Nitrogen Transportation in Oilseed Rape (Brassica napus L.) Plant during Flowering and Early Siliqua Developing

Nitrogen transportation from different organs was investigated by labelling pods, leaves and internodes of upper stem with ¹⁵N-urea during flowering. Labelled plants were harvested one month after flowering and determined the amount of ¹⁵N in relative parts. The results of the experiment show the directions of ¹⁵N applied in different organs during flowering. Transportation of ¹⁵N applied in pods of lower terminal of the main stem and first branch was mainly directed to seeds inside the labelled pods, about 17 % of ¹⁵N entered into seeds 7 days after last labelling, a little transportation each other between the branch and terminal was found, more than 80 % of ¹⁵N applied on leaves during flowering was transported out of the leaves after flowering, 35 % and 67.93 % on average was translocated in pods for early and late flowering, respectively, while 55.97 % of ¹⁵N applied on surface of internodes of upper stem below terminal was found in pods. It was corroborated that nitrogen transportation also occurs within pods by labelling different parts of pods, much greater amount of nitrogen was transported from lower part to upper part of pods than those in opposite direction.     

Effects during Period of Siliqua Developing of KH2PO4 and MgSO4 Application on Nitrogen Transportation in Pods of Oilseed Rape(Brassica napus L.)

An experiment was conducted in field experiment plot to investigate nitrogen transportation from hulls of pods in different periods at early stage of siliqua developing and effect of KH₂PO₄ and MgSO₄ application on it using ¹⁵N-urea.
More than 80 % of ¹⁵N applied on the surface of pods at lower terminal during flowering was recovered from all pods one month after flowering, most of them were still in the hulls of labelled pods, 17-27 % of ^l5N applied was transported into seeds, a small amount was transported to pods at upper terminal, a little amount was found in pods at branch. More ^l5N applied in middle period of flowering was transported to pods at upper terminal and branch than those applied in early period of flowering. It should be further investigated to conclude how will be going on transportation of nitrogen from hulls as preceding of siliqua developing towards maturity of seeds and its difference between ¹⁵N applied in more different periods.
Application of KH₂PO₄ and MgSO₄ with ¹⁵N-urea of surface of pods promoted transportation of ¹⁵N into seeds from hulls, effect of MgSO₄ was more notable.     

Nitrogen Distribution and Dry Matter Accumulation in Oilseed Rape (Brassica napus L.) as Influenced by N Nutrition

A greenhouse experiment was conducted to study N distribution and dry matter accumulation in oilseed rape ( Brassica napus L. cv. Callypso ) in relation to N supply. Three levels of N supply (30, 100 or 170 ppm N) were tested as treatments. Stem and leaf dry weights increased at higher N fertility up to 170 ppm N but root dry weight did not respond to N. Dry matter yield during the vegetative phase was seriously depressed by N deficiency. Most of the plant dry matter was accumulated in the lower segments of the stem and roots. Dry weights of stem and axillary branches increased significantly as N supply increased up to 100 ppm N. Although hull dry weight increased with N supply up to 100 ppm N, seed dry weight did not respond to N. High root N concentration was maintained at 100 or 170 ppm N; but declined as plants advanced in age. N content of leaf and stem also declined with time. Leaf growth was particularly responsive to N fertility and N was mobilised from the older to the younger leaves over time. Nitrogen content of hulls and seeds increased significantly with N supply but N was translocated from the vegetative into the generative organs or from older into younger tissues during pod development. There is need for proper N fertility management in order to achieve successful rape production.     

油菜角果开裂区结构分化对果实开裂的作用

运用半薄切片技术、荧光显微镜技术, 观察不同开裂程度的两个油菜品种中双9号和中双11果实发育过程中“果实开裂区”的结构特征、发生发育规律, 探讨两品种油菜果实不同开裂程度的结构差异。结果表明, 油菜果实在发育过程中, 逐渐分化出由胎座框木化细胞、离区细胞、果瓣边缘木化细胞、紧靠果实内果皮的木化层enb细胞共同组成的开裂区; 易开裂的中双9号果实发育进程总体上比不易开裂中双11的早, 前者在15DAF (开花后第15天)时就已经能分辨出离区, 且胎座框细胞、果瓣边缘细胞、enb层细胞的壁都已经木化加厚, 而后者在25DAF才表现出这些特征;中双9号的离区在25DAF完全形成, 而中双11的离区在30DAF完全形成;中双9号离区部分细胞间在30DAF开始出现分离, 而中双11离区部分细胞间在35DAF开始出现分离。另外, 中双9号开裂区胎座框木化细胞间出现较多的裂缝有利于果实的开裂。这些结构和发育特征对于深入研究果实开裂的分子调控和抗角果开裂品种的选育具有理论指导意义。     

硼对甘蓝型双低春油菜产量和品质的影响

旨在阐明硼对甘蓝型双低春油菜产量和品质形成的影响机理,明确甘蓝型双低春油菜产量和品质形成与施硼量的关系。试验以甘蓝型双低春油菜"青油14"为供试材料,采用单因素五水平随机区组设计,研究了不同施硼量对甘蓝型双低春油菜产量和品质形成的影响。结果表明:甘蓝型双低春油菜单株角果数与施硼量之间呈显著线性关系,而每角果粒数则与施硼量呈二次曲线关系,适量施硼可以协调每株角果数与每角果粒数的关系,有利于提高产量。籽粒产量与每角果粒数呈极显著正相关性(r=0.982 8**),与单株一次有效分枝数和千粒重也呈一定的正相关性,而与单株角果数则呈一定的负相关性。适量施用硼肥,可明显提高甘蓝型双低春油菜的籽粒产量和产油量,增加籽粒粗脂肪和粗蛋白质含量,而降低硫苷含量,进而改善品质。籽粒产量、产油量与施硼量之间均呈二次曲线关系,施硼量分别为17.84 kg/hm2和19.42 kg/hm2时,籽粒产量和产油量分别达到理论最大值3 154.18 kg/hm2和1 344.61kg/hm2,施硼过量,籽粒产量、产油量均下降。粗脂肪含量与施硼量之间呈单峰曲线关系,粗脂肪含量达到最大值(45.3%)时的施硼量为24.62 kg/hm2。硫苷含量与施硼量则呈开口向上的二次曲线关系,施硼量为19.42 kg/hm2时,硫苷含量为10.29 mg/g(≤30 mg/g)。试验综合考虑甘蓝型双低春油菜的籽粒产量、产油量及籽粒综合品质,提出适宜的施硼量(含硼11%)以19.42 kg/hm2为宜。     

Growth and Yield Responses to Plant Density and Stage of Transplanting in Winter Oilseed Rape (Brassica napus L.)

Growth and yield responses to plant density (6.75 × 10⁴, 9.75 × 10⁴ and 12.75 × 10⁴ plants ha^–1) and stage of transplanting (30, 35 and 40 days after sowing) of winter oilseed rape cultivar HO 605 were investigated in two field trials in the 1996/97 and 1997/98 growing seasons at Zhejiang University Farm, Huajiachi Campus, China. Results revealed a progressive decrease in leaf area per plant in response to increasing plant density and delayed transplanting, though leaf area m^–2 and leaf area index were higher in high-density plants. Number of effective branches and pod per branch decreased with increasing plant density and delayed transplanting. There were no significant differences in the mean seed weight among treatments. Although the average number of seeds per pod was significantly lower for high-density plants and delayed transplanting, the economically highest seed yields were realized in relatively high-density plants. Seed oil content was negatively affected by increasing plant density, but no significant differences were observed with delayed transplanting. The highest seed yields of 1730.7 and 1748.1 kg ha^–1 with no significant differences were observed for plant densities of 9.75 × 10⁴ and 12.75 × 10⁴ plants ha^–1, respectively, transplanted at 35 and 30 days after sowing.     

氮磷钾配比对不同肥力土壤油菜产量与经济性状的影响

为合理利用肥料,发挥品种基因型优势,促进油菜高产稳产,本研究以‘丰油10号’为试验材料,在大田条件下考查了氮磷钾配比对2种不同肥力土壤油菜产量与经济性状的影响,采用统计分析法比较分析了不同肥力土壤对施肥响应的特点与差异。结果表明:与不施肥处理相比,不同氮磷钾配比均可显著提高油菜的产量、株高、有效分枝高和主花序有效角果数,氮磷钾肥配比为15:9:6时,油菜产量及主花序有效角果数均达到最高;相同施肥处理条件下,油菜产量、千粒重、单株有效角果数、一次有效分枝数、株高、有效分枝高、主序有效段长及有效角果数均表现出随土壤肥力升高而增加的趋势,但贫瘠土壤中的油菜产量始终低于中等肥力土壤的产量水平。结果说明,土壤肥力对油菜产量与经济性状具有重要影响,平衡配施氮磷钾肥,培肥土壤肥力,保证油菜全生育期正常生长发育的养分供给,是实现油菜稳产高产的关键。     

油菜高效转化系统的研究

以甘蓝型油菜湘油13为试验材料,运用子房注射法将BT毒蛋白基因导入油菜。在授粉后第20小时至第30小时用自制的微玻针从子房中部注射0.5~1.5μg外源DNA,以高达12.8%的频率获得抗卡那霉素植株。分子杂交分析证明BT毒蛋白基因已整合到油菜基因组中,转化频率为1.6%,表明子房注射法是一种有效、实用的油菜遗传转化方法。     

不同油菜品种对油菜菌核病的田间抗性鉴定

为明确不同油菜品种对江西省油菜菌核病的田间抗性表现,以‘中油杂200’、‘赣油杂108’和‘华油杂62’等30个不同遗传背景的油菜品种为研究对象,分别在南昌市、宜春市和九江市开展了田间自然抗性鉴定。【结果】不同的油菜品种在同一地点具有不同的抗性表现,同一油菜品种在不同地点也存在较大的抗性差异;综合各地的抗性表现,‘中油杂22’、‘赣油杂108’、‘富油668’、‘中油589’、‘圣元77’和‘赣油杂1009’对核盘菌有较高的自然抗性且稳定性相对较好。【结论】本结果可为江西省油菜菌核病抗性品种的推广应用及油菜抗性育种提供依据。     

Relationship between Frost Tolerance and Cold-Induced Resistance of Spring Barley, Meadow Fescue and Winter Oilseed Rape to Fungal Pathogens

Plants exposed to one stress factor may become more tolerant to another. Cold is the most often documented factor inducing plant resistance to pathogens. The aim of this work was to investigate whether resistance of spring barley and meadow fescue to Bipolaris sorokiniana and resistance of winter oilseed rape to Phoma lingam induced at 5 °C for 2, 4 or 6 weeks are associated with frost tolerance, water potential and soluble carbohydrate content. Cold‐acclimated plants of each species showed increased resistance to the studied pathogens. Barley, fescue and rape plants demonstrated higher frost tolerance after hardening, but only in the case of fescue a correlation between resistance to frost and resistance to B. sorokiniana was found. A significant decrease in the water potential of leaf cells was observed in cold‐acclimated barley and fescue. In these two species, water potential greatly affected resistance to B. sorokiniana. However, only in barley did accumulation of fructose, glucose and sucrose correlate as well with changes in water potential as with cold‐induced resistance to the pathogen. In the case of hardened rape, no correlation between the studied parameters was found. The results obtained indicated that the temperature of 5 °C used during cold acclimation was not favourable for hardening of this plant species.     

The Influence of Soil Volume on Root and Shoot Parameters in Container-grown Oilseed Rape

Oilseed rape was grown under irrigated conditions at equal plant density per unit area in PVC cylinders of 1 m length with different diameter (0.11, 0.16 and 0.20m). The influence of soil volume, expressed as cylinder diameter, was found not to be significant on root dry weight, root length, root surface area or the shoot: root ratio. However, a significant influence was found on shoot and seed dry weights. It was concluded that cylinders with a length of 1 m and a diameter of a minimum of 0.11 m are appropriate for the study of container-grown root systems.     

甘蓝型油菜烯脂酰-CoA还原酶基因BnECR的克隆及功能分析

反式烯脂酰-CoA还原酶(trans-2, 3-enoyl-CoA reductase, ECR)是催化超长链脂肪酸(VLCFAs)合成的脂肪酰-CoA延长酶之一。根据已报道拟南芥等的ECR基因设计引物,采用RACE (rapid amplification of cDNA ends)方法从甘蓝型油菜中克隆ECR的全长cDNA序列和对应的基因组序列,命名为BnECR (GenBank登录号分别为FJ899705和FJ899706)。序列分析结果显示,BnECR的全长cDNA序列为1 328 bp,对应的基因组序列为2 093 bp,由4个外显子组成,在ORF的上、下游分别有一个163 bp的5′UTR和一个232 bp的3′UTR。根据编码区预测BnECR前体蛋白为一个310个氨基酸残基的多肽链,包含ECR蛋白的重要功能位点K₁₄₄、R₁₄₅及一个NAD(P)H结合基序G₂₂₅SGGYQIPR/HG₂₃₄。NCBI Blastn、氨基酸序列多重比对及保守域分析表明, 该基因与拟南芥AtECR基因的同源性最高,是对应拟南芥AtECR的垂直同源基因。RT-PCR分析表明,BnECR基因在甘蓝型油菜根、茎、叶、花及角果中均有表达,其中在茎中的表达量最高。BnECR在高芥酸材料种子发育中后期的表达量显著高于低芥酸种子,表明BnECR可能参与甘蓝型油菜芥酸的合成。将BnECR克隆到酿酒酵母的穿梭表达载体中,分别转化野生型酵母By4743和突变体菌株YDL015c,添加半乳糖诱导表达。气相色谱分析表明,BnECR在酿酒酵母中有效表达,转化菌株中的芥酸(C22:1)占总脂肪酸含量的1.34%,比对照增加了52%;对突变体的转化结果表明芥酸含量恢复到野生型水平。     

植物提取物减少油菜种子带菌量的初步研究

采用冰冻法研究了十种不同植物提取物对油莱种子表面和种子内部真菌生长的影响，发现多种植物提取物能显著抑制油莱种子表面和种子内部真菌的生长，其中韭菜、辣椒和未灭菌大蒜提取液能完全抑制油莱种子表面和种子内部真菌的生长，可初步选为油莱植物型种衣剂中化学农药杀菌剂的替代品。     

甘蓝型油菜遗传多样性及其与杂种表现的关系

以3个双低甘蓝型油菜自交不亲和系、 22个不同来源的父本品种及其按NCⅡ法配制的66个杂种为材料, 应用AFLP及RAPD标记技术研究亲本的遗传多样性及遗传距离与杂种产量、含油量的关系. 结果表明, 根据遗传距离可将3个自交不亲和系分为2组, SI-1300和SI-1310为一组, SI-1320单独为一组; 父本品种分为5组, 中国品种为1组, 国外品     

Concentrations and Distribution of Some Mineral Elements in Oilseed Rape (Brassica napus L.) Plants in Relation to Nitrogen Supply

A greenhouse experiment was conducted to study the effect of N nutrition (30, 100 or 170 ppm N) on the concentrations and distribution of P, K, Ca, and Mg in oilseed rape ( Brassica napus L.). Leaf K concentration increased with increasing N supply up to 100 ppm N, as did leaf Mg after the bloom stage. Leaf Ca decreased with increasing N nutrition but P concentration was unaffected. Lower leaves had higher P concentrations than did the upper leaves. P, Ca and Mg concentrations in the roots at 34 days before bloom (DBB) declined when N supply was increased but K concentration was unaffected. At 10 and 44 days after bloom (DAB) P concentrations in the roots, stem and branches increased with N supply; whereas K, Ca and Mg concentrations did not respond. Concentrations of P in the pods increased with N nutrition up to 100 ppm N but those of K, Ca and Mg in the pods, hull and seeds were unaffected by N nutrition. P concentrations in the hull and in the seeds also increased with N supply. Most of the K and Ca were in the leaves while the least were in the seeds. Most of the P accumulated in the seeds and roots; whereas the hull contained the least. Of the four nutrients analyzed for, P concentrations were generally the lowest in the various plant parts and K concentrations the highest. Ca/Mg ratios for the hull and branches were increased by 100 ppm N and the ratios for the leaves, pods and seeds were unaffected by N nutrition.     

Leaf Growth and Chlorophyll Content of Oilseed Rape (Brassica napus L.) as Influenced by Nitrogen Supply

An experiment was conducted using a greenhouse hydroponics system to investigate the influence of N nutrition on leaf growth and chlorophyll content in oilseed rape ( Brassica napus L.) during both vegetative and generative growth. Plants were treated continuously with one of three levels of N supply (30, 100 or 170ppm N). Leaf expansion in terms of lamina area of individual leaves and leaf area per plant, and chlorophyll content of leaves during both growth phases were increased significantly by N supply up to 100 ppm N, which was found to be the optimum level for oilseed rape. N supply of 30 ppm N resulted in N stress while 170 ppm N represents an excessive supply. N supply of 100 ppm N enhanced leaf expansion during H–6 weeks after transplanting by 88–260 % over that of 30 ppm N. Lamina areas of younger leaves responded to N nutrition better than did those of older leaves. Leaf area per plant increased 155–194 % due to increasing N supply but leaf number was increased less remarkably (by 25–44 %). N supply enhanced the contents of leaf chlorophyll a , chlorophyll b , and total chlorophyll but had very little influence on chlorophyll a/b ratios; except that increasing N supply tended to reduce these ratios. Results suggest that variation in leaf chlorophyll content of rape plants in response to N nutrition is a function of leaf age and position. The significance of these results in terms of certain physiological implications for the rape plant is discussed.     

甘蓝型油菜成熟角果内源激素对带壳种子发芽的影响

以甘蓝型油菜品系832、780、1-1、1-13、8-6为材料,进行了田间带壳种子发芽调查、室内模拟降雨带壳种子发芽试验、种子发芽试验、不同浓度ABA处理的种子发芽试验,并利用HPLC测定了鲜果壳和种子的吲哚乙酸(IAA)、细胞分裂素(CK)和脱落酸(ABA)的含量。结果表明,各供试甘蓝型油菜品系带壳种子发芽率存在极显著差异,而不带壳种子的发芽率在第5 天以后没有显著差异。油菜成熟角果的果壳ABA含量与带壳种子发芽存在显著负相关（r＝－0.8941）,带壳种子发芽主要受果壳所含ABA的抑制;外源ABA能明显抑制种子发芽。     

油菜生育期氮肥素的吸收、分配及转运特性

在Hoagland完全营养液的砂培条件下,采用¹⁵N示踪方法,研究了两个冬油菜品种不同生育期吸收的氮素在体内的分配、转运及损失情况。结果表明(两个品种平均值),83.5%苗期吸收的氮素和67.3%蕾薹期吸收的氮素分布在叶片中;79.1%开花期吸收的氮素分布在叶片和茎中,其中叶片中分布的氮占42.8%;而角果发育期吸收的氮素有42.4%直接分配到角果中,此时角果已成为氮素直接分配的比例最大的器官。苗期、蕾薹期、开花期和角果发育期吸收的氮素从营养器官向生殖器官的转运比例分别为34.4%、44.3%、41.2%和31.7%,单株转运量分别为203.2、325.8、218.0和82.0 mg。在籽粒全氮中转运氮占65.1%,其中蕾薹期吸收后转运的氮素所占比例最大,为25.8%,其次是开花期和苗期,分别为16.9%和15.9%,角果发育期比例最小,为6.4%。以上4个生育期吸收的氮素损失比例分别为24.0%、10.5%、11.7%和7.3%,单株损失量分别为141.6、79.2、43.2和16.2 mg。     

甘蓝型油菜(Brassica napus L.)千粒重性状遗传体系分析

通过遗传差异较大的2个甘蓝型油菜（Brassica napus L.）纯系亲本组合（HSTC14×宁油7号）衍生后代的世代家系群体分析，应用主基因+多基因家系世代联合分离分析方法研究油菜千粒重的遗传体系。结果表明，甘蓝型油菜HSTC14×宁油7号组合千粒重遗传体系系由一对主基因+多基因构成，主基因中只有加性效应(d = 0.1062),不存在显     

导入LPAAT和KCS基因对油菜种子芥酸含量的影响

采用农杆菌介导法,以下胚轴为转化受体,将溶血性磷脂酸酰基转移酶（LPAAT）和酮脂酰辅酶A合成酶（KCS）基因导入2种不同基因型（“Drakkar”和“Maplus”）的甘蓝型油菜,共获得247株再生植株,其再生频率分别为15.1%和2.0%。PCR检测和Southern杂交分析证实,外源基因已整合到油菜基因组中,转化频率分别为3.6%和0.7%。种子中芥酸含量因外源基因的导入使零芥酸油菜“Drakkar”提高到10.5%,高芥酸品种“Maplus”提高了5.0%,最高达62.8%。