PCR-based detection of Xanthomonas campestris pathovars in Brassica seed

Xanthomonas campestris is a seedborne bacterium that causes black rot of crucifers. Substantial crop losses may result from the rapid spread of the bacteria under favourable conditions, especially those occurring during seedling production. A PCR-based method has been developed for the rapid and sensitive detection of the pathovars of X. campestris that affect crucifers. Primers were designed to specifically amplify a 619 bp fragment of the hrpF gene from X. campestris . Amplification products were not detected from other Xanthomonas species, or from other pathogenic or epiphytic bacteria occurring on these plants. To avoid false-negative results arising from the presence of amplification inhibitors in plant extracts, primers targeting a 360 bp section of the internal transcribed spacer (ITS) region from Brassica spp. were included in a multiplex PCR. The assay readily detected X. campestris pv. campestris infections in diseased plants and from bacterial colonies isolated on growth media, and was more sensitive and specific than traditional plating methods and a commercially available ELISA. A seed-washing protocol was optimized to allow the detection of a single artificially infected seed among 10 000 healthy seeds using the multiplex PCR.     

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.     

北方地区白菜型冬油菜与春油菜的SSR和InDel遗传多样性分析

为了合理评价北方地区白菜型油菜种质资源,为抗寒育种及组合配制提供依据,从252对标记中筛选出9对SSR和36对In Del标记对感温性、抗寒性、品质等性状差异明显的19份白菜型油菜品种的遗传多样性和亲缘关系进行了分析。结果表明,共检测到95个等位变异,平均每个标记2.15个;有效等位基因变幅为1.05~3.27个,平均为1.70个。Shannon指数的变幅范围在0.121 7~1.269 5间,平均值为0.580 3;多态性信息量PIC变幅范围为0.049 9~0.637 7,平均值为0.308 1。通过NTSYS计算遗传相似系数GS并按加权配对法(UPGMA)聚类,结果表明19份材料的GS变异在0.52~0.86之间。在GS为0.605水平上可将19份材料按两室与多室性划分为I-1和I-2两大类群,I-1类群在GS为0.655水平上可按冬春性分为II-1、II-2两个亚类群。在GS为0.71水平上,可将冬性材料划分为4个小群。聚类结果表明北方地区白菜型油菜的遗传多样性丰富,冬、春性品种间及春性品种间亲缘关系较远,存在较大遗传差异。     

白菜型冬油菜‘陇油7号’叶片响应低温胁迫的差异蛋白鉴定与分析

为了从蛋白质组学的角度探讨超强抗寒品种白菜型冬油菜‘陇油7号’的抗寒机理,本研究采用TCA(三氯乙酸)-丙酮沉淀法,提取低温胁迫(4℃,7 d)前后的叶片总蛋白,对蛋白提取方法、IPG(固定pH梯度)胶条种类等环节进行了优化,运用双向电泳和质谱分析技术,鉴定了低温胁迫下‘陇油7号’5叶期叶片总蛋白质组分的表达差异模式。结果表明:改进后的蛋白质提取液(含DTT,二硫苏糖醇)和PVPP(聚乙烯吡咯烷酮)得到的蛋白质平均浓度较改进前高3.42μg·μL-1,除盐时间较改进前短1.14 h;同时,含蛋白酶抑制剂苯甲基磺酰氟(PMSF)的蛋白提取液获得的蛋白质种类丰富,凝胶图谱中可检测到661个蛋白点,较改进前可测蛋白点数(587)提高11.2。采用17 cm p H 4~7的IPG胶条的电泳能更好地分离蛋白,得到重复性好、分辨率高的蛋白质组图谱。利用PDQuest 8.0软件分析比较了超强抗寒品种‘陇油7号’低温胁迫前后的蛋白组表达谱,发现低温胁迫前后共有15个质变的蛋白质点,推测这些差异蛋白点可能与低温胁迫的响应有关。进一步对质变的蛋白质点进行了质谱分析,鉴定出11个与低温胁迫相关的蛋白质点,这些蛋白包括光合作用相关的蛋白、糖代谢相关的蛋白、物质运输相关的蛋白和逆境响应相关的蛋白。而且,低温胁迫处理前后,‘陇油7号’叶片蛋白质的表达水平存在明显差异,这些差异蛋白可能在冬油菜抗寒响应中发挥重要作用。     

A genetic study of growth characters and yield characters of oilseed rape

Summary Analysis of single plants in parental, F₁ and F₂ populations of three crosses of oilseed rape indicated cytoplasmic effects in F₁ or F₂ generations for most of the observed characters. There was evidence of dominance for early flowering and early maturity. Heterosis was exhibited for yield and yield components. The heritabilities for the characters under study were generally very low.     

油菜不育系与菜心杂种后代的品种选育

进行了油菜不育系与菜心杂种后代的品种选育研究。通过对BC3代群体植株品质指标总糖、还原糖、蛋白质、维生素C含量的测定及生长优势观测,研究了杂种后代的品质特性。结果表明:BC3代群体植株具有了较好的营养品质,还原糖、总糖的超亲优势分别为40.39%和39.51%;蛋白质、维生素C含量的超亲优势分别为16.67%和21.82%;植株BC3代也具有侧芽生长快,收获期长,外形趋于菜心等生长优势,具备了选育的价值。     

羽衣甘蓝抗寒生理特性研究

观赏羽衣甘蓝作为秋冬季节重要的园林绿化植物,抗寒性直接影响其推广和应用。为了阐明羽衣甘蓝响应低温的生理特性,揭示抗寒机理,以北京市农林科学院蔬菜研究中心生物技术课题组选配的优良F1杂种作为研究试材,分析不同低温处理下叶片电导率变化和半致死温度,以及渗透调节物质含量和抗氧化酶活性的变化。结果显示,羽衣甘蓝叶片电导率在-5℃以下迅速升高,-10℃左右达到最大值;半致死温度为-10.3~-13.7℃,红色类型低于白色类型,羽叶和圆叶低于皱叶类型。上述研究结果与观赏羽衣甘蓝田间抗寒表现一致。低温处理下渗透调节物质含量和抗氧化酶活性响应特性表明,不同指标呈现不同的变化趋势,除了可溶性糖在-10℃含量最高外,可溶性蛋白和游离脯氨酸含量,以及超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均在-5℃或-8℃达到最大值,并随温度进一步降低而下降。主成分分析结果表明半致死温度、可溶性糖和游离脯氨酸含量是导致羽衣甘蓝抗寒性差异的主要因素。研究结果为建立羽衣甘蓝抗寒性评价体系,进一步解析抗冻机理,培育抗寒新品种奠定理论基础。     

Breeding system,taxonomy, and breeding strategy in cauliflower,Brassica oleracea var. botrytis L.)

Summary Cauliflowers representing those maturing in Britain in autumn, winter and spring were assessed for self-compatibility by self-pollen tube growth. A tendency existed for groups taking longer to mature to be more self-incompatible, but a range of incompatibilities was apparent in all groups. These results complement those of other workers.It is argued that despite demonstrable heterosis within many groups of cauliflowers, radical advances are probably best made by selecting self-compatible material from annual × biennial hybrid populations.     

甘蓝型油菜种子无机磷含量变异的初步分析

以微量比色法对100个甘蓝型油菜品种的种子无机磷含量进行初步检测，发现不同甘蓝型油菜品种之间种子无机磷含量存在一定差异。大部分品种的成熟种子中无机磷含量为0.2-0.4μg/g，有2个品种的无机磷含量达到0.7μg/g,1个品种超过1.1μg/g。     

新麦草种子成熟过程中活力变化的研究

１９９７年对新麦草种子成熟过程中活力变化进行了研究。研究结果表明：新麦草种子活力随着种子的成熟而逐渐增加并于种子获得最大干重时，活力达到最高。试验所选的指标均反映了新麦草种子活力变化状况，种子发芽率不能直接反映种子活力的变化，但它仍是检验种子活力不可缺少的指标。单项活力指标不能全面反映活力的变化，需采用多种指标，进行综合分析。