THE EFFECT OF LOW TEMPERATURE ADVERSITY ON MALE FLOWERS AND POLLEN IN LARIX OLGENSIS

The electrie conductivity of pollen life-force and male flowers of Larix olgensis on condition of low temperature adversity has been respectively measured by means of fluorescent dying method and conductivity method in 1992 and 1994. The results indicate that:(1 ) If the same clonal pollen is treated at equal time at different low temperatures, there are significant differences in pollen life-force, the pollen life-force is the largest between O℃aild -3℃, in higher or lower temperature range, the pollen life-force will decrease. The measurement of electric conductivity of male flowers provcs that the low temperature of below -3℃ is the inain reason that the cell membrane is damaged and the pollen.life-force decreases. (2) The same clonal pollen life-force at the saine low temperature will gradually decrease with the increasing of frozen time. Its main reason is that suffocation and losing body fluid result in the damage of cell membrane, the measurement of electric conductivity of male flowers call prove that. (3) If pollen is treated with the same low temperature, the humidity will be the main factor of affecting pollen life-force. (4) There are significant differences in Larix olgensis's resistance against low temperature in its different growth stage, the male flower's resistance of near pollen spreading period is low. (5) The resistance is different within clones. (6) The resistance against low temperature of Larix call be incrcased by means of chemical treatment.

Intrafloral differentiation of stamens in heterantherous flowers

Flowers that have heteromorphic stamens （heterantherous flowers） have intrigued many researchers ever since the phenomenon was discovered in the 19th century. The morphological differentiation in androecia has been suggested as a reflection of ＂labor division＂ in pollination in which one type of stamens attracts pollinators and satisfies their demand for pollen as food and the other satisfies the plant＇s need for safe gamete dispersal. The extent and patterns of stamen differentiation differ notably among taxa with heterantherous flowers. Seven species with heteromorphic stamens in three genera were sampled from Leguminosae and Melastomataceae, and the morphological difference of androecia, pollen content, pollen histochemistry and viability, pollen micro- morphology, as well as the main pollinators were examined and compared. Pollen number differs significantly between stamen sets of the same flower in most species investigated, and a correlation of pollen number and anther size was substantiated. Higher pollen viabilities were found in the long （pollinating） stamens of Senna alata （L.） Roxb. and S. bicapsularis （L.） Roxb. Dimorphic pollen exine ornamentation is reported here for the first time in Fordiophytonfaberi Stapf. The height of stigma and anther tips of the long stamens in natural conditions was proved to be highly correlated, supporting the hypothesis that they contact similar areas of the pollinator＇s body.

QTL effects and epistatic interaction for flowering time and branch number in a soybean mapping population of Japanese×Chinese cultivars

Flowering time and branching type are important agronomic traits related to the adaptability and yield of soybean. Molecular bases for major flowering time or maturity loci, E1 to E4, have been identified. However, more flowering time genes in cultivars with different genetic backgrounds are needed to be mapped and cloned for a better understanding of flowering time regulation in soybean. In this study, we developed a population of Japanese cultivar（Toyomusume）×Chinese cultivar（Suinong 10） to map novel quantitative trait locus（QTL） for flowering time and branch number. A genetic linkage map of a F_2 population was constructed using 1 306 polymorphic single nucleotide polymorphism（SNP） markers using Illumina Soy SNP8 ki Select Bead Chip containing 7 189（SNPs）. Two major QTLs at E1 and E9, and two minor QTLs at a novel locus, qFT2_1 and at E3 region were mapped. Using other sets of F_2 populations and their derived progenies, the existence of a novel QTL of qFT2_1 was verified. qBR6_1, the major QTL for branch number was mapped to the proximate to the E1 gene, inferring that E1 gene or neighboring genetic factor is significantly contributing to the branch number.

Flowering of Sugarcane Genotypes under Different Artificial Photoperiod Conditions

Flowering is essential in any breeding programme, particularly in genetic introgression programmes in which flowering synchronism is required. In this work, 16 sugarcane genotypes were evaluated using three different flowering-inductive photoperiod treatments (30 s, 45 s, and 1 min of a daily photoperiod decrease from 12 h 55 of light). Each genotype was planted in 43 L pots (equal proportion of soil, sand, and substrate) with three tillers per pot. Plants with 4 to 6 internodes were placed in a photoperiod facility with three controlled chambers, each chamber containing all 16 genotypes (one treatment per chamber). The temperature range (21°C to 32°C) and humidity were the same for all of the treatments. The flower induction started in September 2010 and ended in April 2011. The plant elongation and flag leaf and inflorescence emergence were recorded and the pollen viability was evaluated by using the iodine staining method. The photoperiod facility provided suitable conditions for flowering, as the plants in the three treatments successfully flowered. The genotypes in the three treatments behaved differently in relation to the date of panicle emergence, with the treatment of 45 s showing better results. The results here presented contribute to synchronise flowering for desired sugarcane crosses, particularly those from introgression programmes between commercial cultivars and species from the Saccharum complex.

Potential Inbreeding in a Small Population of a Mass Flowering Species, <i>Xanthorrhoea johnsonii</i>(Xanthorrhoeaceae): Is Your Mother My Father?

Xanthorrhoea johnsonii is a long lived slow growing perennial understorey species, that produces a large quantity of passively dispersed seed every 3 - 5 years. Reproductive maturity is not reached until 20 - 30 years of age. The temporal asynchrony of the flowering event in this population was analogous to geographic isolation through fragmentation. A small population of plants flowering in isolation provided the opportunity to examine outcrossing rates, genetic diversity and the paternity of progeny at a small spatial scale (0.2 ha). The geographic location and physical characteristics of the adult plants were recorded, and both adults and their seed were sampled for genetic analysis. Four microsatellite loci were screened for genetic diversity and spatial structure analysis. A population outcrossing rate was estimated, as well as the number of paternal parents required to resolve the progeny multilocus genotypes. High genetic diversity was found in both adults and progeny with an estimated 97% outcrossing rate. All maternal lines required several paternal contributors, with no evidence of dominant paternal genotypes. Pollen transfer occurred between both geographically close and distant plants.

The flowerpiercers interactions with a community of high Andean plants

Background:Flowerpiercers(Diglossa)are traditionally considered as“parasites”of the pollination processes,as they can access the nectar without entering in contact with the reproductive structures of the plants.Nevertheless,the effect of flowerpiercers seems to vary according to their behavior and the flower’s traits.So,in this work,we aimed to explore the floral characteristics that may determine the susceptibility to robbing and pollen transport by flowerpierc-ers.Also,we identified the potential types of interactions and studied interaction network properties.Methods:We collected the information of 16 ornithophilic plants regarding their floral traits and robbing frequency.Also,we captured 4 species of flowerpiercers and evaluated pollen transport(frequency and loads).We tested the correlation between floral traits,robbing frequency,and pollen transportation.Later,we used these variables in a cluster and principal component analyses to identify the potential types of interactions.Finally,we analyzed and com-pared the structure of the plants-flowerpiercers interaction network.Results:Nectar production significantly influenced both nectar robbing and pollen transportation.While the corolla length was only correlated to the robbing susceptibility.Also,we found that particular flowerpiercers species trans-ported higher loads of some plant pollen,which can be related to the differences in behavior and morphometric traits.We proposed the classification of five different types of plant-flowerpiercer interactions,that showed differ-ent potential mutualist or antagonist relations based on the affectation of nectar robbing and the service of pollen transportation.The interaction networks consisted of 49 links,with 2.4 links per species,and presented indicators of a medium to high resilience,stability,and resistance(nestedness,connectance,and robustness).Also,the network presented medium to low specialization and substantial niche overlap.Conclusions:The ecological role of the flowerpiercers goes beyond its classic assignation as“parasites”as they can actively transport pollen of several Andean plants,affecting its evolutionary history and the stability of the systems.

Changes of Oxidative Stress and Soluble Sugar in Anthers Involve in Rice Pollen Abortion Under Drought Stress

Two rice maintaining lines with different drought tolerances, viz., Jin 23B （tolerant） and Zhenshan 97B （sensitive）, were used to study the oxidative stress and soluble sugar in rice anthers and pollen viability under drought stress during flowering stage. Higher antioxidant enzyme activities and lower malonaldehyde （MDA） content in rice anthers were observed in Jin 23B than in Zhenshan 97B under drought stress. Further, a great increase in the content of soluble sugar in rice anthers of Jin 23B was observed across the whole drought exposure, while Zhenshan 97B showed significant decrease in soluble sugar during 9-12 d after drought stress （DADS）. Accordingly, a marked decline of pollen fertility and activity, pollen numbers in an anther and pollen numbers on a stigma was observed in Zhenshan 97B, whereas little difference was found in Jin 23B. Thus, we suggest that pollen abortion caused by drought stress may be related with the reciprocity between oxidative stress and soluble sugar content in rice anthers.

New taxa of Berberis (Berberidaceae) with greenish flowers from a biodiversity hotspot in Sichuan Province, China

A new species,Berberis viridiflora X.H.Li,and a new variety,Berberis sanguinea Franch.var.viridisepala X.H.Li,L.C.Zhang & W.H.Li are described and illustrated from Baoxing County,a biodiversity hotspot located on the eastern edge of Hengduan Mountains in Sichuan Province,Southwest China,Both new taxa resemble B.sanguinea Franch.var.sanguinea,but B.viridiflora differs by the greenish flowers,and the petals being truncate,obtuse,or undulate at apex;while B.sanguinea var.viridisepala differs by the greenish or yellowish green flowers.Morphological features of the pollen grains of B.sanguinea and the two new taxa are revealed by scanning election microscope.B.sanguinea var.sanguinea displays obvious similarities with a sympatric congener,Berberis multiovula T.S.Ying in the morphology of flowers,stems and leaves,especially its ovule number varies greatly from 2 to 9,thus,B.multiovula characterized by the5-ovuled ovary is reduced to a synonymy of B.sanguinea var.sanguinea.On the basis of field surveys and study of herbarium specimens,a total of 16 species and varieties of Berberis are recorded from Baoxing County,and a key is provided.Among the 16 taxa,most phenotypic variations in Chinese Berberis can be displayed,including the habit of plants,most morphological variations of stems,branches and leaves,all types of inflorescences,all color types of flowers,and nearly all types of the shape and color of fruits.Baoxing County and its adjacent Sichuan Giant Panda Sanctuaries possibly constitute an active diversification center of Berberis in eastern Hengduan Mountains of China.

In vitro anther culture and Agrobacterium-mediated transformation of the AP1 gene from Salix integra Linn. in haploid poplar(Populus simonii × P. nigra)

A reliable,efficient anther culture system,the dominant technique for generating haploid plants in breeding programs,that can be used for generating transgenic poplar plants has been needed.In the present study,therefore,an anther culture system was developed using isolated mid-and late-uninucleate anthers of poplar(Populus simonii x P.nigra).From a combination of SSR and ploidy analyses,six double haploid and two haploid lines were characterized from 86 plants grown from 16 regenerated anther cultured lines.After 48 months of development,two plant lines from the regenerated plants maintained their haploid level in vitro for over 2 years.A number of haploid plants from the different lines weretransferred to soil.The leaves of these transplants were then used as explants for transformation with the APETALA1(AP1) gene using Agrobacterium tumefaciens.Overexpression of AP1 in haploid poplar induced early flowering with obvious petals when ectopically expressed.To our knowledge,this is the first report on changes in flowering time in AP1-trangenic poplar,which is important for elucidating the regulatory mechanism of tree flower development.

The Influence of Altitude and Latitude on Breeding of Amomum tsaoko (Zingiberaceae)

Objective: To explore the effect of altitude and latitude on breeding of Amomum tsaoko Crevost et Lemaire, a flexistylous ginger, which fruit is used as common materia medica and a food condiment. Methods: The 7 populations were selected randomly from the three floristic zones of Yunnan. Adult plants and infructescences were chosen randomly to gain flower number and fructification percentage per inflorescence, and seed number per fruit. All date was analyzed by SPSS (13.0 version). Results: As A. tsaoko was distributed (or transplanted) from a habitat at lower latitude and/or altitude to a site of higher latitude and/or altitude, the flower number per inflorescence increased, on the contrary, the fructification percentage per inflorescence decreased. The competition for reproductive resource was beneficial to increase flower number and seed production. Conclusions: The habitats in south of the tropic of cancer were favorable to the reproduction of A. tsaoko, which reproductive costs were lower and harvest was higher. Increasing flower number per inflorescence may be a strategy to promote the plant to distribute into alpine habitats for both female and male reproductive success.

Salinity Effect at Seedling and Flowering Stages of Some Rice Lines and Varieties(Oryza sativa L.)

This study used 10 rice lines and varieties,including the salt tolerant variety(Pokkali)and salt susceptible variety(IR29)as control.Experiment for screening rice salinity tolerance at seedling stage was conducted in hydroponic system using five different salinity concentrations(0,4,6,8 and 10 dS/m).Flowering stage was evaluated at the salinity level of 8 dS/m.The experiment was designed in randomized completely block(RCBD)with three replications for each line/variety under non-saline and saline condition.The results showed that the growth of rice lines/varieties was retarded severely with increasing salinity levels,and almost all of leaves were drying and dead completely(score 7 and 9).Plants of IR29 and OM7347 were dead at the electrical conductivity(EC)=10 dS/m,whereas Pokkali(the tolerant variety)and IR93350 were evaluated at score 5.Salinity stress caused the reduction of overall vigor of rice lines/varieties especially in the pollen germination,fertilization and grain yield.Rice lines/varieties were classified to salinity tolerance levels as following:IR5040,IR93350,IR86385-8D-1-2-B and Pokkali(tolerant);OM8104,IR93340 and IR93343(moderate susceptible);OM7347,IR87832-303-1-B and IR29(susceptible).

Rice False Smut Fungus, <i>Ustilaginoidea virens</i>, Inhibits Pollen Germination and Degrades the Integuments of Rice Ovule

Ustilaginoidea virens is a flower-infecting fungus that forms false smut balls in rice panicle. Rice false smut has long been considered a minor disease, but recently it occurred frequently and emerged as a major disease in rice production. In vitro co-cultivation of U. virens strain with young rice panicles showed that U. virens enters inside of spikelets from the apex and then grows downward to infect floral organs. In response to U. virens infection, rice host exhibits elevated ROS accumulation and enhanced callose deposition. The secreted compounds of U. virens can suppress rice pollen germination. Examination of sectioning slides of freshly collected smut balls demonstrated that both pistil and stamens of rice flower are infected by U. virens, hyphae degraded the contents of the pollen cells, and also invaded the filaments. In addition, U. virens entered rice ovary through the thin-walled papillary cells of the stigma, then decomposed the integuments and infected the ovary. The invaded pathogen could not penetrate the epidermis and other layers of the ovary. Transverse section of the pedicel just below the smut balls showed that there were no fungal hyphae observed in the vascular bundles of the pedicel, implicating that U. virens is not a systemic flower-infecting fungus.

Heterosis Study on Developmental Behavior of Flowering and Boll Setting in Upland Cotton

The developmental behavior was examined for flowering and boll setting in upland cotton （Gossypium hirsutum L.） at different boll-setting sites and blooming periods. Conventional and conditional methods were applied to analyze heterosis by an additive-dominance model with genotype by environment （GE） interaction effects. Positive general heterosis was significantly detected on middle-lower nodes at positions 1 and 2 for a number of flowers and bolls per plant. Deviation between HPBE1 and HPBE2 was relatively large for a number of flowers per plant at positions 3, 4, and 5, but much smaller for number of bolls per plant. There was increase of heterosis before the end of July, and the highest heterosis was observed at 22 DAF （22 days after flowering） for flowers and at 16 DAF for bolls, and then declined. There existed significant diversity of interaction heterosis for flowers as well as for bolls during blooming stages, but deviation between HPBE1 and HPBE2 was smaller for number of bolls per plant than that of flowers per plant. The cross of DP-15 （late-season variety）＇ HG-H-12 had positive general heterosis since 19 DAF, and negative HPB was observed for the cross of GL-5 （early-season variety）＇ HG-H-12 after 37 DAF. Interaction heterosis was mostly not significant for cross DP-15＇ HG-H-12, but the reverse was true for cross GL-5＇ HG-H-12. Positive conditional HPB was detected since 16 DAF until 43 DAF for cross DP-15＇ HG- H-12, and before 13 DAF for cross GL-5＇ HG-H-12.

Research Progress of Cell Wall Breaking Technology and Its Application in Eucommia ulmoides Male Flower Tea

Eucommia ulmoides male flowers are rich in secondary metabolite,which have anti-tumor,sedative hypnotic,hypotensive,hypolipidemic,anti-fatigue,bacteriostatic,antioxidant and anti-aging effects.The conventional processing of E.ulmoides male flowers leads to the loss of nutrients and active ingredients.In recent years,cell wall breaking technology has been developed and utilized in various fields such as traditional Chinese medicine,good,chemical industry and biology.In order to promote the development of the E.ulmoides industry,the cell wall breaking technology and its characteristics are reviewed,and the application advantages of the cell wall breaking technology in the male flowers of E.ulmoides are discussed,and the prospect of the cell wall breaking of E.ulmoides is proposed in this article.

耐热型西番莲品种“钦蜜9号”花器官发育特征与繁育系统研究

为明确耐热型黄果西番莲品种“钦蜜9号”花器官发育进程特性和繁育系统类型,测定其花器官表型性状、花粉活性、柱头可授性、异交指数和花粉胚珠比。结果表明,“钦蜜9号”花器官发育进程为现蕾期—花冠发育期—雌雄蕊发育期—裂蕾期—开花授粉期—谢花期,时间持续25~27 d,开花时间为下午13:00—15:00,单花开放时长约24 h,开花前3 d左右(花药即将开裂时)至裂蕾时柱头可授性最强;花粉数量为7.94×10^(5)个/花药,活性为90.11%,繁育系统类型为异交型,自交亲和,异交需要传粉者。这些特征为“钦蜜9号”35℃以上高温还能正常开花结果提供重要参考条件。

玉米花粉高温胁迫相关miRNA的筛选及其靶基因分析

以高耐热玉米品种郑单958、低耐热玉米品种先玉335为材料,以正常生长条件为对照,在花期进行高温胁迫,通过miRNA高通量测序筛选玉米花粉中的差异表达miRNA,然后预测其靶基因,并对靶基因的本体特征和代谢通路进行富集分析。结果表明,共筛选到818个miRNA前体序列。在郑单958高温胁迫花粉与对照花粉对比组(HT958 vs CK958)中共筛选到19个显著差异表达miRNA序列,其中15个miRNA序列上调表达,4个下调表达,3个miRNA序列达到极显著水平(P<0.01)。对这19个显著差异表达miRNA的靶基因进行预测,共获得了503个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、微管生物学过程、磷酸化作用、RNA聚合酶Ⅱ正向调控转录过程、甲基化作用等,KEGG富集较显著的代谢通路分别是谷胱甘肽代谢、碳代谢、花生四烯酸代谢、糖酵解/糖异生、叶酸生物合成等。在先玉335高温胁迫花粉与对照花粉对比组(HT335 vs CK335)中共筛选到15个显著差异表达miRNA序列,其中7个miRNA序列上调表达,8个下调表达,1个miRNA序列达到了极显著水平(P<0.01)。对这15个显著差异表达miRNA的靶基因进行预测,共获得了454个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化作用、蛋白质水解、DNA修复等,富集较显著的KEGG代谢通路分别是其他多糖降解、亚油酸代谢、代谢通路、硫胺素代谢、内质网内蛋白质加工过程等。在郑单958高温胁迫花粉与先玉335高温胁迫花粉对比组(HT985 vs HT335)中共筛选到85个显著差异表达miRNA序列,其中35个miRNA序列为上调表达,50个为下调表达,24个miRNA序列达到了极显著水平(P<0.01)。对这85个显著差异表达miRNA的靶基因进行预测,共获得了2 286个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化、蛋白质水解、跨膜转运等,富集较显著的代谢通路分别是鞘脂类代谢、淀粉和蔗糖代谢、其他多糖降解、代谢通路、半胱氨酸及甲硫氨酸代谢等。在HT958 vs CK958与HT335 vs CK335对比组中共筛选到94个显著差异表达miRNA序列,其中(预测全新)PC-3p-10069_1143、(预测全新)PC-3p-18335_646、(玉米)zma-miR164f-5p等28个miRNA序列达到了极显著水平(P<0.01)。对这94个显著差异表达miRNA的靶基因进行预测,共获得了4 569个基因转录本,其富集较多的GO生物学过程条目分别为转录调控DNA-模板、磷酸化作用、蛋白质磷酸化、蛋白质转运、蛋白质水解等,其富集较显著的KEGG代谢通路分别是内质网内蛋白质加工过程、真核生物核糖体生物合成、剪接体、鞘脂类代谢、内吞作用等。

配方施肥对紫薇花序着花数和花期的影响

为探究紫薇花序着花数和花期对氮、磷、钾配方施肥的响应,获得氮、磷、钾优化的施肥量,以紫薇优良新品种“紫精灵”为研究对象,采用氮、磷、钾“3414”施肥设计进行田间施肥试验,测定不同处理的花序着花数和花期,拟合花序着花数的肥料效应模型,采用频次分析法获得优化施肥量。结果表明:氮、磷、钾配方施肥显著提高了紫薇花序着花数,能提早始花期和盛花期、推迟末花期;施肥对紫薇花序着花数、花期、始花期、盛花期、末花期的单因子影响效应均是N>K>P,交互作用影响效应都是NK>NP>PK;氮、磷、钾对花序着花数的单因素效应为正,氮与磷交互效应为正,氮与钾、磷与钾的交互效应都是负;花序着花数最大的施肥量为氮肥(N)19.50g·株^(-1)、磷肥(P_(2)O_(5))13.82g·株^(-1)、钾肥(K_(2)O)3.66g·株^(-1),此时花序着花数为117.94朵;用频次分析法获得的优化施肥量为氮肥(N)10.95~17.37g·株^(-1)、磷肥(P_(2)O_(5))5.89~9.37g·株^(-1)、钾肥(K_(2)O)7.01~10.25g·株^(-1),预期花序着花数平均值为126.52朵。

唐古特瑞香开花物候及繁育系统研究

针对药用植物唐古特瑞香(Daphne tangutica Maxim)野生植株花多果少、坐果率低的问题,以唐古特瑞香野生种群为试验对象,观察其开花物候、花器官形态变化、花粉活力、柱头可授性等特征,并结合花粉-胚珠比(P/O)、杂交指数(OCI)的测定,访花者行为观察,揭示其繁育系统类型及坐果率低的限制因素。结果表明:唐古特瑞香为两性花,顶生或腋生头状花序,花期5—6月,群体开花持续17~22 d,单花序花期8~11 d,单花花期7~9 d;雌蕊先于雄蕊成熟,单花待开时柱头可授性最强,盛开时花粉活力最强;P/O和OCI的判定以及访花者观察显示其以异交为主,部分自交亲和,多数需要如中华蜜蜂(Apis cerana)、三条熊蜂(Bombus trifasciatus)、灰熊蜂(Bombus grahami)等有效传粉者。柱头可授性与花粉活力的最强时期不遇,细长的花冠管需要有效传粉者授粉,盛花期散粉量不高,异交竞争力弱和自交亲和度低,以及有效访花昆虫的数量和种类少等因素可能是造成唐古特瑞香开花量大坐果率低的主要原因。本研究结果为今后规模化、优质化人工繁育唐古特瑞香及祖师麻药材产量提升提供理论依据和实践基础。