白菜亚硝酸还原酶基因BcNiR的克隆及表达分析

 以白菜品种‘苏州青’自交系叶片cDNA为模板, 采用RT-PCR、3′RACE和5′RACE技术, 获得了编码亚硝酸还原酶基因(NiR) 的cDNA全序列1 852 bp, 包含有1 749 bp的开放阅读框, 编码583个氨基酸, 命名为BcNiR。所推导的氨基酸序列与拟南芥NiR1、烟草nii2编码的氨基酸序列具有较高同源性, 分别为83%和76%。生物信息学分析表明, BcNiR具有完整的NiR蛋白结构, 含血红素蛋白β - 化合物区域, 一个明显的西罗血红素siroheme结合位点和4Fe-4S区域, 可以在SWiSS-MODEL数据库中搜索到与之相近的三维结构。RT-PCR结果显示, 该基因在叶片中的表达量远远高于根系, 在以0、10、20、30、40 mmol·L ^{- 1}硝态氮各分别处理0、2、4、6、8、12 h的试验中, 30 mmol·L ^-1处理4 h可使BcNiR的表达量达到最大; 5和10 mmol·L ^{- 1}铵态氮处理试验表明, 高浓度的铵抑制该基因的表达。     

利用DAD1反义片段转化创建菜薹可调控雄性不育材料

 菜薹因为没有好的雄性不育材料或自交不亲和系,至今尚无一代杂种用于生产,根据拟南芥及白菜型油菜的花药不开裂基因DAD1的保守序列设计引物,扩增菜薹的DAD1基因片段（DAD1F）,构建反义DAD1F植物表达载体,用农杆菌介导法转化菜薹,对转基因植株进行分子检测,鉴定其雄性不育性并进行育性恢复试验.克隆得到的菜薹的DAD1基因片段大小为678 bp,命名为BrcpDAD1F,其序列与拟南芥和白菜型油菜的DAD1高度同源,同源率分别为88％和99％;共得到了12株转基因植株,有6株在转录水平上得到表达,表现为雄性不育,花器官畸形,花粉活力低,萌发率不到10％,且开花后不能结角果或结空角果,或者得到极少种子但种子不萌发;用对照的花粉给转基因植株授粉可使其正常结实.以500 μmol·L^-1茉莉酸甲酯处理可使其雄性不育得到恢复,花粉可以在柱头和培养基上萌发,具有受精能力。T₁代可育株与不育株的比例都呈1:3分离, T₂代不同株系的育性分离比例不同,有些株系继续呈1:3的分离,有些株系全是可育株或全是不育株,说明反义抑制呈单基因稳定遗传。     

茄子离体叶片光系统Ⅱ的冷激胁迫效应及热力学分析

 以耐冷性较强的短把黑圆茄和耐热性较强的黑帅圆茄为试材,经冷激胁迫后采用植物效率仪PEA,进行快速叶绿素荧光参数测定,并利用最大光化学效率Fv/F m和活性中心RC/CSo的标准状态变性自由能变△GD进行PSⅡ冷稳定性的热力学分析。随着冷激胁迫温度的降低和时间的延长,PSⅡ的Fv/Fm、实际光化学效率ΔF/Fm′、RC/CSo呈"S"型下降趋势;单位反应中心DIo/RC和非光化学猝灭qN呈"S"型上升趋势;综合分析反映出冷激胁迫下PSⅡ反应中心的可逆失活和依赖于叶黄素循环的热耗散的双重机制在保护PSⅡ防止光抑制中起到重要作用。另外,通过两品种间PSⅡ行为差异,引入了两组新的参数作为便于直观比较冷胁迫的评价指标。黑帅圆茄Fv/Fm、ΔF/Fm＇的半衰温度T1/2和t1/2值分别高于短把黑圆茄1.4 ℃和0.8 ℃。茄子叶片Fv/Fm和RC/CSo的△GD随着冷激胁迫温度的降低而减少呈瀑布型的下降趋势。黑帅圆茄的△GD值和变性中点温度Tm都低于短把黑圆茄。它们均反映出黑帅圆茄的耐冷性低于短把黑圆茄。     

月季RcHSP17.8 基因表达提高大肠杆菌对非生物胁迫的耐性

 月季RcHSP1718为编码小分子热激蛋白基因, Southern检测其在月季基因组中为多拷贝存在。38 ℃/3 h热激处理后, 该基因在耐热月季品种‘曼海姆宫殿’ ( Schloss Mannieim) 、‘彩虹’ (Radio) 、‘赌城’ (Las Vegas) 、‘梅郎随想曲’ (Caprice de Meiland) 、‘小女孩’ ( Girl) 中强表达, 而在不耐热品种‘新十全’ (Kordes’Perfecta) 、‘绯扇’ (Hiogi) 、‘莱茵黄金’ ( Pfalzer Gold) 中弱表达或不表达, 表明该基因与月季耐热性关系密切。为确定月季RcHSP1718基因功能, 将其转化E.coli BL21, 结果表明重组菌株能正常诱导表达包含RcHSP17.8的融合蛋白, 并因此提高了重组菌株对高温、低温、高盐、高pH、重金属、氧化等非生物胁迫的耐性, 表明RcHSP17.8参与了上述非生物胁迫的响应。     

苹果园春季土施尿素的利用及其在土壤中的累积

 以7年生嘎拉苹果/平邑甜茶为试材, 利用¹⁵N示踪技术, 研究了苹果生产体系中氮素年周期 的利用、残留、损失及在土壤中的迁移动态。结果表明, 对春季土施尿素的利用率盛花期较低, 为11.38% , 至采收后达到最高。土壤氮素残留率盛花期最高, 为57.10% , 果实采后残留率最低。年周期中各土层氮素残留量不同, 盛花期20～40 cm土层残留量最高, 采收后最低, 0～20 cm土层在新梢旺长期残留量最高, 果实成熟期最低, 而40～60 cm土层在果实膨大期残留量达到最高, 在采收后0～20 cm土层残留有所增加, 其余各土层残留量均达到最低值。氮素损失与土壤残留呈相反的变化趋势, 氮素损失率在盛花期最低为31.53% , 随物候期的推迟逐渐升高, 在果实采后高达58.40%     

‘岩溪晚芦’椪柑果皮与果肉差减cDNA文库的构建及初步分析

 以‘岩溪晚芦’(Citrus reticulata Blanco)成熟果皮和果肉为材料,采用抑制性差减杂交技术,成功构建了果皮（tester）与果肉（driver）的差减cDNA文库。结果显示：cDNA克隆外源插入片段大小介于100～500 bp之间。成功对411个克隆进行了测序,测序结果经与NCBI基因库中序列进行比较,377个EST 找到了同源序列,它们分属于126个基因,涉及到与色素合成、能量代谢、初级代谢、次生代谢、抗逆防御、蛋白代谢、信号转导、香味形成、果皮软化（衰老）、精油合成、抗氧化代谢等代谢途径和生理生化过程。还有一些基因涉及到三价铁螯合物、反转录转座子gag蛋白、查尔酮合成、硼离子转运、儿茶酚氧位甲基转移酶等功能。功能已知且没有重复的EST共有63个,占总数的49.2%。有5个基因共62个克隆虽在Blast搜索时找到了较高的同源性序列,但功能目前尚未明确,有待进一步深入分析。另有34个基因未搜索到同源序列,可能为新发现的基因。     

The concept of habitat specificity revisited

Habitat specificity indices reflect richness (α) and/or distinctiveness (β) components of diversity. The latter may be defined by α and γ (landscape) diversity in two alternative ways: multiplicatively () and additively (). We demonstrate that the original habitat specificity concept of Wagner and Edwards (Landscape Ecol 16:121–131, 2001) consists of three independent components: core habitat specificity (uniqueness of the species composition), patch area and patch species richness. We describe habitat specificity as a family of indices that may include either area or richness components, or none or both, and open for use of different types of mean in calculation of core habitat specificity. Core habitat specificity is a beta diversity measure: the effective number of completely distinct communities in the landscape. Habitat specificity weighted by species number is a gamma diversity measure: the effective number of species that a patch contributes to landscape richness. We compared 12 habitat specificity indices by theoretical reasoning and by use of field data (vascular plant species in SE Norwegian agricultural landscapes). Habitat specificity indices are strongly influenced by weights for patch area and patch species richness, and the relative contribution of rare vs. common species (type of mean). The relevance of properties emphasized by each habitat specificity index for evaluation of patches in a biodiversity context is discussed. Core habitat specificity is emphasized as an ecologically interpretable measure that specifically addresses patch uniqueness while habitat specificity weighted by species number combines species richness and species composition in ways relevant for conservation biological assessment. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Regeneration of adventitious shoots from mature stored cotyledons of Japanese plum (Prunus salicina Lind1)

Adventitious shoot regeneration from mature stored cotyledons of Japanese plum (Prunus salicina Lind1) was achieved in vitro. The influences of the presence and absence of the light, different concentrations of thidiazuron (TDZ) and benzyladenine (BA) in the culture media, TDZ pretreatments and different basal salts on shoot regeneration were evaluated. TDZ was more effective in inducing shoot regeneration from mature stored cotyledons than BA. Dark incubation significantly increased the regeneration frequencies. Quoirin/Lepoivre (QL) basal salts stimulated shoot regeneration more than woody plant (WPM) or B5 salts did. The frequency of adventitious shoot formation varied among the varieties and the regeneration ability appeared to be genotype depended. The frequency of regeneration under the optimum tested conditions for ‘Bruce’, ‘Shiro’, ‘Redheart’, ‘Gladstone’ and ‘Early Golden’ cotyledons were 66.7%, 46.7%, 43.3%, 26.7% and 6.7%, respectively.     

Efficient plant regeneration via organogenesis in “Egusi” melon (Colocynthis citrullus L.)

Plant regeneration protocol of “Egusi” melon (Colocynthis citrullus L.) was established using three local (“Ejagham”, “Sewere” and “Barablackedge”) and one improved (NHC1-130) cultivars. Cotyledonary explants of different lengths (1/2, 1/4 and 1/6) excised from 4- or 8-day-old seedlings germinated in vitro were cultured on MS medium supplemented with different concentrations of 6-benzylaminopurine (BA). The best results were obtained when cotyledons from 4-day-old seedlings were cut into 2 (1/2) halves. Plant regeneration was optimal on medium containing 5 mg/l BA, yielding 86.3%, 77.0% and 76.3% shoot induction frequencies amongst the three local cultivars of “Ejagham”, “Sewere” and “Barablackedge”, respectively. In NHC1-130, the highest shoot induction frequency (85%) was obtained on medium containing 2 mg/l BA. Adventitious shoots were elongated on medium containing 0.1 mg/l BA and successfully rooted on hormone-free MS medium. Flow cytometric analysis revealed 70% of the plants to be diploid.     

Flower yield performance and stability of various Rosa damascena Mill. landraces under different ecological conditions

The flower yield stability of Damask rose as an important medicinal and aromatic plant at different environments has not been well documented. In order to evaluate flower yield and stability, 35 landraces of Damask rose were studied at 8 locations in Iran during 2007–2008. Analysis of variance revealed significant differences (p ≤ 0.01) among landraces (G), environments (E), locations (L) and for landrace × environment (GE) and landrace × location (GL) interactions. Both GE and GL interactions were mainly crossover, a large portion of which was accounted for by non-linear (unpredictable) component. The landraces of IS9, YZ2, WA1, IS7 and IS1 with 3120.63, 2941.63, 2894.62, 2769.15 and 2716.92 kg/ha respectively produced the highest flower yield among studied landraces. Kerman with average flower yield of 3635.46 kg/ha produced the highest yield among studied locations. According to the results, most of landraces that originated from temperate, warm temperate and arid regions produced higher flower yield than those from cool, cool temperate, semi-arid and humid regions. The landraces of YZ2, IS5, IS8, IS4, KZ1, AR1_, IS3 and BA1 were stable and YZ2, IS5, IS8, IS4, KZ1, AR1 IS6, IS3, BA1, IS10 and YZ1 were adaptable landraces for flower yield according to Eberhart and Russell (1966) model. The presence of some high flower yield and stable landraces such as YZ2 and IS5 suggests that a genotype can demonstrate high flower yield and stability for yield simultaneously. Thus, simultaneous selection for flower yield and stability using nonparametric methods could be possible. In addition, taking into consideration flower yield and stability potential, the landraces of YZ2, IS5, IS8, IS4 and KZ1 as general stable, adaptable, and high flower yield are recommended. Furthermore, the landraces of IS9 and WA1 as high flower yield and specific adaptable landraces can be recommended for temperate and arid areas and the landraces of IS7 and IS1 for semitemperate and cool areas.