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41.
Dominik Burger DVM Claus Wedekind Bettina WespiIsabel Imboden DVM Sabine Meinecke-Tillmann Harald Sieme 《Journal of Equine Veterinary Science》2012
The reproductive efficiency of stabled domestic stallions is often lower than what could be expected from observations in feral herds. In the wild, stallions typically live with mares in harem bands, with other stallions in bachelor bands, or occasionally in mixed-sex transitional bands. We, therefore, argue that permanent contact with mares may increase reproductive efficiency of stallions suffering from low libido and/or fertility. We also provide a summary of our present knowledge of natural conditions, management, and husbandry of domestic stallions, and of intra- and intersexual behavioral interactions in horses. 相似文献
42.
Paola Laiolo 《Biological conservation》2010,143(7):1635-276
This review reports on the effects of human activities on animal acoustic signals published in the literature from 1970 to 2009. Almost 5% of the studies on variation in animal communication tested or hypothesised on human impacts, and showed that habitat fragmentation, direct human disturbance, introduced diseases, urbanization, hunting, chemical and noise pollution may challenge animal acoustic behaviour. Although acoustic adaptations to anthropogenic habitats have been documented, human impacts have most often generated neutral variation or potential maladaptive responses. Negative impacts have been postulated in the sexual signals of fishes, amphibians, birds, and mammals; these are concerning as any maladaptive alteration of sexual behaviour may have direct bearings on breeding success and ultimately population growth rate. Acoustic communication also facilitates other vital behaviours influenced by human-driven perturbations. Bat and cetacean echolocation, for instance, is disrupted by noise pollution, whereas bird and mammal alarming is also affected by introduced diseases and hunting. Mammal social signals are sensitive to noise pollution and hunting, and birds selecting habitats by means of acoustic cues are especially vulnerable to habitat loss. Anthropogenic intervention in these cases may have a negative impact on individual survival, recruitment and group cohesion, limiting rescue-effects and triggering Allee effects. Published evidence shows that acoustic variation may be used as an early-warning indicator of perturbations even when not directly affecting individual fitness. Acoustic signalling can be studied in a broad range of ecosystems, can be recorded, analyzed, synthesised and played back with relative ease and limited economic budget, and is sensitive to many types of impacts, thus can have great conservation significance. 相似文献
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Intergeneric sexual hybridizations were conducted between two genera of Rutaceae, with Satsuma mandarin (Citrus unshiu Marc) and Red tangerine (C. reticulata Blanco) as maternal parents, and Poncirus trifoliata (L.) Raf as the paternal parent, in an effort to generate hybrid populations for both molecular mapping and rootstock breeding.
Embryo rescue is important for citrus sexual breeding because polyembryony can interfere with hybrid embryo recovery. Immature
embryos of 80, 85, 90 days after pollination (DAP) from the Satsuma mandarin (S) × trifoliate orange (P) cross, 80 and 85
DAP from the Red tangerine (R) × trifoliate orange (P) cross, were cultured on MG1.0 medium consisting of MT basal medium
supplemented with 1.0 mg l−1 GA3 and 4% sucrose. The results showed that 80 DAP was the optimal time for embryo rescue of the tested crosses, as evidenced
by embryos at this stage exhibiting high germination rates, 37.3% for S × P and 51.3% for R × P. Among the eight tested media,
MT medium supplemented with 0.5 mg l−1 GA3 was the best one for Satsuma mandarin, and MT plus 1.0 mg l−1 GA3 for Red tangerine. A total of 85 plants were obtained from S × P, and 340 from R × P. Out of them, 44 progenies from S × P
and 111 from R × P were sufficiently confirmed to be hybrids by morphological characterization and SSR analysis. In addition,
two hybrid callus lines were obtained from S × P and R × P respectively. 相似文献
45.
恶疫霉有性生殖交配行为的研究 总被引:6,自引:1,他引:5
对同宗配合疫霉种——恶疫霉(Phytophthora cactorum Schroter)抗甲霜灵突变株和抗地茂散突变株的抗药性在游动孢子和卵孢子后代的遗传分析,筛选到抗性分别由细胞核纯合显性单基因控制的抗甲霜灵突变株和由细胞质可稳定遗传的线粒体基因控制的抗地茂散突变株。将携带抗甲霜灵对地茂散敏感(即MtrCns)标记的亲本与携带抗地茂散对甲霜灵敏感(即MtsCnr)标记的亲本共同培养,在200个有性生殖单卵孢后代中检测到携带3种不同抗药性标记的单孢株,其中32株携带MtrCns标记,165株携带MtsCnr标记,另有3株同时携带双亲的标记性状即MtrCnr。结果表明:恶疫霉种内不同菌株共同培养时,有性生殖以配对亲本的各自自交为主,同时配对亲本间也可发生一定频率的杂交。 相似文献
46.
天麻质量与有性杂交态势关系的研究 总被引:1,自引:0,他引:1
通过对不同质量的麻种进行栽培,对其株数、茎粗、株穗长、有效开花数、株有效数和成果率进行观察统计,并通过方差分析和通径分析,结果表明,不同天麻质量对有性杂交态势存在着极显著的影响。有性杂交态势性状对成果率的影响差异明显。选择质量好的母麻种是天麻进行有性杂交的关键。 相似文献
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‘正午’牡丹有性生殖败育的形态学观察 总被引:1,自引:0,他引:1
采用光镜和杂交等方法对牡丹远缘杂交一代品种‘正午’有性生殖败育进行系统形态学观察发现: (1) 雄蕊较雌蕊先成熟, 初花期即散粉, 正常2 - 细胞花粉仅占2.41% , 且花粉在多种培养液中、在自身和其它两种柱头上均不萌发; 柱头在谢花期大量分泌粘液, 进入最佳授粉状态; (2) 同一胚珠中多个大孢子母细胞减数分裂高度不同步, 胚囊发育与受精延迟, 部分胚乳游离核在细胞化时期分裂异常;(3) 自花及品种内异花授粉不结实, 天然授粉结实率为0.053‰~0.130‰。认为‘正午’牡丹有性生殖败育的主要原因是不能形成足够多的有生活力的配子和缺乏有效授粉。 相似文献
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