雌雄异株植物性别鉴定的研究进展

雌雄异株植物为研究植物的性别决定和进化提供了一个模式体系,由于不同性别的植物具有不同的经济价值,所以其性别鉴定的研究不仅具有重要的理论意义,而且具有极为重要的实践价值。从外部形态、生理生化指标、染色体组型、同工酶、特异蛋白质分子、分子标记等方面,对近15年来国内外有关雌雄异株植物性别鉴定研究的进展作了总结,并对各种鉴定方法的优缺点进行了评价,同时对其研究发展趋势作了展望。     

黄连木雌雄株叶水溶性酚类物质和两种氧化酶活性的比较

黄连木为雌雄异株植物。为探索鉴别黄连木幼苗性别的方法,应用比色法对其雌雄株不同发育阶段叶片中水溶性酚类物质的含量、过氧化物酶(POD)活性和多酚氧化酶(PPO)相对活性进行测定和比较分析,结果表明:不同性别的黄连木叶片水溶性酚类物质含量存在极显著的差异(p<0.01);POD、PPO相对活性在雌雄株间也存在显著差异,特别在老叶中则存在极显著差异,认为黄连木雌雄株老叶中的水溶性酚类物质含量差异,可以作为其性别鉴定的依据,为进一步研究黄连木植株早期性别鉴定提供参考。     

海南尖峰岭热带山地雨林60 ha大样地木本植物性别系统数量特征

热带山地雨林中植物不同性别系统的数量和空间分布特征如何? 是否受自然环境条件影响? 这些问题的回答有助于更深入理解群落物种多样性是如何形成的。本文以海南尖峰岭热带山地雨林60 ha大样地中胸径大于1 cm的木本植物为研究对象, 描述了样地内木本植物性别系统的数量特征, 分析了雌雄异株植物空间分布与地形因子的相关关系。结果表明: 大样地内289种木本种子植物中有两性花植物176种, 单性花植物113种; 在单性花植物中, 51种为雌雄同株, 62种为雌雄异株。单性花植物植株数占所有植株总数的36.2%; 雌雄异株植物植株数占所有植株总数的21.5%, 占单性花植物植株数的59.5%。在20 m × 20 m样方的空间尺度, 雌雄异株植物呈现聚集分布的物种共有31种。以20 m × 20 m样方为分析单元, 雌雄异株植物种类的性别比例与海拔、凹凸度和坡度呈弱正相关; 个体相对多度仅和海拔呈弱正相关, 与坡度和凹凸度无相关; 而3个性别系统多样性指数与海拔、凹凸度和坡度均无显著关联。可见雌雄异株植物在海南热带山地雨林中占据了较大的比例, 但大部分种类种群较小, 其数量分布特征与地形因素紧密相关, 雌雄异株植物的存在对群落物种多样性的形成有较大贡献。     

植物DNA条形码技术的发展及应用

在对DNA条形码技术的发展过程进行归纳分析的基础上,对植物DNA条形码技术的研究进展、工作流程及分析方法、影响其鉴定准确性的因素及其在植物分类学研究中的应用现状及存在的争议进行了综合分析和阐述,并展望了植物DNA条形码技术的发展趋势及应用前景。通过具体实例说明将植物DNA条形码技术与传统植物学知识相结合可作为民族植物学的研究手段之一。认为:目前常用的植物DNA条形码主要有单一片段和多片段组合2种方式,这2种方式各有优缺点;常用的DNA序列有matK、trnH-psbA、rbcL和ITS等,但均有一定的局限性;针对不同的使用目的,应选择不同的植物DNA条形码标准;影响植物DNA条形码鉴定准确性的因素包括物种的类型和数量、系统树构建方法、杂交/基因渗入、物种起源时间的差异、分子进化速率差异等;当前植物DNA条形码研究工作的重点是选择合适的DNA片段并对其进行评价。     

用溴麝香草酚蓝鉴定石刁柏（芦笋）雌雄株

石刁柏(芦笋)是一种雌雄异株植物,但在雌雄花分化之前,性别很难区分。雄株芦笋产量高于雌株20％～30％,生产上需要早期鉴定其性别。据报道溴麝香草酚蓝(BTB)可以鉴定杨梅和银杏的雌雄性,本文用以进行芦笋植株早期性别鉴定,效果也好。     

气候变化对雌雄异株植物影响的研究进展

雌雄异株植物作为陆地生态系统的重要组成部分,在维持生态系统结构和功能稳定性方面发挥着关键作用。但是,由于雌雄异株植物的不同性别植株在形态特征、生理特征和资源分配等方面均存在明显差异,至今对全球气候变化背景下雌雄植物的性别差异响应机制的认识仍十分有限。本文综述了全球变暖、降水变化和大气CO2浓度升高等主要气候因子变化对雌雄异株植物的影响,探讨了雌雄异株植物对气候变化响应的性别差异,提出了未来雌雄异株植物与气候变化关系研究的重点,以期为揭示陆地生态系统结构和功能稳定性对气候变化的响应机制提供参考依据。     

构树雌雄株过氧化物酶同工酶的研究

构树雌雄株过氧化物酶同工酶的研究赵云云,田汝岭,刘捷平（首都师范大学生物系,北京１０００３７）在雌雄异株植物种类中,常因性别的不同而有不同的经济价值,因此植物性别的早期鉴定有着重要的实践意义,构树为雌雄异株植物,根据其过氧化物酶同工酶谱进行早期性别鉴...     

性别和发育阶段对绒毛白蜡光合特征及叶功能性状的影响

雌雄异株植物资源分配模式上往往表现出显著的性别二态性,但在叶片光合及功能性状上是否有差异目前仍未有定论,且与发育阶段的关系尚不明确。阐明上述问题,能够进一步了解雌雄异株植物的生理生态特征,并为理解性别对性二态植物生长发育的影响机制提供理论依据。以雌雄异株绒毛白蜡(Fraxinus velutina Torr.)为研究对象,针对不同发育阶段不同性别植株进行光合特征及叶功能性状测定,采用双因素方差分析了不同发育阶段下雌雄植株光合能力及叶功能性状的性别间差异,采用Pearson检验了雌雄植株各叶功能性状之间的相关性,并采用标准化主轴分析(Standardized major axis regression, SMA)分析不同性别植株净光合速率与叶功能性状的相关性。结果表明性别和发育阶段显著影响植物个体的光合能力和叶功能性状。总体而言,雄树在坐果期和果实成熟期均表现出更强的净光合速率(Pn)、更高的比叶面积(SLA)、叶绿素含量(Chl)和叶氮含量(LNC);而雌树在果实膨大期表现出更强Pn、SLA和Chl。雌雄性别内Pn与SLA、Chl和LNC间均呈显著正相关(P<0.05),雄树的S...     

被子植物雌雄异株性别决定与性别连锁标记

雌雄异株是雌雄性别分离的一种性系统,在被子植物中广泛分布。一般认为雌雄异株的性别决定受遗传、环境和激素三者的影响和调控。随着第二代测序技术和分子标记技术的发展,对于被子植物雌雄异株性别决定的研究已深入到基因水平。现从性别决定机制及性别连锁的分子标记对被子植物雌雄异株的研究进行总结,并对未来的研究方向进行了展望,以期为深入研究雌雄异株的遗传机制及系统发生奠定基础。     

植物性染色体进化及性别决定基因研究进展

植物性染色体起源于1对常染色体, 其在不同雌雄异株植物中多次起源并独立演变, 是研究性染色体起源和进化机制的理想材料。过去的研究在一定程度上阐明了植物性染色体的起源和演化动力; 且性染色体遗传退化、性别决定基因以及剂量补偿效应正逐渐成为研究的热点。近年来, 关于植物性染色体进化及性别决定基因的研究取得了一些重要进展。该文综述了植物性染色体的起源、进化、遗传退化、剂量补偿效应以及性别决定基因等, 并对植物性染色体进化研究发展趋势进行了展望。     

A highly reliable sex diagnostic PCR assay for mass screening of papaya seedlings

Female plants of several dioecious angiosperms are commercially valued for production of fruits or seeds, viz. papaya, nutmeg, pistachio, kiwi fruit and jojoba. To make the cultivation profitable it is necessary to grow more female than male plants. To discriminate between male and female plants, sex-specific molecular markers have been identified in a few dioecious species such as Silene and pistachio. However, accurate and convenient sex diagnostic methods for early sexing of seedlings are not available to date. For the first time, we report here a PCR-based Seedling Sex Diagnostic Assay (SSDA) specially designed for early sexing of papaya seedlings. We have developed a male-specific SCAR marker in papaya by cloning a male-specific RAPD (831 bp) fragment and designing longer primers. The potential of this SCAR marker is further exploited to develop a simplified and highly accurate sex diagnostic assay by (1) including an internal PCR control, (2) following a single-step DNA extraction procedure and (3) optimising the PCR conditions to simultaneously amplify male-specific and control bands from the crude leaf extract. This diagnostic approach would be of great commercial significance to papaya growers as well as to seed companies and plant nurseries for early identification of female seedlings of dioecious species. In principle, this experimental design could be easily applied to molecular analysis of any agriculturally important trait for which specific DNA probes could be identified and hence opens new avenues of research in the field of genetic diagnostics of plants.     

Identification of sex in hop (Humulus lupulus) using molecular markers.

The rapid identification of sex in the dioecious hop (Humulus lupulus) is important for the breeding of this cultivated plant because only unfertilized flowers of the female plants are used as an ingredient in the production of beer. It is thought that a sex-chromosome mechanism controls the development of male or female plants. We have compared pools of male and female plants derived from a hop cross to identify molecular markers associated with the Y or male-specific chromosome. Of 900 functional RAPD primers, 32 revealed fragments specific for male plants that were absent in female plants of this cross. Subsequently, the 32 positive primers were tested on unrelated male and female plants. Three of these 32 primers were specific for the Y chromosome in all lines. The Y-specific product derived from one of these primers (OPJ9) was of low copy in hybridization experiments and predominantly present in male plants. Primers developed from the DNA sequence of this product provide a marker for rapid sex identification in crosses of hop by means of PCR.     

Identification of two markers linked to the sex locus in dioecious <Emphasis Type="Italic">Asparagus officinalis</Emphasis> plants

One hundred decamer primers of random-amplified polymorphic DNA were tested on dioecious Asparagus officinalis plants to identify sex-linked molecular markers. One primer (S368) produced two markers (S368-928 and S368-1178) in female plants. These two DNA markers were identified in 30 male and female plants, respectively, and a S368-928 marker was proved to be linked to the female sex locus. The female-linked S368-928 marker was sequenced and specific primers were synthesized to generate a 928 bp marker of sequence characterized amplified regions (SCAR) in female plants, SCAR₉₂₈. SCAR₉₂₈ could be used to correctly screen homozygous mm female plants of A. officinalis. However, results of Southern blot analysis suggest that the hybridization pattern of S368-928 was presented in both sex plants. This text was submitted by the authors in English.     

Male-specific DNA in the dioecious species Atriplex garrettii (Chenopodiaceae)

The mechanism of sex determination in dioecious species of the genus Atriplex (Chenopodiaceae) has not been determined. This paper reports the discovery of a male-specific DNA fragment in the diploid dioecious species A. garrettii. DNA samples extracted individually from ten male and ten female plants were bulked by sex. Random amplified polymorphic DNA (RAPD) fragments were generated in the two bulks in order to identify markers that were polymorphic between male and female plants. A total of 158 decamer primers were tested. A 2075 base-pair (bp) male-specific DNA fragment generated with the OPAF-14 primer was identified. The fragment was cloned and partially sequenced and 24-mer primers that exclusively amplified this fragment were constructed. When 124 male plants, 126 female plants, and one hermaphroditic plant were tested individually, the male-specific 2075-bp DNA fragment was present in the hermaphrodite and all but one of the male plants, and was absent in all female plants. A smaller DNA fragment (~1800 bp) that was homologous to the 2075-bp fragment was amplified from the single male plant that lacked the 2075-bp fragment. Cytogenetic analysis revealed no apparent heteromorphic sex chromosomes. These observations suggest that sex determination in A. garrettii is genetic, with no evidence of heteromorphic sex chromosomes.     

A rapid means of sex identification inSilene latifolia by use of flow cytometry

Sex identification in dioecious plants using nonflowering material would have broad applications in both basic and applied research. We present a method using flow cytometry for diagnosing the sex of the dioecious speciesSilene latifolia Poiret (Caryophyllaceae) by means of sexual differences in nuclear DNA content and base-pair composition. Males have a significantly larger genome, attributable to the known sex-chromosome heteromorphism. Males and females also differ in the AT/GC composition, attributable to differences in non-recombining portions of the sex chromosomes. The two measures enable assignment of individuals to sex with a combined error rate of 9%. These results forS. latifolia indicate useful directions for future research into sex diagnostics for other dioecious species.     

芦笋雌性特异性片段的克隆和分析(简报)

芦笋(Asparagus officinalis L.)又名石刁柏、龙须菜,系雌雄异株宿根性植物,是重要的经济作物之一。芦笋的性染色体为一对同形的L5染色体,雌性的性染色体为XX,雄性的性染色体为XY。性别决定的多态性是由位于一对L5性染色体上的一个显性基因M决定的[1-3],雌株基因型为隐性纯合子mm,雄株为显性纯合子MM(又称超雄株)或杂合子Mm。在生产上,由于雄株比雌株高产25%以上[4],并具有极强的抗病性和生命力,故雄株特别是超雄株则倍受生产者的青睐,但芦笋雌雄鉴定只有等到种植的第二年待植株开花时才能进行,这就严重影响了芦笋的有目的种植和经济效…     

Comparative genetic mapping points to different sex chromosomes in sibling species of wild strawberry (Fragaria)

Separate sexes have evolved repeatedly from hermaphroditic ancestors in flowering plants, and thus select taxa can provide unparalleled insight into the evolutionary dynamics of sex chromosomes that are thought to be shared by plants and animals alike. Here we ask whether two octoploid sibling species of wild strawberry--one almost exclusively dioecious (males and females), Fragaria chiloensis, and one subdioecious (males, females, and hermaphrodites), F. virginiana--share the same sex-determining chromosome. We created a genetic map of the sex chromosome and its homeologs in F. chiloensis and assessed macrosynteny between it and published maps of the proto-sex chromosome of F. virginiana and the homeologous autosome of hermaphroditic diploid species. Segregation of male and female function in our F. chiloensis mapping population confirmed that linkage and dominance relations are similar to those in F. virginiana. However, identification of the molecular markers most tightly linked to the sex-determining locus in the two octoploid species shows that, in both, this region maps to homeologues of chromosome 6 in diploid congeners, but is located at opposite ends of their respective chromosomes.     

The development of two flanking SCAR markers linked to a sex determination locus in Salix viminalis L

Most studies of sex determination systems in plants involve dioecious annuals that have known sex chromosomes. Despite the absence of such structures in the majority of dioecious plants, gender seems to be under relatively strict genetic control in some species. Genetic markers linked to a female sex-determination locus in Salix viminalis L. have been discovered through bulked segregant analysis of three full-sib families using approximately 1,000 arbitrary primers. Two RAPD markers that were present in the common female parent as well as in predominantly female progeny of these families were subsequently sequenced and converted to sequence characterized amplified region (SCAR) markers. The two SCAR markers are correlated with gender in the three full-sib families and are present in 96.4% of the female progeny and 2.2% of the males, providing evidence of linkage to a putative female-specific locus associated with gender determination in S. viminalis. Estimates of recombination suggest that the two markers are flanking a putative sex determination locus, SDL-II, in certain families of S. viminalis.     

Identification of a sex-specific SCAR marker in dioecious Pandanus fascicularis L. (Pandanaceae).

Pandanus fascicularis L. is a dioecious plant native to South Asia with significant numbers in coastal areas. With the aim of distinguishing male genotypes from female genotypes early in the vegetative growth phase, the current study was initiated using molecular markers. Based on the principle of bulked segregant analysis, the sampled plants were separated into 2 bulks depending on their sex. Of the 89 random amplified polymorphic DNA and inter-simple sequence repeat markers used, one decamer (OPO-08) consistently amplified a 1263 bp band in the males that was absent in the females. Its DNA sequence did not exhibit significant similarity to previously characterized sequences, but the presence of mononucleotide and dinucleotide repeats suggested that it was a repeat-rich region. A sequence-characterized amplified region marker (MSSRF-01) designed for this fragment continued to amplify the specific allele in all the male plants. Southern hybridization performed using the sex-specific fragment as a probe yielded results consistent with those previously obtained by polymerase chain reaction. These results strongly suggest that MSSRF-01 is a male-specific molecular marker. With no information available on the presence of sex chromosomes in Pandanus, this marker can be used to differentiate the sexes.     

Patterns of sex ratio variation and genetic diversity in the dioecious forest perennial <Emphasis Type="Italic">Mercurialis perennis</Emphasis>

In small populations of plant species with separate sexes, it can be expected that besides the local environment also stochastic events influence population sex ratios. Biased sex ratios may in turn negatively affect genetic diversity due to increased genetic drift and, in clonal plants, due to reduced sexual reproductive output. Empirical evidence for these processes is scarce, however. We investigated the pattern of sex ratio variation and the distribution of genetic variation of the dioecious clonal forest herb Mercurialis perennis using AFLP markers. Analysis of molecular variance indicated a pronounced genetic structure. Overall within-population genetic diversity was moderate and local sex ratios were slightly male biased. The proportion of male to female plants in large populations slightly increased with increasing light penetration to the herb layer. Small populations, on the contrary, displayed high variability in sex ratios, unrelated to the local light environment. Genotypic diversity decreased with more male-biased sex ratios. We conclude that stochastic events related to small population size and the local forest environment, related to canopy closure, affect the proportion of female plants and indirectly influence local genotypic diversity, likely through the degree of sexual reproduction. This is one of the first studies to report a clear association between gender proportions and genetic diversity of a dioecious plant species in a fairly large survey.