URS Campestre seedless orange: a new mutant with female sterility

ABSTRACT: Seedlessness in fruit is a trait that is much sought after by juice making industries. Close to the city of São Sebastião do Caí, in the state of Rio Grande do Sul (RS), Brazil, a new mutant orange originating from natural mutation was identified and selected as a seedless material. To determine the mechanisms involved in the absence of seeds, the reproductive structures of this new mutant by comparison with a Valencia sweet orange as control, a cultivar with a profusion of seeds, was analyzed in terms of meiotic behavior, meiotic index, pollen viability, in vitro germination, and ovule features to determine the grounds for seed absence. Other morphological analyzes allowed for visualizing the structures of normal appearance and size in both cultivars. Meiotic analysis identified chromosome normal pairing with a predominance of bivalents at diakinesis and metaphase 1. URS Campestre flowers at different developmental stages had anthers and ovaries whose dimensions are typical while pollen grain analysis pointed to a standard developmental pattern, normal meiosis, high viability (84 %) and elevated in vitro pollen tube germination rates (63 %). The cv. Valencia and URS Campestre ovules had a similar shape and morphology, sharing an anatropous orientation, and two integuments. In the internal ovule analyses of Valencia sweet oranges, normal embryo sac cells were identified: presence of one egg cell and two synergids, three antipodes and a bigger and central cell containing two polar nuclei. However, the analysis of ovules from URS Campestre reveals an apparent senescence or non-formation of an embryo sac, where only a few highly stained and collapsed cells could be identified. These results led to the conclusion that female sterility in URS Campestre, with a total absence of a female gametophyte, is the limiting factor for fertilization and seed production.

Biosecurity in the production of swine / Biosseguridade na produção de suínos

The pig farming has been highlighted globally over the last few years. In Brazil the production of swine deserves to be recognized in growth terms owed mainly the changes in the breeding systems. With the integration model, the producers started to have greater contribution and technical orientation, as well as a pre-established sale with the integrating company. As a result, swine production developed rapidly in three southern states (Paraná, Santa Catarina and Rio Grande do Sul) that have the largest swine herds in the country. This work had as an objective the current situation of piglets production units the northwestern region of Rio Grande do Sul the main items that make up the biosecurity program, identifying critical points and listing opportunities to improve the process.The adopted methodology consisted of the application of semi structured questionnaire and visiting the properties of the integrated producers. As a result, it was observed that (27.3%) of the farms produce Weaned Pigs, and (72.7%) are units producing pigs without day care. Regarding the enclosure, where 72.6% of the farms answered the question, another item was the access to water for animal watering, where 54.5% have access via an artesian well. Most of the units studied reached the objectives and standards of biosafety, thus guaranteeing the health and quality of the pork produced, but there were alsoopportunities for improvements in relation to some of the requirements, among which the enclosure,chlorination of water for Animal welfare, the location of treatment lagoons and aspects related to thedischarge and loading of animals.

A suinocultura vem se destacando mundialmente nos últimos anos. No Brasil a produção de suínos merece destaque em termos de crescimento devido principalmente as mudanças nos sistemas de criação. Com o modelo de integração, os produtores passaram a ter maiores aportes e orientações técnicas, bem como uma venda pré-estabelecida com a empresa integradora. Com isso, a produção de suínos desenvolveu-se rapidamente nos três Estados do Sul (Paraná, Santa Catarina e Rio Grande do Sul) que possuem os maiores rebanhos de suínos do País. Este trabalho teve como objetivo avaliar a situação atual das unidades produtoras de leitões da região Noroeste do Rio Grande do Sul acerca dos principais itens que compõem o programa de biosseguridade, identificando pontos críticos e elencando oportunidades de melhoria. A metodologia adotada consistiu na aplicação de questionário semiestruturado e visitas às propriedades dos produtores integrados. Com os resultados, observou-se que 27,3% das granjas são Unidades Produtoras de Leitões Desmamados, e 72,7% são Unidades Produtoras de Leitões Descrechados. Com relação ao cercamento, 72,6% das granjas atenderam ao quesito, outro item apontado foi o acesso a água para dessedentação animal, onde 54,5% possuem acesso por via de poço artesiano. A maioria das unidades estudadas atingiu os objetivos e normas de biosseguridade, garantindo assim a sanidade e qualidade da carne suína produzida, mas também se observaram oportunidades de melhorias em relação a alguns quesitos, destacando-seentre estes o cercamento, a cloração de água para dessedentação animal, a localização das lagoas detratamento e os aspectos relacionados à descarga e carga de animais.

URS Campestre seedless orange: a new mutant with female sterility

ABSTRACT: Seedlessness in fruit is a trait that is much sought after by juice making industries. Close to the city of São Sebastião do Caí, in the state of Rio Grande do Sul (RS), Brazil, a new mutant orange originating from natural mutation was identified and selected as a seedless material. To determine the mechanisms involved in the absence of seeds, the reproductive structures of this new mutant by comparison with a Valencia sweet orange as control, a cultivar with a profusion of seeds, was analyzed in terms of meiotic behavior, meiotic index, pollen viability, in vitro germination, and ovule features to determine the grounds for seed absence. Other morphological analyzes allowed for visualizing the structures of normal appearance and size in both cultivars. Meiotic analysis identified chromosome normal pairing with a predominance of bivalents at diakinesis and metaphase 1. URS Campestre flowers at different developmental stages had anthers and ovaries whose dimensions are typical while pollen grain analysis pointed to a standard developmental pattern, normal meiosis, high viability (84 %) and elevated in vitro pollen tube germination rates (63 %). The cv. Valencia and URS Campestre ovules had a similar shape and morphology, sharing an anatropous orientation, and two integuments. In the internal ovule analyses of Valencia sweet oranges, normal embryo sac cells were identified: presence of one egg cell and two synergids, three antipodes and a bigger and central cell containing two polar nuclei. However, the analysis of ovules from URS Campestre reveals an apparent senescence or non-formation of an embryo sac, where only a few highly stained and collapsed cells could be identified. These results led to the conclusion that female sterility in URS Campestre, with a total absence of a female gametophyte, is the limiting factor for fertilization and seed production.(AU)

Phenotypic, cytogenetic and spike fertility characterization of a population of male-sterile triticale

Triticale (X Triticosecale Wittmack) is a good cereal for production of flour and feed. A segregating population of triticale was developed from a male-sterile (MS) plant. To determine whether this new source of male sterility in triticale is appropriate for use in breeding programs the expression of the male sterility phenotype was characterized through spike fertility, meiotic behavior, and pollen. Controlled crosses between male-sterile plants and control varieties male-fertile (MF) of triticale were also conducted, and cytological analyses were performed in the F2 and backcross plants. Plants with male-sterile phenotypes displayed reduced spike fertility when compared to plants with male-fertile phenotypes. Compared to male-fertile plants, male-sterile plants exhibited a lower percentage of normal meiotic cells, a reduced meiotic index and reduced pollen viability. The F2 plants had improved pollen fertility when compared to the male-sterile population; however there were no corresponding improvements in the percentage of normal meiotic cells or in the meiotic index. A single generation of backcrosses resulted in an improved meiotic index and increased pollen viability. However, no changes in the percentage of normal meiotic cells were observed. Meiotic instability, which was shown to be inheritable, was the likely cause of male sterility. Therefore, the use of this population in triticale breeding was considered to be inappropriate because it could promote or contribute to the maintenance of meiotic instability, which is commonly observed in this species.

Phenotypic, cytogenetic and spike fertility characterization of a population of male-sterile triticale

Triticale (X Triticosecale Wittmack) is a good cereal for production of flour and feed. A segregating population of triticale was developed from a male-sterile (MS) plant. To determine whether this new source of male sterility in triticale is appropriate for use in breeding programs the expression of the male sterility phenotype was characterized through spike fertility, meiotic behavior, and pollen. Controlled crosses between male-sterile plants and control varieties male-fertile (MF) of triticale were also conducted, and cytological analyses were performed in the F2 and backcross plants. Plants with male-sterile phenotypes displayed reduced spike fertility when compared to plants with male-fertile phenotypes. Compared to male-fertile plants, male-sterile plants exhibited a lower percentage of normal meiotic cells, a reduced meiotic index and reduced pollen viability. The F2 plants had improved pollen fertility when compared to the male-sterile population; however there were no corresponding improvements in the percentage of normal meiotic cells or in the meiotic index. A single generation of backcrosses resulted in an improved meiotic index and increased pollen viability. However, no changes in the percentage of normal meiotic cells were observed. Meiotic instability, which was shown to be inheritable, was the likely cause of male sterility. Therefore, the use of this population in triticale breeding was considered to be inappropriate because it could promote or contribute to the maintenance of meiotic instability, which is commonly observed in this species.

Biosecurity in the production of swine / Biosseguridade na produção de suínos

The pig farming has been highlighted globally over the last few years. In Brazil the production of swine deserves to be recognized in growth terms owed mainly the changes in the breeding systems. With the integration model, the producers started to have greater contribution and technical orientation, as well as a pre-established sale with the integrating company. As a result, swine production developed rapidly in three southern states (Paraná, Santa Catarina and Rio Grande do Sul) that have the largest swine herds in the country. This work had as an objective the current situation of piglets production units the northwestern region of Rio Grande do Sul the main items that make up the biosecurity program, identifying critical points and listing opportunities to improve the process.The adopted methodology consisted of the application of semi structured questionnaire and visiting the properties of the integrated producers. As a result, it was observed that (27.3%) of the farms produce Weaned Pigs, and (72.7%) are units producing pigs without day care. Regarding the enclosure, where 72.6% of the farms answered the question, another item was the access to water for animal watering, where 54.5% have access via an artesian well. Most of the units studied reached the objectives and standards of biosafety, thus guaranteeing the health and quality of the pork produced, but there were alsoopportunities for improvements in relation to some of the requirements, among which the enclosure,chlorination of water for Animal welfare, the location of treatment lagoons and aspects related to thedischarge and loading of animals.(AU)

A suinocultura vem se destacando mundialmente nos últimos anos. No Brasil a produção de suínos merece destaque em termos de crescimento devido principalmente as mudanças nos sistemas de criação. Com o modelo de integração, os produtores passaram a ter maiores aportes e orientações técnicas, bem como uma venda pré-estabelecida com a empresa integradora. Com isso, a produção de suínos desenvolveu-se rapidamente nos três Estados do Sul (Paraná, Santa Catarina e Rio Grande do Sul) que possuem os maiores rebanhos de suínos do País. Este trabalho teve como objetivo avaliar a situação atual das unidades produtoras de leitões da região Noroeste do Rio Grande do Sul acerca dos principais itens que compõem o programa de biosseguridade, identificando pontos críticos e elencando oportunidades de melhoria. A metodologia adotada consistiu na aplicação de questionário semiestruturado e visitas às propriedades dos produtores integrados. Com os resultados, observou-se que 27,3% das granjas são Unidades Produtoras de Leitões Desmamados, e 72,7% são Unidades Produtoras de Leitões Descrechados. Com relação ao cercamento, 72,6% das granjas atenderam ao quesito, outro item apontado foi o acesso a água para dessedentação animal, onde 54,5% possuem acesso por via de poço artesiano. A maioria das unidades estudadas atingiu os objetivos e normas de biosseguridade, garantindo assim a sanidade e qualidade da carne suína produzida, mas também se observaram oportunidades de melhorias em relação a alguns quesitos, destacando-seentre estes o cercamento, a cloração de água para dessedentação animal, a localização das lagoas detratamento e os aspectos relacionados à descarga e carga de animais.(AU)