罗氏沼虾雌虾规格对生殖性能和胚胎质量的影响

为了解罗氏沼虾(Macrobrachium rosenbergii)雌虾体质量对其生殖性能和胚胎质量的影响,本研究比较了4种规格（A组：16~20 g/尾、B组：24~28 g/尾、C组：32~36 g/尾、D组：40~44 g/尾）的雌虾亲本的生殖性能、胚胎质量和胚胎色泽,以及分析了体质量和生殖性能之间的相关性. 结果显示：随着雌虾体质量的增加,雌虾抱卵量呈显著上升趋势,D组的抱卵量显著高于A、B、C组的抱卵量,C组显著高于A组(P<0.05),生殖力和生殖指数也随着体质量的增加而呈上升,D组显著高于A组(P<0.05),但是A、B、C组之间无显著性差异,B、C、D组之间无显著性差异;各组之间的单卵湿质量、单卵干质量和卵径均无显著性差异;各组之间的胚胎色泽参数均无显著性差异;体质量与抱卵量（r=0.847, P=0.000）、生殖力（r=0.508, P=0.004）和生殖指数（r=0.551, P=0.001）均呈显著正相关. 结果表明,大规格罗氏沼虾的生殖性能优于小规格,但是规格对胚胎质量无明显的影响,该研究为罗氏沼虾亲本选择、生殖性能评价和人工育苗提供了重要基础资料     

应用胴体重鉴定高山姬鼠种群年龄

为完善贵州省农区主要害鼠种群年龄鉴定划分标准体系建设内容,对2008～2010年贵州省大方县捕获的285只高山姬鼠(雌鼠138只,雄鼠147只)胴体重数据进行了统计分析.结果表明:高山姬鼠平均胴体重为(16.29±3.41)g.根据胴体重的频次分配特征,参照繁殖状况,将高山姬鼠划分为5个年龄组,制定了各年龄组的胴体重划...     

应用胴体重指标鉴定贵州省褐家鼠的年龄

为完善贵州省农区主要害鼠种群年龄鉴定划分标准体系建设内容。对2002~2009年贵州省余庆、息烽、三都、关岭、大方5个县捕获的441只褐家鼠(雌鼠201只,雄鼠240只)胴体重统计分析表明,褐家鼠平均胴体重为(69.16±30.45)g,雌、雄鼠之间胴体重差异不显著。根据胴体重的频次分配特征,参照繁殖状况,本研究将褐家鼠划分为5个年龄组,并制定了各年龄组胴体重划分标准:幼年组(Ⅰ)(≤40.0 g),亚成年组(Ⅱ)(40.1~80.0 g),成年Ⅰ组(Ⅲ)(80.1~120.0 g),成年Ⅱ组(Ⅳ)(120.1~160.0 g),老年组(Ⅴ)(160.0 g以上)。研究表明,不同年龄组胴体重、体重、体长、尾长、后足长、耳长之间具有极显著差异,随着种群年龄的增长而不断增加;胴体重与体重、体长、尾长、后足长、耳长之间具有极显著的正相关关系;不同年龄组种群繁殖力存在显著差异,随着种群年龄的增长,种群繁殖力不断增加;参与种群繁殖的主要群体为成年Ⅰ组、成年Ⅱ组和老年组,平均怀孕率为51.39%,平均睾丸下降率为93.51%,平均繁殖指数为2.583 9。种群年龄组成具有明显的季节变化特征。     

The ecological context of life history evolution

There is now a good theoretical understanding of life history evolution, and detailed explicit optimality models have been constructed. These present a challenge for empirical work examining some of the assumptions, such as the extent and mechanisms of the costs of growth and reproduction. In addition, there is an obvious need for comparative tests of the models. These tests, properly applied, may be particularly informative because they can deal with multiple independent variables, including ecological variables, and can reveal broad trends against a background of constraints on optima and the rate of evolutionary approach to them. Life histories are the probabilities of survival and the rates of reproduction at each age in the life-span. Reproduction is costly, so that fertility at all ages cannot simultaneously be maximized by natural selection. Allocation of reproductive effort has evolved in response to the demographic impact of different environments but is constrained by genetic variance and evolutionary history.     

锡金小家鼠种群年龄鉴定及繁殖变化规律

为制定锡金小家鼠年龄鉴定的体重划分标准,采用夹夜法调查,收集鼠类标本。对1984～2012年贵州省关岭、三都、大方3个县历年捕获的249只锡金小家鼠体重进行统计分析,结果表明:锡金小家鼠平均体重为(15.57±5.97)g,根据体重的频次分配特征,参照其繁殖状况,将其年龄划分为5个年龄组,制定了各年龄组的体重划分标准:幼年组(Ⅰ)体重≤8.0 g,亚成年组(Ⅱ)体重8.1～13.0 g,成年Ⅰ组(Ⅲ)体重13.1～18.0 g,成年Ⅱ组(Ⅳ)体重18.1～23.0 g,老年组(Ⅴ)体重>23.0 g。不同年龄组体重之间差异极显著,且随着种群年龄的增长而不断增加。不同年龄组种群繁殖力存在显著差异,参与种群繁殖的主要群体为成年Ⅰ组、成年Ⅱ组。种群年龄组成具有明显的季节变化。     

西兰花定植苗龄与幼苗质量、生育期、商品性及产量的相关性研究

为进一步提高西兰花优质栽培技术,明确不同苗龄定植与其产量和品质的相互关系,增强西兰花产业的竞争力,开展西兰花定植苗龄与其幼苗质量、生育期、商品性及产量的相关性研究,并建立相应的回归数学模型,从多角度提供西兰花高产优质栽培的技术依据。结果表明,随着定植苗龄的增加,其单株生长势和单株生物量增加,但其壮苗指数表现为“小-大-小”变化特征,其营养生长期、花球生育期及全生育期随之拉长并呈线性变化趋势,其花球蕾粒密度、商品花球合格率及花球产量则为“低-高-低”的曲线变动,以35~40天苗龄定植为宜,品质优、产量高。通过对试验结果的分析,建立了不同苗龄（d）与壮苗指数（p）的曲线关系模型：p=-0.0004d2+0.035d-0.3952,不同定植苗龄（d）与其营养生长期（e）、花球生育期（f）、全生育期（g）的线性关系模型：e=1.52d+40.66,f=0.3143d+24.714,g=1.8343d+65.381;以及不同定植苗龄（d）与其蕾粒密度（x）和商品花球合格率（u）、花球产量（y）的关系模型：x=-0.0901d2+6.4756d-41.614,u=-0.1037d2+7.5757d-46.929,y=-40.497d2+3089d-31257。应用这些规律和模型,对有效提高安全优质栽培水平具有良好的指导、参考作用。     

高致病性蓝耳病毒与低致病性蓝耳病毒RT-PCR检测方法

将高致病性蓝耳病和低致病性蓝耳病病毒接种于Marc145细胞培养并观察细胞病变情况,将有细胞病变的病毒进行连续传代培养。根据高致病性蓝耳病与低致病性蓝耳病在NSP2基因上有87 bp连续缺失,从NCBI上下载7对高致病性蓝耳病保守序列设计一对引物。通过RT-PCR方法进行检测证明实验室所保存的这两株毒株分别为高致病性蓝耳病和低致病性蓝耳病,并且建立了高致病性蓝耳病与低致病性蓝耳病的检测方法。     

Wolbachia and virus protection in insects

Wolbachia pipientis bacteria are common endosymbionts of insects that are best known for their ability to increase their prevalence in populations by manipulating host reproductive systems. However, there are examples of Wolbachia that exist in nature that seem to induce no reproductive parasitism trait and yet are able to invade populations. We demonstrate a fitness benefit for Wolbachia-infected insects that may explain this paradox. Drosophila melanogaster flies infected with Wolbachia are less susceptible to mortality induced by a range of RNA viruses. The antiviral protection associated with Wolbachia infection might be exploited in future strategies to reduce transmission of pathogens by insects.     

能量对蛋鸡性成熟过程中卵巢卵泡的影响

通过研究日粮能量水平对蛋鸡性成熟过程中卵巢卵泡的影响,结果表明:22周龄前,卵巢表面卵泡数随着周龄和能量水平的提高而增多。到22周龄,除低能Ⅱ组外,其它各组优势卵泡(10mm以上)明显增多,与低能Ⅱ组达差异显著水平(P<0.05),说明过低的能量饲料对性成熟过程中生殖器官的发育有显著的影响。14和18周龄,低能组初级卵泡的闭锁率明显高于对照和高能组,说明在生殖器官发育的早期,能量过低对初级卵泡的影响比对次级卵泡影响的程度要大。22周龄,高能Ⅰ组卵泡的闭锁率高于其它各组。     

Sex matters in meiosis

In mammals, fertilization typically involves the ovulation of one or a few eggs at one end of the female reproductive tract and the entry of millions of sperm at the other. Given this disparity in numbers, it might be expected that the more precious commodity-eggs-would be subject to more stringent quality-control mechanisms. However, information from engineered mutations of meiotic genes suggests just the opposite. Specifically, the available mutants demonstrate striking sexual dimorphism in response to meiotic disruption; for example, faced with adversity, male meiosis grinds to a halt, whereas female meiosis soldiers on. This female "robustness" comes with a cost, however, because aneuploidy appears to be increased in the resultant oocytes.     

猪体重和体尺性状与繁殖性能间的相关

研究了母猪不同阶段的体重和6月龄体尺性状与繁殖性能间的关系,结果表明:母猪的体重、6月龄体尺性状与各繁殖性状的表型相关很小,只有6月龄体长与断奶头数的表型相关达显著水平。而各体重、体尺性状与繁殖性状间却存在很强的遗传相关,其中70日龄体重、4月龄体重、6月龄体重、6月龄体高、6月龄胸围、6月龄背膘厚与产仔数等繁殖性状呈负遗传相关,而6月龄体长与产仔数等繁殖性状是强的正遗传相关,这表明,腿短体长、体重适宜的母猪产仔多,繁殖性能好,应该留作种用。     

海南特有兰科植物华石斛的繁殖分配规律

华石斛为兰科石斛属多年生附生植物,在自然条件下结实率低,种子萌发条件苛刻。除了有性生殖,华石斛也可以克隆繁殖。笔者在海南省霸王岭设置5条样带,对样带内的华石斛进行种群监测,通过研究不同株龄华石斛个体的繁殖分配规律来为附生兰科植物的保育提供科学依据。结果表明,在华石斛整个生活史阶段,个体具备至少4根假鳞茎才能开始有性生殖,且对有性繁殖的投入逐年增大。华石斛的克隆生长则没有个体大小限制。根据繁殖器官生物量与植株总生物量的比例来看,随着华石斛个体株龄的增长,投入给繁殖活动的资源比例始终维持在27%左右,并且克隆繁殖始终占据2种繁殖方式的优势地位。     

Pollinator-mediated selection on flower color allele drives reinforcement

Reinforcement is the process by which reduced hybrid fitness generates selection favoring the evolution of stronger prezygotic reproductive barriers between emerging species. Using common-garden field experiments, we quantified the strength of reinforcing selection in nature by demonstrating strong selection favoring an allele conferring increased pigment intensity in the plant Phlox drummondii in areas of sympatry with the closely related species Phlox cuspidata. Incomplete hybrid sterility between the two species generates selection for traits that decrease interspecies hybridization. In contrast, selection on this locus is undetectable in the absence of P. cuspidata. We demonstrate that reinforcing selection is generated by nonrandom pollinator movement, in which pollinators move less frequently between intensely pigmented P. drummondii and P. cuspidata than between lightly pigmented P. drummondii and P. cuspidata.     

珍贵绢丝昆虫天蚕雌性内生殖器官的结构及其发育

报道了天蚕幼虫、蛹和成虫雌性内生殖器官结构及其发育的系统观察结果．幼虫卵巢大小随虫龄增长而增大．其中以５龄取食期增长最快，老熟结茧后增长明显减缓．蛹（化蛹第４天开始）和成虫内生殖系统由卵巢、侧输卵管、中输卵管、导精管、交配囊、受精囊和附腺等组成．蛹期各内生殖器官大小一般随日龄增长而增大；卵巢鲜重随日龄增长的趋势及同一卵巢管中卵室体积自顶端至基端增长的趋势，均可用Ｌｏｇｉｓｔｉｃ曲线较好地加以描述     

南海鸢乌贼微型群肌肉和性腺组织能量积累及其分配

利用组织能量密度测定技术和残差指标分析方法,分析了南海鸢乌贼微型群个体肌肉组织和性腺组织的能量积累及其分配规律的变化过程。结果显示,微型群个体的肌肉、性腺组织之间的能量密度存在显著性差异;除缠卵腺之外,其它组织的能量密度均随性腺发育变化显著。肌肉组织和性腺组织的组织能量积累均随性腺发育增加显著。同一性腺成熟度等级,肌肉组织的相对组织能量积累较高,性腺组织的相对组织能量积累相对较低。雌性个体性腺组织相对组织能量积累随着性腺发育增长显著,雄性个体性腺组织相对组织能量积累在Ⅰ期~Ⅴ期增长较快,在Ⅵ期~Ⅶ期趋于稳定。肌肉和性腺组织在性腺发育后期的质量特征较发育前期均显著改善,并且肌肉组织能量积累-胴长残差与性腺组织能量积累-胴长残差呈显著的正相关关系,表明性腺发育过程中的肌肉组织与性腺组织之间不存在能量交流。研究表明,南海鸢乌贼微型群个体的生殖能量倾向于外源性投入,肌肉和性腺组织的组织能量密度、组织能量积累和相对组织能量积累存在雌雄差异性。     

棉花矮秆品系的干物质积累研究

对3个棉花矮秆品系的干物质积累动态进行了对比研究。结果表明:从开花期到吐絮期是3个棉花品系干物质积累的关键时期。除了茎枝干物质积累没有一致性外,3个棉花品系在叶面积、叶重、生殖器官干重和地上部干物质总量的增长动态上都表现出一致性。品系2、3的地上部干物质总量大于品系1,这也体现在了籽棉产量上。品系2、品系3的生殖器官干物质分配高峰在吐絮期,均占到地上部生物学总量的50%左右;而品系1的生殖器官干物质分配高峰在收获期,占到43.8%。     

细叶百合生物量的生殖分配

对野生环境中多年生球根类植物细叶百合（Lilium pumilum DC.)进行了生物量生殖分配季节动态研究，各构件在不同季节生物量分配的平均值从大到小的顺序为：鳞茎＞茎＞叶＞生殖构件；从蕾期至花期生殖构件生殖生物量分配增加近44倍，两性结构与雄蕊、雌蕊的生殖生物量比为9：5：1；不同季节生殖构件生物量分配与地下构件生物量呈负相关，与地上非生殖构件生物量分配呈正相关。     

黑线姬鼠不同体重种群繁殖力变化

对贵州省余庆县1987～2007年2563只黑线姬鼠体重统计分析,结果表明:黑线姬鼠体重最低5.36g,最高53.41g,平均体重为26.31±8.14g,其个体体重主要分布在15.01～35.00g之间.占总鼠数的79.01%,是活动能力较强的个体.黑线姬鼠怀孕鼠最低体重为17.61g,睾丸下降鼠最低体重为16.50g,体重达16.0g以上时开始繁殖,随着体重的增加,种群繁殖力不断增加,体重达24.0g以上时,种群繁殖力迅速增加,怀孕率、睾丸下降率分别达31.82%、67.02%,接近雌鼠总怀孕率30.06%和雄鼠总睾丸下降率52.67%,繁殖指数达0.7138,亦接近总繁殖指数0.7599.黑线姬鼠不同年龄组种群繁殖力存在显著差异,随着种群年龄的增长,雌鼠怀孕率、胎仔数、雄鼠睾丸下降率、繁殖指数不断增加,成年Ⅰ组、成年Ⅱ组、老年组是黑线姬鼠种群的繁殖群体,因此,它们在种群中所占比例的多少与种群数量消长关系密切,可以作为预测黑线姬鼠种群数量的重要依据.     

Estimating the rock volume bias in paleobiodiversity studies

To interpret changes in biodiversity through geological time, it is necessary first to correct for biases in sampling effort related to variations in the exposure of rocks and recovery of fossils with age. Data from New Zealand indicate that outcrop area is likely to be a reliable proxy of rock volume in both stable cratonic regions, where the paleobiodiversity record is strongly correlated with relative sea level, and on tectonically active margins. In contrast, another potential proxy, the number of rock formations, is a poor predictor of outcrop area or sampling effort in the New Zealand case.     

Effects of plastic mulching film-induced leaf burning on seedling growth in tobacco cultivation: Different findings beyond conservation view

Solving high-temperature plastic mulching film-induced leaf burning in the first week during tobacco cultivation would take much time and effort. In the present study, the growth as well as the leaf sugar and nicotine contents of seedlings with or without leaf burning induced by high-temperature plastic mulching film were tested at two independent sites in 2015 and 2016 to identify the influence of leaf burning on seedling growth. The results showed that the growth of seedlings with leaf burning was improved with increased leaf area, leaf number and plant height compared to those without leaf burning, combined with an increased seedling survival rate at two sites in two years. In seedlings with leaf burning, the contents of fructose and glucose increased and peaked at 11:00 and 13:00 in the leaf and root, respectively, with an increased root nicotine content beginning at 13:00, highlighting the signalling role of sugars. Activities of antioxidant enzymes including peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) were all increased in seedlings with leaf burning. More plant biomass was allocated to roots in seedlings with leaf burning with increased root volume compared to control seedlings, which might facilitate the absorption of water and nutrients from the soil. Our findings demonstrate that high-temperature plastic mulching film-induced leaf burning not inhibited but benefited seedling survival and growth, suggesting that the time and labour-consuming manual plucking of burnt leaves can be avoided during tobacco cultivation.