日本臭菘体细胞胚胎发生及植株再生体系的建立

以日本臭菘幼叶为外植体,应用均匀设计法筛选其最适合的胚性愈伤组织及胚性细胞复合体诱导、体细胞胚胎发育及植株再生的培养基配方,建立日本臭菘体细胞胚胎发生体系。结果表明,LS+6-BA 1.0 mg/L+2,4-D 2.0 mg/L+IAA 0.1 mg/L适宜日本臭菘幼叶胚性愈伤组织及胚性细胞复合体诱导,诱导率为98%;LS+6-BA 0.50 mg/L+NAA 0.10 mg/L+IAA 0.10 mg/L最适宜体胚发育及植株再生,体胚萌发率为100%,萌发的体胚在发育培养基上继续培养42 d后全部发育成完整植株。对不同阶段培养材料的形态结构及超微结构的观察证明,成功建立了日本臭菘体细胞发生及植株再生体系。     

快中子辐照对花生胚小叶体细胞胚胎发生的影响

以花生品种鲁花11号成熟干种子为试材,经快中子0、9.7、14.0和18.0Gy辐照后,取胚小叶外植体接种于添加10.0mg/L 2,4-D的MSB5诱导培养基上诱导体细胞胚胎发生。培养4周后,将其转移到添加4.0mg/L BAP的培养基上进行培养。结果表明,快中子辐照处理对胚小叶组织培养及体细胞胚胎发生有很大影响。未...     

乌拉尔甘草胚状体的诱导及再生体系的建立

用L9(34)正交试验设计方法研究了乌拉尔甘草外植体、植物生长调节剂对胚状体诱导的影响,并对胚状体诱导和成苗技术进行了探索。结果表明:适宜乌拉尔甘草胚状体诱导培养的最佳外植体为芽,优化培养基为MS+甘氨酸0.3g/L+蔗糖30g/L+琼脂5g/L+2,4-D0.2mg/L;2,4-D对胚状体诱导具有促进作用。适宜胚状体诱导成苗的最佳外植体为芽,培养基为MS,成苗率达到66.67%,外源激素对胚状体诱导成苗具有抑制作用。     

花生体细胞胚胎发生的组织细胞学研究

成熟花生胚轴在MS 40mg/\L2,4-D 0.5mg/L KT培养基中可直接诱导产生体细胞胚，降低2，4-D的浓度，将诱导产生的体细胞胚组织块继代2-3次可诱导产生出米黄色颗粒状的胚性愈伤组织，继而产生体细胞胚。花生体细胞胚直接诱导起源于表皮或近表皮的细胞，其形成经历了跟合子胚相似的过程。花生胚性愈伤组织的细胞具有细胞小、胞质浓、核大、核仁明显，排列紧密的特点。经愈伤组织形成的体细胞胚以单细胞内起源方式发生。首先由体细胞胚单个原始细胞分裂形成2-细胞原胚，2-细胞原胚继续分裂成3-细胞原胚或4-细胞原胚，3-细胞原胚或4-细胞原胚继续分裂形成多细胞原胚，进一步发育形成一个完整的体细胞胚。     

高羊茅高频植株再生体系的建立及其影响因子的分析

研究了高羊茅(Festuca anmdinacea)愈伤组织诱导培养基和分化培养基组分的最适配比，建立了高羊茅高频再生体系。结果表明，培养基MSM 5mg／L 2,4-D 0．02mg／L KT诱导高羊茅种子出愈率高达92％；愈伤组织可在培养基MSM 4．5mg／L 2,4-D 0．2mg／L KT上长期保持；愈伤组织在培养基MSM 2mg／L 2,4-D 0．2mg／L KT诱导体细胞胚发生后，可在添加2mg／L KT和20mg／L蔗糖的SH培养基(MSH)上诱导分化形成丛生芽，愈伤组织分化率可达96％。再生芽在1／2MS培养基上14d生根率达100％。     

苹果离体叶片培养直接体细胞胚胎发生的形态学研究

研究了苹果离体叶片直接体细胞胚胎发生体系和外植体直接体细胞胚胎发生过程中的形态学特征。结果显示 ,苹果直接体细胞胚胎发生过程经历原胚、球形胚、心形胚、子叶形胚、成熟胚等阶段 ;子叶形胚以前的阶段没有观察到形态学多样性 ,发育至子叶形胚期的直接体细胞胚胎表现出形态学多样性 ,分别观察到一子叶胚、两子叶胚、三子叶胚、杯状胚、多子叶胚、畸形胚等 ,这些类型的胚最终都能发育成正常的成熟胚进而发育成小植株。     

不同激素不同外植体对苜蓿品种再生的影响

试验以4种苜蓿的子叶和下胚轴为外植体,采用了11种愈伤诱导培养基,10种分化培养基,研究了不同品种、不同激素处理和不同外植体对苜蓿愈伤和芽分化的影响。结果表明,不同品种苜蓿、不同外植体均容易形成愈伤组织;2,4-D是苜蓿愈伤组织形成的主要因素;在0.8mg/L2,4-D 2mg/LKT的作用下,下胚轴和子叶愈伤诱导率最高为100%;在4mg/L6-BA的作用下,子叶再生芽率最高为43.9%;在KT浓度为1mg/L时子叶芽的再生率最高为33.3%。     

甘蓝类植物小孢子培养及植株再生研究

对3个甘蓝类植物(甘蓝、青花菜、羽衣甘蓝)19个品种小孢子胚胎发生和植株再生的影响因素进行了研究,结果表明,基因型不仅影响供试材料的小孢子胚状体发生频率,也影响胚状体的质量;4℃低温预处理0 ～2d结合32.5℃热激1d,能显著提高供试基因型小孢子出胚率.胚状体先在NLN-13液体培养基中培养25d,有利于胚状体分化成苗;后在B5固体分化培养基中添加1％ ～1.2％琼脂,可有效促进胚状体萌发和植株再生.小孢子再生植株先使用流式细胞仪在生长初期鉴定倍性,后对单倍体植株采用200mg·L-1秋水仙碱浸根处理20h,并用流式细胞仪鉴定,此方法可快速、有效地获得双单倍体植株.     

棉花体细胞胚发生模式和植株再生

棉花体细胞胚的发育先后经历了球形期、心形期、鱼雷期、子叶期等四个阶段，且仅有鱼雷后期和子叶期的体细胞胚能萌发成苗，而其它阶段的胚在萌发培养基上仅能产生次生胚或根。棉花组织培养中存在着各种各样的畸形胚，其发生频率可高达８０％以上。棉花体细胞胚的发育是不同步的，在同一块愈伤组织中存在着不同发育时期的体细胞胚，其中球形胚和心形胚数目较多，而子叶胚等成熟胚则数目极少。棉花体细胞胚的萌发有三种类型，且受各种     

花生子叶节高效芽诱导体系的研究

花生是一种重要的油料作物,培育高产、优质、抗病、耐逆新品种是促进花生增产、增效的主要手段,但较低的花生外植体再生效率严重阻碍了花生基因工程的研究。因此,建立高效的花生再生体系对于科学研究具有重要意义。试验以3份不同花生品种的子叶节作为外植体,探究不同预培养天数和不同浓度的不同植物激素对子叶节丛生芽分化的影响。结果表明:预培养5d的子叶节芽诱导情况最好。不同品种进行激素诱导培养时也有一定的差异规律:麻油1-1和弗落蔓生的子叶节外植体在MSB_5+6 mg·L~(-1) 6-BA+2 mg·L~(-1) 2,4-D培养基中诱导芽效果最好;濮花23号的子叶节最佳诱导芽培养基是MSB_5+10 mg·L~(-1) 6-BA+2 mg·L~(-1) 2,4-D。     

Seed triglyceride content and glyoxysomal activity variation in sorghum cultivars 1

Three sorghum [Sorghum bicolor (L) Moench] cultivars (Funk G522DR, SC283, and SC574) were germinated for 4‐days in sand and the isocitric lyase activity of the embryos was assayed. Glyoxysomal activities (nmol/g fresh weight/min) were: Funk G522DR (593.6), SC574 (117.6), and SC283 (6.5). Seed triglyceride contents were 26.96, 14.88, and 10.80 (μ triglyceride fatty acid/g fresh weight) for Funk G522DR, SC574, and SC283, respectively, with approximately 90% of the triglyceride being in the embryos which constituted 15–21% of the total seed weight. SC574 and SC283 are acid soil tolerant cultivars. Association of high glyoxysomal activity and very low amylase activity in SC574 and the reverse relative activities in SC283 explains the differences in growth of these two cultivars during the seedling impact phase under acid soil conditions. High glyoxysomal and amylase activities in acid soil sensitive Funk G522DR indicates that the acid soil response in juvenile sorghum seedlings is a multi‐factorial influence.     

木薯AGPase酶活性及其同工酶位点检测

本文以3个亲缘关系较远的高产木薯品种（SC124,SC8和Arg7）为材料,对块根发育过程中的AGPase活性和淀粉含量进行了测定,并利用AGPase同工酶电泳技术（非变性聚丙烯酰胺凝胶电泳）对AGPase酶活性较高时期同工酶位点进行检测,旨在分析木薯块根AGPase同工酶位点与AGPase酶活性和淀粉积累的关系。结果表明：木薯块根发育过程中AGPase酶活性和淀粉含量呈极显著正相关（R=0．80212）,Arg7的AGPase酶活性和淀粉含量在块根发育都显著高于SC124和SC8。同工酶分析表明,木薯至少有6个同工酶位点（AGPa,AGPb,AGPc,AGPd,AGPe和AGPf）,且品种间具有多态性。其中,3个品种共有的4个同工酶位点分别为AGPa、AGPc、AGPd和AGPf,AGPe位点只在Arg7中出现,初步判断同工酶位点AGPe可能与其较高的酶活性和淀粉含量有关。本研究为系统研究木薯品种间AGPase酶活性与淀粉积累的关系提供了参考。     

Influence of split‐applied nitrogen on grain yield and protein content in ten grain sorghum culti‐vars 1

More information on the response of newly developed or introduced grain sorghum cultivare to split‐applied nitrogen (N) in semi‐arid rainfed agriculture is needed. Therefore, the influence of four split‐applied N schedules (100/0, 66/34, 50/50, and 34/66) on six American (SC 283, SC 274, SC 669, B 66181, SC 33, and RTam 428), and four West African (CSm 63, 1S 6704c, 1S 7173c, and 1S 7419c) grain sorghum cultivars was evaluated. The split‐applied N significantly increased grain yield and percent protein in grain sorghum over a one‐time application of N. The increase in yield and protein content varied among varieties and schedules of N application. Varieties SC 574, RTam 428, and Csm 63 at split‐applied schedules of 66/34, 50/50, and 34/66, respectively, gave the highest yield over one‐time application of N. Similar differences in percent protein in grain among cultivars due to split‐applied N were observed.     

Effect of cadmium on growth and the uptake of cadmium and other elements by durum wheat

A solution culture study was conducted to determine the effects of cadmium (Cd) application on the uptake of Cd, potassium (K), zinc (Zn), manganese (Mn), copper (Cu), iron (Fe) and on the growth of seedlings of three wheat (Triticum turgidum L. var Durum) cultivars, Kyle, Nile, and SC84–994. Cadmium application decreased shoot and root biomass, root length, and leaf area. Cadmium application did not produce any differences among cultivars in these growth parameters. There were differential cultivar responses in the uptake of Cd and K but not for Zn, Mn, Cu, and Fe uptake. A solution Cd concentration of 0.1 μM did not affect the concentration of Cd and K compared to zero Cd but at and above 0.5 μM Cd, Nile had a higher concentration and contents of Cd and K in root and shoot than SC84–994 and Kyle. Kyle and SC84–994 were not different in any of the elements tested except K concentration in shoot where the order was SC84–994<Kyle<Nile. Cadmium application increased the Cd concentration but decreased the concentration of K, Zn, and Mn in root and shoot, while the Fe and Cu concentrations in shoot and root were not affected. Cultivar differences were observed in the translocation of Cd from root to shoot. In SC84–994 and Kyle, 0.5 μmole Cd/L decreased the total Cd translocated to shoot, Further addition of Cd did not affect Cd translocation, whereas in Nile, increased Cd concentration in solution did not affect Cd translocation to the shoot. A modified version of Weibull frequency distribution [y = a exp.(b.Cd^c)] was applied to explain the effect of Cd on plant growth parameters and on the uptake of K, Mn, Zn, and Cu in plants.     

Diltiazem influence on mineral nutrient uptake by sorghum primary root tips

Seedling sorghum [Sorghum bicolor (L.) Moench. cv GP10, SC283, SC574, and Funk G522DR] primary root tip (1‐cm) content of calcium (Ca), zinc (Zn), iron (Fe), magnesium (Mg), copper (Cu), boron (B), manganese (Mn), and phosphorus (P) in response to a known Ca‐channel blocker (diltiazem, 0,0.1, 1, or 10 mM) was measured after a 1‐hr exposure to Hoagland and Arnon complete mineral nutrient solution. Diltiazem (10 mM) significantly decreased content of Ca, Mn, and Mg in all four cultivars, P, Zn, and Fe in three cultivars, Cu in two cultivars, and B content was not altered. Differences among cultivars was observed in ion contents by the diltiazem untreated controls for all elements. Multiple avenues of ion movement across the plasma membrane are evident. Genetically determined mechanisms and rates of activity between cultivars were demonstrated.     

Interactions of metolachlor and excess hydrogen (H+) influences on sorghum (sorghum bicolor) cultivar roots

Sorghum [Sorghum bicolor (L.) Moench] cultivars were planted in 8 cm × 8 cm × 8 cm pots filled with ‘white quartz flintshot’ sand containing 0, 0.25, 0.50, 1.0, or 2.0 mg/kg metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2 methoxy‐1‐methylethyl)acetamide] and the pots were watered on alternate days with 100 mL 0.1 M sodium acetate at pH 6.0, 5.5, 5.0, 4.5, or 4.0 to determine the influence of excess H⁺ and metolachlor concentrations on sorghum root growth. Cultivars utilized were Funk G522DR, SC574, SC283, GP‐10, 58M, and 38M. At pH 4.5 and 4.0 (0 metolachlor), root lengths of Funk G522DR and SC574 were significantly decreased compared to roots from plants grown at pH 6.0. The other four cultivars had decreased root growth at pH 4.0 (0 metolachlor). Metolachlor influence on sorghum cultivar root growth was dependent on pH, cultivar, and metolachlor concentration. None of the cultivars showed increased metolachlor activity which was influenced by pH. Metolachlor (0.25 mg/kg) reversed the influence of excess H⁺ concentration (pH 4.0) in SC574. Metolachlor (0.5, 1.0, and 2.0 ppmw) reversed the excess H⁺ concentration inhibition of root growth at pH 4.0 in Funk G522DR.     

Nifedipine influence on calcium and aluminum absorption in roots of three sorghum cultivars

A 1,4‐dihydroxypyridine type of ion channel blocker, nifedipine [1,4‐dihydro‐2,6‐dimethyl‐4‐(2‐nitrophenyl)‐3,5‐pyridinedicarboxylate dimethyl ester], was tested on the root absorption of Al³⁺ and Ca²⁺ by sorghum [Sorghum bicolor (L.) Moench] cultivars with varying acid stress tolerance. In an acid stress sensitive cultivar, Funk G522DR, nifedipine (1 μM) influenced Ca²⁺ but not Al³⁺ absorption. In one acid stress tolerant cultivar, SC574, nifedipine (1 μM) influenced both Ca²⁺ and Al³⁺ absorption. In a second acid stress tolerant cultivar, SC283, nifedipine (1 μM) did not influence Ca²⁺ but did influence Al³⁺ absorption. Considerable genetic diversity is present in Ca²⁺ and Al³⁺ absorption between sorghum cultivars.     

Protein Profile and Molecular Markers Related to the Baking Quality of Brazilian Wheat Cultivars

To carry out wheat breeding programs, proteins were identified and quantified (through sodium dodecyl sulfate polyacrylamide gel electrophoresis [SDS‐PAGE] and size‐exclusion high‐performance liquid chromatography [SE‐HPLC]) and six allele‐specific markers were tested on 45 Brazilian cultivars. A microscale baking test was applied to associate analytical and genetic responses with baking quality. The results suggested a prevalence of the subunits 2* and 1 in chromosome 1A; 7+8, 7+9, and 17+18 in 1B; and 5+10 in 1D; absence of 1BL/1RS translocation in 62.2% of the genotypes; and presence of Pinb‐D1b and Glu‐A3d in 8.9% of the genotypes. The average SE‐HPLC values were 37.50 and 45.42% for polymeric protein in total protein (PPP) and unextractable polymeric protein (UPP), respectively, and 1.29 for the gliadin‐to‐glutenin (GLI/GLU) ratio, with significant variation among the genotypes (P ≤ 0.05). The baking test also showed a significant difference (P ≤ 0.05) between the cultivars under the same conditions. The cultivars without the 1BL/1RS translocation with rye also showed better results for UPP, PPP, and GLI/GLU in relation to those possessing translocation. These results corroborate for selection of HMW subunits 5+10, cultivars without translocation with rye, with high UPP values and a balanced GLI/GLU ratio (around 1.0) with the objective of obtaining greater wheat baking quality.     

不同氮效率木薯品种根系形态、构型及氮吸收动力学特征

【目的】比较分析低氮 (N) 条件下不同氮效率木薯品种的根系形态、构型及吸收动力学变化,以阐明木薯氮高效吸收机制,为指导木薯生产和木薯品种选育提供理论基础。【方法】于2015年在广西大学国家重点实验室温室大棚内进行了试验。盆栽试验采用双因素 (品种 × 氮水平) 区组设计。供试木薯品种包括氮高效品种华南10号 (SC10) 与氮低效品种华南205(SC205)。氮水平包括不施氮 (N0) 和施N 55.2 mg/kg土 (N1)。每盆装10 kg土,种植1株幼苗。木薯出苗60天后,取出并洗净根系,利用根系扫描仪EPSON2000进行根系图像采集,利用WinRHIZO PRO根系分析软件分析图片,获得根系形态指标。将整株植株分成根、茎、叶三个部分,测量干重和氮含量。根系分层试验在大型根系观测系统中进行。吸收动力学试验采用改进常规耗竭法,并比较分析了木薯根系形态、根系构型特征及硝态氮吸收动力学参数差异。【结果】N1和N0条件下,氮高效品种SC10生物量和氮素积累量均显著高于氮低效品种SC205(P < 0.05)。N0条件下,SC10的整株生物量降幅为37.4%,SC205的降幅为69.4%,品种SC10的降幅显著低于SC205 (P < 0.05);SC10的根、茎、叶和全株氮积累量均显著高于SC205,全株氮积累量为SC205的152%。与N1相比,N0处理的木薯品种SC10总根长、根系表面积和细根根长的降幅分别为11.0%、10.0%和20.4%,SC205的降幅分别高达35.9%、27.7%和50.2%,两个品种下降幅度差异显著 (P < 0.05)。低氮诱导木薯根系分布下移,SC10根系呈上宽下窄三角形,最深可达180 cm土层;SC205根系呈椭圆形,最深达130cm土层。氮素吸收动力学试验结果发现SC10、SC205的Km分别为3.27和7.87 mmol/L,表明SC10根系对NO₃–的亲和性更高。【结论】氮高效品种SC10的根系对硝态氮的亲和力 (Km) 几乎是氮低效品种SC205的两倍。在氮素胁迫条件下,氮高效品种可形成优于氮低效品种的根系构型,特别是根系的总根长、根系表面积和细根根长的下降幅度显著小于氮低效品种,是有效缓解氮胁迫的重要原因。     

Screening wheat and sorghum cultivars for aluminum sensitivity at low aluminum levels

Screening cultivars for aluminum (Al) tolerance is often conducted in acid soils or in complete nutrient solutions. The former method lacks precise measurements of Al, and the second requires high Al concentrations because of precipitation and chelation of the Al and is less representative of the actual environmental stresses to which plants must adapt. These experiments were designed to determine Al tolerance of wheat (Triticum aestivum L. em Thell) and sorghum (Sorghum bicolor L. Moench) using incomplete solutions with very low Al concentrations. Six wheat and five sorghum cultivars were screened for Al tolerance in solution culture with 0 to 10 μM Al and only Ca, K, Mg, NO₃, and Cl in the solutions. Plants were subjected to the solutions for 4 d, and the change in relative root length was measured. Solution Al levels and pH were measured after the termination of the experiments. ‘Atlas’ 66 and ‘Stacy’ were the most tolerant wheat cultivars ('Atlas 66’ = ‘Stacy’ ≥ ‘Monon’ ≥ ‘Scout 66’ ≥ ‘Arthur 71’ = ‘Oasis'). The wheat cultivars were effectively separated on a genetic response basis at 2 μM Al. Sorghum cultivars were uniform in their Al tolerance, but did show some separation at 1 μM Al (SC56 > Tx430 > ‘Funk GS22DR’ > SC283 = SC599). The pH and Al variations did not account for any of the differences observed, indicating that root length differences were caused by genetic control of response to high Al.