Using Hemispherical Radiation Measurements to Predict Weight-Related Growth Traits in Oilseed Rape (Brassica napus L.) and Barley (Hordeum vulgare L.) Canopies

Methods for determining growth traits in the field are mostly work‐intensive and/or often erroneous. Further development of multi‐temporal techniques of growth analyses provided by fast and non‐destructive tools for monitoring canopy properties may result in a substantial gain for practical use. Among them, the LAI‐2000 Canopy Analyzer can be used to determine the canopy area index (CAI) resulting from radiation measurements. In plant breeding, single‐date measurements were usually made across a wide number of genoptypes. In contrast, multi‐temporal information on canopy status is needed in agronomy. In our study, data of the CAI based on hemispherical radiation measurements with the LAI‐2000 were used to estimate developmental courses of weight‐related growth traits. For this purpose, seasonal courses of shoot fresh matter, shoot dry matter, shoot N and water content and CAI of winter oilseed rape (Brassica napus L.) and spring barley (Hordeum vulgare L.) were investigated simultaneously in field experiments from 2002 to 2006 in northern Germany with and without nitrogen (N) fertilization. Courses of 2003 and 2004 were used to calculate relationships between CAI and growth traits. Results show that each of the weight‐related growth trait is related to the CAI. In this mechanistic approach relationships were found gathered across 2 years, two N‐treatments and several growth stages being unaffected by N‐fertilization, cultivar and experimental year. These relationships were verified using independent data sets of the years 2005 (winter oilseed rape and spring barley) and 2006 (winter oilseed rape). The results of the current study show that the use of LAI‐2000 and its rapid and non‐destructive determination of weight‐related growth traits over the entire growth period will substantially improve the determination of weight‐related growth traits in agriculture.     

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.     

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.     

On Harvest Indices of Winter Oilseed Rape (Brassica napus L.)

Ten quite different European winter rapeseed cultivars were grown in a 3-year field trial at one location. The traits grain yield and biomass were measured based on single plant measurements (first year) or on plot basis (second and third year). Individual harvest indices were calculated.
Besides a general discussion of the experimental results for this collection of winter rapeseed cultivars the main aim of the present investigations was an examination whether these experimental results are in agreement with the theoretical conclusions on harvest indices which have been published in this journal in three preceding publications.
Hence the investigations of this paper are divided into the three chapters: 1) Calculation of mean harvest indices, 2) Variability of harvest indices and 3) Correlations among harvest index, grain yield and biomass. In all three chapters the agreement between the empirically obtained and the theoretically expected values is quite good.     

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.     

Inheritance of Total and Individual Glucosinolate Contents in Seeds of Winter Oilseed Rape (Brassica napus L.)

Genetic analyses were carried out with B. napus lines that differed in total content of individual glucosinolates (GSLs), as well as in their profile. Inheritance of total GSL content was studied with a complete F₁ diallel mating of eight doubled haploid (DH) lines (5–120/μmol GSL/g dry seed) as well as with the segregating populations of two crosses between DH lines. Most of the genetic variability was caused by gca effects; heterosis was not important; heritability of GSL content was high (h²_b, = 0.95, h²_n= 0.87). For GSL contents below 20/μmol/g seed, heritability values reached h²_b, = 0.69 and h²_n, = 0.66. Low total GSL content was found to be controlled by 4–5 recessive genes with additive gene action. Alkenyl GSL profiles studied in F₂ from resynthesized rapeseed lines were determined by four loci, two that are responsible for the elongation of the butenyl to pentenyl GSLs and two that are responsible for hydroxylation of alkenyl GSLs. Initial genetic studies of indolyl GSL contents from 0.1–4.5/μmol/g show that two or three genes may be involved. The frequency distribution of F₂ phenotypes was virtually continuous due to both segregational and environmental variation. Genotypes with low alkenyl and low indolyl GSL contents were selected after crossing parents with low alkenyl/high indolyl and high alkenyl/low indolyl GSL content. The alkenyl GSL profiles are discussed with regard to the parental diploid species B. oleracea and B. campestris.     

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。     

甘蓝型油菜抗裂角品种(系)的选与分析

利用随机碰撞测试方法,对229份自交纯合的甘蓝型油菜品种（系）进行了抗裂角指数测定,以期筛选出抗裂角种质。结果表明,抗裂角性状在现有品种（系）中存在广泛变异,变异系数达114．4％。发现了2份抗裂角的品种（系）,占0．9％;较抗的资源占3．93％;处于中间状态的品种（系）占8．73％;易裂角资源占27．07％,极易裂角的品种（系）占59．39％。选择6个品种（系）进行了连续3年的测试,表明抗裂角性状由品种（系）的遗传特性决定,但受环境条件影响;随机碰撞法具有较好的重现性。简单相关分析显示,抗裂角指数与角果密度呈显著负相关,与角皮厚度、角果长度、角果宽度、角喙长度、角粒数呈显著正相关,但相关系数都很小。     

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。     

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.     

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.     

缓释型配方肥在晚稻套播油菜上的施用效果研究

油菜套播是利用双季稻区冬闲田的有效手段,为探究缓释型配方肥（N-P₂O₅-K₂O：25-7-8,及5%的中微量元素）在晚稻套播油菜上的施用效果,设置一次性基施缓释型配方肥与分次施常规肥效果对比试验和配方肥施用量试验,调查油菜产量形成、肥料利用率及经济效益。结果表明,在减少肥料养分投入且一次性基施的情况下,缓释型配方肥仍能达到甚至优于常规肥分次施用的效果。菜籽产量与缓释型配方肥用量呈线性加平台关系,适宜施肥量可保证较大的收获密度并产生较多的每株角果数和每角粒数,同时维持较高的肥料利用率,从而提高籽粒产量和经济效益。根据本试验结果推算出晚稻套播油菜的目标产量为1 500~1 800kg/hm²时,缓释型配方肥的适宜用量为645~715kg/hm²。     

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。     

四川甘蓝型油菜地方种和推广品种休眠特性的比较研究

对52份四川甘蓝型油菜地方种和24份四川推广品种作了收获前种子发芽试验,研究了四川甘蓝型油菜的休眠特性。结果表明四川甘蓝型油菜品种间的休眠期差异达显著水平,抗收获前发芽资源数量少;地方种与推广品种间发芽指数差异不显著,但发芽率和发芽指数的变幅及分布差异达0.05显著水平,四川甘蓝型油菜推广品种发芽指数的分布较地方种更集中于低和高的范围内;根据材料发芽进程和发芽指数进行聚类分析,将推广品种聚为三类：第一类为第1天发芽高峰类型,第二类为第1、2天发芽高峰类型,第三类为抗收获前发芽类型;地方种聚为四类,比推广品种多一种类型：第1、2天发芽高峰类型。鉴定筛选的四川甘蓝型油菜抗收获前发芽的宝贵资源及其休眠特性,将为甘蓝型油菜的抗收获前发芽生理研究和育种提供信息和材料。     

Effects of Nonregular Spatial Distribution of Plants on Yield per Area: A Theoretical Approach with Applications to Winter Oilseed Rape (Brassica napus L.)

In this study a stochastic approach, based on several simplifying assumptions, is developed that allows an estimation of the effects of nonregular spatial patterns of the distribution of individual plants on yield per area. In this approach, two random variables were attached to each individual plant: single plant yield and individual space per plant. The latter can be estimated, for example, by the area of Thiessen polygons. Yield per area is calculated theoretically by the expectation (=mean) of the ratio between individual yield and area. Based on the logarithmic relationship between single plant yield and individual space per plant, yield per area can be broken down into three additive terms: the first term depends only on the mean of individual plant areas, while the second depends on their mean and variance simultaneously. This second term is the product of the variance and a factor which depends only on the mean. The third term is a function of the mean and of higher order (≥ 3) central moments of a fractional linear transformation of individual plant area. Finally, these theoretical concepts were applied to 17 experimental data sets of three cultivars of winter oilseed rape (Brassica napus L.) with measurements for single plant yields and individual areas for the Thiessen polygon tesselations. Since yield per area is theoretically defined by the expectation of the ratio between individual yield and area, it is estimated by the arithmetic mean of the individual yield/area‐ratios. The agreement between this estimate and the sum of the estimated terms from the aforementioned additive decomposition of yield per area is particularly good. For the 17 data sets, percentages for these additive terms of approximately 71.4 % up to 98.4 % (mean: 89.0 %) for the first term, 1.6 % up to 20.0 % (mean: 9.8 %) for the second term and 0 % up to 8.7 % (mean: 1.2 %) for the third term are obtained. As a consequence it may be concluded, that yield per area can be explained mainly by dependencies on the means of individual plant areas while the variance of individual plant spaces is of only minor importance. The effect of the third term is insignificant. These results clearly indicate an answer to the main issue raised in the paper, namely the importance of seeding density as opposed to seeding accuracy/uniformity: nonuniformity is of limited influence and seeding density is the main correlate of yield/area. Seed placement accuracy of seeding technology therefore plays an only minor role.     

甘蓝型油菜耐荫性的品种差异

以耐荫性强、弱不同的4个甘蓝型油菜品种为试材,比较研究了不同品种甘蓝型油菜的光合生理特性。结果表明：在遮荫（1/4自然光下处理20 d）条件下,与不耐荫品种相比,耐荫品种的单株干重、比叶重、RuBP羧化酶活性、希尔反应活力、PSⅡ活性下降幅度较小,而叶绿素组分中叶绿素b所占比例较高。说明耐荫的甘蓝型油菜品种具有较     

Effective Diploidization of Microspore-Derived Haploids of Rape (Brassica napus L.) by In Vitro Colchicine Treatment

A technique for the in vitro colchicine treatment of microspore-derived haploids of rape (Brassica napus L.) is presented. This allows effective and time-saving chromosome doubling. The most effective method consists of an application of 50 mg/1 colchicine in a liquid B5 medium to the rooted micro-spore-derived plantlets for 4–8 days. By this treatment more than 50 % of the plants developed at least diploid sectors. A change of medium after some days may even increase this diploidization rate.     

Effect of Completion of Vernalization on Generative Development of Winter Rape (Brassica napus L. var. oleifera) Plants

Germinating seeds and young plants of winter rape var. Górczañski were vernalized for 56–63 days under conditions of 9-hour day, at the temperature 2 and 5 °C and in continuous darkness at the temperature 2 °C. After vernalization the plants grew under conditions enabling to complete vernalization: in a glass-house at the temperature day/night 15/10 °C and in semi natural conditions of open vegetation hall in the period from June till August. After sub-optimal vernalization further growth of the plants at lowered temperature increased its effectiveness (completion of vernalization). Depending on the degree of the vernalization of the plants the completion of their vernalization was both obligatory, i.e. conditioning the acquisition of the ability of generative development, and facultative i.e. accelerating this development. It has been demonstrated that the population of plants of the examined variety is strongly differentiated not only with respect of vernalization requirements in the particular plants, but also what regards the effectiveness of vernalization completion. New observations have been made indicating that the mechanisms controlling the successive phases of generative development, i.e. phase of forming flower buds and the flowering phase are not identical which may be interpreted as indicating that the "flowering factor" is polymorphous.     

Components of a Cytoplasmic Male Sterility System in Resynthesized and Cultivated Forms of Oilseed Rape (Brassies napus L.)

Male sterile Brassica napus L. plants were found in breeding material which was used for the development of yellow-seeded oilseed rape. The genetic studies indicated that the male sterility was conditioned by the presence of maintamer genes in the nuclear backgrounds of two newly resynthesized B. napus lines, No7076 and No7406, in combination with a male sterility-inducing cytoplasm (S) which is frequently found in cultivated forms of B. napus. Test crosses with nap maintainer and restorer lines support the conclusion that the observed male sterility is of nap type. Furthermore, the Eco RI restriction pattern of mitochondrial DNA of the (S) cytoplasm was identical to that of the nap cytoplasm. Hence, we conclude that we have uncovered a new source of maintainer lines for the nap system which could potentially lead to the production of a better maintainer/restorer system for use in hybrid oilseed rape breeding programmes. However, more work is needed to reduce the glucosinolate content of the maintainer lines and to determine the factors controlling the phenotypic expression of the system.