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Genetic Management (genetic + management)
Selected AbstractsEffects of elevated temperature and carbon dioxide on seed-set and yield of kidney bean (Phaseolus vulgaris L.)GLOBAL CHANGE BIOLOGY, Issue 8 2002P. V. Vara Prasad Abstract It is important to quantify and understand the consequences of elevated temperature and carbon dioxide (CO2) on reproductive processes and yield to develop suitable agronomic or genetic management for future climates. The objectives of this research work were (a) to quantify the effects of elevated temperature and CO2 on photosynthesis, pollen production, pollen viability, seed-set, seed number, seeds per pod, seed size, seed yield and dry matter production of kidney bean and (b) to determine if deleterious effects of high temperature on reproductive processes and yield could be compensated by enhanced photosynthesis at elevated CO2 levels. Red kidney bean cv. Montcalm was grown in controlled environments at day/night temperatures ranging from 28/18 to 40/30 °C under ambient (350 µmol mol,1) or elevated (700 µmol mol,1) CO2 levels. There were strong negative relations between temperature over a range of 28/18,40/30 °C and seed-set (slope, ,,6.5% °C,1) and seed number per pod (, 0.34 °C,1) under both ambient and elevated CO2 levels. Exposure to temperature >,28/18 °C also reduced photosynthesis (, 0.3 and ,,0.9 µmol m,2 s,1 °C,1), seed number (, 2.3 and ,,3.3 °C,1) and seed yield (, 1.1 and ,,1.5 g plant,1 °C,1), at both the CO2 levels (ambient and elevated, respectively). Reduced seed-set and seed number at high temperatures was primarily owing to decreased pollen production and pollen viability. Elevated CO2 did not affect seed size but temperature >,31/21 °C linearly reduced seed size by 0.07 g °C,1. Elevated CO2 increased photosynthesis and seed yield by approximately 50 and 24%, respectively. There was no beneficial interaction of CO2 and temperature, and CO2 enrichment did not offset the negative effects of high temperatures on reproductive processes and yield. In conclusion, even with beneficial effects of CO2 enrichment, yield losses owing to high temperature (> 34/24 °C) are likely to occur, particularly if high temperatures coincide with sensitive stages of reproductive development. [source] Aspects of the reproductive biology and breeding management of Asian and African elephants Elephas maximus and Loxodonta africanaINTERNATIONAL ZOO YEARBOOK, Issue 1 2006T. B. HILDEBRANDT Elephants possess many unique qualities, including some that relate directly to their reproductive biology. Thus, comparative studies on elephants provide valuable information to the growing biological database for extant mammals. Left undisturbed, Asian Elephas maximus and African Loxodonta Africana elephants reproduce well in the wild. It is ironic then that most captive populations face possible,extinction'because of historically poor reproductive performance. Some of the problems with breeding elephants in captivity are logistical but others, like ovarian and uterine pathologies and bull infertility, have management-related aetiology. Through advances in endocrine monitoring and ultrasound imaging techniques, we are beginning to understand some of the complex mechanisms controlling reproductive function in elephants. Several reproductive characteristics appear to be unique to the taxon, such as luteal steroidogenic function, follicular development patterns, pituitary gonadotrophin secretion, a 22 month-long gestation and musth (in ,,). One example is the,double LH surge'occurring 3 weeks apart during the follicular or non-luteal phase of the cycle, with only the second surge inducing ovulation. These qualities have at times both enhanced and hampered efforts to understand and control reproduction. We have learned that techniques developed for domestic or laboratory species are not always directly applicable to elephants. However, the recent success of artificial insemination based on new ultrasound and endocrine methodology offers hope that establishing selfsustaining populations is possible. This paper reviews our current knowledge of elephant reproduction and how it is being used to aid species conservation for maximal reproductive efficiency and enhancement of genetic management. [source] Understanding the multiple meanings of ,inbreeding' and ,effective size' for genetic management of African rhinoceros populationsAFRICAN JOURNAL OF ECOLOGY, Issue 4 2009Stanton Braude Abstract Although some African rhinoceros populations are currently increasing, others are critically endangered. Even healthy populations are extensively managed in the wild and in captivity. While political and demographic considerations are of primary concern, many decisions are made in the name of genetic management. Such decisions should be informed by a full understanding of the multiple meanings of inbreeding and effective population size. In this essay, we examine inbreeding and effective size of wild and captive populations of African rhinoceroses. We conclude by showing how misunderstanding of effective size and Franklin's 50/500 rule can make a crucial difference in informing management decisions. Résumé Bien que certaines populations de rhinocéros africains soient actuellement en augmentation, d'autres sont en danger critique. Même les populations saines sont gérées très activement dans la nature et en captivité. Alors que les considérations politiques et démographiques soient les principaux motifs d'inquiétude, de nombreuses décisions sont prises au nom de la gestion génétique. Ces décisions devraient se faire en pleine connaissance des multiples implications de l'inbreeding et de ce qu'est une taille de population nécessaire. Dans cet essai, nous examinons l'inbreeding et la taille nécessaire des populations sauvages et captives de rhinocéros africains. Nous concluons en montrant comment une mauvaise compréhension de la taille nécessaire et de la règle 50/500 de Franklin peut entraîner une différence cruciale lorsqu'il s'agit de prendre, en connaissance de cause, les décisions opportunes. [source] Genetic quality of domesticated African tilapia populationsJOURNAL OF FISH BIOLOGY, Issue 2004R. E. Brummett Anecdotal and empirical evidence exists for substantial (up to 40%) declines in growth among Oreochromis populations domesticated in both large and small-scale fish farms in Africa. These declines are at least partly attributable to poor genetic management, including inadvertent selection, inbreeding, bottle-necks and founder effects. Due to restricted cash flow and investment capital, genetic management and selective breeding for the improvement of domesticate populations are difficult for small-scale farmers, but feasible on larger-scale farms. In managing domesticated gene pools, feral populations can serve as a broodstock reservoir, making the use of indigenous species advantageous. A development model of large-scale hatcheries producing selected lines of sex-reversed, indigenous tilapia for sale to smaller-scale farmers is proposed as a solution to the problems of poor genetic management in African aquaculture. [source] PRIMER NOTE: Microsatellite markers for the June sucker (Chasmistes liorus mictus), Utah sucker (Catostomus ardens), and five other catostomid fishes of western North AmericaMOLECULAR ECOLOGY RESOURCES, Issue 3 2007B. L. CARDALL Abstract We developed and optimized five new microsatellite markers for the genetic management of the endangered June sucker. We report the cross-amplification of these markers, and seven microsatellites previously developed for Klamath Basin suckers, in seven catostomid species of western North America. No linkage disequilibrium was detected between pairs of loci. Since most of these loci exhibited conserved priming sites, they may be useful for landscape-scale studies of speciation and patterns of gene flow among multiple sucker lineages. [source] More polymorphic microsatellite markers in the European sea bass (Dicentrarchus labrax L.)MOLECULAR ECOLOGY RESOURCES, Issue 4 2002Y. Ciftci Abstract We provide details of five microsatellite loci screened in 163 individual sea bass. Large numbers of alleles were observed at three loci (20,25) and heterozygosities ranged from 0.52 to 0.86. These loci should prove useful for population genetic studies and for the pedigree analysis and genetic management of this species in aquaculture. [source] | ||||||||||