or sexually, depending on the plant species. Most probably, aheterochronic expression of sexually expressed genes is one of the reason that causes apomixis. A better understanding ofthe genetic components regulating apomixis is important for developmental and evolutionary studies and also for engineering apomixis traits into crop plants that may realize a possibility to propagate hybrid vigor in a range of subsequentgenerations.

Assessment of Culture Potentialities of Hybrids from Crosses between Oreochromis niloticus and Sarotherodon melanotheron Reared in Ebrié Lagoon (Côte d’Ivoire) Using Geometric Morphometric Approach

Culture potentialities of the hybrids from crosses between Oreochromis niloticus (Linnaeus, 1758) and Sarotherodon melanotheron (Rüppel, 1852) were assessed in breeding design through morphological features using geometric morphometric approach. The crosses and rearing procedure, that lasted six months, are performed into a concrete pond at Layo Aquaculture Station. The morphological studies were undertaken with morphometric biomarkers such as average body shape and components of developmental homeostasis (canalisation and developmental stability). Average body shape between groups was investigated using Relative Warps Analysis (RWA) and Canonical Variates Analysis (CVA), whereas canalisation and fluctuating asymmetry were evaluated from ANOVA Procrustes. The results showed that the body shape of the hybrids is intermediate between those of the two parental species and that the reciprocal hybrids of first generation exhibit heterosis in size. This hybrid vigor appeared more on the hybrids resulting from crosses between S. melanotheron males and O. niloticus females. In a general way, the morphology of the head of the hybrids is similar to that of the parent O. niloticus and their fins resembled to those of the parent S. melanotheron. Moreover, fluctuating asymmetry in shape does not vary between parental species and hybrids, contrary to fluctuating asymmetry in size, which is lesser in latter. Canalisation was found to be smaller in the hybrids compared to the parental ones. So, these results revealed that the hybrids could benefit from most of accrued advantages of parental species.

The Correlation between Gene Effects and Mid-Parent Heterosis in Selected Crops

This study was conducted to investigate the relationship between heterosis and gene effects estimated by the generation mean analysis. Nine traits with 74 cases of combinations cross-sit and cross- abiotic or biotic stress levels were assessed in three crops (durum wheat, pepper, and oat) and evaluated by lines crosses analysis. Trait performances of the F1 hybrid showed evident mid-parent heterosis varying from 0.6% to 89% for the 74 cases investigated. Results of Generation mean analysis revealed that the additive-dominance model was demonstrated adequate in 7 cases. Therefore the epistatic model was found appropriate in 67 cases. Analysis of correlations between gene effects estimated by the generation mean analysis revealed that heterosis was not correlated to additive, dominance or epistasis effects. Therefore, the majority of geneticists considered the non-additives effects as the genetic basis of heterosis. Thus, the lower correlations obtained between heterosis and non-additives effects were due to the bias of the classical approach’s models of genetic quantitative. In fact, many assumptions were proposed to develop this model. To conclude, non-additives results are apparently of great importance in the inheritance of quantitative traits and their roles in the heterosis expression are not to discuss. However, the quantitative genetic interpretation of mid-parent heterosis as a function of genetic effects was not possible basing on the model of line crosses analyses.

Selection of Coffea canephora parents from the botanical varieties Conilon and Robusta for the production of intervarietal hybrids / Seleção de genitores de Coffea canephora das variedades botânicas Conilon e Robusta visando à produção de híbridos intervarietais

ABSTRACT: The objective of this research was to quantify the genetic divergence of potential Coffea canephora parents, with the goal of developing progenies that associate the best traits of the Conilon and Robusta botanical varieties for hybrid vigor expression. Thus, 10 morphological and productive characteristics of 130 clones of Conilon and Robusta botanical varieties and their intervarietal hybrids were evaluated over 2 years. The experiment was conducted in a randomized block design with four replicates of four plants per plot. For selection of parents, the main component analysis was used to associate values with reference points obtained from the average of each botanical variety. The first two principal components allowed for the separation of the botanical varieties representing the variability contained in the original data with 76% for the first year and 69% for the second year. Although, the genotype × years interaction had significant effects, there were minor differences in the grouping from one year to the next, which is associated with the higher repeatability estimates observed in this study. It was observed that crosses with the 16-1-81I, 9-1-82L, and 13-1-61I parents of the botanical variety Robusta and the 167I, 890E, and 130I parents of the Conilon botanical variety presented greater potential for obtaining selection gains.

RESUMO: O objetivo deste trabalho foi quantificar a divergência genética entre matrizes de C. canephora visando desenvolver progênies que associem características das variedades botânicas Conilon e Robusta à expressão do vigor do híbrido. Para isso, foram avaliadas dez características morfológicas e produtivas de 130 clones das variedades botânicas Conilon, Robusta e de híbridos intervarietais, ao longo de dois anos, em delineamento de blocos casualizados com quatro repetições de quatro plantas por parcela. Para seleção de genitores foi utilizada a técnica de componentes principais associada a pontos referenciais obtidos a partir da média de cada variedade botânica. Os dois primeiros componentes principais permitiram a separação das variedades botânicas e dos híbridos intervarietais com uma representação da variabilidade contida nos dados originais de 76% no primeiro ano e 69% no segundo ano. Apesar da significância da interação genótipos x anos, observou-se pouca diferença no agrupamento ao longo do tempo, o que está associado às maiores estimativas de repetibilidade observadas nesse estudo. Observou-se que as matrizes 16-1-81I, 9-1-82L e 13-1-61I da variedade botânica Robusta e as matrizes 167I, 890E e 130I da variedade botânica Conilon apresentaram maior potencial para a obtenção de ganhos com a seleção.

Parâmetros fisiológicos de vacas F1 Holandês x Zebu criadas em ambientes com e sem sombreamento / Physiological parameters of F1 Holstein X Zebu cows raised in environments with and without shading

Objetivou-se, com este estudo, caracterizar o efeito do microclima proporcionado por dois ambientes distintos, sobre as respostas fisiológicas de vacas F1 HxZ em fase de lactação, durante o verão. Foram avaliadas 34 vacas oriundas de quatro diferentes grupos genéticos F1 HxZ. Durante o período experimental, foram feitas medições diárias das variáveis ambientais: temperatura do ar, umidade relativa do ar e temperatura de globo negro, para cálculo dos valores de ITGU. Os parâmetros fisiológicos frequência respiratória, batimento cardíaco, temperatura de superfície corporal, temperatura retal e taxa de sudação foram obtidos às 7h e às 14 horas. A pesagem do leite foi feita semanalmente. Os animais F1 avaliados não apresentaram alterações fisiológicas, e não houve redução na produção láctea em função dos ambientes de criação. O ITGU atingiu valores considerados estressantes (87,7), porém os ambientes de criação não proporcionaram estresse nem redução na produção dos animais.(AU)

The objective of this study was to characterize the effect of microclimate provided by two distinct environments on the physiological responses of F1 HxZ cows lactating during the summer, where 34 cows were evaluated originating from 4 different genetic groups F1 HxZ. During the trial period, daily measurements of environmental variables were determined: dry bulb temperature, relative humidity and black globe temperature, to calculate the BGT values. The physiological parameters respiratory rate, heart rate, body surface temperature, rectal temperature, and sweat rate were obtained at 07:00 and 14:00h. Weighing of milk was done weekly. The F1 animals evaluated did not present physiological changes, nor was there a reduction in milk production as a function of breeding environments. The BGT reached levels considered stressful (87.7), but the breeding environments provided no stress or reduced production of animals.(AU)

Rice Genomics: over the Past Two Decades and into the Future / 基因组蛋白质组与生物信息学报·英文版

Domestic rice (Oryza sativa L.) is one of the most important cereal crops, feeding a large number of worldwide populations. Along with various high-throughput genome sequencing projects, rice genomics has been making great headway toward direct field applications of basic research advances in understanding the molecular mechanisms of agronomical traits and utilizing diverse germplasm resources. Here, we briefly review its achievements over the past two decades and present the potential for its bright future.

Evaluation of fitness in F2 generations of Africa Biofortified Sorghum event 188 and weedy Sorghum bicolor ssp. drummondii

Background: Introgression of transgenes from crops to their wild species may enhance the adaptive advantage and therefore the invasiveness of and weedy forms. The study evaluated the effect of Africa Biofortified Sorghum (ABS) genes from ABS event 188 on the vegetative and reproductive features of the F2 populations derived from crosses with Sorghum bicolor subsp. drummondii. Results: F1 populations were obtained from reciprocal crosses involving ABS event 188 and its null segregant with inbred weedy parents from S. bicolor subsp. drummondii. Four F2 populations and four parental populations were raised in RCBD with 4 replications in a confined field plot for two seasons. Vegetative and reproductive traits were evaluated. The vigour shown in the F2 populations from the reciprocal crosses involving ABS event 188 and S. bicolor subsp. drummondii was similar to that in the crosses involving the null segregant and S. bicolor subsp. drummondii. Differences in vegetative and reproductive parameters were observed between the parental controls and the F2 populations. Examination of the above and below ground vegetative biomass showed lack of novel weedy related features like rhizomes. Conclusions: Therefore, release of crops with ABS 188 transgenes into cropping systems is not likely to pose a risk of conferring additional adaptive advantage in the introgressing populations. The interaction of ABS genes in weedy backgrounds will also not have an effect towards enhancing the weedy features in these populations.

Seroprevalence and risk factors of several bovine viral diseases in dairy farms of San Pedro de los Milagros, Antioquia, Colombia / Seroprevalencia y factores de riesgo para varias enfermedades virales en bovinos de hatos lecheros de San Pedro de los Milagros, Antioquia, Colombia / Soroprevalência e fatores de risco para várias doenças virais em bovinos de rebanhos leiteiros do Município de San Pedro de los Milagros, Antioquia, Colômbia

Bovine viral diarrhea virus (BVDV), Bovine herpesvirus-1 (BoHV-1) and enzootic bovine leucosis (EBL) are viral infections that cause three of the most important cow diseases in the world. Antibody detection is the quickest and most cost-effective method to detect exposition to the virus. The aim of this study was to determine the seroprevalence and risk factors associated with these diseases in cows from the town of San Pedro de los Milagros, Antioquia. A total of 791 bovines of 24 dairy farms were sampled for blood between may and june of 2014, and analized for antibodies against BVDV and BoHV-1. These 24 farms plus other five were analized for antibodies against EBL for a total of 1003 bovines from 29 farms sampled. All tests were done with ELISA kits commercially available. The risk factors for farm and cow selected were evaluated to analize their relation with the serological state of these three diseases using logistic regression. In general, seroprevalence at the animal level for BVDV BoHV-1 and EBL was 75.7% (95% CI: 68.7-82.6%), 31.1% (95% CI: 22.1-40.1%) and 47.8% (95% CI: 40-55.7%), respectively. The odds ratio of being seropositive for BoHV-1 was significantly higher (OR=3.0) in animals older than 3 years in comparison to bovines younger than a year. Not using disposable needles was associated with prevalence of EBL. In conclusion there was a high seroprevalence of EBL and BVDV, and a lower one for BoHV-1. Seropositivity to BoHV-1 was associated with cows older than 3 years and seropositivity to EBL was associated with not using disposable needles in the farm.

Las infecciones por virus de la diarrea viral bovina (BVDV), el herpes virus bovino-1 (BoHV-1) y la leucosis enzoótica bovina (EBL) causan tres de las enfermedades más importantes de la vaca a nivel mundial. La detección de anticuerpos es el método más rápido y costo-efectivo para detectar la exposición a estos virus. El objetivo de este estudio fue determinar la seroprevalencia y los factores de riesgo asociados a estas enfermedades en vacas del municipio de San Pedro de los Milagros, Antioquia. Un total de 791 bovinos de 24 hatos lecheros no vacunados fueron muestreados para sangre entre mayo y junio de 2014 y analizados para anticuerpos contra BVDV y BoHV-1. Estos 24 hatos más otros cinco fueron analizados para anticuerpos contra EBL para un total de 1003 bovinos de 29 hatos. Todas las pruebas fueron efectuadas con kits de ELISA disponibles comercialmente. Los factores de riesgo de hato y de vaca seleccionados fueron evaluados para analizar su relación con el estado serológico de estas tres enfermedades por medio de regresión logística. En general, la seroprevalencia a nivel de animal para BVDV, BoHV-1 y EBL fue 75,7% (95% CI: 68,7-82,6), 31,1% (95% CI: 22,1-40,1) y 47,8% (95% CI: 40-55,7), respectivamente. La relación de disparidad de ser seropositivo para BoHV-1 fue significativamente más alto (OR=3,0) en animales mayores de 3 años en comparación con bovinos menores de un año. No usar agujas desechables en la granja estuvo asociada con la prevalencia a EBL. En conclusión hubo una alta seroprevalencia de EBL y BVDV y una baja para BoHV-1. La seropositividad a BoHV-1 estuvo asociada con vacas mayores a tres años y la seropositividad a EBL estuvo asociada con el no uso de agujas desechables en la granja.

As infecções por vírus da diarreia viral bovina (BVDV), herpes vírus bovino-1 (BoHV-1) e leucose enzoótica bovina (EBL) causam três das doenças mais importantes da vaca no mundo todo. A detecção de anticorpos é o método mais rápido e custo-efetivo para detectar a exposição a estes vírus. O objetivo desta pesquisa foi determinar a soroprevalência e os fatores de risco associados a estas doenças em vacas de diferentes rebanhos leiteiros do município de San Pedro de los Milagros, Antioquia, Colômbia. Um total de 791 bovinos pertencentes a 24 rebanhos leiteiros não vacinados foram amostrados para sangue entre os meses de maio e junho de 2014 e analisados para anticorpos contra BVDV e BoHV-1. Estes 24 rebanhos mais outros cinco foram analisados para anticorpos contra EBL para um total de 1003 bovinos de 29 rebanhos. Todos os testes foram feitos com kits de ELISA disponíveis comercialmente. Os fatores de risco do rebanho e do animal selecionados foram avaliados para analisar sua relação com o estado sorológico de estas três doenças por médio de regressão logística. Em geral, a soroprevalência no animal para BVDV, BoHV-1 e EBL foi 75,7% (95% CI: 68,7-82,6), 31,1% (95% CI: 22,1-40,1) e 47,8% (95% CI: 40-55,7), respetivamente. A relação de disparidade de ser soropositivo para BoHV-1 foi significativamente maior (OR=3,0) em animais maiores de três anos em comparação com os menores de um ano. O fato de não utilizar agulhas descartáveis na fazenda, esteve associada com a prevalência a EBL. Em conclusão, houve uma alta soroprevalência de EBL e BVDV e a sua vez, uma baixa para BoHV-1. A soropositividade a BoHV-1 esteve associada com vacas maiores a três anos e a soropositividade a EBL esteve associada com a não utilização de agulhas descartáveis na fazenda.

Taxa de fertilidade de novilhas de diferentes grupos genéticos com primeiro serviço aos 14 meses de idade / Fertility rate of heifers of different genetic groups with 1st service at 14 months of age

Foram avaliadas as taxas de reconcepção de 98 novilhas primíparas (34 Guzerá - G, 32, 1/2 Guzerá x 1/2 Nelore - GN e 32,1/2 Red Angus x 1/2 Nelore - AN) com 14 meses de idade e peso médio de aproximadamente 249,65kg, criadas em pastos de Brachiaria brizantha cv Marandu. Na segunda estação de monta (EM), foram utilizadas apenas as 36 primíparas gestantes na primeira EM (três G, nove GN e 24 AN), com média de idade de 26 meses e peso corporal de 313,67±25,01kg, 336,50±45,84kg e 399,86±44,45kg, respectivamente, para as fêmeas dos grupos G, GN e AN. O grupo AN apresentou ganho médio diário (GMD) de 0,30±0,06 (kg/dia) e maiores taxas (58,33) de reconcepção (P<0,05), comprovando que a heterose resultante do cruzamento entre raças distintas com maior distância genética (Bos taurus taurus x Bos taurus indicus) proporciona maior desempenho produtivo e reprodutivo.

A total of 98 heifers of three genetic groups: 34 Guzerá (G), 32, 1/2 Guzerá x 1/2 Nelore (GN) and 32 1/2 Red Angus x 1/2 Nelore (AN), 14 month old and average body weight of 249,65kg, raised in Brachiaria brizantha cv Marandu were used to evaluate reconception rates. In the second breeding season (BS), only those 36 pregnant in the first BS (three G, nine GN and 24 AN), age 26 months and body weight of 313.67±25.01kg, 336.50±45.84kg and 399.86±44.45kg, respectively, G , GN and AN were evaluated. The highest reconception rate (58.33%, P<0.05) was registered for the AN group and showed that average daily gain of 0.30±0.06kg, showing that crosses between Bos taurus taurus x Bos taurus indicus leads to higher reproductive and productive performances.

Performance of beef cows of different genetic groups in natural and cultivated pastures / Pastagens naturais e cultivadas no desempenho de vacas de corte de diferentes grupos genéticos

The objective was to assess the performance of 96 pregnant cows of the genetic groups (GG) Charolais (C), Nellore (N), ½ CN and ½ NC, subjected to the following treatments: kept exclusively in natural pastures (NP) throughout the experimental period; kept in cultivated pastures (CP) from July 15 to Setp 15 (CPNP) or from Sept 15 to Nov 15 (NPCP) and the remainder of the experimental period in NP. The weight at the end of the first grazing period (Sept 15) was higher for the CPNP cows than those of the NPCP and NP. The weight at the end of the second period (Nov 15) was 456, 428 and 392 kg respectively for NPCP, CPNP and NP. At calving, the heaviest cows were the CPNP, followed by the NPCP and the NP. At weaning, 90 days postpartum, the heaviest were the NPCP, followed by the CPNP and NP. Nelore cows were less heavy in all evaluations, followed by C, with the F1s' weight higher than the purebreds. The grazing sequences did not affect the percentages of the cows in estrus and pregnancy, but did influence the invervals between calving and first estrus postpartum (ICE). The GG influenced the rate of cows in estrus, pregnant and the ICE which was lower in the F1 (103 days), followed by the C (109 days) and had the largest interval N (119 days). The grazing sequences affect the average daily weight gain (ADG) of calves until weaning at 90 days of age. The GG of the calf affected the ADG at to 210 days.

Objetivou-se determinar o desempenho de 96 vacas prenhas dos grupos genéticos (GG) Charolês (C), Nelore (N), ½ CN e ½ NC, submetidos aos seguintes tratamentos: mantidas exclusivamente em pastagens naturais (PN) durante todo o período experimental; mantidas em pastagens cultivadas (PC) a partir de 15 de julho a 15 de setembro (PCPN) ou a partir de 15 de setembro a 15 de novembro (PNPC) e o restante do período experimental em PN. O peso no final do primeiro período de pastejo (15 de setembro) foi maior para as vacas PCPN que as do PNPC e PN. O peso no final do segundo período (15 de novembro) foi de 456, 428 e 392 kg, respectivamente, para PNPC, PCPN e PN. No parto as vacas da PCPN foram mais pesadas, seguidas pela PNPC e a PN. Ao desmame 90 dias de pós-parto o grupo mais pesado era de vacas da PNPC, seguido pelo PCPN e PN. Vacas N foram menos pesadas em todas as avaliações, seguidas pelas C, com o peso dos F1s maior do que os puros. As seqüências de pastagem não afetaram os percentuais de vacas em cio e prenhes, mas influenciou os intervalos entre partos e pós-parto ao primeiro cio (IPC). O GG influenciou a taxa de vacas em estro, prenhes e IPC que foi menor nas F1 (103 dias), seguidas das C (109 dias) e as N tiveram o maior intervalo (119 dias). As sequencias de pastejo influenciaram o ganho de peso médio diário (GMD) de bezerros até a idade do desmame aos 90 dias de idade. O GG do bezerro afetou a GMD até os 210 dias.

Heterobeltiosis in Wheat (Triticum aestivum L.) F1 Diallel Crosses under Contrasting Soil-N Conditions.

Breeding wheat cultivars with improved adaptation to low soil-N, has gained importance worldwide in order to decrease N fertilizer consumption and overcome the ecological and economic problems of the misuse of this fertilizer. Identification of wheat crosses that show useful heterosis (heterobeltiosis) is an important issue in breeding programs. The main objective of the present investigation was to estimate heterobeltiosis for nitrogen use efficiency and other studied traits of F1 diallel crosses among six wheat parents in order to identify the superior ones for future use in breeding programs. Genetic materials were evaluated at two seasons (2007/2008 and 2008/2009) in a split-plot design with randomized complete block arrangement, using three replications. Main plots were assigned to N levels (0 and 75 kg N/fed), while sub plots were devoted to genotypes. Data combined across the two seasons were presented. In general, low N caused a significant reduction in 9 out of 14 studied traits. These reductions were relatively high in magnitude for number of spikes/ plant (SPP) for parents (23.65%) and F1's (23.99%). On the contrary, low–N caused increases in the averages of nitrogen use efficiency (NUE) by 89.5 and 97.60% for parents and F1's, respectively. Averages of heterobeltiosis for all studied characters were either nonsignificant or significant but non favorable, except for plant height under both low and high N, NUPE under high N and GPS under low N. However, some crosses for each trait showed significant and favorable heterobeltiosis. Under low–N, the highest favorable and significant heterobeltiosis estimate was shown by L27 x Gem 7 for GYPP (14.94%), NUTE (44.81%) and GPS (25.82%), L25 x L26 for 100 GW (13.87%), L 25 x L 27 for SPP (12.53%), L 27 x Gem 9 for GPS (26.19%) and Gem 7 x Gem 9 for BYPP (28.99%).