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.

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.

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.

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.

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.

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.

正交设计优化菜薹ISSR反应体系研究

菜薹原产中国,是华南地区重要的特产蔬菜之一。目前,分子标记技术已广泛应用于多种作物研究,但在菜薹上的应用研究刚刚起步。ISSR主要是由单一引物且以重复序列为主要引物序列的PCR标记,其反应条件受模板DNA、Taq DNA聚合酶、Mg2+、dNTP和引物等因素的影响。正交试验设计能明确各因素间的互作效应,建立最优化的反应体系。本研究利用正交试验设计,从Taq DNA聚合酶、dNTP、引物、Mg2+4种因素3个水平对菜薹ISSR反应体系进行了优化,确立了适合菜薹的ISSR反应体系并在7个菜薹品种中进行了验证。在20μl反应体系中,含Taq DNA聚合酶1U、dNTP250μmol/L、引物0.25μmol/L、1×PCRbuffer、Mg2+2.5mmol/L、模板DNA30ng。通过梯度PCR测验,确定了适宜的退火温度。这一体系的建立为今后利用ISSR技术进行菜薹种质资源分类、遗传图谱构建和基因定位奠定了技术基础。

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.

镉对小白菜光合作用特性影响的研究

研究表明,微量镉(Cd)(0.01、0.1 mg/L)促进小白菜(Brassica campestris ssp.chinensis)生长,对苏州青的促进作用更明显;高浓度Cd显著抑制地上部生长,对根系生长影响相对较小.Cd降低小白菜叶绿素含量,特别是苏州青降低幅度较大.低浓度Cd对小白菜净光合速率Pn影响不大,高浓度Cd可能是由于非气孔限制而引起Pn降低.Cd降低气孔导度,但高浓度Cd增加胞间CO2浓度.叶绿素荧光测定表明,Cd对小白菜叶片光化学效率Fv/Fm影响不大,而高浓度Cd明显降低光合电子传递量子效率PSⅡ、光化学淬灭系数qP和电子传递速率ETR.Cd增加沪青一号非光化学淬灭系数qNP,而苏州青在高Cd浓度下qNP下降.

青菜子叶离体再生体系的建立

以子叶为外植体 ,研究了苗龄、培养基中 Agar浓度、BA与 NAA的组配和添加 Ag NO3、GA3对子叶产生不定芽的影响 .结果表明 ,5～ 9d苗龄的外植体最易诱导出不定芽 ;培养基中 BA浓度是影响不定芽形成的关键 ,BA浓度低于 2 mg/ L,不定芽难以发生 ,BA6mg/ L与 NAA0 .0 5mg/ L的搭配有利于不定芽形成 ;在一定范围内不定芽发生频率随着 Agar浓度的提高而提高 ;培养基中添加 5mg/ LAg NO3,2～ 3mg/ L GA3可以提高不定芽的发生频率 ;在此基础上建立了青菜离体再生体系 ,利用该体系能够获得较高的芽苗再生频率 。

小白菜种质资源对小菜蛾的抗性评价

本文就小白菜种质资源对小菜蛾的抗性进行室内鉴定,结果表明2 6 8份材料的虫害指数分布在18 10～10 0 0 0之间,种质资源间抗虫性差异达到显著水平。聚类分析将2 6 8份种质资源分为6大类,与高抗、抗、中抗、中感、感、高感相对应,其中筛选出高抗和抗性材料分别为6和11份。对2 6 8份材料的主要形态性状与虫害指数和抗性级别的相关分析表明,小白菜种质资源叶面的皱缩度与抗虫性存在一定的相关性,认为从叶面平滑型的种质资源中筛选抗虫性材料的可能性更大。

菜心基因组DNA提取及RAPD反应体系的优化

用改良的CTAB法提取菜心基因组DNA,并利用紫外分光光度法测定其纯度和含量,用琼脂糖凝胶电泳法检测DNA的降解状况和纯度．结果表明:此法提取的DNA具有典型的天然DNA分子的标准紫外吸收光谱特点, 且适于进行RAPD分析．RAPD分析的优化反应体系为:25μL的反应液中含有0．8 U的Taq酶,0．28 μmol／L primer,30 ng的DNA,2．0 mmol／L Mg2+,0．20 mmol／L dNTPs．PCR扩增循环为94℃、5 min;94℃、1 min; 36℃、1 min;72℃、2 min,37个循环;72℃延伸10 min．

27个菜心品种遗传多样性的ISSR分析

利用ISSR技术对27个菜心品种的遗传多样性进行了分析.结果表明,12条引物共检测到103个可重复位点,其中多态位点58个,多态位点百分率(P)为56.31%.平均多样性指数(I)为0.229,遗传相似系数(H)为0.144,观察等位基因数(Na)和有效等位基因数(Ne)分别为1.563和1.225,遗传距离(GD)的范围在0.029～0.344之间,表明菜心遗传多样性较低.经UPGMA聚类分析,将27个菜心品种分为六大类群.

白菜核基因雄性不育系转育研究

以大白菜核基因雄性不育系‘1NA’转育成的白菜核不育系00S107为不育源,根据大白菜核基因雄性不育“复等位基因遗传假说”设计转育方案,向白菜可育品系‘青梗奶油白菜’中转育核不育基因,经过3年5个世代杂交转育,获得了新的白菜核基因雄性不育系及其相应的甲型“两用系”和临时保持系。

几种化肥对外源Cr(Ⅵ)形态和小白菜吸收铬的影响

通过盆载试验探讨了几种化肥对土壤铬的形态和小白菜吸收铬的影响。结果表明:1)外源Cr(Ⅵ)可显著增加土壤有效铬含量,但增施氯化钾、硝酸钙和硫酸钠能有效抑制外源Cr(Ⅵ)向残渣态和有效态铬转化,并促进外源Cr(Ⅵ)向有机态铬转化;2)增施硅酸钠可抑制外源Cr(Ⅵ)向残渣态铬转化,但有利其向有机态、沉淀态和有效态转化,对土壤铬的活化有明显效果;3)适量施用氯化钾和硫酸钠均可有效抑制小白菜对铬的吸收,并提高产量品质,但硝酸根离子有促进小白菜铬吸收的作用,故增施硝酸钙会提高小白菜铬含量;4)增施硅酸钠对小白菜吸收铬有较强的抑制作用,对降低小白菜铬吸收有明显效果,但由于其活化铬提高了土壤铬毒性,故妨害作物营养而降低小白菜产量。

不同青菜品种吸锌能力差异及与根系分泌物的关系

青菜 [Brassicacampestrisvar chinensis(L )Makino]不同品种对土壤中锌的累积吸收有明显差异[1] ,我们推断根系分泌物在青菜吸收锌的过程中可能起着重要作用。因此在本项研究中 ,对 2个不同锌利用效率的青菜品种的根系分泌物组成、数量及其与锌吸收的关系进行了探讨。结果表明 ,2种锌水平下 ,五月慢根系分泌物中低分子量有机酸及氨基酸的总量均明显高于黑油白菜 ,缺锌时品种间差异达 0 0 5显著水平 ;缺锌条件下 ,五月慢根系分泌物中草酸、丙氨酸的含量同样显著高于黑油白菜。五月慢在缺锌时有较高的根系分泌物总量及其草酸、丙氨酸含量都显著增加 ,这可能是五月慢具有较高累积吸锌量及锌利用效率的重要原因之一。

菜心ISSR-PCR反应体系的优化

以菜心（Brassica campestris L．ssp．Chinensis Var．utilis Tssen．et Lee．）为材料，对影响ISSR-PCR扩增结果的因素如Mg^2＋、Taq DNA聚合酶、dNTPs、Primer、模版DNA的浓度及引物退火温度、延伸时间和循环次数进行了探讨，确立了适合菜心ISSR-PCR分析的最佳反应体系和PCR扩增参数：在25pL反应体系中含10×buffer 2．5μL，2．0mmol／LMg^2＋，0．5U Taq DNA聚合酶，0．2mmol／LdNTPs，0．5μmol／L引物，30ng模板DNA．PCR扩增程序：94℃预变性3min；94℃变性1min，49．7～56℃退火（退火温度随引物不同而定）1min，72℃延伸45s，40个循环；72℃延伸5min．

菜薹细胞质不育系小孢子发生的细胞形态学研究

菜薹雄性不育系小孢子发生的细胞形态学观察表明，孢原细胞分化期之前败育的花占５９．６％，不形成花粉囊；有花粉囊发育的花占４０．４％，其中绝大多数花中只有一个雄蕊能形成一个体积很小的花粉囊，雄性不育系小孢子发育在小孢子母细胞期、四分体及单核小孢子期均有败育，败育方式有绒毡层细胞异常肥大，挤压小孢子母细胞；减数分裂异常，无胞质分裂而形成巨细胞；单核小孢子粘连成花粉块，异常膨大等。还有雄蕊雌蕊化等花器异常现象。