雀稗属无融合生殖研究进展

雀稗属(Paspalum)为禾本科黍亚科多年生或一年生植物,是黍亚科内最有经济价值的类群之一。雀稗属植物种群极其复杂,大多数为多倍体。由于多倍体的存在及有性生殖的自交不亲和等原因,雀稗属植物表现出复杂多样的生殖特性,是禾本科中具备无融合生殖特性种类最多的属。对雀稗属无融合生殖的分布、无融合生殖相关的细胞学和胚胎学基础、无融合生殖的特点及其遗传学和分子生物学研究进展进行了综述。     

雀稗属花粉形态及其多萌发孔现象

在广东广泛收集禾本科雀稗属的基础上,观察了雀稗属（Paspalum)9个种及其类群的花粉形态。其花粉一般为球型,平均直径在34－50um之间,花粉表面纹饰一般为疣状突起或皱波状。在四倍体的台湾雀稗（P.formosanum),双穗雀稗（P.paspaloides),雀稗（P.thunbergii),两耳草（P.conjugatum),圆果雀稗（P.orbiculare),长叶雀稗（P.longifolium)和一个十倍体的南雀稗（P.commersonii)的一个类群上发现了禾本科罕见的花粉多萌发孔现象。     

2号固氮菌株的筛选及其对水稻产量的影响

自Dbereiner等报道多年生牧草雀稗与雀稗固氮菌以来,国内也有玉米、水稻根系固氮菌存在的研究报道。从1972—78年,我们筛选出具有较高固氮酶活力、生长繁殖快、对水稻有增产作用的2号固氮菌,现报道如下。     

喀斯特山地煤矿废弃地几种优势植物的重金属耐性特征

对贵阳花溪区麦坪乡煤矿废弃地进行了野外调查, 对该地优势植物和土壤进行了采样, 测定样品As、Cd、Cu、Hg、Pb和Zn的含量, 发现当地优势植物雀稗(Paspalum thunbergii Kunth ex Steud.)地上部分Cu含量达到1058.12 mg•kg-1, 转移系数2.89, 富集系数16.07。研究了雀稗在铜离子胁迫实验中的根系活力变化和叶绿素浓度变化, 雀稗根系活力随实验进行而逐渐降低, 铜离子浓度为500 µg•mL-1的实验进行到第四周时TTC还原量达到最低值; 叶绿素浓度随着铜离子浓度的增加而缓慢降低, 进一步确认当地土著植物雀稗对铜离子有一定的耐受性。     

土壤种子库与矿业废弃地植被恢复研究：定居植物对重金属的吸收和再分配

研究了从引入的土壤种子所萌发,并成功地铅锌尾矿上定居的4个优势种植物,雀稗（Paspalum thunbergii)、双穗雀稗（P.disichum)、黄花稔（Sida rhombifolia)和银合欢（Leucaena leucocephala),对理金属的吸收及其在体内的再分配。植物组织中铜（Cu）和锌(Zn)的浓度,除了雀稗和双穗雀稗根中的锌浓度分别为344．2mg.kg^-1和331．9mg.kg^-1显得较高外,其作仍属植物体内正常水平范围（Zn:27-150mg.kg^-1,Cu:5-30mg.kg^-1)。草本植物雀稗、双穗稗和黄花稔对有毒重金属元素铅（Pb）的吸收表现出不同的模式,Pb在地上部与地下部分的浓度比以雀稗最低（为0．209）,表明雀稗所吸收的Pb大部分被滞留在根部,使之较少影响到地上部茎叶的光合作用功能及生长,从而使植物对重金属Pb环境更具耐性。相反,双穗雀稗和黄花稔则较高（分别为0．509和0．653）,显示所吸收的Pb较多地被转移到便于收获移走的地上部分,因而具有较大的植物修复潜力（Phytoremediation potential)。木本植物银合欢,所吸收的重金属Pb总量的80％以上是积累在根、茎的皮和木质部及枝条部分,只有15％左右分布在叶片中。这表明随着生长,有越来越多的Pb被吸收和积累在更新周期较长的器官中,只有很小的比例会随着落叶而归还到环境中去,因此,在利用植物重复金属污染土壤的实践中,这是一个特别值得利用的优点。     

展毛翠雀花期繁殖特征和生物量分配对放牧的响应

生物量分配影响植物生长和繁殖,是植物生活史研究的重要内容。为了了解植物生活史性状对放牧的响应,该研究以青藏高原高寒草甸毒杂草展毛翠雀为对象,分析了放牧干扰对展毛翠雀的花期繁殖分配和性分配的影响。结果表明:放牧显著降低了展毛翠雀的总生物量、个体大小和繁殖投入; 放牧未改变展毛翠雀的营养部分与繁殖部分的等速生长关系,但显著增加了繁殖部分的生物量分配和总花数; 展毛翠雀的个体大小与总花数呈显著的正相关关系,但与性分配呈显著的负相关关系; 展毛翠雀的总花数与单花大小、单花的花瓣比例均表现出负相关关系,表明总花数与单花大小之间、总花数与单花的花瓣比例之间均存在权衡。因此,在放牧条件下,展毛翠雀的繁殖分配和性分配均表现出显著的可塑性。     

白腰雪雀分类地位的商榷

自腰雪雀Onychostruthus taczanowskii(Przewalski)的分类地位比较混乱.在早期的分类系统中,它被归属于雪雀属Montifringilla下.后期由于生态习性与行为特征的不同,被划分至地雀属Pyrgilauda下;又有将它划分为独立属--高原雀属Onychostruthus的观点.本文结合身体量衡度数值特征、外部形态特征以及遗传差异上的研究,综合探讨白腰雪雀的分类地位.对量衡度特征的因子分析发现:白腰雪雀与地雀属种类在体长、体重、翅长、尾长、嘴长与跗蹠长上明显不同,其体形明显偏大.形态特征的聚类分析显示:白腰雪雀与地雀属种类的平均特征差异为0.3902～0.5122,而这些种类间平均特征差异为0.1281～0.2195.比较属间差异发现:石雀Petronia petronia与地雀属种类为0.4878～0.5385,树麻雀Passer montanus与地雀属种类为0.4872～0.5610.麻雀属与石雀属为0.3415,这些结果显示自腰雪雀与地雀属种类的差异已经达到石雀属、麻雀属与地雀属属间的差异.通过比较白腰雪雀与石雀的遗传差异(0.2578),地雀属种类与石雀的遗传差异(0.2386～0.3193),发现白腰雪雀与地雀属种类具有较大的遗传差异(0.2267～0.3143),几近于地雀属与石雀属间的差异.综合量衡度、形态以及遗传等特征的分析结果,作者认为白腰雪雀与地雀属种类有较大的差异,两者间的差异已经达到了它们与近缘属石雀属和麻雀属间的差异,以及近缘属之间的差异,因此,建议白腰雪雀应作为一个独立的属,高原雀属Onychostruthus.     

雪雀属系统发育关系的研究（雀形目：文鸟科)

雷雀属Montifringilla7种36个形态特征作为分类单元,进行支序分析。以麻雀属Passer、石雀属Petronia部分种类作为比较外群,讨论雪雀属的分类地位及其与近缘属麻雀属、石雀属系统发育关系;分析了雪雀属内种间的系统发育。支序分析的结果表明雪雀属为单系群,建议将雪雀属划分成两个亚属,讨论了雪雀属种类在进货上的位置,在3个近缘属的系统发育关系中,麻雀属类群较原始,雪雀属类群较进化,石雀属在进货中介于二之间。     

中国主要农区稻田稗草分类与多样性研究

将采自中国15个省和1个直辖市的206份稗属（Echinochloa）植物种子分别播种在相同栽培条件下,获得了206份子代样本及其21项形态性状数据,基于这些形态性状对206份稗属植物样本进行了聚类和主成分分析。结果表明：（1）从206份稗属植物样本中鉴别出了形态性状相对一致的8个分类群（G1-G8）,依次对应于湖南稗子（Echinochloa frumentaceae,2份样本）、水田稗（E.oryzoides,5份）、细叶旱稗（E.crus-galli var.praticola,6份）、硬稃稗（E.glabrescens,14份）、光头稗（E.colona,2份）、长芒稗（E.caudata,16份）、孔雀稗（E.cruspavonis,8份）、稗复合群（稗原变种E.crus-galli var.crus-galli、稗的变种无芒稗var.mitis、短芒稗var.breviseta和西来稗var.zelayensis,共150份）,还有3份样本没有聚合成组。它们依次占总样本量的0.97%、0.97%、2.42%、2.91%、3.88%、7.77%、6.80%、72.81%和1.46%,反映出中国主要农区稻田稗属植物主要以稗及其变种为主;（2）单因素方差分析表明,9个数量性状,包括叶长、叶宽、圆锥花序长度、总状花序长度、小穗芒长、小穗长度、第1颖长度/小穗长度、主茎直径和株高,在稗属植物的8个分类群（G1-G8）之间有显著差异;（3）根据8个分类群之间的形态性状特点及差异,给出了鉴别中国主要农区稻田稗属植物的分种检索表;（4）由于细叶旱稗具有总状花序简单、小穗无芒、叶较宽、植株高大、小穗紫黑色等独特形态性状,在206份稗属植物样本的聚类图上单独聚成一组,故建议将细叶旱稗作为独立种处理。     

白腰雪雀体重、脂肪累积的阶段性变化

2004年在青海省河南县和兴海县于繁殖早期、育雏期、换羽期等不同阶段用粘网捕获白腰雪雀,称量体重,半定量法测定脂肪的含量,游标卡尺测量泄殖腔的高度,以考察白腰雪雀体重、脂肪的季节性变化.结果 表明:白腰雪雀体重在繁殖早期从2月到3月增加,育雏期下降,换羽期再次增加.脂肪含量在繁殖早期从2月到3月增加,育雏期的6月、7月...     

Behavioural responses of female Neogobius melanostomus to odours of conspecifics

The behavioural responses of reproductive and non‐reproductive female round gobies Neogobius melanostomus to water conditioned by reproductive and non‐reproductive males and females were tested. The behavioural responses of reproductive female round gobies exposed to odour of reproductive males included increased time spent near the source of the odour, elevated swimming velocities and directed movement to and around the odour source when compared with their responses to control water. These results suggested that pheromones released from reproductive males may induce spawning behaviour in reproductive females. Non‐reproductive females exposed to reproductive female odour spent significantly more time near the odour source of reproductive females compared with control water. Non‐reproductive females also showed directed movement towards and around the odour source when exposed to reproductive female odour. These results suggested that round gobies use inter‐sexual and intra‐sexual pheromones and that both sex and reproductive status are important in the detection and release of these pheromones.     

Behavioural and electrophysiological responses by reproductive female Neogobius melanostomus to odours released by conspecific males

Behavioural and electrophysiological responses of reproductive and non‐reproductive female round gobies Neogobius melanostomus to water previously occupied by male round gobies (reproductive male water) were compared. Reproductive females spent more time than non‐reproductive females in a tank near the input of water conditioned from reproductive males. Also, reproductive females swam significantly faster than non‐reproductive females, suggesting that reproductive male odour may have activated spawning behaviour. Olfactory epithelial field potential measurement (electro‐olfactogram, EOG) showed that reproductive male water was a potent olfactory stimulus to reproductive females, but not to non‐reproductive females. Reproductive females responded significantly more than non‐reproductive females to solid‐phase (octadecylsilane) extracts of reproductive male water. Also, when these extracts were separated on reverse phase high performance liquid chromatography (HPLC), reproductive females showed noticeably greater responses than non‐reproductive females to the fractions that eluted between 30 and 40 min. The behavioural data support the hypothesis that reproductive male round gobies release compounds into the water that attract potential mates. The EOG data indicate that these compounds can be quantitatively extracted from the water and be partially purified by HPLC. The evidence is not sufficient to indicate whether or not the compounds are steroids. The relatively early elution time on HPLC, however, suggests that if these compounds are steroids, then it is more likely that they will be conjugated rather than free steroids.     

缙云山四川大茶种群繁殖适应性的数量特征研究

 在对缙云山3种含有四川大头茶种群的不同群落调查测定,研究四川大头茶种群年龄结构,繁殖分配,编制静态生命表的基础上,研编了四川大头茶种群的生殖力表,生殖表。对诸生殖参数进行了综合分析,剖析了构成四川大头茶繁殖对策的几个重要组成部分。结果表明：四川大头茶种群在常绿阔叶林中的繁殖寿命最长,适合度最大;四川大头茶种群的生殖值(Vx),现时生殖值(bx),剩余生殖值(RRV),累积剩余生殖值(SRRV)以及整个生活史的总生殖值(TRV)是时间的函数,并受环境制约,诸指标综合反映了遗传特性与环境因素相互作用对四川大头茶特定年龄个体繁殖能力影响的方式和强度,反映了四川大头茶种群繁殖动态规律;存活率lx与bx的负相关关系,SRRV与bx的负相关关系以及生命期望与生殖投资策略的负相关关系进一步反映了较大的生殖投入与较大的死亡概率之间的定量关系。     

REPRODUCTIVE PATTERNS OF THE HAWAIIAN MONK SEAL

We evaluated reproductive patterns of the Hawaiian monk seal ( Monachus schauinslandi ) using a combination of fitted age-specific reproductive curves and analysis of reproductive patterns of individual females. We review the difficulties inherent in the acquisition and modeling of reproductive data with emphasis on the significance of reproductive senescence to populations with dissimilar age/sex compositions. Validation of the fitted reproductive parameters was accomplished by Monte Carlo sampling of parameter distributions to compare the expected number of pups with the observed production. Although the fitted reproductive functions appear to provide an acceptable fit to the raw reproductive data, we found that the fitted curves did a poor job of predicting the actual pup production in individual years because of high variability among years. To further verify, and elaborate on, the patterns in the pooled (multi-seal, and multi-year) rates, we examined attributes of the reproductive performance of individual seals. The attributes included age of primiparity, reproductive rates computed over several age ranges, and the relationship between reproductive performance and seal longevity. Analysis of individual seal patterns reinforced the conclusion that reproductive senescence is operative in monk seal populations.     

Current-year shoot based approach for annual variation in the reproductive output in Siberian alder (<Emphasis Type="Italic">Alnus hirsuta</Emphasis> var. <Emphasis Type="Italic">sibirica</Emphasis>)

Siberian alder (Alnus hirsuta var. sibirica) shows annual variation in reproductive output. However, this phenomenon has not been explained by hypotheses proposed in previous studies. In this study, we constructed a matrix model of current-year shoot dynamics to estimate and compare the reproductive output of current-year shoot population with or without annual variation, and explained the annual variation of reproductive output in terms of a reproductive strategy of the current-year shoot population of Siberian alder. The current-year shoot population of Siberian alder was divided into three functional groups: reproductive, maintenance, and explorative shoot sub-populations. A transition matrix was calculated from the relationships between 1-year-old shoots and the current-year shoots on them. The dynamics of the current-year shoot population was simulated using the estimated matrix on the patterns with or without annual variation in reproductive output. The pattern with annual variation in reproductive output yielded more reproductive current-year shoots than the pattern with high reproductive output every year. The annual variation of reproductive output may well be regarded as a reproductive strategy of current-year shoots to increase lifetime fecundity.     

Optical coherence tomography for dynamic investigation of mammalian reproductive processes

The biological events associated with mammalian reproductive processes are highly dynamic and tightly regulated by molecular, genetic, and biomechanical factors. Implementation of live imaging in reproductive research is vital for the advancement of our understanding of normal reproductive physiology and for improving the management of reproductive disorders. Optical coherence tomography (OCT) is emerging as a promising tool for dynamic volumetric imaging of various reproductive processes in mice and other animal models. In this review, we summarize recent studies employing OCT-based approaches toward the investigation of reproductive processes in both, males and females. We describe how OCT can be applied to study structural features of the male reproductive system and sperm transport through the male reproductive tract. We review OCT applications for in vitro and dynamic in vivo imaging of the female reproductive system, staging and tracking of oocytes and embryos, and investigations of the oocyte/embryo transport through the oviduct. We describe how the functional OCT approach can be applied to the analysis of cilia dynamics within the male and female reproductive systems. We also discuss the areas of research, where OCT could find potential applications to progress our understanding of normal reproductive physiology and reproductive disorders.     

Effects of shift in flowering time on the reproductive output of Xanthium canadense in a seasonal environment

We studied the effects of a change in flowering date on the reproductive output of a short-day annual plant, Xanthium canadense. The flowering date was changed by photoperiodic manipulation to 1 month earlier or later than the natural flowering date. Plants with the natural flowering date attained the highest reproductive output. For those flowering 1 month earlier or later, the reproductive output was decreased by 42% or 23%, respectively. The reproductive output was analyzed as the product of the biomass production during the reproductive period and its allocation to the reproductive organs. Although delay in flowering increased biomass production, it decreased its fractional allocation to the reproductive organs. The highest reproductive output in the natural flowering plants resulted from a compromise between these two effects of flowering. Plants flowering earlier had higher translocation rates to the reproductive organs and accelerated plant senescence. Later flowering caused a reduction in biomass translocation to the reproductive organs and thus extended the reproductive period. These experimental results are discussed in relation to the cost of reproduction and the optimal time for flowering that maximizes the final reproductive output. It is suggested that the natural flowering time maximized the reproductive output while minimizing the cost of reproduction. Received: 11 September 1997 / Accepted: 12 December 1997     

Caenorhabditis elegans reproductive aging: Regulation and underlying mechanisms

Female reproductive decline is one of the first aging phenotypes in humans, manifested in increasing rates of infertility, miscarriage, and birth defects in children of mothers over 35. Recently, Caenorhabditis elegans (C. elegans) has been developed as a model to study reproductive aging, and several studies have advanced our knowledge of reproductive aging regulation in this organism. In this review, we describe our current understanding of reproductive cessation in C. elegans, including the relationship between oocyte quality, ovulation rate, progeny number, and reproductive span. We then discuss possible mechanisms of oocyte quality control, and provide an overview of the signaling pathways currently identified to be involved in reproductive span regulation in C. elegans. Finally, we extend the relevance of C. elegans reproductive aging studies to the issue of human female reproductive decline, and we discuss ideas concerning the relationship between reproductive aging and somatic longevity.     

Genetic and pharmacological factors that influence reproductive aging in nematodes

Age-related degenerative changes in the reproductive system are an important aspect of aging, because reproductive success is the major determinant of evolutionary fitness. Caenorhabditis elegans is a prominent organism for studies of somatic aging, since many factors that extend adult lifespan have been identified. However, mechanisms that control reproductive aging in nematodes or other animals are not well characterized. To use C. elegans to measure reproductive aging, we analyzed mated hermaphrodites that do not become sperm depleted and monitored the duration and level of progeny production. Mated hermaphrodites display a decline of progeny production that culminates in reproductive cessation before the end of the lifespan, demonstrating that hermaphrodites undergo reproductive aging. To identify factors that influence reproductive aging, we analyzed genetic, environmental, and pharmacological factors that extend lifespan. Dietary restriction and reduced insulin/insulin-like growth factor signaling delayed reproductive aging, indicating that nutritional status and a signaling pathway that responds to environmental stress influence reproductive aging. Cold temperature delayed reproductive aging. The anticonvulsant medicine ethosuximide, which affects neural activity, delayed reproductive aging, indicating that neural activity can influence reproductive aging. Some of these factors decrease early progeny production, but there is no consistent relationship between early progeny production and reproductive aging in strains with an extended lifespan. To directly examine the effects of early progeny production on reproductive aging, we used sperm availability to modulate the level of early reproduction. Early progeny production neither accelerated nor delayed reproductive aging, indicating that reproductive aging is not controlled by use-dependent mechanisms. The implications of these findings for evolutionary theories of aging are discussed.     

生殖道微生物与生殖健康

人类生殖道有多种微生物定殖,它们构成生殖道正常微生物菌群.乳酸杆菌是健康人群生殖道中最主要的微生物,具有维持生殖道生态平衡和防止病原体入侵的功能.微生态环境遭到破坏会导致各种感染,如细菌性阴道病、性传播感染、不良妊娠结局、不孕不育和肿瘤等.对生殖道炎症的治疗除常规的抗菌治疗外,益生菌在恢复菌群结构和维系生殖健康方面发挥...