辐照对黄籽油菜种子活力、超氧物歧化酶活性和脂质过氧化作用的影响

用~(60)Coγ射线辐照2个杂交组合高世代材料中分离出的黄籽和黑籽甘蓝型油菜(Brassica napus L.)近等基因系种子,测定辐照前、后种子在发芽过程中的种子活力,超氧物歧化酶(SOD)和脂质过氧化产物丙二醛(MDA)的变化。结果表明,辐照后,黄籽比黑籽的SOD活性上升幅度小,MDA含量上升幅度大,种子活力下降较多。黄籽油菜种子的辐射敏感性比黑籽强;油菜的辐射抗性或敏感性不仅与体内保护酶水平有关,也可能与种皮的特殊保护结构和保护物质有关。     

硼对不同甘蓝型油菜品种细胞壁酶活性的影响

在溶液培养条件下,选用甘蓝型油菜硼高效和硼低效品种,研究硼对细胞壁酶活性的影响。结果表明,不同生育期缺硼均使油菜根系细胞壁过氧化物酶(POD) 活性显著升高;上部叶片细胞壁POD 活性显著下降;下部叶片处理间的差异不显著,但同一生育期细胞壁POD 活性硼高效品种显著高于硼低效品种。油菜根系细胞壁IAA 氧化酶活性,缺硼时两品种薹期和花期显著升高,苗期差异不显著;上部叶片细胞壁IAA 氧化酶活性缺硼时显著降低,硼高效品种花期差异不显著;缺硼对下部叶片细胞壁IAA 氧化酶活性影响不大,但低效品种花期该酶活性显著降低。     

不同硼效率甘蓝型油菜苗期对硼镁营养的反应

利用溶液培养研究硼低效和高效甘蓝型油菜(Brassica.napus)苗期对硼镁营养的反应。结果表明,低硼浓度下提高镁时,油菜的生长受影响不大,硼含量和累积量降低,镁含量和累积量及叶绿素上升。低镁浓度下提高硼时,油菜镁含量、镁积累量降低,且硼低效品种降低幅度大于硼高效;叶绿素降低幅度则硼高效大于硼低效品种。高硼浓度下提高镁时,硼镁含量和累积量及叶绿素含量均提高,提高幅度为硼高效品种大于低效品种。高镁浓度下提高硼时,硼镁表现出显著的相互促进,硼高效品种促进效应大于低效品种。在很大程度上镁影响油菜叶绿素a的含量,而硼影响油菜叶绿素b的含量。硼镁营养对锌含量无大的影响;在低镁浓度下,油菜低效品种锰含量显著增加。无论是低镁或高镁浓度下提高硼,硼高效和低效品种铁含量均有所增加,低效品种增加显著。     

不同硼效率甘蓝型油菜品种中硼的形态及其相互关系

采用硼高效 (9589,9590)和硼低效 (9141,95105)甘蓝型油菜品种各 2个及其 4个杂交种 (95105 9589,95105 9590 ,91419589,9141 9590)作试材 ,研究了不同硼效率甘蓝型油菜品种及其F1代花期各部分叶片中硼的形态。结果表明 ,在B2 (0 .35mg/kg)处理下 ,硼高效品种上叶 ,中叶 ,下叶和花中水溶态硼含量和束缚态硼含量低 ,半束缚态硼含量高 ,而硼低效品种 3种硼形态的含量则与此相反 ;F1代基本居于二者之间 ,且趋向于高效品种 ;在B1(0 .2 0mg/kg)处理下 ,各叶片和花中各硼形态含量也呈现类似的特征 ,但存在例外 ,尤其在花中。B1和B2处理下 ,除B1处理上叶外 ,硼高效品种和F1代的花和叶片中水溶态硼和束缚态硼相对含量较低 ,半束缚态硼相对含量较高 ,硼低效品种与此相反。建立了硼形态之间的相互平衡关系 ,并把这种平衡关系同硼效率联系起来 ,表明硼形态和硼效率存在密切关系 ,可望由此揭示不同甘蓝型油菜品种硼效率差异的生理机制。     

甘蓝型油菜硼高效基因等位性检测

甘蓝型油菜 8Z05和青油 10号为硼高效品种 ;Bakow 为硼低效品种。 2000～2001年度 ,硼高效品种 8Z05青油 10号F2代 588个单株种植在缺硼土壤上。花期调查缺硼症状 ,表现硼高效的单株数与硼低效的单株数之比为 574∶14 ;结实期分离规律与花期相似。这说明甘蓝型油菜硼高效品种 8Z05和青油 10号硼营养高效主效基因是等位的 ,同时可能存在微效基因的修饰作用 ,但微效基因的QTL可能不完全相同。 2个年度的试验结果一致。     

长江流域主要甘蓝型油菜品种苗期耐湿性鉴定

以32 个长江流域主要甘蓝型油菜品种为材料, 在模拟田间湿害环境下, 研究了甘蓝型油菜不同种质资源耐湿性及其适宜的耐湿性指标。结果表明, 湿害使甘蓝型油菜脯氨酸含量显著升高, 根系活力、叶绿素含量、蛋白质含量、根干重、总干重不同程度降低。甘蓝型油菜耐湿性受基因型控制, 遗传差异较大, 其中耐湿性强的品种有6 个(“中油821”、“黔油18 号、“中双11 号”、“09L553×L559”、“中双9 号”及“SWU7”), 占总品种数的18.75%; 耐湿性差的品种有3 个(“先油杂2 号”、“川油58”、“川油20”), 占总品种数的9.38%; 其他属于中等耐湿品种。相关分析表明, 不同品种各性状湿害指数与综合湿害指数相关性均达显著或极显著水平, 各性状湿害指数之间相关性大部分达显著或极显著水平, 其中根系活力、总干重和脯氨酸含量3 项指标对湿害综合指数贡献率达79.41%, 可作为鉴定甘蓝型油菜幼苗耐湿性的指标。     

春播半冬性甘蓝型油菜光温因子与产量及农艺性状的典型相关分析

西藏甘蓝型油菜种质资源匮乏。为探讨西藏春播条件下半冬性甘蓝型油菜的温光特性,提高其在高原春播区的利用价值,以18个半冬性甘蓝型油菜品种为材料,应用典型相关分析方法分析了春播条件下光温因子与半冬性甘蓝型油菜产量及农艺性状的典型相关性。结果表明:春播区光温因子与半冬性甘蓝型油菜的产量及农艺性状均有显著典型相关关系,不同生育时期起主导作用的光温因子不同:营养生长期光温因子与分枝性状典型相关,影响分枝数的主要光温因子是营养生长期的积温;蕾花期光温因子与主茎、分枝性状典型相关,影响主花序和主茎生长的主要光温因子是蕾花期累计日极端温差和总日照时数;角果成熟期光温因子与主茎、分枝、产量性状显著相关,影响单株有效角果数、千粒重的主要光温因子是角果成熟期累计日极端温差;角果期较长日照总时数可降低有效分枝高度,促进主花序伸长及单株产量的提高。西藏半冬性甘蓝型油菜的引种及新品种选育中,在早熟和"双低"特性的基础上应重点选育适应光照充足,能够忍耐极端温差的品种。农艺性状的选择应注重主花序长、二次有效分枝数、有效角果数和千粒重等具有较大潜力的品种。     

硫、硼、锌对黄籽油菜营养特性的影响

采用盆栽试验与化学分析的方法，对甘蓝型黄籽油菜——“渝黄一号”进行了分析。结果表明：(1)增施S或Zn肥和土壤差异对苗期油菜生物量影响达显著性水平；(2)增施S、B或Zn肥，油菜苗期和苔期叶片S、B、Zn含量也相应地增加，对苗期叶片N、P和苔期叶片硫影响达极显著水平；(3)土壤差异，对叶片苗期吸收P和苔期吸收K、S的影响达显著性水平。     

Artificial miRNA调控甘蓝型油菜芥酸的研究

芥酸是重要的工业原料,主要来源是甘蓝型油菜种子,为调节甘蓝型油菜种子内芥酸含量,针对甘蓝型油菜芥酸合成过程中的关键酶基因Bnfad2设计特异性amiRNA,并构建种子特异表达载体,转化高芥酸甘蓝型油菜品种MY15和低芥酸甘蓝型油菜品种LEA01,并对转化植株T_0种子脂肪酸进行分析。结果表明,转化的高芥酸甘蓝型油菜芥酸的增加最高达到5.12%,最低2.11%;而转化的低芥酸品种,最高仅为0.45%,最低只有0.16%,而且所有转化低芥酸材料的芥酸含量都小于1%;同时转化种子内油酸的含量得到了明显的提高,最低为4.99%,最高达到了10.71%,亚油酸降低的幅度十分明显,最大降幅达到17%。表明amiRNA技术可以通过影响脂肪酸合成过程中特定基因的表达,有效改变种子内脂肪酸的组成,从而改变其营养结构,提高营养价值,进一步提高油菜种子的附加值。本研究为运用amiRNA技术调节油菜脂肪酸组成和改变其营养结构提供了一定理论依据。     

硫、硼、锌对黄籽油菜营养特性的影响

采用盆栽试验与化学分析的方法,对甘蓝型黄籽油菜———"渝黄一号"进行了分析。结果表明:(1)增施S或Zn肥和土壤差异对苗期油菜生物量影响达显著性水平;(2)增施S、B或Zn肥,油菜苗期和苔期叶片S、B、Zn含量也相应地增加,对苗期叶片N、P和苔期叶片硫影响达极显著水平;(3)土壤差异,对叶片苗期吸收P和苔期吸收K、S的影响达显著性水平。     

磷肥对甘蓝型春油菜产量、磷肥利用效率及经济效益的影响

利用大田试验研究了不同磷肥用量对甘蓝型春油菜产量、养分积累、磷素利用效率和经济效益的影响。结果表明,在低磷土壤上施用125 kg/hm2N和135 kg/hm2K2O基础上增施磷肥,可显著增加油菜不同部位产量,其中籽粒产量平均提高12.5%,生物量平均提高29.0%。施磷明显提高油菜地上部P素含量,有利于促进油菜K素营养累积,但对N素、K素含量无显著影响。随磷肥施用量的增加,磷肥偏生产力显著下降,施磷后磷肥农学效率、磷肥表观利用率和磷肥生理利用率平均分别为4.6 kg/kg P2O5、13.0%和40.2 kg/kg P2O5,磷肥对籽粒产量的贡献率仅为10.9%。根据经济效益分析结果,青海甘蓝型春油菜生产中磷肥用量以75 kg/hm2为宜。     

Effect of cadmium on the chemical composition of xylem exudate from oilseed rape plants (Brassica napus L.)

Abstract

Phytoremediation is a good technique for removing cadmium (Cd) from farmland soils. To remove Cd from these soils effectively, it is necessary for Cd ions to be transported to the shoot organs for later harvest. However, the mechanism of Cd translocation to shoot organs via xylem vessels has not yet been elucidated. We selected oilseed rape plants (Brassica napus L.) and established a method to collect xylem exudates from these plants. After 3 days of Cd treatment (10 µmol L^?1 and 30 µmol L^?1) the Cd concentrations in the xylem exudates were approximately 6.5 µmol L^?1 and 16 µmol L^?1, respectively. The detection of Cd in the xylem exudate indicated that Cd was moving to shoot organs via xylem vessels. The effect of these Cd treatments on the amino acid, organic acid and protein composition of xylem exudates from oilseed rape plants was investigated. The level of amino acids and organic acids detected was enough to bind Cd transported via the xylem. Sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis revealed that proteins with molecular weights of 36 kDa and 45 kDa clearly increased in the exudates with Cd treatment. The possibility that these compounds are binding Cd in the xylem exudates was discussed.     

农杆菌介导的油菜遗传转化研究进展

综述油菜遗传转化中再生体系的建立、农杆菌侵染方法、适宜菌株及载体选择等方面的研究进展,并对转化中寄主基因型、目的基因及其启动子的选择、筛选方法、外源基因稳定性等方面存在的问题进行了分析与讨论,为优化油菜等芸薹属的遗传转化提出可行性建议.     

Regulatory effects of sulfur on oilseed rape (Brassica napus L.) response to selenite

Selenite is a form of selenium (Se) commonly found in Se-excessive soils. To regulate the Se content in plants in high-Se areas, a potted soil experiment was performed on oilseed rape (Brassica napus L.) to evaluate the effects of varied amounts of sulfur (S) on the biomass, accumulation and distribution of Se in B. napus under the conditions of different amounts of Se in the soil. The results showed that the seedlings of B. napus were more sensitive to Se than the mature plants were. The addition of S significantly alleviated the growth inhibition in seedlings and facilitated the growth of mature plants under higher Se (15 mg kg^?1) conditions. S treatment significantly decreased soil pH within the range of 0.22–0.60. An appropriate moderate amount (150 mg kg^?1) of S exerted the strongest inhibition on Se concentration and accumulation in B. napus at the seedling stage, but a higher amount (300 mg kg^?1) of S led to a more significant decrease in the mature plants under higher Se conditions, with the maximum reduction in various parts of B. napus reaching 51.3–60.9% and 42.5–53.4%, respectively. The application of S only affected the uptake of Se, and not the translocation of Se; the accumulation of Se in B. napus follows the sequence of pod ≈ stem > rapeseed > root, and the distribution ratio is approximately 1.00:0.97:0.69:0.49. Overall, the application of S alleviated the inhibitory effect on growth caused by excessive Se by reducing the Se concentration in B. napus and facilitating its growth, suggesting that S treatment is a suitable and highly cost-effective method to regulate the content of Se in B. napus.     

Identification of Phosphorous Efficient Germplasm in Oilseed Rape

ABSTRACT

Plant species and genotypes within one species may significantly differ in phosphorus (P) uptake and utilization when they suffer from P starvation. The objective of this research was to screen P-efficient germplasm of oilseed rape (Brassica napus L.) and analyze the possible mechanism responsible for P efficiency by two-steps screening experiments and validation of P efficiency. Phosphorus efficiency coefficient at seedling stage, namely, ratio of shoot dry weight under low P to that under adequate P (PECS) of 194 oilseed rape cultivars varied from 0.050 to 0.62 and was significantly related with shoot dry weight under low P level (r = 0.859??, P < 0.01). Oilseed rape cultivar ‘Eyou Changjia’ presented the highest P efficiency coefficient in each growth stage and had the highest seed yield at low P, whereas oilseed rape cultivar ‘B104-2’ was the most sensitive to low P stress among the 12 candidate cultivars obtained from the two-steps screening experiments. Under low P condition in validation experiments of soil and solution cultures, ‘Eyou Changjia’ could produce much more dry matter and acquire more P than ‘B104-2.’ Moreover, P efficient coefficient obtained from the pot experiment was comparable to those from the field experiment. This might be attributed to high P uptake efficiency for ‘Eyou Changjia’ when it suffered from low-P stress. Comparison of results from the hydroponics with those from the pot and field experiments led to the conclusion that the P uptake efficiency in the hydroponics is highly related to that in soil culture conditions. These results show that there are large genotypic differences in response to phosphorus deficiency in oilseed rape germplasm (Brassica napus L.) and ‘Eyou Changjia’ is P-efficient and ‘B104-2’ is P-inefficient. By comparing these results further, the mechanism responsible for P efficiency was suggested to be mainly due to high P uptake efficiency by forming larger root system, and improving the ability of mobilizing and acquiring soil P in P-efficient oilseed rape under the condition of P starvation.     

The effect of co‐composted cabbage and ground phosphate rock on the early growth and P uptake of oilseed rape and perennial ryegrass

Phosphorus (P) availability to crops in organic systems can be a major issue, with the use of readily available forms often restricted. One product that can be used in organically managed systems, that is also relatively easily accessible to growers, is phosphate rock, although its solubility and therefore crop availability is often poor. One possible approach to improve this situation is co‐composting phosphate rock with selected organic waste materials. Various ratios of phosphate rock and cabbage (Brassica oleracea L.) residues were co‐composted and the products tested at different rates of application. The effects were assessed over 12 weeks using oilseed rape (Brassica napus L.) and perennial ryegrass (Lolium perenne L.) as bioassay crops in a pot experiment. At harvest, estimates of P derived from cabbage and phosphate rock for the lowest of two rates of compost were ≈ 2 and 10 mg P pot^–1 for oilseed rape, compared to 5 and 2 mg P pot^–1 for perennial ryegrass, respectively. Roots tended to have higher P concentrations than shoots. The crops showed differences in their abilities to access various P sources, with oilseed rape effectively taking P from phosphate rock, whereas perennial ryegrass was more effective at accessing cabbage‐derived P (the main substrate in the compost). Oilseed rape was able to take up 20% of the total P applied as phosphate rock, whereas perennial ryegrass took up less than 5% of the total P applied from this material. Both pre‐ and post‐application solubilisation/transformation mechanisms were involved in supplying plant‐available P. Quantifying the relative contribution from individual P sources remains problematic even within this relatively simple system.     

油菜硼高效的遗传

Field experiments were conducted to study the inheritance of boron efficiency in oilseed rape (Brassica napus L.) by evaluating the boron (B) efficiency coefficient (BEC, the ratio of the seed yield at below the critical boron level to that at the boron-sufficient level) with 657 F_2:3 lines of a population derived from a cross between a B-efficient cultivar, Qingyou 10, and a B-inefficient cultivar, Bakow. Qingyou 10 had high BEC as well as high seed yield at low available soil B. On the contrary, Bakow produced low seed yield at low B status. Boron deficiency decreased the seed yield of the F_2:3 lines to different extents and the distribution of BEC of the population showed a bimodal pattern. When the 657 F_2:3 lines were grouped into B-efficient lines and B-inefficient lines according to their BEC, the ratio of B-efficient lines to B-inefficient lines fitted the expected ratio (3:1), indicating that one major gene controlled the B-efficiency trait. 127 F_2:3 lines selected from the population at random, with distribution of BEC similar to that of the overall population, were used to identify the target region for fine mapping of the boron efficiency gene.     

Effects of Boron and Calcium Supply on Calcium Fractionation in Plants and Suspension Cells of Rape Cultivars with Different Boron Efficiency

Abstract

In this study, the effects of boron (B) and calcium (Ca) supply on Ca fractionation in suspension cells and different tissues of rape (Brassica napus L.) plants of two cultivars with different B efficiency were studied, with a purpose to elucidate the mechanism by which B affects Ca concentration in plants. As Ca supply increased in nutrient solution or culture medium, the relatively easily extractable Ca fractions, that is H₂O and 80% ethanol extractable Ca in leaves, 1 mol L^?1 NaCl extractable Ca in upper leaves, roots and suspension‐cell were significantly increased. While the recalcitrant Ca fractions extracted by 2% acetic acid, 0.6 mol L^?1 HCl and Ca in the residue were not affected by Ca supply. Increasing B supply in nutrient solution or culture media significantly reduced 1 mol L^?1NaCl extracted Ca in suspension cell and roots of both cultivars, which were most likely related to the alteration of cell wall metabolism. Calcium extracted by 2% acetic acid, 0.6 mol L^?1 HCl and Ca in residue in suspension‐cell and roots of B inefficient cultivar Bakow were easily improved by B deficiency as compared to that of B efficient cultivar Tezao16. Increasing of these relative recalcitrant Ca fractions was related to the different response of cultivars to the B deficiency, which may reflected different extent that Ca deposited in the two cultivars due to impaired membrane integrity under B deficiency. The effects of B on Ca concentration in lower and upper leaves of the two cultivars were quite different and were the integrated effects of B on Ca metabolism, Ca transport in plants and growth of certain organ. Increasing B supply increased total Ca concentration in upper leaves of Bakow and reduced that of Tezao16, which might relate to the different adaptability of the two cultivars to comparatively higher B supply.     

镉对油菜幼苗生长及微量元素含量的影响

通过营养液培养,重点研究了不同浓度镉（Cd）胁迫下,中双9号冬油菜（Brassica napus L.）幼苗体内生理生化及微量元素（Fe、Mn、Zn、Cu）含量的变化特征,目的是进一步阐明Cd胁迫对油菜生长产生毒害的作用机理。结果发现,Cd胁迫显著抑制了油菜幼苗的生长,植株根系和地上部干重随着Cd浓度的升高而显著降低;油菜幼苗叶片中光合色素含量也随着Cd浓度的升高而显著降低;油菜幼苗根系和地上部4种微量元素浓度也随着Cd浓度的升高发生了显著变化;同时,油菜幼苗体内抗氧化酶（SOD、POD和CAT）活性随着Cd浓度的升高表现出先显著升高后显著降低的趋势。这些结果表明,外源Cd胁迫通过降低油菜幼苗光合色素含量、抑制植株光合作用,引起幼苗体内养分代谢紊乱,诱导产生氧化胁迫等抑制了油菜幼苗的生长。研究还发现,中双9号油菜幼苗地上部Cd浓度和Cd富集量显著低于根系,中双9号应该属于低吸收Cd的冬油菜品种。     

Manganese Deficiency in Canola Induced by Liming to Ameliorate Soil Acidity

Applying lime to ameliorate soil acidity has been observed to induce manganese (Mn) deficiency in canola (Brassica napus L.) crops grown on acid sandy soils near Albany and gravelly acid sands of the Great Southern Districts of southwestern Australia. These soils were often Mn-deficient in patches for wheat (Triticum aestivum L.) production when they were newly cleared for agriculture requiring application of Mn fertilizer to ensure grain yields were not reduced by the deficiency. Since then, these soils have acidified and in the 1990s, canola started to be grown on these soils in rotation with wheat and lupins (Lupinus angustifolius L.). These limed soils may now have become marginal to deficient in Mn for canola production. The effect of liming may change the effectiveness of fertilizer Mn. In addition, the effect of liming on the residual value of Mn fertilizer applied to these soils for canola production is unknown. Therefore, a glasshouse experiment was conducted using Mn deficient sand. Three levels of finely-powdered calcium carbonate were added and incubated in moist soil for 42 days at 22±2°C to produce 3 soils with different pH values [1:5 soil:0.01 M calcium chloride (CaCl₂)]: 4.9 (original soil), 6.3, and 7.5. Five Mn levels, as solutions of Mn sulfate, were then added and incubated in moist soil for 0, 50, and 100 days before sowing canola. To estimate the residual value (RV) of incubated Mn for canola production, the effectiveness of the incubated Mn was calculated relative to the effectiveness of Mn applied just before sowing canola (freshly-applied Mn). The RV of the incubated Mn was determined using yield of dried canola shoots, the Mn application level required to produce 90% of the maximum shoot yield, and Mn content in dried shoots (Mn concentration in shoots multiplied by yield of dried shoots). As measured using both yield of dried shoots and Mn content of dried shoots, the residual value of Mn decreased with increasing soil pH and with increasing period of incubation of Mn with moist soil. The critical Mn concentration, for 90% of the total yield of dried canola shoots, was (mg Mn kg^?1) ～17 in youngest mature growth (apex and youngest emerged leaf, YMG), and ～22 for the rest of dried shoots. These values were similar to current critical values for un-limed soils suggesting critical Mn concentrations remain the same for limed soils. Plant testing of canola is recommended if soils are to be limed to ameliorate soil acidity. When plant tests indicate a high likelihood of Mn deficiency, foliar Mn sprays need to be applied to that crop to ensure Mn deficiency does not reduce grain production that year, and fertilizer Mn needs to be re-applied to the soil when sowing the next crop to reduce the likelihood of Mn deficiency for subsequent crops.