Development of a KASP Marker on Chromosome A05 for Seed Oil Content of Brassica napus

In order to identify the molecular markers that can be widely used in the breeding of Brassica napus L.varieties with high seed oil content under different genetic backgrounds,we developed a Kompetitive Allele Specific PCR(KASP)marker for seed oil content on the basis of the results from available studies.The verification in the F_(2) population showed that the marker was closely linked to the quantitative trait locus(QTL)for oil content on chromosome A05.The findings helped to breed the‘Fengyou’varieties with high seed oil content in the middle reaches of the Yangtze River.

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 (BrassicanapusL )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 10 6 2 ) ,不存在显性效应 ;多基因存在加性 ([d]=0 2 2 2 8)和显性效应 ,但显性效应为负值 ([h]=- 0 2 80 0 )。表明该组合千粒重主要由主基因加性效应和多基因效应决定 ,但无杂种优势。F2∶3家系群体主基因遗传力为 83 39% ,多基因遗传力为 11 71%。HSTC14×宁油 7号组合千粒重的改良可能受主基因无显性效应 ,多基因显性效应为负值的制约。

锰胁迫对甘蓝型油菜Brassica napus L.种子活力和幼苗抗氧化系统的影响

用不同质量分数的锰溶液(0.2%,0.4%,0.8%和1.2%Mn2+)处理甘蓝型胜利油菜Brassica napuscv.Shengli,研究锰对其种子活力、幼苗细胞膜透性、脂质过氧化及抗氧化剂的影响.结果表明:锰胁迫降低了种子活力、幼苗抗坏血酸(Vc)质量分数、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,破坏了细胞膜的完整性,并使丙二醛(MDA)质量分数、脯氨酸(Pro)质量分数和过氧化物酶(POD)活性增加.

甘蓝型油菜（Brassica napus L．）的春化作用及其应用

研究了甘蓝型春性、半冬性和冬性油菜（ＢｒａｓｓｉｃａｎａｐｕｓＬ．）春化时间，不同设备条件和不同生长阶段的春化效果，以及人工春化技术的利用，结果表明春性油菜的开花株率不受春化处理时间的影响，半冬性和冬性油菜的开花株率与春化处理时间有关．半冬性和冬性油菜的萌芽种子在春化室内通过春化阶段，分别需时２０ｄ和４５ｄ；冬性油菜在冰箱冷藏室通过春化阶段需时５０ｄ；三叶期冬油菜通过春化阶段需时３５ｄ．冬油菜在春化室的春化效果比冰箱冷藏室的效果好．适当延长春化时间能提高春化效果。延长每天光照时间能加快油菜的生育进程．利用冰箱冷藏室和生长室可以在上海当地完成半冬性和冬性油菜的春化和夏繁工作。

A Comparative Study on the Quality Components Between Self Pollinated Seeds and Naturally Pollinated Seeds in Brassica napus L. in Sichuan Ecological Region

[ Objective] This study was to reveal the differences in crude fat and glucosinolates between self pollinated seeds and naturally pollinated seeds in Brassica napus in sichuan ecological region.. [ Method] Near-infrared spectroscopy method （NIRS） was employed to measure the quality components in self pollinated seeds and naturally pollinated seeds of 861 shares of Brassica napus from Sichuan ecological region. And correlation analysis and regression analysis were conducted based on the experimental data via SPSS （statistics package for social science）. [ Result] The contents of crude fat in the self pollinated seeds were commonly a higher than that in the naturally pollinated seeds at 0.01 significant level; while the contents of glucosinolates in the self pollinated seeds and the naturally pollinated seeds were insignificantly different. Both the correlation relationship and linear regression for the crude fat between the self pollinated seeds and naturally pollinated seeds reached the significant level. The regression equations for the contents of crude fat（y1 ） and glucosinolates（ y2 ） in the naturally pollinated seeds and of crude fat（ x1 ） and glucosinolates（ x2 ） in self pollinated seeds were respectively determined to be y1 = 16.844 ＋0.614x1 and y2 = -0.620 ＋ 1.017 x2. [ Conclusion] In Brassica napus breeding, crude fat in naturally pollinated seeds should be emphatically taken into account, meanwhile concurrently considering that in self pollinated seeds; while glucosinolates in both the self pollinated seeds and the naturally pollinated seeds must be simultaneously concerned.

油菜(Brassicanapus L.)千粒重性状主位点组遗传分析

应用作物数量性状QTL体系的主位点组检测方法分析不同遗传来源的 12个甘蓝型油菜(BrassicanapusL. )亲本的千粒重性状的遗传差异类型、主位点组基因型和基因效应。结果表明: 12个甘蓝型油菜亲本间千粒重性状受 3个主位点组基因控制,各主位点组基因效应的方向、大小不等。3个主位点组基因的加性效应 (dM )分别为0 316 3**、-0 141 9*和-0 003 7; 3个主位点组基因的显性效应(hM)分别为-0 033 7、0 184 3*和-0 212 9*。主位点组基因加性效应(dM)的和为正值;显性效应(hM)的和为负值。主位点组遗传变异百分率为 54 44%,微位点组的遗传变异百分率为 33 26%。文中讨论了亲本和亲本间杂种千粒重性状的遗传特点和改良潜力。

Effects of Cadmium Stress on Seed Germination and Seedling Growth of Brassica napus L.

To investigate the effects of the heavy metal cadmium （Cd） on seed ger- mination and seedling growth of Brassica napus L., 25 B. napus lines with different genetic background were treated with four concentrations （0, 1, 5 and 10 mg/L） of Cd, and then, their germination potential, germination rate, seedling length, main root length, seedling fresh weight, and seedling dry weight were measured. The re- sults showed that the response of the B. napus lines to Cd stress was different. With the increase of Cd concentration, the relative germination potential and relative seedling rate increased first and then decreased, and reached the maximum levels when the Cd concentration was 5 rag/L. The inhibitory effects of Cd stress on seedling growth indices in a decreasing order were root length〉seedling length〉 seedling fresh weight〉seedling water content. There were extremely significant differ- ences in the relative root length, relative seedling length, relative seedling fresh weight and relative seedling water content among the B. napus lines treated by dif- ferent concentrations of Cd, while there were no significant differences in the rela- tive germination potential and relative seedling rate among the lines, except that the relative seedling rate was significantly different among the lines treated by 5 mg/L Cd. The results suggested that seedling growth was more sensitive than seed ger- mination to heavy metal stress.

浙北地区优质甘蓝型油菜(Brassica napus L.)产量性状与产量的关系

对24个高产优质甘蓝型油菜品种(系)的单株产量及9个产量性状进行统计分析,结果表明,单株有效角果数、每角果实粒数、千粒重对单株产量的正效应达显著或极显著水平;单株有效角果数和每角果实粒数对产量的直接通径系数分别为0.9702和0.8439,且净效应均达极显著正值;而千粒重对产量的直接通径系数虽为正值且较大,但净效应呈负值;结角密度对产量的直接通径系数及净效应均为负值。研究结果分析,浙北优质甘蓝型油菜高产的育种方向,在选择合适结角密度的基础上,重点应放在每角果实粒数和单株有效总角果数两个主要目标性状的选择上,同时兼顾千粒重。

Effects of Nitrogen Fertilizer Management on Biological Traits and Physiological Indexes at Seedling Stage and Yield of Directly-sown Rapeseed(Brassica napus L.)

Field experiments were carried out to study the effects of different nitroge- napplication rates and application times on biological traits and physiological indexes of directly-sown rapeseed （Brassica napus L.） at the seedling stage and investigate the relationship between these biological traits or physiological indexes at the seedling stage and yield, so as to provide scientific theoretical support for high yield and efficient fertilization management in production of winter rapeseed. Field trials were conducted in Chengdu plain of Sichuan Province under rice-rapeseed rotation system during the period of 2011-2012. The nitrogen application rate trial consisted of five nitrogen levels （0, 90, 180, 270 and 360 kg/hm2） and the nitrogen application time trial included NTl（single application as base fertilized）, NT2 （bottom application ＋one time of topdressing at seedling stage） and NT3 （bottom application＋two times of topdressing at seedling stage） under the same nitrogen rate （225 kg/hm2）. The results indicated that compared with no nitrogen application （NO） treatment, the in- crease of nitrogen fertilizer is beneficial to the increase of biological traits including plant height, green leaf number, leaf area index and dry weight of rapeseed at the seedling stage, the improvement of physiological indexes including total nitrogen content, chlorophyll content and soluble protein content of functional leaves, and the reduction of soluble sugar content. Nitrogen rate was linearly correlated with various biological traits at the seedling stage and physiological indexes including total nitro- gen content, chlorophyll content and soluble sugar content in functional leaves over- a/I, but in parabolic correlation with soluble protein content. Under the same nitrogen rate, NT2 treatment exhibited biological traits remarkably or significantly higher than NT1 treatment and NT3 treatment. The nitrogen application times were linearly cor- related with the physiological indexes of functional leaves at the seedling stage. The various biological traits and physiological index of functional leaves at the seedlings stage were in quadratic function parabolic correlation with seed yield, and the corre- lation was significant （P〈0.05）. Therefore, under the rice-rapeseed rotation system in Chengdu plain, the economic rational nitrogen rate is 180-225 kg/hm2, and the mode of bottom application ＋ one time of topdressing （NT2） is suitable.

显性核不育油菜(Brassica napusL.)无蜡粉纯合两型系的选育

采用杂交、兄妹交和自交等育种方法，育成无蜡粉的显性核不育纯合两型系。利用该两型系进行全不育系制种，无蜡粉可作为苗期育性的指示性状，能有效地区别因纯合两型系内可育株迟拔或漏拔而产生的杂株，从而提高全不育系和杂交种的纯度。

Mechanical Harvesting Effects on Seed Yield Loss,Quality Traits and Profitability of Winter Oilseed Rape (Brassica napus L.)

China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 （Brassica napus L.） was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C （CHA, CHB, and CHC） were designed and manual harvesting （MH） as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting （MS/CH） showed an input/output ratio of 1：1.6, and it was 1：1.2 in mechanical sowing/manual harvesting （MS/MH）. Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River.

Transcriptome analysis reveals genes expression pattern of seed response to heat stress in Brassica napus L.

Seeds might deteriorate,and lose the ability to germinate when stored under high temperature and high humidity.Brassica napus is one of the most important oil crops in China.However,B.napus seeds were generally stored through summer season with high ambient temperature,which lead to seed viability loss.In order to understand the mechanism of seed response to heat stress and improve seed heat tolerance,B.napus seeds were treated with high temperature(40℃)and ultra-high temperature(60℃)for 4 h.The germination of heatstressed seeds were obviously slower,the germination index and vigor index decreased with temperature increase from 40 to 60℃,and the 40℃ pretreatment could improve the seed tolerance to 60℃ heat stress.Transcriptomics results showed that 442 differentially expressed genes(DEGs)were identified in seeds after heat stress.Gene ontology and KEGG pathway enrichment analysis revealed that some of the genes were involved in posttranslational modification,protein turnover,chaperones and carbohydrate transport,metabolic pathways and secondary metabolites biosynthesis pathway.Among these DEGs,sHSP and transcription factors genes were involved in heat stress tolerance.Thirty-two overlapping genes under different high temperature stress(40℃ and 60℃)were enriched in biological processes of response to oxidative stress and abiotic stimulus.The expression trends of 12 genes randomly selected from the RNA-seq data were almost consistent with the results of qRT-PCR.Our results revealed several potential candidate genes and pathways related to heat responsive by high temperature,which is beneficial for further improving the heat tolerance in B.napus seeds.

Genetic Diversity of Testa Pigments and RAPD Marker of Yellow-Seeded Rapeseed (Brassica napus L.)

14 yellow-seeded rapeseed lines (Brassia napus L.) from different genetic sources were used to analyze diversity of testa pigments content, oil and protein content, and RAPD markers. The results showed that the anthocyanin and melanin were the most important pigments in testa and their content were responsible for the variation in seed color ranging from orange to black yellow, 14 yellow-seeded lines could be classified into 3 groups: high anthocyanin content group with anthocyanin content over 2. 54 mg g-1 DW, the seed color was light yellow or orange; low pigments content group with low content of anthocyanin and melanin, the testa was transparent and the seed color was light yellow, greenish yellow or twany; high melanin content group with melanin content over 178. 4U(A290nm) , the testa was black, the seed color was black yellow. Oil content changed from 36.2% to 45. 5%, protein content from 21.1% to 27.7% , and the correlation analysis revealed that the oil content is highly significantly negatively correlated with the protein content. The cluster analysis showed that the extensive genetic variation existed among 14 yellow-seeded lines by using unweighted paired group method with arithmetic average (UPGMA) based on RAPD markers which were amplified with decamer primers, the genetic similarity among them ranged from 0. 25 to 0.909, and 14 yellow-seeded lines could put into 2 clusters corresponding to genome difference.

吡虫啉和甲基硫菌灵对油菜(Brassica napus L.)和光叶紫花苕(Vicia sativa L.)的化感作用

油菜(Brassica napus L.)和光叶紫花苕(Vicia sativa L.)为重要蜜源植物。以这2种植物种子为受体,用不同浓度(20 mg/L、40 mg/L、60 mg/L、80 mg/L、100 mg/L)的吡虫啉和(200 mg/L、400 mg/L、600 mg/L、800 mg/L、1000 mg/L)的甲基硫菌灵采取室内培养皿滤纸法胁迫处理,以探讨这2种农药对油菜和光叶紫花苕的化感作用。结果表明,吡虫啉和甲基硫菌灵明显降低了油菜种子活力,抑制幼苗生长;吡虫啉总体上提高了苕子种子活力,促进幼苗生长,而甲基硫菌灵则降低苕子种子活力,抑制幼苗生长。总之,吡虫啉和甲基硫菌灵对上述2种蜜源植物均有强烈的化感作用。

Detection of new candidate genes controlling seed weight by integrating gene coexpression analysis and QTL mapping in Brassica napus L.

Seed weight is a component of seed yield in rapeseed(Brassica napus L.).Although quantitative trait loci(QTL)for seed weight have been reported in rapeseed,only a few causal quantitative trait genes(QTGs)have been identified,resulting in a limitation in understanding of seed weight regulation.We constructed a gene coexpression network at the early seed developmental stage using transcripts of 20,408 genes in QTL intervals and 1017 rapeseed homologs of known genes from other species.Among the 10 modules in this gene coexpression network,modules 1 and 2 were core modules and contained genes involved in source–flow–sink processes such as synthesis and transportation of fatty acid and protein,and photosynthesis.A hub gene SERINE CARBOXYPEPTIDASE-LIKE 19(SCPL19)was identified by candidate gene association analysis in rapeseed and functionally investigated using Arabidopsis T-DNA mutant and overexpression lines.Our study demonstrates the power of gene coexpression analysis to prioritize candidate genes from large candidate QTG sets and enhances the understanding of molecular mechanism for seed weight at the early developmental stage in rapeseed.

Effects of Heat Stress during Seed Filling Stage on Brassica napus Seed Oil Accumulation and Chlorophyll Fluorescence Characteristics

As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified.

Characteristics and High Yield Seed Production Technology of Zhuoyou No.11 in Brassica napus L.

Belonging to the recessive genic male sterility hybrid rape in Brassica napus L., Zhuoyou No.11 is characterized for its semiwinterness, reniform cotyledon, flourishing lobed leaves, wide parietal lobe, and obvious leaf margin serrate. With compact plant type, resistance to stalk break, mid-length pods and great 1 000 grain weight, it has the advantages in high and stable yield, high oil content, and high protein content. During the hybrid seed production, the isolation distance should be over 1 000 m, and seedling transplantation is adopted by transplanting the male parent first and then planting female parent with the line-ratio of 1：3-4, and cultivation and management measures are in accordance with the high yield standard of growth in autumn; about 50% of the fertile plants in the female parent rows should be removed timely and completely before the flowering stage, and picking off the flower stalks of male parents can extend flowering time, and artificial pollination or bees release can improve the seed setting rate.

Physiological Differences Between Yellow-Seeded and Black-Seeded Rapeseeds (Brassica napus L.) with Different Testa Characteristics During Artificial Ageing

Yellow-seeded rapeseed (Brassica napus L.) is a new kind of breeding resources with yellow color, increased oil and protein content and less unwanted crude fiber content due to the thinner and transparent testa compared with traditional black or brown-seeded rapeseed. To analyze the longevity of the yellow-seeded rapeseed during storage, the physiological differences between the yellow and black-seeded near-isogenic lines were studied by artificial ageing method. The testa rate, anthocyanin content and melanin content of yellow-seeded rapeseeds decreased by 20.1, 25.2, and 80.4% respectively than black-seeded rapeseed. During artificial ageing, the yellow-seeded rapeseed showed significantly different effect of ageing compared with the black-seeded, as demonstrated by faster deterioration with lower germination percentage, seed vigour index, reducing sugar and soluble protein contents than the black-seeded, as well as a drastic increase in electrical conductivity, malnodialdehyde (MDA) content and a rapid decrease in activities of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). The results suggested that the transparent testa of the yellow-seeded rapeseed lost some abilities to protect the embryo against adverse environmental conditions and thus led to a poor storability.

Identi cation of seed heat tolerance and its correlation with agronomic traits in Brassica napus L.

To better understand the effect of high temperature on seed viability, artificial aging treatments were implemented on 472 accessions of rapeseed (Brassica napus L.) by constant high temperature at 70℃for 8h. Results showed a remarkable impact of constant heat on seed germination. After heat treatment, considerable variation was found in seed germinability, some genotypes even lost the ability to germinate. The effect of accelerated aging was highly significant. Germination parameters varied among ecotypes. Seed viability varied with different origin, and was significantly and positively correlated with seed yield per plant and dry weight of aboveground parts per plant among 14 agronomic traits. Germination traits were positively correlated with oil contents.

外源蔗糖对甘蓝型油菜种子萌发与幼苗发育的影响

萌发调控是促进甘蓝型油菜快速出苗、齐苗的重要基础,为探索外源蔗糖对甘蓝型油菜种子萌发与幼苗发育的影响,选用早熟油菜品种湘油420进行了不同条件下萌发试验,检测了水分、脱落酸、内源糖及关键基因的表达变化。结果表明:外源蔗糖延缓湘油420种子萌发启动过程,提高萌发整齐度,在子叶展开后促进子叶转绿、真叶形成,抑制主根过度伸长同时促进侧根发育。外源蔗糖对湘油420种子萌发过程中水分吸收表现先抑制后促进,播种后3 h内抑制水分吸收,并在播种后6 h内解除吸水抑制;萌发过程中种子内ABA含量持续降低,外源蔗糖促进播种后3 h内ABA含量的下降;播种后15~18 h内可溶性总糖含量迅速降低,还原性糖含量在萌发初期随萌发进程增加,外源蔗糖对可溶性总糖含量变化无明显影响,但抑制播种后9 h还原糖的增加、促进播种15 h后还原糖含量增加;萌发过程中2个蔗糖磷酸合酶(BnaSPS)基因BnaC09g37470D和BnaA10g15120D相对表达量在胚根萌出阶段显著降低、子叶转绿后表达回升,外源蔗糖抑制胚根萌出前2个BnaSPS基因表达,在子叶转绿后显著诱导其中BnaC09g37470D基因表达。综上,研究初步揭示了外源蔗糖通过渗透性作用调节吸涨起始阶段水分吸收,通过糖代谢调节萌发阶段种子内源糖利用和幼苗发育初期糖类转化而延缓甘蓝型油菜种子萌发启动、促进吸涨后种子萌发进程而提高种子萌发整齐度、促进幼苗发育的多重作用。