A Genetic Linkage Map of Brassica campestris L.ssp. pekinensis (syn. B. rapa L. ssp. pekinensis)

A molecular genetic map of Chinese cabbage was constructed with a 102 recombinant inbred (RI) population from a cross of two cultivated Chinese cabbage lines 177 and 276, using AFLP and RAPD markers. 352 markers including 265 AFLP markers and 87 RAPD markers were integrated into 17 linkage groups. It covered a total of 2 665. 7 cM with an average interval of 7. 6 cM. AFLP marker is efficient for map construction while it easily forms clusters to cause big gaps in map. A total of 13.92 % abnormal segregation markers distributed in the map. The molecular genetic map is fundamental for gene localization, comparative genomics, and QTL mapping of important agronomic traits.

Effect of Combined Use of Boron and Manganese Fertilizers on the Nutritional Quality and Physiological Indices of Brassica campestris L.ssp.chinensis L.var.utilis

[Objective] The purpose of this study is to determine the effects of com-bined use of boron and manganese fertilizers on the nutritional quality and physio-logical indices of Brassica campestris. [Method] In the nutrient solutions for growing B. campestris by hydroponics, boric acid and manganese sulfate were added at 0.5, 2.5, and 7.5 mg/L respectively. Another treatment without boron and manganese was prepared as the control. Quality and physiological indices of B. campestris in the 10 treatments were measured. [Result] Boron and manganese shared obvious in-teraction in improving the quality and physiological indices of B. campestris. To cul-tivate B. campestris with high quality and strong resistance, the optimum concentra-tions of boron and manganese in the nutrient solution should be 2.5 mg/L boric acid and 2.5-7.5 mg/L manganese sulfate. [Conclusion] The findings wil provide refer-ence for studying effects of trace elements on nutrient composition of vegetables.

Role of nitrification inhibitor DMPP(3,4-dimethylpyrazole phosphate) in NO^-_3-N accumulation in greengrocery( Brassica campestris L. ssp. chinensis ) and vegetable soil

The influence of nitrification inhibitor(NI) 3,4 dimethylpyrazole phosphate(DMPP) on nitrate accumulation in greengrocery( Brassica campestris L. ssp. chinensis ) and vegetable soil at surface layer were investigated in field experiments in 2002 and 2003 Results showed that NI DMPP took no significant effect on yields of edible parts of greengrocery, but it could significantly decrease NO - 3 N concentration in greengrocery and in vegetable soil at surface layer. In addition, NI DMPP could reduce the NO - 3 N concentration during the prophase stage of storage.

Effect of Nitrogen and Sulfur Supply on Glucosinolates in Brassica campestris ssp.chinensis

Glucosinolates （GSs） are a group of plant secondary metabolites containing abundant nitrogen （N） and sulfur （S） mainly in Brassica and have the beneficial effects on human health including anti-carcinogenic, cholesterol-reducing and other pharmacological effects. The objective of this study was to investigate the effect of different concentrations of N （5, 10, and 20 mmol L-a, denoted by N5, N10 and N20） and S （0,5, 1, and 2 mmol L^-1, denoted by S0.5, S1 and S2） on the yield and GSs in pakchoi （Brassica campestris L. ssp. chinensis var. communis） in hydroponics. Results showed that N10 and N20 significantly enhanced the yield compared with N5, however, N20 had a negative effect relative to N10. Only with N10 and N20 low S supply （S0.5） reduced the yield. The concentrations of aliphatic GSs, aromatic GS and total GSs were enhanced by N5 and indolyl GSs were enhanced by N20. S2 enhanced the concentration of individual GS and total GSs. The concentrations of indolyl GSs were maximized in N20S2 treatment, whereas the highest concentrations of aliphatic GSs, aromatic GS and total GSs were found in N5S2 treatment. Effects of N and S on aliphatic GSs were higher than on indolyl GSs. The results suggest that the accumulation of aliphatic GSs and aromatic GS could be enhanced by low N and high S and restricted by high N while that of indolyl GSs could be enhanced by high N and high S.

Effect of the Antisense BcMF12 Driven by the BcA9 Promoter on Gene Silencing in Brassica campestris L.ssp.chinensis

The study analyzed the silencing of BcMF12 gene regulated by BcA9 promoter in the transgenic pakchoi and confirmed the effect of antisense BcMF12 gene on the pollen development. A conserved BcMF12 gene fragment was amplified from the cDNA of flower buds in pakchoi （Brassica campestris L. ssp. chinensis, syn. B. rapa L. ssp. chinensis） and was fused to the anther specific BcA9 promoter. The plant antisense expression vector was constructed and then introduced into pakchoi via Agrobacterium-mediated transformation. The transgenic plants were screened by antibiotics and molecular analysis. PCR and Southern blot revealed that the antisense BcMF12-GUS fusion gene regulated by BcA9 promoter was integrated into transgenic plants. Northern blot suggested that the expression of BcMF12 gene was down-regulated significantly. The pollen germination rate of transgenic plants with antisense BcMF12 gene decreased as compared with that of the control plants. The expression of the gene BcMF12 related to the pollen development was inhibited by the antisense BcMF12 driven by BcA9 promoter, which consequently affected the pollen development in pakchoi.

Preliminary Study on Tissue Culture Technique of Brassica campestris L. ssp. chinensis (L.) Makino var. utilis

In order to establish a rapid propagation system for Brassica campestris L. ssp. chinensis var. utilis, the anther and cotyledon-cotyledonary petioles were used as explants to conduct tissue culture research. The results showed that not bloomed flower buds with higher styles than petals were appropriate for anther cul- ture. Moreover, most microspores were at the mid-late uninucleate stage at that time. The pollen germination rates of Brassica campestris L. ssp. chinensis var. u- tills were low and the germination rates in autumn and winter were higher than that in summer. The induction medium of anther callus of Brassica campestris L. ssp. chinensis var. utilis was MS＋1.0 mg/L KT＋1.0 mg/L 2, 4-D＋3% sugar＋6 g/L agar＋ 8% coconut milk and the induction media of adventitious bud were MS＋2.0 mg/L 6-BA＋ 0.5 mg/L NAA＋I.0 g/L activated carbon＋2% sugar＋6 g/L agar or MS＋2.0 mg/L ZT＋ 0.5 mg/L IAA＋0.5 g/L AgNO3＋1.0 g/L activated carbon＋2% sugar＋6 g/L agar. The induction percentage of adventitious bud by anther culture was 36.7%. Browning phenomenon appeared during the culture of adventitious bud and regeneration plant could not be formed. The plant regeneration rate reached 80% when cotyledon- cotyledonary petioles were used as explant.

Effects of Different Cadmium Levels on Active Oxygen Metabolism and H_2O_2-Scavenging System in Brassica campestris L.ssp.chinensis

The effects of different Cd (Cadmium) levels on generation of active oxygen speceies(AOS) and H2O2-scavenging system in the leaves of Brassica campestris L. ssp. chinensiswere studied. The results showed that generation rate, and H2O2 content were enhancedand malondialdehyde (MDA) content increased with the increase of Cd concentrations inthe growth medium. The activities of ascorbate peroxidase (APX), dehydroascorbatereductase (DR) and glutathione reductase (GR) were promoted by the addition of Cd.Exposed to Cd also increased the contents of ascorbate (AsA) and glutathione (GSH) in theleaves.

Genetic linkage map of Brassica campestris L.using AFLP and RAPD markers

A genetic linkage map comprised of 131 loci was constructed with an F 2 population derived from an inter subspecific cross between Brassica campestris L. ssp. chinensis cv. 'aijiaohuang' and ssp. rapifera cv. 'qisihai'. The genetic map included 93 RAPD loci, 36 AFLP loci and 2 morphological loci organized into 10 main linkage groups (LGs) and 2 small groups, covering 1810.9cM with average distance between adjacent markers being approximately 13.8cM. The map is suitable for identification of molecular markers linked to important agronomic traits, QTL analysis, and even for marker assisted selection in breeding programs of Chinese cabbage and turnip.

Nitrogen Dioxide-Induced Responses in Brassica campestris Seedlings: The Role of Hydrogen Peroxide in the Modulation of Antioxidative Level and Induced Resistance

This article investigates the responses of Brassica campestris seedlings to an acute level of nitrogen dioxide （NO2） exposure in a plant growth chamber, and examines whether pretreating plants with hydrogen peroxide （H2O2） will alleviate NO2-caused injury. Twenty-eight-day-old B. campestris plants sprayed with 10 mmol L^-1 H2O2 aqueous solution （corresponding to approximate 1.0 mg H2O2 per single plant） were exposed to different concentrations of NO2 （0.25, 0.5, 1.0, and 2.0 μL L^-1, respectively） for 24 h under controlled environment. To measure the plant biomass, the plants were fumigated with the same NO2 concentrations as mentioned above for 7 h per day （8.00-15.00） for 7 days. As a control, charcoal filtered air alone was applied. Data were collected on plant biomass, total chlorophyll, photosynthetic rate, stomatal conductance, nitrate and nitrate reductase （NR）, antioxidative enzymes, ascorbate （ASA）, and malondialdehyde （MDA）, immediately after exposure. The results showed that exposure to a moderate dose of NO2 （e.g., 0.25 μL L^-1） had a favorable effect on plants, and the dry weight of the above-ground part increased, whereas the exposure to high NO2 concentrations （e.g., 0.5 μL L^-1 or higher） caused a reduction in the plant biomass and the total chlorophyll, when compared with the control. In addition, at 0.5 μL L^-1 or higher NO2 concentrations, prominent increases in the MDA level and superoxide dismutase （SOD） and NR activities were observed. Exposure to 1 μL L^-1 and higher NO2 resulted in necroses appearing on older leaves, and an increase in catalase （CAT） activity, decrease in ASA content, increased accumulation of NO3^-, and reduction in photosynthesis, when compared with the controls. No changes were detected in stomatal conductance under NO2 fumigation. The pretreatment with 10 mmol L^-1 H2O2 alleviated significantly NO2- caused biomass decrease and photosynthetic inhibition when compared with H2O2-untreated plants. Under NO2 fumigation, further induction in SOD and CAT activities occurred in H2O2 treated plants when compared with H2O2- untreated plants. The effect of NO2 on the ASA and MDA contents was also absent in H2O2-treated plants. However, the H2O2 treatment did not alter the nitrate content and NR activity in plants under NO2 fumigation. The H2O2 treatment caused a lower rate of stomatal conductance. Taken together, these data suggest that fumigation with an acute level of NO2 causes oxidative damage to B. campestris seedlings. The H2O2 pretreatment markedly protects plants against NO2 stress and this may be associated with inducible antioxidative level. NO2 fumigation contributes, at least in part, to the enhanced levels of nitrate in B. campestris leaves.

Differential expression of salt tolerance related genes in Brassica campestris L. ssp. chinensis (L.) Makino var. communis Tsen et Lee

We examined salt tolerance responsive genes in Pak-choi under salt stress and analyze their potential function. The LRNA differential display was used to screen the transcript derived fragments （TDFs） related to salinity tolerance in tolerant and Loderately tolerant Pak-choi germplasm. Seventy-eight primer combinations generated 101 differential eDNA fragments, which ere divided into 10 expression types. Seven cDNA sequences （GenBank accession Nos. DQ006915-DQ006921） obtained and ,~quenced were highly homologous to some known expression genes or the genes related to the signaling pathways in plants under ifferent abiotic stress.

白菜抽薹性状相关基因的cDNA-AFLP分析

先期抽薹严重制约着我国春大白菜及高原或高海拔地区的春夏白菜栽培,给生产造成重大损失,因而研究白菜作物低温春化途径抽薹和开花的相关基因对白菜育种具有重要意义。文章选取极早抽薹株系DH-54和极晚抽薹株系DH-43为材料,利用256对引物组合进行cDNA-AFLP分析,筛选到与抽薹开花相关的差异表达的转录衍生片段(Transcript-derived fragment,TDF)191条,对其中82个TDF进行克隆测序。结果表明:52个TDF与NCBI或TIGR已有序列同源,功能涉及代谢、胁迫及逆境应答、信号转导、转录调控等等;22个TDF在NCBI或TIGR找到同源序列,但功能未知;有8个TDF在NCBI或TIGR找不到同源序列,可能是一些新基因。

白菜核雄性不育两用系AFLP扩增特异片段的克隆及序列分析

利用AFLP技术从白菜核不育两用系"矮脚黄"可育系DNA中得到一个特异扩增片段MF-14.Southern杂交结果证实不育系也存在该片段的同源序列;回收该特异扩增片段并将其克隆到pGEM-TEasy载体进行序列测定.测序结果表明,该片段全长289bp,其碱基组成为A+T=46.02%.与白菜RAPD特异片段S107及其他育性相关基因核苷酸序列比较,同源性均低于50%.表明该片段为一新的序列.

大白菜叶球相关性状的QTL定位与分析

应用 35 2个标记位点的大白菜AFLP和RAPD图谱和一套品种间杂交获得的重组自交系群体 ,采用复合区间作图的方法 ,对大白菜叶球相关的 7个农艺性状进行QTL有定位及遗传效应研究。结果表明 ,在 14个连锁群上检测到 33个QTL ,其中控制生育期的有QTL 3个 ,控制外叶数的QTL有 3个 ,控制球高的QTL有 7个 ,控制球径的QTL有 5个 ,控制球叶数的QTL有 4个 ,控制球重的QTL有 4个 ,控制荒重的QTL有 7个。另外 ,估算了单个QTL的遗传贡献率和加性效应 ,其加性效应各不相等 ,各位点的遗传贡献率介于 4 .72 %～ 2 1.0 4

大白菜干烧心病性状的QTL定位和分析

在含有105个标记位点的大白菜AFLP连锁图谱上,利用MAPQTL4.0软件采用区间作图方法对控制大白菜干烧心病数量性状基因位点进行QTL定位和遗传效应分析。利用离体叶片扦插方法进行干烧心病的苗期鉴定,共检测到4个与抗干烧心病有关的QTL位点,分布在4个连锁群上。cal-1和cal-2表现为增效加性效应,cal-3和cal-4表现为减效加性效应。4个QTL解释的遗传变异范围在11.0%￣58.9%之间,其中cal-4最大,cal-2次之,而cal-1最小。这为大白菜抗干烧心病分子标记辅助选择提供了依据。

菜心cDNA-AFLP分析体系的优化与建立

以菜心的顶端分生组织为试材,对影响菜心cDNA-AFLP体系的关键因子进行了探讨,以期建立适于菜心转录组差异表达的cDNA-AFLP分析体系。结果表明:Trizol法适用于菜心总RNA提取;SMART双链cDNA合成法效率较高,其中第二链cDNA合成的最佳循环数为24个;Taq I/Ase I分步各酶切3 h可使双链cDNA酶切完全;预扩增体系以模板稀释20倍,27个循环扩增效果较好,退火温度对扩增结果影响不大,但Mg2+对PCR扩增影响较大,经比较加入2.5μL Mg2+(25 mmoL/L)的预扩及选扩电泳的效果均最佳;预扩产物稀释20倍用于选择性扩增,其PAGE电泳可以获得丰富且重复性好的带型。cDNA-AFLP分析体系的优化与建立为菜心抽薹开花分子机理进一步研究奠定了基础。

利用cDNA-AFLP分析大白菜、萝卜及其杂交种差异表达基因

为更好地理解十字花科蔬菜杂种优势的分子机理,对大白菜(Brassica rapa L. ssp. pekinensis)、萝卜(Raphanus sativus L.)及其杂交种的差异表达基因进行了初步研究。利用cDNA-AFLP技术对杂种F1及其双亲进行基因差异表达分析,共得到44个在杂种F1特异表达的差异片段,分属40个Unigene;通过Blast搜索,有43个差异片段可以在GenBank数据库中找到同源序列(包括EST序列),其中仅32个序列功能已知。这些已知功能基因参与了碳代谢、激素合成、转录、细胞周期、物质运输、信号转导、逆境响应和花发育等相关过程。

CaCl_2对盐胁迫下小白菜生长和相关生理特性的影响

采用CaCl2根际注射结合叶面喷施的方法,研究了不同浓度(0、5、10、20、30 mmol/L)CaCl2对盐胁迫下小白菜(Brassica campestris ssp.chinensis L.)幼苗生长及其生理生化特性的影响。结果显示,10 mmol/LCaCl2处理显著提高了幼苗的株高、单株干重、单株鲜重和展开叶片数等,降低了叶片丙二醛(MDA)含量,增强了叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)等保护酶活性,显著提高盐胁迫下小白菜叶片的光合色素含量、净光合速率等。表明适宜浓度的外源钙可以通过增强植株的渗透调节能力和抗氧化能力,保护膜结构和功能,增强光合能力,从而减轻NaCl对小白菜的胁迫伤害。

白菜GLDH基因cDNA的克隆及序列分析

以白菜品种‘苏州青’cDNA为模板,采用RT-PCR、巢式PCR、3’RACE和5’RACE技术,获得了L-半乳糖酸-1,4-内酯脱氢酶(EC1.3.2.3,GLDH)基因cDNA2034bp全长序列。序列分析表明,GLDH基因cDNA序列编码601个氨基酸。其氨基酸序列与花椰菜GLDH基因具有98%的同源性,与拟南芥GLDH基因具有90%的同源性。该基因在GenBank中登录号为AY899298。

NaCl胁迫对不同生育期红菜薹的影响

研究了NaCl胁迫对不同生育时期红菜薹[Brassica campestris L.ssp.chinensis(L.)Makino var.utilis Tsen et Lee]的影响。结果表明,在种子萌发期,300 mmol/L的NaCl处理显著降低了红菜薹种子的发芽率、发芽势和发芽指数;在幼苗期,不同浓度的NaCl处理对红菜薹的地上部鲜重、根鲜重、根干重、丙二醛含量、根系活力均无显著影响,在300 mmol/L的NaCl胁迫下红菜薹的地上部干重反而显著增加;在成株期,不同浓度的NaCl处理对红菜薹的叶片数、主薹高度、主薹茎粗、侧薹数、单株产量、丙二醛含量、根系活力均无显著影响。

大白菜叶片长宽性状的QTL定位

利用一套大白菜双单倍体(DH)群体和包含287个分子标记的遗传图谱,运用复合区间作图法对叶长、无柄叶长、有柄叶长、叶宽、叶柄长、叶柄宽6个叶部形态学性状进行QTL定位及遗传效应的分析。结果表明:在4个连锁群上共检测到12个QTL,分别为叶长相关的3个,无柄叶长相关的2个,有柄叶长相关的2个,叶宽相关的1个,叶柄长相关的2个,叶柄宽相关的2个。各位点的遗传贡献率介于7.5%～18.9%之间。其中,叶长与叶柄长的QTL存在共定位,叶宽与叶柄宽的QTL也存在共定位。