云南地方稻种资源核心种质的微卫星分析

摘要：以来自云南地方稻(Oryza sativa L.)种资源核心种质中的113份材料为研究对象，运用36对微卫星引物，研究了籼(indica )粳( japonica )两个亚种间和云南5个稻作生态区间的遗传多样性分布趋势，并筛选了籼粳亚种、水陆生态型和不同生态区的特异指纹标记。结果表明，粳稻的遗传多样性大于籼稻，遗传分化水平较低；而5个生态区中滇西南水陆稻区遗传多样性最大，遗传分化水平较低；滇东北高原粳稻区的遗传多样性最小。这种遗传多样性的分布趋势与前人在形态和同工酶水平上对云南稻种资源多样性的考察，以及云南地方稻种资源核心种质在形态和同工酶水平上的遗传多样性分布趋势基本一致。另外，在所出现的416个指纹标记中，分别发现籼粳特异指纹标记6个，水陆特异指纹标记15个，不同生态区特异指纹标记3个。初步认为，云南地方稻种资源核心种质代表了云南省地方稻种资源的遗传多样性；从DNA水平上看，云南地方稻种资源的遗传多样性中心在云南省的西南部，粳稻的分化水平低于籼稻。微卫星标记是种质资源遗传多样性检测、分类和生态型确认以及核心种质研究中有用的工具。     

两系杂交水稻主要性状配合力与亲本籼粳分化关系的研究

选用4个光温敏核不育系及54个常规品种（系）,按NCII设计配制杂交组合,以籼粳特异RFLP标记及形态指数法检测供试品种（系）的籼粳分化程度,研究两系杂交水稻主要性状一般配合力及特殊配合力与双亲籼粳分化的关系。结果表明,①多数品种的籼粳遗传分化和形态分化相一致,只有个别品种不一致;②组合间一般配合力方差大于特殊配合力方差,基因加性效应更重要;③亲本的一般配合力效应及其特殊配合力效应对F     

江西省“籼改粳”发展现状及问题分析

近年来,"籼改粳"逐渐成为水稻研究领域的一个热门话题,我国各水稻种植大省纷纷开始籼稻改粳稻领域的探索。江西省作为我国一个水稻种植大省,在"籼改粳"领域的研究中取得了不错的成效。基于此,概述江西省当前推行"籼改粳"工程的现状,结合江西省地理位置和自然条件,分析江西省发展"籼改粳"的优势条件,并对比周边省市粳稻发展经验,提出在推行"籼改粳"过程中存在的部分问题以及建议。     

Rim2因子超级家族的分布及分子指纹技术 在水稻品种鉴定中的应用*

通过GenBank中230Mb水稻序列的对比分析,新鉴定的水稻Rim2因子家族编码亚组和假基因亚组不均匀地分布于12条染色体上,以着丝点区域分布频率为最高。由基因内缺失和插入使得Rim2因子序列多变,结合其众多的拷贝数尝试将其开发为一新的分子指纹。以水稻(Oryzasativassp.indica)品种R963及其育种亲缘材料为测试样本,尽管材料间可能存在极其相近的遗传背景,利用Rim2因子设计的5个引物,还是检测出材料间DNA水平的差异。采用同样引物,对2份杂交籼稻(O.sativassp.indica)和1份杂交粳稻(O.sativassp.japonica)组合及相应亲本的PCR检测,获得所有材料的特异指纹。Rim2因子可作为水稻品种鉴别的分子指纹,也可应用于杂交稻纯度的快速鉴定。     

Bt水稻"克螟稻"杂交后代中转基因的遗传表达及育种利用

利用GUS反应检测了Bt转基因粳稻(克螟稻)与籼稻、粳稻杂交的不同世代群体的叶片染色情况,结果发现粳粳交F2出现抗性株与非抗性株的3∶1的分离,籼粳交的BC1出现1∶1分离,籼粳交的BC1F2出现3∶1分离,表明转基因在杂交后代的传递属单基因显性遗传.利用Western 点杂交技术结果发现F1、F2 和BC1代的Bt蛋白表达量均超过转基因株供体,呈现出表达能力上的杂种优势.农艺性状考察结果发现,无论是籼粳交,还是粳粳交后代,两者在株高、穗长、单株分蘖数、播始历期和千粒重上无显著差异.这无疑为Bt水稻的育种利用提供了良好的证据.     

外源芸苔素内酯对不同基因型杂交稻开花期耐热性的影响

为了明确不同基因型杂交稻对高温耐受性的差异及芸苔素内酯(BR)对提高不同类型杂交稻耐热性的作用效果,本研究以杂交籼稻、偏籼型籼粳杂交稻和偏粳型籼粳杂交稻各2个品种为材料,在开花期设置常温、高温和高温下喷施0.15%BR 3种处理,分析其对水稻产量及产量构成因素、花粉活力和抗氧化能力等的影响。结果显示,高温导致杂交稻的结实率、单株产量和花粉活力显著下降,其中杂交籼稻耐热系数为0.73,显著高于偏粳型籼粳杂交稻(耐热系数0.47)。而高温下喷施BR可以显著提高水稻结实率、单株产量和花粉活力,杂交籼稻、偏籼型和偏粳型杂交稻恢复系数分别为1.23、1.43和2.00,以偏粳型杂交稻的缓解效果最明显。喷施BR降低了高温处理下不同基因型杂交稻的超氧阴离子含量,并提高了甲基乙二醛酶(GlyⅠ)活性及抗坏血酸(AsA)、谷胱甘肽含量(GSH),同时改变了抗氧化酶相关基因OsAPX1、OsCATB、OsGPX3和OsGLYI8的表达水平。综上可知,杂交籼稻常温下产量表现低于籼粳杂交稻,但具有较强耐热性,高温下喷施BR对杂交籼稻产量下降的缓解效果明显低于籼粳杂交稻;籼粳杂交稻尤其是偏粳型,尽管对高温表现敏感,但与BR的相互作用可有效抵御高温胁迫,喷施后产量可接近或达到常温对照水平。本研究结果为提高杂交水稻开花期耐高温能力的研究提供了理论基础和实践经验。     

利用基础导入系群体定位氮胁迫下水稻产量性状QTL

水稻产量性状的遗传机制复杂,在低氮胁迫下进行QTL定位,可为产量性状遗传机制的解释、基因的精细定位和克隆提供参考价值,也可为筛选耐低氮水稻材料提供有价值的参考.本研究以66个水稻籼粳交片段导入系群体[粳稻(Oryza sativa ssp,japonica)楚粳12是供体亲本,籼稻(O.sativa ssp,indica)蜀恢527是受体亲本,采用回交和分子标记辅助选择相结合的方法构建]为定位群体,利用单标记作图法,对正常与低氮胁迫条件下水稻有效穗、单株产量、株高和生物学产量等性状进行QTL定位.共检测到24个QTLs,20个为新检测出的QTL,而qph-1、qpn-1、qby-2、qby-4与前人研究结果相似,另外,qph-1a和qph-1b为在不同处理下均能影响株高的位点;生物学产量的QTL仅在低氮处理下被检测到;qpn-2b与qyd-2具有共同的连锁标记RM521;qpn-1b、qpn-2a、qpn-2b等加性效应值都小于1.结果表明,低氮胁迫明显影响单株有效穗、单株产量和生物学产量,且导入系群体检测微效QTL的能力较强.     

籼粳杂种后代支链淀粉结构及其与稻米糊化特性相关性分析

为了探讨利用优质粳稻改良灿稻品质的可行性,以食味品质极佳的粳稻品种越光为母本、食味品质差的籼稻品种桂朝2号为父本构建的重组自交系群体(RIL)为试验材料,研究了籼粳杂种后代的支链淀粉结构变异特征及其与稻米胶稠度、起始成糊温度和RVA谱特征值的相关关系。结果表明,在RIL群体中,所有性状呈现连续分布,且双向超亲分离明显,双亲平均值除最高粘度和崩解值低于低亲值外,其余性状均介于双亲之间。RIL群体中支链淀粉短链(6≤DP≤11)分配比率表现为籼型偏籼型偏粳型粳型,中链(12≤DP≤24)分配比率表现为籼型偏籼型偏粳型粳型,存在极少量短链分配率较高而中链分配率较低的灿型株系,说明利用优质粳稻与籼稻杂交,其后代的籼粳特性对稻米支链淀粉结构有较显著影响,但通过加强后代选择,也可以选到支链淀粉结构象粳型的优良株系。在RIL群体中,支链淀粉短链分配率与起始成糊温度呈极显著负相关,中链分配率与起始成糊温度呈极显著正相关,长链分配率与消减值呈极显著负相关关系,而支链淀粉链长与胶稠度和RVA谱其他特征值的相关性表现因种植地点不同而有差异。研究结果为灿粳亚种间杂交育种的品质改良提供了理论参考。     

GENETIC ANALYSIS AND GENE FINE MAPPING FOR MUTATION OF YELLOW-GREEN LEAF IN RICE

通过甲基磺酸乙酯（EMS）诱变晚粳稻品种秀水09,获得了1个稳定遗传的全生育期黄绿叶突变体Ygl,遗传分析表明该突变性状由1对隐性核基因控制。利用突变体与籼稻品种珍汕97杂交,构建F2群体对突变基因进行定位,发现目的基因与第11号染色体上的SSR标记RM2459连锁,在该标记附近发展了14对InDel标记,将突变基因定位在约82kb区间内。通过在线最新水稻注释系统的基因功能预测分析,寻找候选基因,经测序发现突变体发生单碱基突变。     

Bt水稻“克螟稻”杂光后代中转基因的遗传表达及育种利用

利用ＧＵＳ反应检测了Ｂｔ转基因粳稻（克螟稻）与籼稻、粳稻杂交的不同世代群本的叶片染色情况,结果发现粳粳交Ｆ２出现抗性株与非抗性株的３：１的分离,籼粳交的ＢＣ１出现１：１分离,籼粳交的ＢＣ１Ｆ２出现３：１分离,表明转基因在杂交后代的传递属单基因显性遗传。利用Ｗｅｓｔｅｒｎ点杂交技术结果发现Ｆ１、Ｆ２和ＢＣ１代的Ｂｔ蛋白表达量均超过转基因株供体,呈现出表达能力上的杂种优势。农艺性状考察结果发现,无论是     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.