Sex Determination and Sexual Organ Differentiation in Flowering Plants

The research in the genetics of sex determination and the differentiation of reproductive organs in flowering plants has long been a topic in recent years. Understanding the genetic and molecular mechanisms that control sex determination in flower- ing plants relies on detailed studies of the differentiation of sexual organs. Current theories about sex chromosomes have illuminated the mechanisms of plant sex determination. In addition, recent progress in cloning floral homeotic genes which regulate the identity of the floral organs has generated molecular markers to compare the developmental programs of male, female and hermaphrodite flowers in several species. In this review, the authors focus attention on these recent findings and provide a brief overview of the genetics of plant sex determination and the mechanism of sex determination gene expression and gene programs.

FLOWERING PLANTS AND ENTOMOPHAGOUS ARTHROPODS IN THE AGRICULTURAL LANDSCAPE: A PRACTISE-ORIENTED SUMMARY OF A COMPLEX RELATIONSHIP

There is a growing demand for high-quality agricultural products and morecountries have adopted landscape management by sowing flowering plants inagricultural fields as an important branch of conservation biological control.However, there has been less concern over the interactions and trade-offsbetween floral plants and entomophagous arthropods. This paper reviewprogress in pollen/nectar feeding habits of entomophagous insects includingparasitoids and predators which are important natural enemies of crop pestsin agricultural fields. Factors that influence the preference of different guilds of natural enemies are reviewed to guide the selection of flowering plants inconservation biological control practices. Most studies find that floralresources have positive effects on both biological traits of natural enemies andtheir abundance and diversity, and this is believed to contribute greatly to pestcontrol. Furthermore, the potential impacts of floral resources on crop yieldsare also discussed with an emphasis on a guild of entomophagous insects thatprovides both pest control and pollination services.

Analysis on Effects of Chilling Damages on Flowers and Plants at Beibei Area in Winter and Its Prevention Countermeasures

[Objective] The aim was to provide direction for the development of flowers and plants industry at Beibei area of Chongqing.[Method] Effects of temperature ranges and influencing time of chilling damages in winter on local flowers and plants at Beibei area were analyzed,using extreme minimum temperature data during 1960 to 2009 and the phenological growth conditions and phenological observation data of Bougainvillea spectabilis Willd and Michelia champaca during 2005 to 2007 at Beibei area.[Result] Chilling damages affecting flowers and plants at Beibei area mostly emerged from late December to early February,the effects of which were relative serious in January with a temperature range from-2 to 5 ℃;the optimum temperatures were 12-28 ℃ for flowers and plants grown at Beibei area in Chongqing,being higher or lower than that temperature range will affect the normally overwintering flowering and growing;chilling damages affecting the flower seedlings would appear when being at extreme minimum temperatures lower than 6 ℃ for 3 d in any phenophase in winter.[Conclusion] According to the characters of chilling damages in winter,the influences of which on flowers and plants can be reduced through combining tendency prediction and adopting corresponding measures.

Geographic patterns of taxonomic and phylogenetic β-diversity of angiosperm genera in regional floras across the world

Beta diversity(β-diversity)is the scalar between local(α)and regional(γ)diversity.Understanding geographic patterns ofβ-diversity is central to ecology,biogeography,and conservation biology.A full understanding of the origin and maintenance of geographic patterns ofβ-diversity requires exploring both taxonomic and phylogeneticβ-diversity,as well as their respective turnover and nestedness components,and exploring phylogenetic p-diversity at different evolutionary depths.In this study,we explore and map geographic patterns ofβ-diversity for angiosperm genera in regional floras across the world.We examine both taxonomic and phylogeneticβ-diversity and their constituent components,and both tip-weighted and basal-weighted phylogeneticβ-diversity,and relate them to latitude.On the one hand,our study found that the global distribution ofβ-diversity is highly heterogeneous.This is the case for both taxonomic and phylogeneticβ-diversity,and for both tip-weighted and basal-weighted phylogeneticβ-diversity.On the other hand,our study found that there are highly consistent geographic patterns among different metrics ofβ-diversity.In most cases,metrics ofβ-diversity are negatively associated with latitude,particularly in the Northern Hemisphere.Different metrics of taxonomicβ-diversity are strongly and positively correlated with their counterparts of phylogeneticβ-diversity.

Study on the Pollen Rain in Lanzhou University in Spring in 2009

[Objective] The aim was to explore the relationship of pollen types and blooming plants,pollen fertility and meteorological factors during the falling process of pollen in the atmosphere.[Method] The falling record of pollen in Lanzhou University in spring in 2009 was obtained by 10 m platform natural falling method.The pollen falling number,duration,relationship among falling types and surrounding plants,as well as weather were discussed.[Result] Main pollen types included Populus L.,Salix,Paulownia and Platanaceae.Its pollen falling number,duration was consistent with the flowering period of corresponding plants in the garden;the classification and richness of falling of pollen was influenced by wind.The larger the wind was,the richer the variety become.There was basically no pollen from outside.The authors failed to observe the distinct changes of palynological assemblage in sandy storm weather.[Conclusion] The study could lay basis for the study of the modern progress of natural plants pollen.

A comprehensive evaluation of flowering plant diversity and conservation priority for national park planning in China

Establishment of a national park protection system in China,including the latest target proposed to protect at least 30%of the land area,calls for a comprehensive exploration of conservation priorities incorporating multiple diversity facets.We herein evaluate the spatial distribution of Chinese flowering plants from the perspectives of richness,uniqueness,vulnerability,and evolutionary history,by integrating three mega-phylogenies and comprehensive distribution data.We detect significantly high consistency among hotspots of different diversity measures for Chinese flowering plants,suggesting that multiple facets of evolutionary diversity are concentrically distributed in China.Affording legal protection to these areas is expected to maximize positive conservation outcomes.We propose two integrative diversity indices by incorporating three richness-based and three phylogeny-based measures,respectively.Both methods identify areas with high species richness,but the integrative phylogeny-based index also locates key areas with ancient and unique evolutionary histories(e.g.,Ailao-Wuliang Mts,Dabie Mts,Hainan rainforest,Karst area of Yunnan-Guizhou-Guangxi,Nanling Mts,and southeast coastal regions).Of all the diversity indices explored,phylogenetic endemism maximizes the incidental protection of other indices in most cases,emphasizing its significance for conservation planning.Finally,42 priority areas are identified by combining the 5%-criterion hotspots of two integrative indices and the minimum area to protect all threatened species analyzed.These priorities cover only 13.3%of China's land area,but host 97.1%of species richness(23,394/24,095),96.5%of endemic species(11,841/12,274),100%of threatened species(2,613/2,613),and 99.3%of phylogenetic diversity for flowering plants involved in this study.These frameworks provide a solid scientific basis for national park planning in China.

Effects of sesame nectar on longevity and fecundity of seven Lepidoptera and survival of four parasitoid species commonly found in agricultural ecosystems

Ecological engineering involves the use of plants to promote establishment, survival and efficiency of natural enemies in agricultural systems. Some plant species may be hosts or provide resources to some pest species. We assessed the risks and benefits of sesame （Sesamum indicum L.）, as a nectar source for seven economically important Lepidopteran pest and four parasitoid species in a range of vegetable crop systems. Our results showed that the mean Iongevities of arthropod parasitoids Pteromalus puparum （L.）, Encarsia sophia （Girault ＆ Dodd） and male Microplitis tuberculifer （Wesmael） were significantly extended when fed on sesame flowers compared to the water control. Sesame flowers had no effect on adult Iongevities and fecundities of six out of the seven Lepidoptera pest species tested except Plutella xyllostella （L.） females laid more eggs when fed on sesame flowers. It is likely that the increased fecundity is due to accessibility to nectar at the bottom of corolla because of their smaller body sizes. Our findings provide a first step towards better understanding of the risks and benefits of using sesame to implement ecological engineering for the management of vegetable pests.

Exploitation of Wild Flowers and the Sustainable Development of Flowers Industry in China

This article introduced the new methods on the research of the wild flowers and plants idioplasmic resources, elaborated the introduction and domestication and exploitation of wild flowers and plants idioplasmatic resources and the sustainable development of flowers and plants industry in China, and put forward some proposals on the existing question and the prospects for the development.

Nuclear phylogenomics of angiosperms and insights into their relationships and evolution

Angiosperms(flowering plants) are by far the most diverse land plant group with over 300,000 species. The sudden appearance of diverse angiosperms in the fossil record was referred to by Darwin as the “abominable mystery,”hence contributing to the heightened interest in angiosperm evolution. Angiosperms display wide ranges of morphological, physiological,and ecological characters, some of which have probably influenced their species richness. The evolutionary analyses of these characteristics help to address questions of angiosperm diversification and require well resolved phylogeny. Following the great successes of phylogenetic analyses using plastid sequences,dozens to thousands of nuclear genes from next-generation sequencing have been used in angiosperm phylogenomic analyses, providing well resolved phylogenies and new insights into the evolution of angiosperms. In this review we focus on recent nuclear phylogenomic analyses of large angiosperm clades, orders, families,and subdivisions of some families and provide a summarized Nuclear Phylogenetic Tree of Angiosperm Families. The newly established nuclear phylogenetic relationships are highlighted and compared with previous phylogenetic results. The sequenced genomes of Amborella,Nymphaea, Chloranthus, Ceratophyllum, and species of monocots, Magnoliids, and basal eudicots, have facilitated the phylogenomics of relationships among five major angiosperms clades. All but one of the 64 angiosperm orders were included in nuclear phylogenomics with well resolved relationships except the placements of several orders. Most families have been included with robust and highly supported placements, especially for relationships within several large and important orders and families.Additionally, we examine the divergence time estimation and biogeographic analyses of angiosperm on the basis of the nuclear phylogenomic frameworks and discuss the differences compared with previous analyses. Furthermore,we discuss the implications of nuclear phylogenomic analyses on ancestral reconstruction of morphological, physiological, and ecological characters of angiosperm groups, limitations of current nuclear phylogenomic studies, and the taxa that require future attention.

Gamete Dialogs in Green Lineages

Gamete fusion is a core process of sexual reproduction and, in both plants and animals, different sex gametes fuse within species. Although most of the molecular factors involved in gamete interaction are still unknown in various sex-possessing eukaryotes, reports of such factors in algae and land plants have been increasing in the past decade. In particular, knowledge of gamete interaction in flowering plants and green algae has increased since the identification of the conserved gamete fusion factor GENERATIVE CELL SPECIFIC 1/HAPLESS 2 （GCS1/HAP2）. GCSl was first identified as a pollen generative cell-specific transmembrane protein in the lily （Lilium Iongiflorum）, and was then shown to function not only in flowering plant gamete fusion but also in various eukaryotes, including unicellular protists and metazoans. In addition, although initially restricted to Chlamydomonas, knowledge of gamete attachment in flowering plants was also acquired. This review focuses on recent progress in the study of gamete interaction in volvocine green algae and flowering plants and discusses conserved mechanisms of gamete recognition, attachment, and fusion leading to zygote formation.

Taxonomic bias in occurrence information of angiosperm species in China

Taxonomic bias is a well-known shortcoming of species occurrence databases.Understanding the causes of taxonomic bias facilitates future biological surveys and addresses current knowledge gaps.Here,we investigate the main drivers of taxonomic bias in occurrence data of angiosperm species in China.We used a database including 5,936,768 records for 28,968 angiosperm species derived from herbarium specimens and literature sources.Generalized additive models(GAMs)were applied to investigate explanatory powers of 17 variables on the variation in record numbers of species.Five explanatory variables were selected for a multi-predictor GAM that explained 69%of the variation in record numbers:plant height,range size,elevational range,numbers of scientific publications and web pages.Range size was the most important predictor in the model and positively correlated with number of records.Morphological and phenological traits and social-economic factors including economic values and conservation status had weak explanatory powers on record numbers of plant species,which differs from the findings in animals,suggesting that causes of taxonomic bias in occurrence databases may vary between taxonomic groups.Our results suggest that future floristic surveys in China should more focus on range-restricted and socially or scientifically less"interesting"species.

Plant flowers transmit various bio-agents through air

Growing air pollution,known as"April snow",by fluffy catkins from plant flowering was frequently observed during the Spring time in China.Current efforts mainly focus on controlling catkin release,while their public health and environmental impacts are unknown.Here,using culturing,microscopic and sequence methods we found that the flying catkins carry a significant amount of bio-agents(bacteria,fungal,viruses,and pollens),e.g.,up to 6.33×10^4 bacterial and 7.46×10^5 fungal cells per catkin.Abundant pollens from plants were also found riding on the flying catkins.For collected fluffy catkins,bacterial Paracoccus,Massilia,fungal Ophiocordyceps,Arthrocladiella,pollen Robina,Pickeringia,Pinus,and viral family Genomoviridae,to name a few,were found to be dominant.With infection and allergic potentials,the detected microbial structures on the fluffy catkins were different from those of local air,varying from one location to another.Being not just white pollution,flying plant fluffy catkins were discovered here also acting as a cloud of biological agents,and further actions need to be taken urgently to understand and limit their environmental and ecological consequences.