942 resultados para cultivated tomato
Resumo:
近几十年来,栽培作物及其野生近缘(祖先)种的群体遗传结构和进化历史的研究日益受到关注,因为此类研究不仅能加深人们对作物起源和驯化的认识,而且有助于作物野生资源的开发以及作物的遗传改良。分子谱系地理分析(Molecular phylogeography)是此类研究中的重要手段之一,能够有效地了解近缘群体的进化历程以及重建作物的驯化历史。菰(Zizania latifolia Turcz.)是东亚广泛分布、具有重要价值的水生草本植物,其栽培型—茭白是中国第二大水生蔬菜。尽管已有不少涉及此类群的研究,但迄今我们对菰的群体遗传结构和进化历史以及茭白的起源几乎一无所知。本研究从29个基因片段中筛选了2个在菰种内水平上具有显著变异量的核基因片段,进行了分子谱系地理研究,揭示了菰的遗传多样性水平及其地理分布格局,探讨了菰的群体演化历史,并初步探讨了茭白的起源和驯化历史。主要结果如下: 1)基因片段筛选 开展分子谱系地理学研究,需要采用具有显著种内变异的分子标记,为此我们通过预实验对一批备选基因片段进行了筛选。在18个叶绿体和2个线粒体片段中,测序的总长度达17100 bp,但没有发现任何变异位点。在9个核基因片段中,7个片段具有变异位点,但只有2个片段的变异量在1%以上,分别是Adh1a(2.70%)和GPATb(1.25%)基因。所以,本研究最后确定了采用这2个核基因片段来进行菰的分子谱系地理的研究。 2)Adh1a基因谱系地理分析 对来自21个天然群体126个个体,通过Adh1a基因的直接PCR和克隆测序共得到了252条序列,中性检测表明,Adh1a基因符合中性进化模型、没有重组并且有足够的变异量,适合用于进行菰的谱系地理研究和进化历史的推断。在物种水平上,菰的核苷酸多态性水平为θsil = 0.0089,跟一些作物近缘类群相比处于中等偏低的水平;不同群体的核苷酸多态性水平相差明显,多态性最高的群体出现在东北地区,并有从北向南递减的趋势。群体间存在着显著的遗传分化(FST = 0.481)表明群体之间的基因流有限。群体间的遗传距离与地理距离没有相关性,地理邻近的群体并没有共享关系相近的单倍型,整个群体缺乏明显的谱系地理结构。目前的遗传多样性分布格局可能是由于近几十年来的生境退化和丧失造成过去群体的片段化所致。根据群体遗传多样性水平的差异和基因谱系的地理分布格局以及分子钟估算的与北美近缘种的分化时间,我们推断菰的群体经历了从东北向华南逐步扩散的过程。 3)GPATb基因谱系地理分析 为更可靠地推断菰的谱系地理格局,我们选择了GPATb基因作为标记开展了进一步的分析。对相同的采样群体和个体共252条序列的分析表明,在物种水平上,GPATb的核苷酸多态性只相当于Adh1a基因的1/4。综合2个基因的结果,可以认为菰的核苷酸多态性水平是维持在较低的水平上。该位点体现的群体遗传分化也没有Adh1a基因明显。群体之间相近的遗传多样性水平和较低分化程度可能意味着该基因位点受到平衡选择作用的影响,这一推论也得到了中性检测结果的支持。因此,GPATb基因可能受到选择作用的影响,不能用来支持或推翻Adh1a基因的结果。 4)茭白的起源和驯化 对来自13个省份的65个茭白品种的Adh1a和GPATb基因片段进行测序,结果发现,所有的品种在这2个基因上都具有相同的基因型,Adh1a位点上表现为杂合体,而GPATb位点上则是纯合体。这说明在茭白的起源过程中发生了严重的驯化瓶颈效应,也即茭白是单次起源的,是从菰的少数几个甚至单个个体驯化而来。虽然文献考据表明,茭白最早的栽培地区为太湖流域,但我们的分子证据却并不支持其为茭白的驯化起源地点,而可能是在太湖流域以北地区起源的。鉴于采样的局限性,这一结论还有待于进一步的验证。同时2个基因的数据表明来自陕西、四川、云南、湖南和福建的6个菰群体可能是从人为引种的茭白逃逸成为野生的。因此,在以后野生菰群体的采集中,特别是在茭白种植地区,要在详细调查的基础上设计采集方案。
Resumo:
野大豆群体3和群体4属盐渍群体,其个体有的是抗盐的,有的是敏感的,有的是中等抗盐的,本文通过随机扩增多态性DNA (RAPD)和DNA扩增指纹(DAF)分析野大豆群体抗盐性与分子标记之间的关系,从而更好地研究野大豆群体的盐适应机理。通过12个RAPD引物和3个DAF引物扩增发现:引物OPF05,OPF19和OPH02的扩增产物中有与抗盐性可能相关的特异标记,分别是OPF05_(213);OPF19_(4361);OPF19_(1727);OPF19_(1400);OPF19_(700);OPH02_(1350)。这些特异标记在所研究的抗盐植株中都存在;在敏感型植株中都不存在;在中等抗盐植株中有的存在,有的不存在。以上表明野大豆群体的抗盐性与RAPD分子标记有一定的相关性。为进一步研究抗盐性的特异标记,本文对栽培大豆抗盐品种Morgan和文丰七号的特异DAF标记片断8-27_(240) (Zhong et al., 1997)进行了克隆测序,测序结果通过BLASTn程序与基因库中的基因序列进行同源比较,发现上的DNA序列中的19组(每组大约二十到三十个碱基)序列与基因库中的其它基因相应序列有很高的同源性,几乎全部100%同源。尤其目的序列第15个碱基到第33个碱基(共19个碱基)之间的序列与基因库中的25个基因的相应序列的同源性全部是100%,并且与之相比的基因大多来自动物和人。因而推测其有可能是保守区,而不是编码区。进一步用DNASIS软件分析其碱基组成(A/T含量是64.9%,G/C含量是35.1%)并进行翻译,结果同样表明此序列可能是一调控序列并非编码区。至于这段序列是否与抗盐紧密相关,这有待于以后把此序列转到敏感型植株中然后检测其抗性来验证。 本文还通过RAPD分析野大豆群体3和群体4的多态性,发现群体3的多态性明显高于群体4。野大豆群体3的抗盐性大于群体4早已通过生理指标的鉴定,至于多态性与抗盐性之间是否有必然联系,还需进一步研究讨论。利用RAPD数据,通过MEGA软件中的NJ计算遗传距离的方法对群体3和4进行聚类分析,研究野大豆群体间及群体内个体间的亲缘及进化关系,探讨野大豆群体盐适应机理的分子起源。
Resumo:
甜菜碱是植物在盐、干旱或其它胁迫下在细胞中迅速积累的一种相容性有机小分子化合物,它在细胞中的积累与植物抗盐性的提高密切相关。甜菜碱醛脱氢酶(BADH)催化甜菜碱醛转化为甜菜碱。我们将来源于耐盐植物山菠菜(Atriplx hortensis L.)的BADH基因通过农杆菌介导法导入‘百丽春’番茄(Lycopersicon esculentum L. ‘Bailichun’)中,并获得15株转化植株,PCR、Southern和Northern检测表明,其中的6株有外源BADH基因的整合,5株中BADH基因能够正常表达,但不同植株间BADH基因的表达水平和BADH酶活力有较大差异。对叶片电导率的测定表明,转基因植株比野生型的耐盐性有较大提高。T1代分析表明,检测的两个转基因株系后代遵循孟德尔分离规律,90mmol/L NaCl胁迫下种子发芽率提高了2~4倍,幼苗的苗高、根长和须根数三个指标均明显优于对照。部分T1代植株在水培条件下能够耐受180mmol/L NaCl胁迫。 植物耐盐的另一机理就是利用液泡膜上存在的转运蛋白将细胞内的有毒离子区域化。我们将已转入编码转运蛋白基因AtNHX1的番茄品种‘Moneymaker’(L. esculentum‘Moneymaker’)株系X1OEA1通过农杆菌介导法转入山菠菜BADH基因,以期获得转双基因耐盐番茄。目前已获得转基因植株,PCR结果证明部分抗性幼苗中已整合了BADH基因,其它各项分子检测正在进行中。
Resumo:
近年来,植物耐盐生物技术研究取得了可喜的进展,特别是通过抗盐基因转化在一定程度上使植物的耐盐性得到了提高。然而,植物的耐盐性是一个多基因控制的复杂性状,依赖于多个基因之间的相互作用。因此,只是将单个基因导入植物获得的抗逆性还是远不能达到满意的效果。一般认为,将多个与耐盐相关的基因转入到同一个植物(即所谓的“复合基因转化”)将会大大提高转基因植物的耐盐能力。 渗透调节是植物抵御盐胁迫的主要方式。植物渗透调节的方式分为两类:一是在细胞中吸收和积累无机盐,如通过离子通道、Na+/H+逆向运输蛋白和ATP酶/H+泵;二是在细胞中合成有机溶质,如脯氨酸和甘氨酸甜菜碱。 我们通过农杆菌介导法向转AtNHX1(拟南芥Na+/H+逆向运输蛋白编码基因)的番茄(Lycopersicum esculentum L. ‘Moneymaker’)株系X1OEA1自交二代植株(T2)中转入山菠菜甜菜碱醛脱氢酶基因(BADH)。PCR、Southern、RT-PCR和甜菜碱含量分析结果证明,BADH已经整合到目标植物基因组,并在转基因植株中转录和翻译表达。叶绿素荧光(Fv/Fm)、相对电导率(Rc/Rc’)、叶绿素含量(Chla+b)、叶绿素a/b比(Chla/b)和光合速率(Pn)测定结果表明,在200 mM NaCl 胁迫下,二次转化的番茄植株各项生理指标均优于转单基因AtNHX1的番茄。初步证明“复合基因转化”有助于进一步提高植物的耐盐性。同时对番茄的转化系统进行了优化,结果表明使用抗生素‘特美汀’作为抑制农杆菌的抗生素的转化效率明显高于使用头孢霉素。
Resumo:
土壤的盐碱化问题已经严重影响到世界范围内许多重要作物的生产。培育耐盐作物是解决这一问题的最有效途经。利用耐盐相关基因的转化可以在不改变或很少改变植物其它性状的情况下提高植物的耐盐性,因此基因工程方法对于改良植物耐盐性及其机理的研究具有重要的意义。目前植物耐盐基因工程从调控渗透调节物质和盐离子区隔化两个方面开展了较多的研究。已经获得一些耐盐性提高的转基因植物。 本研究拟用耐盐性较强植物山菠菜中的甜菜碱合成关键基因BADH和盐生植物盐角草的液泡膜Na+/H+ anitiporter基因SeNHX1对模式植物烟草进行转化,以确定其各自在耐盐性方面所起的作用。同时,现有的研究表明植物的耐盐性是多基因控制的复杂性状,因此拟把SeNHX1和BADH 这两个涉及不同耐盐机理的基因构建到同一个植物表达载体上,以比较单基因转化和双基因转化在提高植物耐盐性方面的优劣。除此之外,并对已经转入BADH基因番茄的耐盐性和遗传稳定性分析进行了研究。 转BADH基因番茄已经稳定遗传到T4世代。通过对5个转BADH基因番茄株系在T0世代、T3世代和T4世代的分析,表明除了株系T4-3由T0世代的3个拷贝变为1个拷贝外,其余各株系拷贝数均没有发生变化。外源基因编码的酶活性和最终催化产物甜菜碱在盐分胁迫下都能较容易的检测到,说明外源基因在番茄基因组中的遗传是稳定的,没有发生丢失。在连续2个世代的耐盐性鉴定中,各转基因株系的耐盐性较为一致,均比野生型有了较大的提高。其中株系T4-5连续2年表现出了较低的减产率,株系T4-8也在连续的2年中表现出了最高的单株产量。盐分胁迫下转BADH基因各个株系比野生型有较高的K+和Ca2+含量,较低的Na+含量,转基因株系较野生型有较低的脐腐病果率。 通过SeNHX1、BADH单独转化以及构建双价载体共转化的方法获得了3种类型的转基因烟草。Southern和Northern 检测结果表明,外源基因已经整合到烟草基因组中,并得到了正确的表达。转BADH基因烟草在盐分胁迫下能检测到明显的BADH酶活性和甜菜碱含量。转基因烟草T0代对盐分胁迫、氧化胁迫的抗性均较野生型对照有较大的提高。转基因株系在200 mM NaCl胁迫下较野生型有较高的光合速度。百草枯处理过的野生型叶盘比转基因株系积累了更多的丙二醛,表明野生型受到了更大的氧化胁迫。 已经获得3种转不同基因烟草的T1代,且T1代具有较强的耐渗透胁迫能力。转基因烟草的T0种子均能在含100 mg/L 卡钠霉素培养基上发芽和正常生长,其中部分种子能够在含200 mM NaCl 培养基上发芽并能较好的生长,而野生型根本不能发芽。从200 mM甘露醇胁迫1周后,又转移到营养液中的生长1周的情况来看,转基因烟草能较快的恢复正常的生长,有新的叶子和根长出,而野生型却不能,同时转基因株系比野生型具有更大的单株鲜重。 转BADH基因番茄在遗传上是稳定的,并且其耐盐性有了较大的提高。双基因转化烟草的抗盐性要好于单基因转化,但SeNHX1基因转化要好于BADH基因转化。说明SeNHX1基因在提高植物耐盐性方面要比BADH基因有更强的功能,同时,也表明多基因转化在植物的耐盐改良方面可能是一个更为有效的方法。
Resumo:
植物激素乙烯作为一种信使分子调节控制果实完熟。ACC合成酶是植物体内乙烯生物合成途径的限速酶,其反义RNA的表达将能有效地抑制乙烯的生物合成而延缓果实完熟,利用反转录PCR技术克隆获得了ACC合成酶多基因家族成员之一LE-ACC2阅读框架约1.7kb的cDNA,经酶切图谱和序列分析鉴定无误后,反向连入植物表达载体pBin437中构建成组成型表达ACC合成酶反义RNA的双元载体。经农杆菌途径转化番茄“丽春”品种,获得了60株抗卡那再生杭株,PCR检测证明有6株为转基因植株,Southern杂交和Northern杂交分析进一步确证了外源基因的插入及其转录活性。反义番茄果实的乙烯释放受到明显抑制,表现出更好的耐储保鲜特性,并且与对照相比,在果实品质上没有明显差别。大田培育Fl和F2代转化番茄植株,反义番茄纯合品系的筛选工作正在进行之中。 同时,本研究利用已经获得的ACC合成酶和PG的cDNA克隆,构建了两个嵌合转化基因载体pPGACC1、pPGACC10,它包括1300bp的ACC合成酶cDNA编码序列,并分别含有反向与正向的250bp的5’端PG基因片断。酶切图谱和序列分析鉴定无误后,以pBin437为植物表达载体构建了双元载体pBPGACC1和pBPGACC10,分别表达PG正义RNA和反义RNA,并均表达ACC合成酶反义RNA。经农杆菌转化番茄子叶,植株的再生培育有待进行。通过对转基因植物的分析,我们期望阐明用单一嵌合基因表达载体通过反义抑制与抑制作用实现对内源两同源基因——PG和ACC合成酶下降调节的可能性,并可望得到具有更好耐储效果且品质优良的番茄品系。
Prospects of integration of aquaculture with animal husbandry and land crop culture in Tripura State
Resumo:
Tripura is a densely populated small state with meagre water resources. 47.51% of the population is constituted by socio-economically backward, illiterate, orthodox, tribal and scheduled castes. Some of them are nomad and a majority of the rest of the population is refugees from Bangladesh, but almost 100% is fish eater. Settlement of tribes in villages, provision of nutritious food and employment therefore calls for proper utilization of every resource they have. The State is poor in water resources but recently has created 21,636.23 ha of new water area. Tripura is rich in pig population, besides poultry birds. Paddy is the main crop cultivated in arable lands. An integration of livestock raising and land based agriculture with pisciculture practices around mini barrages will help in solving the problems to a great extent. The paper is an attempt to outline the prospects of integration of aquaculture with animal husbandry and land based crop culture in Tripura State.
Resumo:
Fish ball in curry was prepared as per the standardized method and recipe, pasteurized and subjected to storage at 0 to 2°C in a domestic refrigerator. The curry prepared with tomato at a level of 20% of onion was found to be suitable organoleptically. A level of 3% of spice mixture improved the taste of curry. Fish balls prepared with concentrated curry paste and oil at a level of 0.5% was found to be suitable organoleptically. Curry prepared by adding oil at the rate of 3% scored high values for all attributes as compared to other levels. Curry prepared by diluting curry paste with water at rate of 20% had been adjudged the best as compared to other water levels. Fish ball in curry with a 50 : 50 ratio pasteurized at 85°C for five minutes had scored higher values under organoleptic evaluation. It was observed that the product was acceptable organoleptically up to the 12th day when stored at 0 to 2°C.
Resumo:
番茄(Lycopersicon esculentum Miller)原产于南美西部高原地带,适应原产地赤道附近高地干燥冷凉的气候特点,不耐高温多湿,种子萌发期间对高温非常敏感。本研究以佳粉17番茄种子为材料,试图寻找诱导番茄种子萌发期间高温耐性的方法,并通过研究高温耐性被诱导前后种子内部发生的生理生化变化,探索番茄种子萌发期间不耐高温以及高温耐性诱导的机理。试验结果显示: 25 ℃是种子萌发的最适温度,种子发芽率为97.5%。高温抑制种子的萌发,33 ℃和35 ℃条件下萌发率分别为58.5%和8.5%。 萌发适宜温度预吸胀、低温预吸胀、吸湿-回干预处理可提高番茄种子萌发期间的高温耐性,而水杨酸处理则没有明显效果。种子经25 ℃预吸胀30 h、0 ℃预吸胀10 h、吸湿-回干预处理后在33 ℃条件下的萌发率分别为81.5%、78.0%、90%,在35 ℃下的萌发率分别达到33.5%、42%、48.5%。经以上处理后,种子萌发速率提高,萌发高峰期提前,幼苗生长健壮,根干重增加,活力指数变大。 番茄种子萌发期间遭受高温危害时,电解质渗漏增加,相对电导率升高;脂膜过氧化作用加剧,其产物MDA的含量增加。经萌发适宜温度预吸胀、低温预吸胀、吸湿-回干等方法预处理后,高温伤害减轻,膜的完整性增强,电解质渗漏减缓,膜脂过氧化作用减弱,因而相对电导率降低,MDA含量减少。 高温抑制了抗氧化酶的活性,种子内部SOD、APX、CAT、GR等抗氧化酶活性降低。经萌发适宜温度预吸胀、低温预吸胀、吸湿-回干等方法预处理以后,抗氧化酶活性有不同程度的提高,清除细胞内超氧阴离子自由基的能力增强,因而使过氧化伤害减弱, 适宜温度预吸胀、低温预吸胀、吸湿-回干等预处理方法在保护生物膜的同时,增强抗氧化作用,抑制过氧化伤害,从而提高了番茄种子萌发的高温耐性,这是番茄种子高温耐性提高的生理机制之一。
Resumo:
The study was conducted with the broad objectives to assess the existing situation of broodstock management and fish seed production in private fish seed farms in Bangladesh. The data were collected from 100 private hatcheries and 40 nurseries in seven upazilas under four districts. There was no shed in forty hatcheries and the owners faced many problems. Brood fish ponds were found suitable for rearing brood fish. About 66% of the hatchery owners collected brood fish from their own ponds and ponds of neighboring areas. Activities like pond preparation; manuring and supplementary feeding were done properly but stocking density of brood fish in 76% of the hatcheries was 3,000-7,000 kg/ha. Infection of argulosis was found in brood fish of 87% of the hatcheries. About 67% of the hatchery owners practiced inter-species crossing. Major problems faced by the hatchery owners were argulosis of brood fish, unavailability of pure brood stock, inadequate brood fish pond. The hatchery owners were found interested to find out the preventive measures of argulosis, develop pure brood stock of indigenous carp and import pure strain of exotic carp. According to the nursery operators, they cultivated hybrid fry because of high demand, rapid growth and good taste. Problems of using hatchery spawn as mentioned by the nursery operators were inbreeding, under sized and aged brood stock, stunted growth, physical deformities and high mortality of spawn due to unknown causes.
Resumo:
Pieces of catla fish (Catla catla, a major carp of lndian subcontinent) of length 10 to 11 cm and thickness 1.0 to 1.5cm were precooked by two methods; steam precooking and frying. The precooked pieces were packed_in No.1 tall can (30lx411) with various hot filling media like oil, brine, tomato sauce and curry. Cans were seamed by a hand seamer and retorted at 117.2° C (12 psi) for 90 minutes. All the canned products had satisfactory cut-out, biochemical and organoleptic characteristics. Steam precooked canned products had moisture content of 65.6 to 74%, protein content of 20.8 to 22%, fat content of 1.1 to 6.6% and ash content of 2.1 to 2.5%; whereas fried canned products had moisture content of 65.4 to 68.2%, protein content of 21.3 to 22%, fat content of 7 to 10.2% and ash content of 2.1 to 2.7% on wet wt. basis. Salt content in steam precooked and fried canned products varied from 1.2 to 1.9% and 2.0 to 2.5% respectively. All the canned products were organoleptically good. However, degree of preference varied for different products. Canned fried catla in curry was the best product among all types of packs. Among the precooking methods, frying was more efficient than steam precooking in controlling the amount of exudate to a desirable limit in canned products. However, crispness, the characteristic quality for a fried fish, was lost during retorting. There was no change in quality characteristics during a storage period of 3 months at ambient temperature (32±2°C).
Resumo:
Ten restriction endonucleases were used to investigate the mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) of 11 native cattle breeds and one cultivated cattle breed in South China. Twenty-three restriction morphs were detected, which can be sorted into five haplotypes, A phylogenetic tree of the haplotypes was constructed by using the 'upgma' method. Our study showed that haplotype I and II are identical to the zebu (Bos indicus) and taurine (Bos taurus) haplotypes, respectively. Zebu and taurine were the two major origins of cattle populations in South China, and the zebu probably had more influence on the native cattle population than taurine did. Haplotype III is identical to haplotype I of yak (Bos grunniens), which was only detected in the Diqing cattle breed. Haplotype IV was detected for the first time. This haplotype, found only in Dehong cattle, might be from an independent domestication event, probably from another Bos indicus population. Divergence of haplotypes I and IV occurred about 268,000-535 000 years ago, much earlier than the 10,000-year history of cattle husbandry. Our results also suggest a secondary introgression of mtDNA from yak to Diqing cattle.
Resumo:
Batch cultures of C. calcitrans were maintained indoors at a temperature range of 21 to 25 C and continuously illuminated by 40-watt daylight fluorescent lights. Cultures were exposed to 5 different intensities from 200 to 25,000 lux.Population counts show that light intensity affects growth and reproduction of the algae cultivated. A comparison of population peak growths showed cultures illuminated by 12,000 lux to have higher cell counts than those exposed to higher or lower light intensities.
Deep RNA sequencing at single base-pair resolution reveals high complexity of the rice transcriptome
Resumo:
Understanding the dynamics of eukaryotic transcriptome is essential for studying the complexity of transcriptional regulation and its impact on phenotype. However, comprehensive studies of transcriptomes at single base resolution are rare, even for modern organisms, and lacking for rice. Here, we present the first transcriptome atlas for eight organs of cultivated rice. Using high-throughput paired-end RNA-seq, we unambiguously detected transcripts expressing at an extremely low level, as well as a substantial number of novel transcripts, exons, and untranslated regions. An analysis of alternative splicing in the rice transcriptome revealed that alternative cis-splicing occurred in similar to 33% of all rice genes. This is far more than previously reported. In addition, we also identified 234 putative chimeric transcripts that seem to be produced by trans-splicing, indicating that transcript fusion events are more common than expected. In-depth analysis revealed a multitude of fusion transcripts that might be by-products of alternative splicing. Validation and chimeric transcript structural analysis provided evidence that some of these transcripts are likely to be functional in the cell. Taken together, our data provide extensive evidence that transcriptional regulation in rice is vastly more complex than previously believed.
Resumo:
This paper presents data and findings from focus group discussions in study communities selected by the CGIAR Research Program on Aquatic Agricultural Systems (AAS) in the Western Province of Zambia. The discussions focused on cultivated crops and vegetables collected from open fields and consumed as food. Participatory tools for agricultural biodiversity (agrobiodiversity) assessment were used to capture community perspectives on plant species and varietal diversity; factors influencing the availability and use of plants for food; unique, common and rare crop species cultivated in a community, identified through a four-cell analysis methodology; and core problems, root causes, effects and necessary actions to tackle them, using problem tree or situation analysis methods.