Gene flow from transgenic oilseed rape (Brassica napus L.) to cruciferous weeds under mentor pollen inducement

The alien gene flow between genetically modified glyphosate-resistant rapeseed variety Q3 (Brassica napus L.) and four cruciferous weeds was studied under mentor pollen inducement. The results showed that when Thlaspi arvense L., Capsella bursa-pastoris (L.) Medic, Cardamine hirsute L. and Rorippa palustris (L.) Besser were pollinated with mentor pollen, the mixed Q3 and the weed, pollen grains aggregated largely and germinated quickly, and the numbers of pollen tubes penetrating into the style and the ovary were greatly increased as compared with corresponding self-pollination groups. Twenty four to forty eight hours after pollination, several pollen tubes were observed to penetrate into the ovule via micropyle in each mentor combination. However, when the mentor progenies were analyzed by PCR, all of them showed negative for the Q3 herbicide-resistant gene. Collectively, these results indicated that crossing between T. arvense, C. bursa-pastoris, C. hirsuta, R. palustris (as female) and Q3 (as male) was highly incompatible and the herbicide-resistant gene could not flow from Q3 to these four weeds.     

Gene flow from transgenic oilseed rape (Brassica napus L.) to cruciferous weeds under mentor pollen inducement

The alien gene flow between genetically modified glyphosate-resistant rapeseed variety Q3 (Brassica napus L.) and four cruciferous weeds was studied under mentor pollen inducement. The results showed that when Thlaspi arvense L., Capsella bursa-pastoris (L.) Medic, Cardamine hirsute L. and Rorippa palustris (L.) Besser were pollinated with mentor pollen, the mixed Q3 and the weed, pollen grains aggregated largely and germinated quickly, and the numbers of pollen tubes penetrating into the style and the ovary were greatly increased as compared with corresponding self-pollination groups. Twenty four to forty eight hours after pollination, several pollen tubes were observed to penetrate into the ovule via micropyle in each mentor combination. However, when the mentor progenies were analyzed by PCR, all of them showed negative for the Q3 herbicide-resistant gene. Collectively, these results indicated that crossing between T. arvense, C. bursa-pastoris, C. hirsuta, R. palustris (as female) and Q3 (as male) was highly incompatible and the herbicide-resistant gene could not flow from Q3 to these four weeds.     

A novel mechanism controls anther opening and closing in Paris polyphylla var. Yunnanensis

The phenomena of anther opening and closing in Paris polyphylla var. yunnanensis (Franch) Hand.-Mazz were described in detail, and the effects of ecological factors on those phenomena related to anther opening, closing and the fly-pollination mechanism were discussed. Anthers of P. polyphylla var. yunnanensis open in the morning and close in the evening every day during an over 20 days’ period of anthesis. Light was detected as the main factor controlling this daily anther opening and closing. Anther opening can be reversed in response to rain and re-opens when rain stops. Relative humidity (RH) has a slight effect on anther opening and closing. Flower spans can be prolonged under laboratory conditions. This novel behavior of anther is likely to be a mechanism to enhance the male fitness in this species, of which has no inherited structure to protect pollen from the perianth.     

昆明小鼠未成熟卵母细胞OPS和SSV冷冻保存的比较

目的寻找昆明小鼠卵母细胞冷冻保存效率的新途径。方法选用5~6周龄雌性昆明小鼠的未成熟卵母细胞,在不同前处理液(10%EG或10%EG+10%DMSO)中平衡5 min,然后在冷冻液(EFS30、EFS40、EDFS30或EDFS40)中平衡30 s后进行OPS(Open pulled straw)法和SSV(Solid-surface vitrification)法玻璃化冷冻保存。结果小鼠未成熟卵母细胞的OPS法冷冻保存中,用EFS液冷冻的卵母细胞解冻后形态正常率最高为84.4%,成熟率低于16.7%;而在SSV法冷冻保存中,用EFS液冷冻的卵母细胞解冻后形态正常率最高为86.0%,成熟率为46.5%。OPS法和SSV法冷冻小鼠未成熟卵母细胞形态正常率为91.6%和91.4%,与对照组间差异较显著(P>0.01);成熟率为42.9%和59.1%,与对照组差异极显著(P<0.01)。结论多种抗冻保护剂组合使用效果好于单种抗冻保护剂;EDFS冷冻液冷冻保存效果好于EFS,尤其是EDFS30;OPS法可以有效地冷冻保存小鼠未成熟卵母细胞,且新型玻璃化冷冻法SSV法冷冻保存效果优于OPS法。     

井冈山地区铁皮石斛的繁殖生物学研究

通过野外实验观察和人工控制套袋等方法,从铁皮石斛的花部基本特征、开花动态、花粉活力、柱头可授性、杂交指数、套袋实验等方面对其繁殖生物学进行了研究。结果显示:(1)井冈山地区铁皮石斛4～6月开花,种群花期近60 d,多数花(50%)在约30 d内开放,果实一般需要180 d左右才能成熟。(2)铁皮石斛花粉活力开花后24 h即可达到(62.67±6.43)%,至开花第三天,活力可达到90%,柱头可授性达到最高,至第5天柱头仍保持高可授性。(3)套袋实验表明,部分自交亲和,异交,需要传粉者。自然条件下未观察到井冈山铁皮石斛居群结实,人工自花授粉率为22.2%。该研究结果为保护和利用井冈山铁皮石斛种质资源提供了科学依据。     

H-ATPase in the plasma membrane of Arabidopsis pollen cells is involved in extracellular calmodulin-promoted pollen germination

In this paper, the role of the plasma membrane (PM) H⁺-ATPase in extracellular calmodulin (CaM)-promoted pollen germination and in tube growth of Arabidopsis thaliana was investigated. Pollen germination, pollen tube growth rate, free cytosolic Ca²⁺ concentration ([Ca²⁺]_cyt) and Ca²⁺ channel activity in the PM of pollen cells were measured. In response to fusicoccin or CaM treatment, in vitro pollen germination and pollen tube growth rate, [Ca²⁺]_cyt and activity of a hyperpolarization-activated Ca²⁺-permeable channel increased. Sodium vanadate inhibited the promotion of these parameters by extracellular CaM. The results suggest that H⁺-ATPase may be involved in extracellular CaM-regulated pollen germination and in tube growth by modulation of the hyperpolarization-activated Ca²⁺ channel in the PM of A. thaliana pollen cells.     

Analysis of F1 hybrid and BC1 monosomic alien addition line plants from Brassica oleracea × Sinapis alba by GISH

Sterile and semi-fertile F₁ plants were obtained by intergeneric sexual hybridization between paternal Brassica oleracea var. alboglabra (genome CC, 2n=18) and maternal Sinapis alba (genome SS, 2n=24), BC₁ plants were obtained by backcrossing between paternal B. oleracea and maternal semi-fertile F₁ plants. Genomic in situ hybridization (GISH) combined with dual-colour fluorescence in situ hybridization (dcFISH) showed that sterile F₁ plants contained 21 chromosomes consisting of one B. oleracea chromosome set and one S. alba chromosome set, belonging to expected hybrids, and semi-fertile F₁ plants contained 30 chromosomes consisting of two B. oleracea chromosome sets and one S. alba chromosome set. It is obvious that the semi-fertile F₁ plants belong to unexpected hybrids. 1―3 trivalents were detected at meiotic metaphase I of semi-fertile F₁ pollen mother cells (PMCs). Different separation ratios of S chromosomes were detected at anaphase I. A monosomic alien addition line (MAAL) was identified by GISH-dcFISH from BC₁ plants; it contained 19 chromosomes consisting of 18 C chromosomes and 1 S chromosome. At meiotic metaphase I, 9 divalents from B. oleracea and one univalent from S. alba could be detected. Sometimes, one putative C-S trivalent could also be detected. The achievement of B. oleracea-S. alba monosomic alien addition lines lays a foundation for gene introgression, location and cloning.     

拟南芥雄性不育突变体opw(only pollen wall)候选突变基因的克隆

在T-DNA插入突变体Salk_059463株系的群体中,筛选到两株雄性不育突变体,对TDNA序列上的一对引物进行PCR鉴定,结果表明:其基因组中没有T-DNA插入.遗传分析表明这两株雄性不育突变体由同一单个隐性基因控制,引起不育的主要原因是从花药发育的第8期开始,小孢子细胞质内容物逐渐减少直至消失,到花药发育的第12期,药室内的小孢子只剩下一个花粉壁空壳,故该突变体命名为opw(only pollen wall).利用图位克隆的方法对OPW基因进行了定位,结果表明OPW基因位于第二条染色体上分子标记T28M21和T3G21之间的12 kb区间内,该区间内一共有21个基因注释.通过克隆区间内的基因并测序发现opw-1突变体基因组中At2g40140基因编码序列的外显子在第289和第290个碱基之间插入了一个A碱基,而opw-2突变体基因组中At2g40140基因编码序列的外显子在第412和第413个碱基之间插入了一个T碱基,造成的编码序列移码使第424至第426碱基成为终止密码子,故At2g40140是编码OPW的候选基因.     

Characterization of an endo-1,4-β-glucanase from Lilium longiflorum that functioned in pollen germination and pollen tube growth

Endo-β-glucanases play vital roles in the regulation of pollen tube growth. Here, a previously identified endo-l,4-β-glucanase from Lilium Iongiflorum （lily）, named LlpCell, was expressed in Escherichia coli, purified, and further investigated for its physiological function. The recombinant LlpCell protein hydrolyzed carboxy-methylcellulose （CMC） and exhibited activity towards laminarin from Eisenia. arborea and 1,3：l,4-β-glucan of barley. The pH for the optimum activity was 6.0 and the value of Km calculated from CMC was 5.0 mg/mL. Adding EDTA resulted in the total loss of the enzymatic activity, and this effect could be restored by the addition of Ca^2＋. Western blotting analysis showed that LlpCell protein was present in pollen grains and rehydrated pollen grains, and the amount of the protein was increased during pollen germinating, but not in the pollen tube. Consistently, the immunofluorescence labeling study with the antibody against LIpCell also indicated the presence of LIpCell at the begin-ning of germination, but not in the elongating pollen tube. Furthermore, incubation of LlpCell with pollen at the beginning of pollen germination increased the germination percentage and the length of pollen tube. All of these results suggested that LlpCell could play an important role in the regulation of lily pollen germination and the initiation of pollen tube growth.     

玻璃化保存对家兔颈总动脉松弛行为的影响

实验测定了玻璃化保存前后家兔颈总动脉的松弛曲线G(t),利用数学方法将连续松弛谱函数简化,并结合经验公式对实验数据进行非线性拟合, 得到了动脉的3个材料参数(C,τ1和τ2). 通过比较玻璃化保存前后动脉松弛行为特征参数的差异,得到了玻璃化保存对动脉力学行为的影响. 结果表明:①经过约600 s的松弛过程后,新鲜动脉约可保持初始应力的70%,而玻璃化保存动脉则仅可保持初始应力的约60%;②玻璃化保存动脉的短期松弛时间常数τ1相对新鲜对照组而言显著较小, 约降低60%, 长期松弛时间常数τ2约降低15%,而C几乎不变.     

Surface pollen assemblages of human-disturbed vegetation and their relationship with vegetation and climate in Northeast China

Pollen assemblages of 53 surface pollen samples from farmlands and wastelands in Northeast China were analyzed. Tree pollen percentages were usually higher than 30%, with Pinus (26.9%), Quercus (0.9%), Betula (0.9%) and Populus (0.7%) as the major types, and herb pollen percentages were usually higher than 50%, with weedy Poaceae (8.7%), Chenopodiaceae (7.1%), Artemisia (1.9%) and Compositae (3.5%) as the major taxa. Thus, the pollen assemblages were consistent with the regional vegetation compositions. However, there were differences in pollen assemblages among regions, especially among different geomorphological units. For example, in the mountains, there were more types of tree pollen and higher total percentages (average 42%) than in other areas, while cereal pollen percentages were lowest (11.2%). In the hills and high plains, herbs made up more than 60% of the pollens, with cereals (average 53.6%) the dominant type. In the low plains, pollen types were similar to those in the hills and high plains, but total pollen concentrations and the proportion of Concentricystes were much higher, while cereal pollen percentages were slightly lower (average 41.6%). Pollen assemblages in different land use types also differed. For example, in farmland, cereal pollen percentages were more than 40% and Chenopodiaceae was usually less than 2.5%, while in wasteland, weedy Poaceae was usually less than 10% and Chenopodiaceae was usually higher than 25%. Total pollen concentrations in farmland (average 3909 grains/g) were much lower than in wasteland (average 15074 grains/g). Redundancy analysis revealed that pollen assemblages were significantly negatively correlated with mean annual temperature (-0.73) and July mean temperature (-0.81) and significantly positively correlated with mean annual precipitation (0.48), indicating that pollen assemblages in the artificial or human-disturbed vegetation reflect regional climate well. Comparison of pollen assemblages in different areas of northern China showed that pollen concentrations reflect the intensities of human impact to some degree. For example, pollen concentrations decrease as human impacts increase in intensity. The cereal pollen proportions in farmland differed by area. In Northeast China, cereal pollen proportions were distinctly higher than in most other areas of northern China, suggesting differences in planting habits and climate.     

Reproductive biology and prospects for conservation ofCaldesia parnassifolia (Alismataceae)—A threatened monocot in China

Caldesia parnassi folia (Bassi ex Linn.) Parl. in China has declined in number in recent years and is increasingly faced with the risk of extirpation arising from anthropogenic changes associated with rapid urbanization and expansion of both agriculture and infrastructure. To aid in provision of the data needed for effective conservation of the species, studies on the habitat, pollination ecology, and breeding system ofC. parnassi folia were carried out on natural populations occurring in Southeastern China. Flowering in the study populations extended for more than eighty days beginning in early summer. Floral anthesis occurred in the morning hours and proceeded rapidly, lasting about 45 min. Flowers lasted ca. 8 h.Caldesia parnassi folia is self-compatible; however autogamy resulted in lower seed set than geitonogamy and xenogamy as well as free pollination. The data on pollen/ ovule (P∶O) ratio is consistent with a partially selfing and outcrossing mating system. Interpopulational crosses yielded similar seed set to within-population crosses. Agamospermy did not occur in the study populations. Propagation is achieved through seeds as well as through turions which commonly occur in the inflorescences. Flies (Insecta; Diptera) were the most frequent visitors to the flowers ofC. parnassi folia; however bees (Insecta; Hymenoptera) composed a larger proportion of effective pollinators. The Syrphidae speciesSphaerophoria indiana (Bigot) presents evidence of oligolectic foraging behavior. Recommendations are made on the immediate steps necessary for conservation ofCaldesia species in China. Foundation item: Supported by the State Key Basic Research and Development Plan of China (973) (G2000046805) and the National Natural Science Foundation of China (30070055) Biography: Robert Wahiti, Gituru (1967-), male, Kenya, Ph. D., research direction: plant biosystematics.     

广西不同林龄和区域马尾松人工林的土壤C、N、P化学计量特征

为探明广西马尾松Pinus massoniana人工林土壤碳(C)、氮(N)、磷(P)化学计量特征,揭示马尾松人工林土壤养分平衡机理及其时空动态变化,为马尾松人工林可持续经营提供理论依据,研究以广西4个典型区域马尾松人工林为对象,采用空间代替时间的方法,比较不同区域各林龄土壤有机碳(SOC)、全氮(TN)和全磷(TP)含量及其化学计量比的变化规律。结果表明：SOC、TN和C/N的变异系数较小,分别为21%、27%和22%,属弱变异,在不同林龄和区域中其值比较稳定。林龄、区域及其交互作用对SOC、TN、TP、C/P、N/P的变化均有显著影响(P<0.05)。SOC、TN含量呈波动性变化,在成熟林阶段最低;SOC含量在幼龄林阶段最高,TN含量在近熟林阶段最高。土壤TP含量在中龄林阶段最低,且随林龄增加呈先减少后增加的趋势。土壤C/N、C/P、N/P平均值均在成熟林中最高,且显著高于近熟林和过熟林(P<0.05);土壤C/P、N/P平均值随林龄增加呈先减少后增加再减少的趋势。华山地区SOC、TN和TP含量最低,而土壤C/N、C/P、N/P平均值最高。天洪岭地区土壤C/N平均值最低...     

Pollen Morphology of Artemisia L. and Its Systematic Significance

The pollen of 57 species representing 7 sections of Artemisia was examined hy light microscope and scanning microscope for the purpose to elucidate the systematic relationships of the genus. The examination indicates that the pollen grains present high concordance which is characterized by the globular or the appruximate shape. 3-lobed circular from polar view while granular or ellipse sphere from tropical plate with tricolporate structure. The exinc of pollen has an obvious double structure of inner and outer layers (including the tecturn and columnar layers) where the outer is thicker than the inner and the sculpture of exine degenerates into small spinules easily distinguishable from other genera of the Compositae. Based on cxine sculpture, the pollen grains of Artemisia can be divided into two types: Myriantha type and Mongolica type, which possesses 4 subtypes according to the distribution forms of spinulc: (1) Sacrorum subtype, (2) Oligocarpa subtype, (3) Lavandulaefolia subtype. (4) Anomale subtype.     

烟蚜茧蜂规模扩繁冬寄主筛选研究

为筛选出烟蚜茧蜂（Aphidius gifuensis Ashmead）规模扩繁中的最佳繁蚜冬寄主,比较了自然条件下7种不同冬寄主上烟蚜的种群数量变化,烟蚜茧蜂对各寄主上烟蚜的防控效果及僵蚜羽化率.结果表明：烟蚜在7种寄主上种群数量的自然增长从大到小依次表现为烤烟K326、芥菜、芥菜型油菜、甘蓝型油菜、萝卜、红菜薹、白菜;芥菜上烟蚜茧蜂的寄生率为70.56%,显著高于其他寄主;7种冬寄主上僵蚜羽化率均高于70%,其中芥菜最高,为97.33%,萝卜最低,为72.87%,二者差异具有统计学意义.烟蚜茧蜂均能寄生7种冬寄主植物上所饲养的烟蚜且僵蚜羽化率相对较高,但总体而言芥菜上烟蚜的种群数量增长较快,烟蚜茧蜂的寄生率和僵蚜羽化率均最高,可利用芥菜来替代烟草作为冬季繁蚜寄主,也可在春烟种植前对芥菜田释放烟蚜茧蜂使其在田间建立自然种群.     

A comparative study of n -alkane biomarker and pollen records: an example from southern China

We report the results of a comparative study of n-alkane biomarkers and pollens in lacustrine and peat deposits at Dingnan, Jiangxi Province in southern China, and discuss the likely causes for the discrepancy in the interpretations of the n-alkane biomarker and pollen records in terms of climate and vegetation change. The results show that past changes in climate and vegetation revealed by the n-alkane record are not always consistent with the pollen assemblage record in the whole section. Biomarkers do not permit direct identification of the plant family and/or genus and mainly record compositions of local plant remains, while pollens mainly reflect the regional vegetation change. Biomarkers and pollen records complement each other, providing a better picture of local and regional environments. Furthermore, biomarkers are more sensitive than pollen to climatic and vegetational change. Several climatic events are clearly identified by the n-alkane biomarker proxies, such as C₃₁/(C₂₇+C₂₉+C ₃₁) ratio and can be correlated to the North Atlantic Heinrich event, B/A, YD and two dry-cool events during the early Holocene such as the periods of 9850 to 9585 cal a B.P. and 8590 to 7920 cal a B.P. These events are consistent with those found in the surrounding regions, suggesting that the regional climate was coupled with global-scale abrupt climatic events. Our results suggest that biomarker and pollen data can record the more detailed climate and vegetation information, thus improving the resolution and precision of vegetation and climate reconstruction. Supported by National Natural Science Foundation of China (Grant No. 40602004) and National Basic Research Program of China (Grant No. 2004CB720200)     

鼠尾藻群体的有性生殖力影响因素研究

【目的】研究鼠尾藻(Sargassum thun bergii)有性生殖相关因子间的关系,分析鼠尾藻群体的有性生殖能力。【方法】通过统计分析方法,研究藻体长度与侧枝数、侧枝长度与生殖托数、生殖托长度与生殖托挂卵数间的关系。【结果】藻体长度与侧枝数、侧枝长度与生殖托数、生殖托长度与生殖托挂卵数间都为线性正相关,利用回归方程推算,1株成熟的鼠尾藻藻体能产生2×105~3.3×106个受精卵。【结论】1株成熟鼠尾藻的产卵量基本可满足1m2的采苗生产需要。     

Preparation of exine-detached pollen inNicotiana tabacum

A method of preparing exine-detached pollen inNicotiana tabacum was established. Anthers containing early-middle binucleate pollen were cold-pretreated at 4–6°C for 7–14 days, and were suspended in 0.3 mol/L sucrose solution for 2 days. During this process, the exine of most pollen grains dehisced. Then they were transferred into an enzyme solution containing 1% cellulase, 1% pectinase, 0.1% pectolyase, 1 mol/L mannitol, 0.3 mol/L sorbitol, 0.5% potassium dextran sulphate and K3 medium macro elements. After 15–20 min enzymatic maceration, the exine was detached resulting in the release of exine-detached pollen. Factors affecting preparation of exine-detached pollen were investigated, including cold-pretreatment, osmoticum concentration and enzymes used. Xia Huijun: born in Oct. 1963, Ph.D. Current research interest is in plant reproductive biology Supported by the National Natural Science Foundation of China