Regulation of some biochemical attributes in drought-stressed cauliflower (Brassica oleracea L.) by seed pre-treatment with ascorbic acid

Cauliflower (Brassica oleracea L. var. botrytis) is widely used as a vegetable in many countries; however, productivity is adversely affected in areas affected by drought. To investigate the role of exogenously applied ascorbic acid (AsA) in mitigating the negative effects of drought on cauliflower, a pot experiment was performed using two cultivars of cauliflower ‘Local’ and ‘S-78’. Seeds of both cultivars were soaked in 75 mg l^–1, or in 150 mg l^–1 AsA, or in water (control) for 16 h. Water-deficit stress suppressed plant growth, reduced leaf chlorophyll concentrations, relative water contents (RWC), shoot and root P and K⁺ ion concentrations, and total soluble protein concentrations, significantly. However, significant drought-induced increases were observed in relative membrane permeability (RMP), the accumulation of total phenolic compounds, leaf free proline, glycinebetaine (GB), endogenous AsA, and hydrogen peroxide concentrations, and in the activity of superoxide dismutase (SOD). Seed treatment with 75 or 150 mg l^–1 AsA resulted in lower accumulations of H₂O₂, while increasing shoot and root fresh weights and dry weights, RWC, total phenolic compound, free proline, GB, and endogenous AsA concentrations, and the activities of SOD and catalase (CAT). No changes were observed in leaf chlorophyll concentrations or in peroxidase (POD) activities, RMP, shoot and root P and K⁺ ion accumulation, or in total soluble protein concentrations under water stress or non-stress conditions following seed treatment with AsA. ‘Local’ had higher proline concentrations and SOD activities; however, ‘S-78’ had higher RWC values, GB, and AsA concentrations. Overall, a pre-sowing treatment of cauliflower seed with 75 or 150 mg l^–1 AsA improved seedling tolerance to drought stress in both cultivars, which could be attributed to AsA-induced decreases in RMP and H₂O₂ concentrations, increases in the activities of CAT and SOD, increased RWC, and higher total phenolic compound, proline, GB, and AsA concentrations. The exogenous application of AsA therefore offers an effective strategy to minimise the adverse effects of drought stress on vegetable crops, including cauliflower.     

花椰菜和小白菜种间杂种子房培养研究

以小白菜雄性不育系h08015为母本,以花椰菜自交系082005、082009、082010、082063为父本进行种间杂种离体子房培养。结果表明：离体培养时杂种子房发育天数、接种方式、激素水平及父本基因型对杂交种子发芽率均有明显影响。授粉后6 d的子房培养能获得较好的效果;4 d后剥取种子继续培养,获得的种子发芽率高于其他接种方式;不加激素的MS培养基好于添加6-BA及NAA的MS培养基;不同父本基因型最适取材时间不同,多数基因型最佳培养时间为授粉后6 d的子房,个别基因型则是授粉后10 d的子房。     

西双版纳州高海拔地区结球甘蓝品种比较试验

通过对西双版纳州勐海县引进的10个结球甘蓝品种进行比较试验,试验结果表明,春丰口感脆,长势好,产量高,可大面积推广,但其叶片脆嫩,只适宜内销。美丽、中甘21号和中甘15号结球紧实,品质优良,丰产性好,耐贮运,商品性佳,其产品除供应当地市场外,还可以外销。     

一种高效稳定的甘蓝染色体制片新方法

介绍一种高效稳定的甘蓝根尖染色体制片新方法,该方法结合传统的压片法和去壁低渗法优点,制片取得了良好的结果:染色体中期分裂相多,染色体分散良好,形态特征清晰,背景干净.制片可应用于染色体核型分析、分带、荧光原位杂交,以及显微切割等细胞遗传学操作.     

RAPD标记构建芥蓝×甘蓝分子标记连锁图

 以芥蓝C_100-12×甘蓝秋_50-Y7为杂交组合, 构建了F₂ 作图群体, 利用300 个随机引物对两亲本进行了RAPD 检测, 共筛选到150 个RAPD 引物在亲本间表现多态, 多态引物的比率为58. 3 %。共分析了52个引物产生的96 个多态性RAPD 标记在该群体中的遗传。96 个RAPD 标记中有94 个在F2 群体中的分离比符合3∶1 , 说明该群体适合于QTL 分析, 共发现两对共分离的RAPD 标记。利用该作图群体构建了甘蓝的基本遗传图谱。该图谱由9 个主要的连锁图构成, 覆盖基因总长度约为555. 7 cM。     

利用SSH技术分离甘蓝抗黑腐病相关基因的研究

采用抑制差减杂交(SSH)技术,构建甘蓝抗病品种A21经黑腐病菌诱导6、8、12、24h后的混合SSH文库。经反向Northern筛选,共获得87条高质量ESTs。通过NCBI中BLAST数据库比对分析发现,83个ESTs与已知蛋白或基因具有不同程度的同源性。     

甘蓝ARF基因家族的鉴定与生物信息学分析

生长素响应因子(auxin response factor,ARF)基因家族是植物特有的转录因子家族,在调控植物生长发育过程中起重要作用。以公布的甘蓝基因组数据库为基础,采用生物信息学方法鉴定出29个ARF基因,命名为BoARFs,研究分析了其基因结构、染色体分布、蛋白质保守结构域、系统进化树及表达模式,以期为甘蓝ARF基因家族功能的深入研究提供参考依据。结果表明:BoARF家族基因结构相对复杂,含有2~14个外显子;在染色体上呈不均匀分布,除BoARF29基因未定位到染色体上外,其它基因均定位在不同的染色体上;所有BoARF蛋白均具有保守的B3结构域和Auxin_resp结构域,但只有21个BoARF蛋白包含1~2个AUX/IAA结构域;转录组数据表达模式分析表明,ARF基因具有不同的组织表达模式,部分基因表现出组织特异性。     

结球甘蓝自花和异花授粉诱导的柱头转录组分析

分别以自花授粉30 min、异花授粉30 min和未授粉处理的甘蓝柱头进行Illumina HiSeq2000高通量转录组测序,分析自交不亲和性甘蓝自花授粉、异花授粉柱头与未授粉柱头中基因表达的差异。转录组测序共获得1.6 × 108对原始序列读取片段,总碱基数为2.38 × 1010 bp,与未授粉对照相比,自花、异花授粉后差异表达的基因分别有2 900个和2 328个,共有的差异表达基因1 904个。在差异表达基因背景和全部基因背景下,自花授粉较大比例的差异基因是细胞杀伤、胞外基质部分和核酸结合转录因子活性;异花授粉较大比例的差异基因是信号传递、胞外区域部分、结构分子活性和营养库活性。GO功能的显著性富集分析表明,自花授粉处理后特有的40个极显著的富集条目主要涉及糖跨膜转运活性、微管结合和钙调素依赖性蛋白激酶活性等。异花授粉特有的53个极显著的富集条目主要涉及法尼酸O–甲基转移酶的活性、微管负向运动和生长素跨膜运输等。自花授粉处理后特异差异表达的996个基因主要涉及钙离子结合、细胞骨架相关、茉莉酸和水杨酸代谢等生物过程,异花授粉处理后特异差异表达的424个基因主要涉及物质跨膜转运及脂质代谢。     

Modelling development of broccoli (Brassica oleracea L. var. italica) from transplanting to head initiation

Summary

A model is suggested to predict head initiation in broccoli. Head initiation is defined as the time when the apex diameter reaches 0.6 mm and predictions are made from observations of air temperature. The model is constructed from three years of field experiments with three cultivars and four plantings per year. No juvenile phase after transplanting could be estimated and the model consists only of a head induction phase starting at transplanting. The rate of head induction is modelled by a piecewise linear temperature response function with a base, optimum, and maximum temperature. At optimum temperature the duration of the head induction phase is shortest. The estimates for base, optimum, and maximum temperature are 9.98C, 16.18C and 22.38C, respectively. The estimates for cultivar dependent thermal time requirements are 49 day-degrees, 55 day-degrees, and 38 day-degrees for cvs Caravel, Shogun and Emperor, respectively. The three cultivars were anticipated to have the same cardinal temperatures for head induction. The model of the head induction phases can account for 68% of the variation in the observed durations from transplanting to head initiation. A model of leaf appearance is used to standardize transplant size to four visible leaves at planting. The leaf appearance rate is described by a linear relationship to number of leaves and air temperature and the model can account for 89% of the variation in time from transplanting to appearance of a certain number of leaves. The temperature response of leaf appearance rate had a base temperature of about 2 to 38C, depending on cultivar, and showed no indications of having a temperature optimum below 208C. The leaf appearance rate at 158C range from 0.2 leaves per day for plants with four visible leaves to 0.4 leaves per day for plants with 14 visible leaves.     

甘蓝OguCMS相关的花药优势表达转录因子BoBHLH1的克隆与表达分析

以甘蓝OguCMS花药中下调表达的EST序列为信息探针,克隆到一个与甘蓝OguCMS相关的bHLH家族转录因子,命名为BoBHLH1（GenBank登录号：GU390530）,该基因编码102个氨基酸,具有典型的bHLH结构域,可识别顺式元件G-box序列,预测该蛋白定位在线粒体上。荧光定量RT-PCR表明,BoBHLH1是一个甘蓝花药中优势表达的基因,且在花药发育的早期和晚期均有一个表达高峰。研究结果为下一步分析其在甘蓝花药发育过程中的功能验证及OguCMS核质互作机理奠定了基础。     

Influence of temperature on selenium and sulphur accumulation in Brassica oleracea L.

Summary

Selenium (Se) and sulphur (S) accumulation are affected by many factors in plants. To understand how growing temperature affected Se and S uptake and accumulation in Brassica oleracea, plants were grown at three different temperatures: 10°, 20° and 30°C. Plant growth, as reflected in fresh weight (FW) and dry weight (DW), increased with increasing temperature. Se and S accumulation were temperature-dependent and tissue-specific. Se levels increased linearly with increasing temperature in the leaves, and varied from 1.73 – 2.54 mg Se g^–1 DW. Conversely, Se accumulation decreased linearly with increasing temperature in the roots, and varied from 2.17 – 2.87 mg Se g^–1 DW. Growing temperature significantly affected S accumulation in leaves, but not in shoots or in roots. Sulphur levels ranged from 20.83 – 30.98 mg g^–1 DW in leaves, and increased with higher temperatures. Sulphate accumulation was similar to S, except that accumulation decreased at the highest growing temperature. Vegetables that accumulate S can be an efficient means and an effective alternative to deliver Se in human diets. To ensure that optimal levels of Se are attained in plants, without negative effects on plant productivity, factors that affect uptake and accumulation, such as growing temperature, need to be better understood.     

甘蓝幼苗期叶片生理指标的变化

研究了3个不同熟期甘蓝品种幼苗期叶片蛋白质含量、可溶性糖舍量、还原糖含量和叶绿素含量的变化.试验结果表明,3种甘蓝幼苗期蛋白质舍量和叶绿素含量总体上都呈上升的趋势.可溶性糖含量都表现为在幼苗期的前3周逐渐升高并在第3周达到最高值,在第4周显著降低后又逐渐升高.还原糖含量多呈现无规律的波动性变化,但是还原糖含量的值都显著低于可溶性糖含量.     

芥蓝与甘蓝其他变种分类关系的研究

为了探讨芥蓝与甘蓝其他变种的分类关系,以2个芥蓝品种、2个青花菜品种、2个球茎甘蓝品种和2个结球甘蓝品种为试材,通过芥蓝与其他3个变种的正反交以及杂交后代自交,测定杂交或自交亲和指数,并以8个亲本和24个杂交组合为材料,对其主要植物学性状进行聚类分析。结果发现：芥蓝与上述具有代表性的甘蓝其他3个变种能正常杂交,平均杂交亲和指数为13.4;杂交后代均正常可育,其植物学形态介于双亲之间,并分别偏向于结球甘蓝、青花菜和球茎甘蓝;各杂交后代自交亲和,平均自交亲和指数为14.1,F2代能正常发芽;聚类分析显示,在欧氏距离为2.78时,2个芥蓝品种单独聚为一类,2个结球甘蓝品种及其与2个芥蓝品种杂交的8个F1可以聚为一类,2个青花菜品种及其与2个芥蓝品种杂交的8个F1可以聚为一类,2个球茎甘蓝品种及其与2个芥蓝品种杂交的8个F1可以聚为一类,芥蓝与结球甘蓝的亲缘关系相对较近。根据试验结果,认为芥蓝与甘蓝其他变种属于同一物种,将其确立为甘蓝的另一个变种是合适的。     

槲皮素对甘蓝自交不亲和性及SRK活性的影响

 对甘蓝自交不亲和系‘022E1’, ‘022A1’, ‘02259’开花前两周的花蕾进行不同浓度的槲皮素处理, 开花后自交。与花期对照相比, 3个自交不亲和系的亲和指数差异达到显著性水平, 其中以1 500 μmol·L ^{- 1}槲皮素溶液处理效果最佳, 在022E1系中其亲和指数由原来的0.03增至4.35, 完全转化为了自交亲和系。采集开花前1 d的花蕾切取柱头进行SRK活性测定, 结果表明, 槲皮素处理后可显著抑制甘蓝自交不亲和系柱头中SRK活性, 从而阻止了自交不亲和性的信号传导, 达到了克服甘蓝自交不亲和性的目的。     

甘蓝Ogura 细胞质雄性不育相关基因BoMF1启动子的克隆及功能分析

 通过TAIL-PCR 染色体步移技术,从甘蓝（Brassica oleracea L. var. capitata L.）基因组中克 隆到胞质雄性不育（OguCMS）相关基因BoMF1 翻译起始位点上游521 bp 的启动子序列。软件分析预测 表明,该启动子序列中存在多个顺式作用元件,包括TATA-box、CAAT-box、MYB 结合位点、植物激 素响应单元等。为了研究该启动子的表达特性,亚克隆了BoMF1 转录起始位点上游521 bp 序列,将其置 换pBI121 中的CaMV35S 启动子,驱动其下游的GUS 基因,构建植物表达载体pBI121-BoMF1P,以pBI121 空载体作为阳性对照,通过农杆菌（LBA4404）介导法转入拟南芥。结果表明,甘蓝BoMF1 启动子序列 能驱动GUS 基因在拟南芥花药发育晚期的花药和花粉中特异表达,表达具有组织特异性。     

Breeding progress in green curded cauliflowers (Brassica oleracea L. Botrytis group)

SUMMARY

Original seedstocks, populations developed by recurrent selection, and inbred lines of two green curded cauliflowers, Di Macerata and Romanesco, were compared in two adjacent but independent trials at Wellesbourne. Trial results indicate that recurrent selection and inbreeding had generally led to significant improvement in uniformity of maturity, increased marketable yield, and improved quality characters contributing to overall appearance and marketability of the product. Depending on the strength of self incompatibility, inbred lines derived from improved populations could potentially be used as varieties, or as parental lines for hybrids.     

西兰花秋播试验初报

我国加入WTO后,西兰花出口量正在逐年增加,由于播期不适,易出现空心、猫眼、黑心病等病害,产品成品率降低,直接影响到出口效益的提高.为此通过播期试验,对植株的花芽分化及产量构成进行了系统分析,以期确定该品种的最佳播种期,并对该品种的空心、猫眼、黑心病等病害的发病规律进行了研究与探讨.     

Shoot zinc (Zn) concentration varies widely within Brassica oleracea L. and is affected by soil Zn and phosphorus (P) levels

Summary

The low availability of zinc (Zn) in soils and crops affects dietary Zn intake worldwide. This study sought to determine if the natural genetic variation in shoot Zn concentrations ([Zn]shoot) is sufficient to pursue a crop improvement breeding strategy in a leafy vegetable crop. The gene-pool of Brassica oleracea L. was sampled using a large (n = 376) diversity foundation set (DFS), representing almost all species-wide common allelic variation, and 74 commercial varieties (mostly F₁). The DFS genotypes were grown at low and high soil phosphorus (P) levels under glasshouse and field conditions, and also in a Zn-deficient soil, with or without Zn-fertilisation, in a glasshouse. Despite the large variation in [Zn]shoot among genotypes, environment had a profound effect on [Zn]shoot. The heritability of [Zn]shoot was significant, but relatively low, among 90 doubled-haploid (DH) lines from a mapping population. While several quantitative trait loci (QTL) associated with [Zn]shoot occurred on chromosomes C2, C3, C5, C7, and C9, these were generally weak and conditional upon growth conditions. Breeding for [Zn]shoot in B. oleracea is therefore likely to be challenging. Shoot P concentrations increased substantially in all genotypes under low soil Zn conditions. Conversely, only some genotypes had increased [Zn]shoot at low soil P levels. Sufficient natural genetic variation may therefore exist to study some of the interactions between Zn and P nutrition.     

大白菜、青花菜和叶用芥菜体细胞杂交种形态学与细胞学特性鉴定

 为拓宽十字花科蔬菜育种种质资源,以大白菜（Brassica campestris L. ssp. pekinensis）、青花菜（B. oleracea L. var. varitalica）和叶用芥菜（B. juncea L. Czern）的子叶、下胚轴为材料,分离、纯化原生质体,采用40% 聚乙二醇（Polyethylene glycol,PEG）融合法进行原生质体融合。融合细胞在附加0.2 mg · L^-1 2,4-D + 0.5 mg · L^-1 6-BA + 0.1 mg · L^-1 NAA + 0.1 mg · L^-1 激动素（kinetin）的改良K8p培养基中液体培养,当细胞分裂至8 ~ 10细胞期时,将分裂的细胞包埋于0.15%琼脂糖,然后在添加0.3 mol · L^-1蔗糖和2 mg · L^-1 6-BA + 2 mg · L^-1 玉米素（zeatin）+ 1 mg · L^-1 NAA + 0.5 mg · L^-1 kinetin的Kao培养基中诱导愈伤组织。将培养获得的936个愈伤组织转到3种不定芽诱导培养基MS + 5 mg ? L-1 zeatin + 2 mg · L^-1 IAA;MS + 2 mg · L^-1 zeatin + 2 mg · L^-1 IAA;MS + 0.5 mg · L^-1 6-BA + 0.5 mg · L^-1 NAA上诱导芽分化,当芽长3 cm左右时,转到1/2 MS + 0.2 mg · L^-1 NAA的生根培养基上诱导生根,共获得了96株再生植株,对其进行形态学、细胞学和分子生物学鉴定。形态学观察显示再生植株表型变化大,包括3个亲本的中间型或两个亲本的中间型;PCR技术鉴定结果显示96株杂种植株中93株为细胞质雄性不育特性;染色体计数显示,再生的植株染色体数变化范围广（2n = 38 ~ 64）,但未发现染色体数总和与3种融合亲本染色体数总数（2n = 74）相一致的个体。基因组原位杂交（Genomic in situ hybridization,GISH）和扩增片段长度多态性（Amplified fragment length polymorphism,AFLP）分析结果表明,再生植株基因组中分别检测出大白菜、青花菜、叶用芥菜的DNA片段,证实了大白菜、青花菜、叶用芥菜种间体细胞杂交种的真实性。     

甘蓝BYPASS1 编码基因的克隆与表达分析

通过双向电泳结合MALDI-TOF-TOF/MS 质谱技术在甘蓝柱头内鉴定出1 个受自花授粉诱导
上调表达的BYPASS1 蛋白（BPS1）。利用PCR 技术扩增甘蓝BPS1 基因的编码序列, 序列分析结果表明：
该基因没有内含子,开放阅读框为1 059 bp,编码352 个氨基酸,蛋白质分子量为38.7 kD。氨基酸同源
性和系统发生树分析结果表明：甘蓝BPS1 与拟南芥BPS1 亲缘最近,氨基酸同源相似性达85%;与烟草
BPS2 关系较远。RT-PCR 检测结果表明：甘蓝BPS1 基因在开花前1～2 d 的花瓣、萼片、花药、柱头和
叶片中均有表达,柱头中的表达量最高。实时荧光 定量PCR 分析结果表明：甘蓝柱头内BPS1 表达水平在
自花授粉后逐渐升高,异花授粉后柱头内BPS1 表达水平先升高后降低再升高。