以二倍体不结球白菜'五月慢'为材料,用质量浓度为0.2％的秋水仙素溶液对植株幼苗生长点进行四倍体诱导,并利用形态学、细胞学等方法进行鉴定.结果表明:'五月慢'四倍体植株叶片、花、种荚、种子等均表现出"巨大性",且叶片颜色较深;'五月慢'四倍体植株根尖染色体数目为40条,是二倍体植株的两倍;流式细胞仪鉴定结果显示,二倍体'五月慢'DNA相对含量约为70,而四倍体'五月慢'的DNA相对含量约为140;相较于二倍体植株,四倍体'五月慢'的可溶性蛋白含量、花青苷含量提高了43.94％、37.08％,硝态氮含量、纤维素含量下降了24.03％、31.84％;四倍体'五月慢'束腰更加明显,叶长、柄长与开展度变小,呈紧凑偏矮的株型特征.本研究可为培育不结球白菜的新种质提供技术方法与科学依据.

采用系谱法对秋水仙素诱变的麻豇变异株进行选育,获得豇豆新品种必播万顷.必播万顷中熟,蔓生,生长势强,株高315.5 cm,始花节位为第5节,出苗至始收65 d(天).连续结荚能力强,商品荚翠绿油亮,荚长85～90 cm,荚粗1.1cm,单荚质量33.2 g,每667 m2产量2 800kg左右,耐采性好.田间对病毒病、锈病和白粉病的抗性强于对照A8.适宜全国各地露地栽培.

Autopolyploids often show growth advantages over their diploid progenitors because of their increased photosynthetic activity; however, the underlying molecular basis of such mechanism remains elusive. In this study, we aimed to characterize autotetraploid pak choi (Brassica rapa ssp. chinensis) at the physiological, cellular and molecular levels. Autotetraploid pak choi has thicker leaves than its diploid counterparts, with relatively larger intercellular spaces and cell size and greater grana thylakoid height. Photosynthetic data showed that the relative electron transport rate (rETR) was markedly higher in autotetraploid than in diploid pak choi. Transcriptomic data revealed that the expressions of genes involved in 'photosynthesis' biological process and 'thylakoids' cellular component were mainly regulated in autotetraploids. Overall, our findings suggested that the increased rETR in the thylakoids contributed to the increased photosynthetic capacity of autotetraploid leaves. Furthermore, we found that the enhanced rETR is associated with increased BrPetC expression, which is likely altered by histone modification. The ectopic expression of BrPetC in Arabidopsis thaliana led to increased rETR and biomass, which were decreased in BrPetC-silenced pak choi. Autotetraploid pak choi also shows altered hormone levels, which was likely responsible for the increased drought resistance and the impaired powdery mildew resistance of this lineage. Our findings further our understanding on how autotetraploidy provides growth advantages to plants.

为获得高产优质的不结球白菜四倍体苏州青,本研究使用浓度分别为0.1％,0.2％及0.3％的秋水仙素溶液,点滴处理二倍体苏州青幼苗植株的子叶生长点,进行5次处理后,通过形态学和细胞学方法筛选鉴定四倍体苏州青植株,并比较二、四倍体苏州青的农艺性状及品质差异.结果 表明:秋水仙素浓度为0.2％时加倍效果最好.形态解剖学鉴定结果表明:四倍体在株型、叶片、花、种荚、种子大小都有较明显的变大趋势;四倍体植株叶片气孔较二倍体变大,气孔密度变小;同时四倍体植株花粉粒比二倍体更膨大,更不规则;细胞学鉴定结果表示,四倍体植株染色体数为40条,二倍体植株为20条;通过流式细胞仪鉴定,四倍体植株荧光强度约为二倍体的2倍.通过品质比较分析,结果显示四倍体苏州青的各项生理指标含量较于二倍体均有不同.通过农艺性状比较,单株质量、叶宽、叶厚都有一定程度的增加.本研究利用秋水仙素操作技术,抑制有丝分裂后期纺锤丝的形成,实现染色体加倍,创制不结球白菜新种质,为选育四倍体不结球白菜提供理论基础和种质资源.

以Polima胞质雄性不育系P44为母本,自交系矮脚白为父本配制抗热白梗小白菜新品种暑热.试验结果表明,该品种丰产(夏季菜秧产量1500 kg/667 m2)、生长迅速(16～18 d即可采收)、抗热、抗病性强(病毒病和炭疽病).

'Yitongtianxia' is a new tetraploid asparagus bean (Vigna unguiculata ssp. sesquipedalis) selectively bred by genealogy method from the lines of 'Mimeixiaoye(2X)' with chemical mutagenesis of colchicine.The plants are trailing with strong growth vigor.Its average plant height is 306.5 cm.The internode length is 20.2 cm.It is of early maturity.The first flower sets on the 3rd node.Its growth period is about 93 days.It takes 58 days from seedling emergence to first harvest.It has strong and successive podding ability. The production ratio of double-pod and four-pod is high.The commercial pod is green white in color with shining smooth surface and beak red color.It has no rat tail and plump seed.The pod is 89.3 cm in length,about 0.9 cm in width.Its average single fruit weight is 27.4 g.There are about 20 pods per plant.It can yield about 33 t?hm-2. Its resistances to virus disease,powdery mildew and rust disease in field are stronger than that of the contrast 'Zaojiang No.4'.And its comprehensive characteristics are super.It is suitable for cultivation in Jiangsu, Zhejiang,Anhui and Henan,etc. provinces.

采用两个自交不亲和系配制F1代青梗小白菜杂交新品种烤青.试验结果表明,该品种具有抗热(>35℃)、耐湿、抗病性强(病毒病和炭疽病)、生长迅速、束腰、商品性好、丰产(夏季菜秧产量1075.95 kg/667 m2,夏秋大棵菜产量2817.82 kg/667 m2)特性.2015年12月通过江苏省农作物品种审定委员会品种鉴定.

A significant fraction of the nuclear DNA of all eukaryotes is comprised of simple sequence repeats (SSRs). Although these sequences are widely used for studying genetic variation, linkage mapping and evolution, little attention had been paid to the chromosomal distribution and cytogenetic diversity of these sequences. In this paper, we report the distribution characterization of mono-, di-, and tri-nucleotide SSRs in Brassica rapa ssp. chinensis. Fluorescence in situ hybridization was used to characterize the cytogenetic diversity of SSRs among morphotypes of B. rapa ssp. chinensis. The proportion of different SSR motifs varied among morphotypes of B. rapa ssp. chinensis, with tri-nucleotide SSRs being more prevalent in the genome of B. rapa ssp. chinensis. We determined the chromosomal locations of mono-, di-, and tri-nucleotide repeat loci. The results showed that the chromosomal distribution of SSRs in the different morphotypes is non-random and motif-dependent, and allowed us to characterize the relative variability in terms of SSR numbers and similar chromosomal distributions in centromeric/peri-centromeric heterochromatin. The differences between SSR repeats with respect to abundance and distribution indicate that SSRs are a driving force in the genomic evolution of B. rapa species. Our results provide a comprehensive view of the SSR sequence distribution and evolution for comparison among morphotypes B. rapa ssp. chinensis.

[目的]对秋水仙素诱导同源四倍体苗期性状进行筛选,提高加倍率,为市场提供更优质高产四倍体萝卜.[方法]以二倍体萝卜‘小顶红’为材料,用1.5、2.0和2.5 g·L-1秋水仙素点滴子叶期生长点,分别处理4次和6次,拉十字期时对叶片响应进行形态分类、形态解剖学和流式细胞仪鉴定,测定二、四倍体农艺性状、肉质根营养成分,以及二、四倍体‘小顶红’和‘穿心红’种子发芽相关物质.[结果]2.0 g·L-1秋水仙素处理4次获得的四倍体植株加倍率最高,为4.76％.幼苗真叶响应形态可分为正常叶、簇状叶、棒状叶和勺状叶,簇状叶类型当代选株中四倍体加倍率最高,占88.24％.与二倍体相比,四倍体的气孔、花粉粒、花器官、叶片和肉质根等表现出明显的“巨大性”,但气孔密度、单果种子数量显著减少.四倍体萝卜肉质根的可溶性糖、可溶性蛋白和维生素C含量分别比二倍体增加23.50％、12.24％和27.36％.经两代选育,四倍体纯度达95％,增产20.21％.四倍体种子的可溶性糖含量、可溶性蛋白含量、脱氢酶活性均较对应二倍体高.[结论]早期选择簇状叶可提高加倍率,经继代选育后,获得纯度较高的四倍体萝卜株系.

Non-heading Chinese cabbage encompasses a wide diversity of morphotypes, like the well-known Pak-choi, Wu ta cai, Cai xin, Tai cai, and Fen nei cai. Despite recent developments in re-sequencing which results in the detection of SNPs, insertions, deletions and copy number variants, there has been no systematical cytogenetic characterization of different non-heading Chinese cabbage morphotypes, aiming to detect large structural variations. To tackle this issue, the karyotypes of five genotypes belonging to five non-heading Chinese cabbage morphotypes were analyzed using fluorescence in situ hybridization (FISH) with ribosomal DNA (rDNA) and blend DAPI band (BDB) on mitotic chromosomes. The ideograms of these five non-heading Chinese cabbage genotypes were produced by exploring and comparing the distributional patterns in terms of rDNA (45S and 5S) and constitutive heterochromatin regions between morphotypes. This study revealed variation in the distributional patterns of ribosomal genes and heterochromatin regions, which point to chromosomal rearrangements in non-heading Chinese cabbage. The 45S rDNA site on chromosome A5 and 5S rDNA signal on chromosome A10 were conserved between all five morphotypes, suggesting that these sites were presented in the ancestor karyotype of non-heading Chinese cabbage. Karyotypic variation and conservation facilitates accurate estimation of the genetic diversity, to better understanding of the evolution, and insight in this variation may facilitate breeding of non-heading Chinese cabbage.

[目的]用秋水仙素诱导晚抽薹不结球白菜二倍体,以期创制抽薹晚、优质、高产的不结球白菜四倍体新种质.[方法]采用1.5和2.0 g·L-1秋水仙素分别对二倍体不结球白菜茎尖生长点进行4次和6次点滴处理,并鉴定筛选同源四倍体.利用实时荧光定量(qRT-PCR)技术检测抽薹基因的表达,测定营养品质和农艺性状,筛选晚抽薹且优质四倍体材料.[结果]用2.0 g·L-1秋水仙素处理二倍体茎尖6次的效果最好,四倍体的诱导率为5.90％;与二倍体相比,四倍体的叶片、花器、角果和种子都呈现明显差异.流式细胞仪鉴定二倍体(2n=2x=20) DNA相对含量为200,四倍体(2n=4x=40)为400.四倍体抽薹时间比二倍体晚.RT-PCR结果表明:在二、四倍体中BcFLC3和FRI基因表达随春化时间的延长下调,而VIN3表达上调,四倍体始终高于二倍体;四倍体可溶性糖、可溶性蛋白、维生素C、游离氨基酸和硒含量分别比二倍体显著增加了75.63％、23.84％、44.66％、47.47％和53.79％,有机酸、纤维素和干物质百分比分别降低10.67％、17.56％和12.5％;四倍体单株质量、开展度、叶宽、叶质量、十叶厚、叶柄长和短缩茎质量7个农艺性状与二倍体差异显著,产量增加11.13％.[结论]四倍体不结球白菜表现出营养价值高、农艺性状好且晚抽薹的特性.

Stem tip of growing point of diploid Yard long bean(Vigna sesqui pedalis Wight.)at cotyleden stage was treated with colchicine of 0.1%-0.3% concentration. An autotetraploid plant was obtained. The morphological,cytological,and agronomical identification on it was carried out. The results showed that treatment with 0.2%colchicine for 4 times could obtain the best effect of autotetraploid,and the induction rate of tetraploid was 2.809%. Compared with the diploid,the autotetraploid plant had giant leaves,floral organs,and pods. The stomatal density and number of seed from a single pod were reduced. The result suggested that the relative DNA content of diploid was 250,and that of tetraploid was 500. And this result was consistent with the identification of root tip chromosomes.

Diploid plants of non-heading Chinese cabbage(Brassica campestris ssp. chinensis) were induced by treating the apical portion of seedlings with different solution of colchicine. After selecting and identification,dwarf and tight white petiole autotetraploid plants with high quality were selected and bred. The test result showed that treatment with 2. 0 mg·g-1for 6 times yielded doubled chromosomes at highest rates and doubling rate was 7. 02%. Compared with diploid plants,autotetraploid plants had significant differences on vegetative mass,stoma,floral organ and silique,with the plant height reduced,the leaf width increased,the petiole shorter,the plant expansion degrees decreased,showing a compact plant type with bright green leaves. Compared with diploid plants, soluble sugar,protein and vitamin C of autoterploid plants contents were significantly increased by 11. 14%,25. 98% and 11. 70%. After two generations of breeding,the tetraploid pure degree was 100% and the uniformity was 95%,the yield of plot was increased by 18. 10% more highly than the diploid,while it has good application prospects.

Cytoplasmic male sterility (CMS) is an important factor to observe heterosis in Brassica rapa. Although several studies have documented the rearrangements of mitochondrial DNA and dysfunction in the mitochondria have been observed in most types of CMS, the basis of the molecular mechanisms involved in these processes and other effects on CMS remain unclear. In this study, suppression subtractive hybridization was performed in the flowers of an alloplasmic Polima CMS system from B. rapa ssp. chinensis to identify genes that are differentially expressed between fertile and sterile plants. A total of 443 clones were isolated (156 were upregulated in fertile buds, and 287 were upregulated in sterile ones). Real-time RT-PCR further demonstrated the credibility of SSH. Among these genes, many membrane protein genes (LTP12, PIP2A, and GRP14) were inhibited in the sterile male line. Mitochondrial membrane potential (MMP) assay was then performed. Results showed that the sterile MMP was unstable and failed to create a potential difference; thus, mitochondrial dysfunction occurred. Moreover, abnormal microtubules and photosynthetic pathways were found in sterile male cells. Unstable MMP, nutritional deficiency, and abnormal microtubules were the causes of Polima CMS in Brassica campestris. H2O2, MDA, and O2–, accumulated as byproducts of energy metabolism disorder in sterile male cells.

对低温胁迫下二、四倍体不结球白菜的抗寒基因表达及相关生理生长特性进行比较,为耐寒四倍体品种的生产提供理论依据。对二、四倍体不结球白菜进行（4±1）℃低温处理,比较其在0、2、6、12和24 h时3个抗寒相关基因CBF3、COR15和ZAT10的表达差异以及保护酶活性和渗透调节物质含量,在田间自然条件下比较其光合特性、冻害指数和农艺性状。结果表明:抗寒相关基因CBF3、COR15和ZAT10在四倍体叶片中的表达量显著高于二倍体。低温胁迫下,二、四倍体的保护酶超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性及渗透调节物质含量变化均表现为先升后降的单峰曲线,12 h达到峰值,四倍体始终高于二倍体。四倍体的叶绿素a、叶绿素b及叶绿素a/b均高于二倍体,二、四倍体净光合速率、气孔导度和蒸腾速率的动态变化趋势基本一致,且四倍体均高于二倍体（P＜0.05）。四倍体单株质量、叶质量/叶柄质量和小区产量等9个农艺性状显著或极显著高于二倍体,冻害指数差异显著。结论:同源四倍体不结球白菜对低温环境的适应性和光合产量均高于二倍体。

Using the flower buds,karyotype analysis of the diploid non-heading Chinese cabbage variety‘Shanghaiqing'during meiosis diakinesis in pollen mother cells was conducted via conventional squash method with some improvements,and comparison of it to the chromosome karyotype of root tip was also made. The results showed the same karyotype formula of non-heading Chinese cabbage was 2n = 2x = 20 = 10m + 8sm(2SAT) + 2st,with 5 pairs of metacentric chromosomes(1,2,3,4,6),4 pairs of submetacentric chromosomes(5,7,8,9),and 1 pair of subtelocentric chromosome(10),and all of two satellites appeared at the third pair of chromosomes. The karyotype belonged to 2A type,with ultimately symmetry karyotype. It is easy to get the phase of meiosis diakinesis when the length of the flower bud was about 1. 1- 1. 5 mm.

研究秋水仙素离体双层培养诱导对3种青花菜染色体加倍的诱导效应,建立青花菜四倍体的离体双层培养诱导体系,为植物倍性育种提供新途径.以子叶期保留下胚轴0.4～0.6 cm的子叶为外植体,接入含不同浓度的秋水仙素离体双层培养基(上层为含秋水仙素的液体培养基,下层为不含秋水仙素的固体培养基)中诱导24、48和96 h.结果表明:以300mg·L-1秋水仙素处理48 h诱导获得四倍体的效果最佳,LQ-2、S139-2和LQ-23三个材料外植体存活率达100.00％,增殖系数分别为2.00、2.33和2.67,四倍体诱导率分别为66.67％、71.42％和62.50％.与二倍体相比,四倍体植株在株高、叶片、花球等性状上增大,气孔大小和密度呈现显著差异,LQ-2、S139-2和LQ-23三个材料的花粉粒增大,增幅分别为18.85％×63.71％、25.00％×34.68％和3.36％×61.86％.四倍体根尖染色体为2n =4x=36.流式细胞仪鉴定发现二倍体DNA相对含量为300,四倍体为600.结论:通过大量试验,找到了秋水仙素双层诱导青花菜的最佳秋水仙素浓度和诱导时间,提高了诱导率,获得了3个同源四倍体青花菜新材料.

To provide excellent parent resource for breeding new non-heading Chinese cabbage cultivars,a test cross was made by the male parent 09P70Rexiao(2n=4x)and female parent of the sterile materials(09PY)of non-heading Chinese cabbage which was obtain by the sexual polyploidization.Then the Shu No.1,of which the sterile rate reached 100%,and their degree was over 95% and their character was stable,was selected by continues back-cross.The plant height was 30.0 cm,the level of unfold was 29.8 cm,the leaf was brilliant green,the petiole was white.It had some properties such as grow faster, high yield,disease-resistant,heat resistant,and so on.

Using diploid non-heading Chinese cabbage‘Yi-ling',the apical portion of their seedlings were treated with colchicine solution in different concentration.The variant plants were selected and identified in their ploidy,and were also studied in their characters of morphology,anatomy,cytology,their heat-tolerance,agronomic and nutritional traits.The results indicated that the treatment in colchicine 0.2 mol·L-1 for 4times resulted of tetraploid doubling in 7.64%.Comparing with the diploid plant,the tetraploid plants were significantly increased in the length and width of leaf and petioles,the number of flowering organs,stomata and pollen,the weight of leaf,petioles and plant,while setting percentage was receded remarkably.Based on the diploid plants,the contents of total soluble sugar,soluble protein and dry matter in autotetraploid plants were increased by 7.32%,74.85%and3.91% for the leaves,and by 17.22%,1.94% and 4.89% for the petioles,respectively.Similarly in the comparison,the content of organic acids in autotetraploid plant leaves and petioles was decreased significantly by22.56% and 25.00%,respectively.Under 42℃ heating stress,the content of MDA and free proline were significantly lower while soluble protein was higher in autotetraploid plants than in diploid plants.The results indicated that autotetraploid plants performed in high-quality and heat-tolerance.

Non-heading Chinese cabbage [Brassica rapa L. ssp. chinensis (L.) Hanelt] is one of the most popular leafy vegetables. Despite the economic importance of non-heading Chinese cabbage, little attention has been given to its cytogenetic profile. This study reveals the karyotype of non-heading Chinese cabbage. Fluorescence in situ hybridization (FISH) with 45S and 5S rDNA probes was performed on mitotic metaphase complementary regions. We located 45S rDNA on the centromeric or adjacent region of chromosomes A1 and A2, with the largest on the satellite of chromosome A5. Meanwhile, 5S rDNA co-localized with 45S rDNA on chromosomes A2 and A5, and on the telomeric region of chromosome A10. We performed DAPI fluorescence banding on the same metaphase chromosomes to identify homologous chromosomes. The DAPI fluorescence pattern was observed mainly on the centromeric heterochromatin regions of each chromosome. However, the lengths of chromosomes A2 and A6 were completely stained, except for their telomeric regions. Meiotic diakinesis chromosomes as new substrates in FISH-developed karyotype were revealed for the first time. The karyotype of non-heading Chinese cabbage reveals that it contains eight submetacentric chromosomes, one subtelocentric chromosome (bearing satellite), and one telocentric chromosome. Diakinetic chromosome pairing can overcome the difficulty of unlabeled chromosome identification. This study provided valuable information for cytogenetic research and molecular breeding of non-heading Chinese cabbage by using the combination of FISH and DAPI fluorescence patterns on mitotic and meiotic chromosomes.