试验表明,不同接种方法,孢子悬浮液浓度和接种后的湿度条件,均能影响接种发病的轻重。黄麻植株不同生育期感病性无明显统计学上的差异。接种后病毒潜育期4～10天不等,依黄麻品种而异。黄麻炭疽病(Colletotrichum corchorumIkata et Tana...试验表明,不同接种方法,孢子悬浮液浓度和接种后的湿度条件,均能影响接种发病的轻重。黄麻植株不同生育期感病性无明显统计学上的差异。接种后病毒潜育期4～10天不等,依黄麻品种而异。黄麻炭疽病(Colletotrichum corchorumIkata et Tanaka)是圆果种黄麻受害最普遍而严重的病害之一。在黄麻品种抗病性鉴定和黄麻炭疽病菌生理分化研究中,接种方法、接种菌量以及接种后的环境条件等因素,往往影响病菌的接种效果和植株发病程度,这与鉴定结果的准确性有直接关系。国内外尚乏这方面的报道.作者于1986～1987年进行本试验.展开更多
Most birds engage in extrapair copulations despite great differences across and within species. Besides cost and benefit considerations of the two sex environmental factors have been found to alter mating strategies w...Most birds engage in extrapair copulations despite great differences across and within species. Besides cost and benefit considerations of the two sex environmental factors have been found to alter mating strategies within or between populations and/or over time. For socially monogamous species, the main advantage that females might gain from mating with multiple males is probably increasing their offspring＇s genetic fitness. Since male （genetic） quality is mostly not directly meas- urable for female birds, （extrapair） mate choice is based on male secondary traits. In passerines male song is such a sexual ornament indicating male phenotypic and/or genetic quality and song repertoires seem to affect female mate choice in a number of species. Yet their role in extrapair mating behavior is not well understood. In this study, we investigated the proportion of extrapair paternity （EPP） in a population of common nightingales Luscinia megarhynchos. We found that EPP rate was rather high （21.5% of all offspring tested） for a species without sexual dimorphism and high levels of paternal care. Furthermore, the occurrence of EPP was strongly related to the spatial distribution of male territories with males settling in densely occupied areas having higher proportions of extrapair young within their own brood. Also, song repertoire size affected EPP： here larger repertoires of social mates were negatively related to the probability of being cuck- olded. When directly comparing repertoires sizes of social and extrapair mates, extrapair mates tended to have larger repertoires. We finally discuss our results as a hint for a flexible mating strat- egy in nightingales where several factors--including ecological as well as male song features-- need to be considered when studying reproductive behavior in monogamous species with complex song.展开更多
文摘试验表明,不同接种方法,孢子悬浮液浓度和接种后的湿度条件,均能影响接种发病的轻重。黄麻植株不同生育期感病性无明显统计学上的差异。接种后病毒潜育期4～10天不等,依黄麻品种而异。黄麻炭疽病(Colletotrichum corchorumIkata et Tanaka)是圆果种黄麻受害最普遍而严重的病害之一。在黄麻品种抗病性鉴定和黄麻炭疽病菌生理分化研究中,接种方法、接种菌量以及接种后的环境条件等因素,往往影响病菌的接种效果和植株发病程度,这与鉴定结果的准确性有直接关系。国内外尚乏这方面的报道.作者于1986～1987年进行本试验.
文摘Most birds engage in extrapair copulations despite great differences across and within species. Besides cost and benefit considerations of the two sex environmental factors have been found to alter mating strategies within or between populations and/or over time. For socially monogamous species, the main advantage that females might gain from mating with multiple males is probably increasing their offspring＇s genetic fitness. Since male （genetic） quality is mostly not directly meas- urable for female birds, （extrapair） mate choice is based on male secondary traits. In passerines male song is such a sexual ornament indicating male phenotypic and/or genetic quality and song repertoires seem to affect female mate choice in a number of species. Yet their role in extrapair mating behavior is not well understood. In this study, we investigated the proportion of extrapair paternity （EPP） in a population of common nightingales Luscinia megarhynchos. We found that EPP rate was rather high （21.5% of all offspring tested） for a species without sexual dimorphism and high levels of paternal care. Furthermore, the occurrence of EPP was strongly related to the spatial distribution of male territories with males settling in densely occupied areas having higher proportions of extrapair young within their own brood. Also, song repertoire size affected EPP： here larger repertoires of social mates were negatively related to the probability of being cuck- olded. When directly comparing repertoires sizes of social and extrapair mates, extrapair mates tended to have larger repertoires. We finally discuss our results as a hint for a flexible mating strat- egy in nightingales where several factors--including ecological as well as male song features-- need to be considered when studying reproductive behavior in monogamous species with complex song.
