结球甘蓝和青花菜小孢子胚植株再生

结球甘蓝(Brassica oleracea var. capitata)和青花菜(Brassica oleracea var. italica)小孢子胚再生植株频率低是目前影响游离小孢子培养技术有效应用的关键问题之一, 研究其小孢子胚植株再生频率的影响因素, 提高胚再生植株频率, 对促进游离小孢子培养技术在甘蓝类蔬菜育种中更好地应用具有重要意义。该文以结球甘蓝中甘11和青花菜TI-111等基因型为试材, 对影响游离小孢子胚再生成植株的固体培养基类型、琼脂浓度、胚的类型及胚在液体培养基中的滞留时间等因素进行了研究。结果表明: 游离小孢子培养25天的子叶胚在琼脂浓度为1%–1.25%的B5培养基上植株再生频率最高。进一步通过8个不同基因型对上述实验结果进行了验证, 结果显示, 游离小孢子培养25天的子叶胚在1%琼脂浓度的B5培养基上植株再生频率达77.8%–97.2%。     

结球甘蓝和青花菜小孢子胚植株再生

结球甘蓝（Brassica oleracea var.capitata）和青花菜（Brassica oleracea var.italica）小孢子胚再生植株频率低是目前影响游离小孢子培养技术有效应用的关键问题之一,研究其小孢子胚植株再生频率的影响因素,提高胚再生植株频率,对促进游离小孢子培养技术在甘蓝类蔬菜育种中更好地应用具有重要意义。该文以结球甘蓝中甘11和青花菜TI-111等基因型为试材,对影响游离小孢子胚再生成植株的固体培养基类型、琼脂浓度、胚的类型及胚在液体培养基中的滞留时间等因素进行了研究。结果表明：游离小孢子培养25天的子叶胚在琼脂浓度为1%–1.25%的B5培养基上植株再生频率最高。进一步通过8个不同基因型对上述实验结果进行了验证,结果显示,游离小孢子培养25天的子叶胚在1%琼脂浓度的B5培养基上植株再生频率达77.8%–97.2%。     

Boron Mobility and Nutrition in Broccoli (Brassica oleracea var. italica

Broccoli (Brassica oleracea var. italica cv Premium Crop) plantswere germinated in soil, transferred to vermiculite three weekslater and grown in the glasshouse, then either supplied continuouslywith boron levels ranging from 0.0 (deficient) to 12.5 (toxic)mg l^–1 of nutrient solution or transferred from 2.5 to0.0 mg B l^–1 at the initiation of inflorescence development.At commercial maturity the concentrations of various inorganicand organic solutes in phloem exudates and xylem saps, as wellas plant characteristics and elemental composition of the variousplant parts, were determined. Under deficient B levels leaf midrib and stem corkiness wereevident, together with signs of stem pith breakdown, symptomswhich resemble the initiation of the hollow stem disorder. Thexylem sap B concentration declined by about 50 % when B wasnot supplied or was removed after a period of adequate supply;the phloem concentration was unaffected. Also, the decreasingB concentration gradients from mature transpiring tissues toyoung developing sinks disappeared. Therefore, it is concludedthat when B is deficient, it is retranslocated from source leavesin the phloem stream supplying the developing leaves and inflorescence.The data also suggested that at toxic levels B undergoes extensivelateral transfer, probably from xylem to xylem, thereby enhancingthe B concentration of developing sinks. The B regime influenced dry-matter partitioning, retranslocationof some elements, and the synthesis and distribution of aminoacids and sugars, reflecting the general nature of B involvementin plant processes. Brassica oleracea var., italica, broccoli, phloem, mobility, retranslocation, boron nutrition, transport fluids, concentration gradients     

青花菜SRAP-PCR体系优化与品种分子鉴定

本试验对青花菜基因组DNA的SRAP-PCR体系中主要影响因子Mg2+、dNTPs和引物浓度进行了优化。结果表明,反应体系中适宜浓度为Mg2+1.5-3.0mmol/L,dNTPs0.4mmol/L,引物0.25-0.50μmol/L(模板DNA约20ng,16μL反应体系)。运用优化的反应体系,对20个青花菜品种进行分子鉴定,从10个引物组合中筛选到7个多态性引物组合,获得60个多态性位点,平均每个引物组合在供试品种中产生8.6个多态性位点,鉴别品种数4.3个。双引物组合me1/em6与me2/em9可以区分所有供试材料。     

Taxonomy and evolution of broccoli (Brassica oleracea var. italica)

The origin and application of the name broccoli are discussed and a distinction between cauliflower and broccoli is proposed, based on their relative ontogeny at marketable maturity. The history and evolution of broccoli is considered in relation to cauliflower and its diversification into annual and biennial types is discussed. White-sprouting broccoli is considered to be closely related to English winter-hardy cauliflower. Calabrese, though representing only a small part of the italica gene pool, has been the most intensively developed, being currently represented by many cultivars, including F₁ hybrids. The potential for breeding new Cape and sprouting broccolis is discussed, and the need to conserve existing genetic variability of existing cultivars within Cape and sprouting broccoli is stressed.     

Factors that influence Agrobacterium rhizogenes-mediated transformation of broccoli (Brassica oleracea L. var. italica)

 An improved broccoli transformation system was developed by optimising several factors that affect the rate of effective Agrobacterium-mediated transformation. Leaf explants of cultivar Shogun were co-cultivated with Agrobacterium rhizogenes strain A4T harbouring the binary vector pART278. The T-DNA of this binary vector contains a neomycin phosphotransferase II (NOS-NPTII-NOS) gene for kanamycin resistance and a β-glucuronidase (35S-GUS-OCS) gene. Several media and factors were evaluated including combinations of arginine, mannopine, acetosyringone and the use of feeder cell layers. The new protocol includes the use of 200 μm acetosyringone in LB medium for bacterial growth, the use of a Brassica campestris feeder cell layer, 10 mm mannopine and 50 μm acetosyringone in the co-cultivation medium and 1 mm arginine in the selection medium. The use of this optimised protocol produced transformation rates of 33% in preliminary experiments transforming broccoli with the antisense 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase gene from pTOM13. Received: 2 July 1998 / Revision received: 9 February 2000 / Accepted: 17 February 2000     

Regulation of Harvest-induced Senescence in Broccoli (Brassica oleracea var. italica) by Cytokinin, Ethylene, and Sucrose

Broccoli (Brassica oleracea var. italica) deteriorates rapidly following harvest. The two plant hormones ethylene and cytokinin are known to act antagonistically on harvest-induced senescence in broccoli: ethylene by accelerating the process, and cytokinin by delaying it. To determine the level at which these hormones influenced senescence, we isolated and monitored the expression of genes normally associated with senescence in broccoli florets treated with exogenous 6-benzyl aminopurine (6-BAP), 1-aminocyclopropane-1-carboxylic acid (ACC), a combination of 6-BAP and ACC, and sucrose, in the five days following harvest. Exogenous 6-BAP caused both a reduction (BoACO) and an increase (BoACS) in ethylene biosynthetic gene expression. The expression of genes used as senescence markers, BoCP5 and BoMT1, was reduced, whereas BoCAB1 levels were maintained after harvest in response to exogenous 6-BAP. In addition, the expression of genes encoding sucrose transporters (BoSUC1 and BoSUC2) and carbohydrate metabolizing enzymes (BoINV1 and BoHK1) was also reduced upon 6-BAP feeding. Interestingly, the addition of ACC prevented the 6-BAP-induced increase in expression of BoACS, but 6-BAP negated the ACC-induced increase in expression of BoACO. The culmination of these results indicates a significant role for cytokinin in the delay of senescence. The implication that cytokinin regulates postharvest senescence in broccoli by inhibiting ethylene perception and/or biosynthesis, thus regulating carbohydrate transport and metabolism, as well as senescence-associated gene expression, is discussed and a model presented.     

Agrobacterium tumefaciens-mediated transformation of broccoli (Brassica oleracea var. italica) and cabbage (B. oleracea var. capitata)

Transgenic broccoli (Brassica oleracea var. italica) was produced by two Agrobacterium tumefaciens-mediated transformation methods. One used flowering stalk explants from mature plants; the other used hypocotyl and petiole explants from in vitro-grown seedlings. Several hundred transformants containing a Bacillus thuringiensis -endotoxin gene (CryIA(c)-type) and the neomycin phosphotransferase gene were recovered. Rooted transformants were obtained in as little as 3 months using seedling explants. Transgenic cabbage was also obtained by the seedling explant method. Parameters important for high efficiency regeneration and transformation rates included use of a tobacco nurse cell layer, sealing of petri dishes with a porous surgical tape instead of Parafilm, preculture of seedling explants and appropriate length of co-cultivation with Agrobacterium. Advantages and disadvantages of each transformation procedure are discussed.     

Indole-3-acetonitrile Is a Critical Molecule with Weed Allopathic Suppression Function in Broccoli (Brassica oleracea var. italica)

Cruciferous plants are frequently used for ecologically benign weed control in agricultural production. Most effective Broccoli varieties were screened using the entropy method-based topsis model at first. Result showed that varieties of Lvwawa and Lvbaoshiwere most effective in allelopathic suppression on radishes. Column and thin-layer chromatography were used to extract the allelopathic compounds from broccoli residues, which contained various herbicidal active substances; among them, purified single-molecule indole-3-acetonitrile has a stronger inhibitory effect than pendimethalin (commercial herbicide). The weed inhibition rate increased with increasing broccoli residue dosage, with a 40 g/m² broccoli residue dose yielding the highest suppression rate. Its effect was similar to that of indole-3-acetic acid. Too much of this substance leads to the plant's death. Moreover, broccoli residues had effective control effect on weeds in natural soils in greenhouse and field trials. The results demonstrated that broccoli residue could be used for weed management in field for abundant allopathic suppression molecules to weeds, and that Indole-3-acetonitrile is one of the most important allopathic molecule.     

外源赤霉素(GA3)对青花菜花芽分化和花球发育的影响

喷施GA3可在一定程度上促进青花菜的花芽分化进程,因而使花球的现蕾期、膨大期和采收始期相应提前,50mg·L-1GA3处理的最佳,产量和花球紧实度也增加,喷施100 mg·L-1 GA3的青花菜花球维生素C含量显著下降.     

芥蓝植株再生体系的优化

采用正交设计方法对影响芥蓝植株再生体系的因素进行了优化研究,结果表明：影响芥蓝植株再生的最主要因素是外植体类型,其次依次为NAA,BAP,蔗糖和AgNO3。结果进一步显示,最利于芥蓝再生植株的培养基条件为：MS BA P2mg／L NAA0．03mg／L 1％蔗糖 AgNO3 7．0mg／L 0．8％琼脂,最适宜的外植体类型为下胚轴,植株再生频率高达97．5％。     

High temperature arrest of inflorescence development in broccoli (Brassica oleracea var. italica L.)

High temperature causes unevenly-sized flower buds on broccoli inflorescences. This deformity limits production of broccoli to areas where summer temperatures rarely exceed 30 C. The stage of development sensitive to heat was determined by exposing plants of 'Galaxy' broccoli at varying developmental states to 35 C day temperature for 1 week, and subsequently analysing the head structure. During the high temperature exposure, the development of certain flower buds was arrested. There was no corresponding cessation of bud initiation at the apex. No injury resulted if heat was applied before the reproductive induction, or was their injury to differentiated flower buds. Meristems were affected only if heat was applied during inflorescence production or the floral initiation process. Shorter heat exposures produced little injury, and longer exposures were lethal. The plant's development at this sensitive period still appeared vegetative externally, but the youngest leaves had just begun to reorientate as a consequence of the reduced stem elongation rate. The meristem was less than 1 mm wide, and floral primordia were just forming, still subtended by leaf primordia. The injury was fully expressed by the time the head was first exposed (approximately 5-10 mm wide), though it became more apparent as the head matured. The buds that were delayed in development by the high temperature developed into normal flowers.Key words: Brassica oleracea, broccoli, flowering, heat injury, developmental arrest      

青花菜两类雄性不育系主要农艺性状的研究

通过对青花菜显性细胞核雄性不育系(DGMS)、改良的萝卜细胞质雄性不育系(Ogura CMS)和由其与相同父本配制的F1杂交种植株的主要农艺性状的生长趋势和花球相关性状的研究,明确两类雄性不育系的应用价值,为青花菜两类雄性不育系的选育和利用及新品种的选育提供理论依据。本研究以结球甘蓝中的显性细胞核雄性不育材料DGMS 79-399-3和改良的细胞质雄性不育材料Ogura CMSR3629为原始不育源,利用优良的青花菜自交系8554和93219为转育父本,通过回交和杂交的方法获得的青花菜高代(n≥9代)两类雄性不育系和由不育系与相同父本配制的F1为试材,采取定期观测整个生长期内植株主要农艺性状和绘制生长曲线相结合的方法,系统地研究了植株的主要农艺性状的生长趋势和花球相关性状。结果表明,相同遗传背景下,保持系、DGMS、Ogura CMS及由不育系与相同父本配制的F1在株幅、株高、外叶长和外叶数方面的生长趋势基本一致,其中株幅、株高、外叶长,总体上表现出前期增长速度较快,之后变慢,最后趋于平缓或略呈下降的趋势;外叶数均表现出先增加后减少的趋势;侧枝数目因年份和遗传背景不同而异。由相同保持系获得的两类不育系的显球时间、采收时间基本相同,由其配制的F1显球和采收时间相同,花球产量因遗传背景的不同而异,花球外观品质性状表现一致。由DGMS和改良的Ogura CMS两类不育源转育的青花菜雄性不育系表现优良,该两类雄性不育源在青花菜杂交育种中具有重要的应用价值。     

Genotype-specific response of cultured broccoli (Brassica oleracea var. italica) anthers to cytokinins

Anther culture medium was prepared with different types and concentrations of cytokinins to gain greater insight into the control of embryo formation during Brassica oleracea L. var. italica (broccoli) anther culture. The independent addition of the four cytokinins tested had widely divergent effects dependent upon cytokinin concentration and the genetic background of the test plants. All cytokinins were generally inhibitory at high concentrations, however, individual plants showed significant stimulation of embyro formation at typical physiological levels. The influence of cytokinins was highly cultivar-specific, some lines were stimulated, others inhibited and still other test lines were largely unaffected. Although the addition of cytokinins was needed for embryo formation for some plants, in no instance were cytokinins able to replace the inductive effect of high-temperature treatments.     

Effects of temperature and irradiance on vegetative growth of cauliflower (Brassica oleracea L. botrytis) and broccoli (Brassica oleracea L. italica)

Cauliflower (Brassica oleracea L. botrytis) and broccoli (Brassicaoleracea L. italica) plants were grown in large pots in growthchambers for a range of temperatures (mean air temperaturesfrom 7.0-25.3 C) and irradi-ances (from 9.3-50.8 mol m^–2d^–1 or 4.7-25.4 MJ m^–2 d^–1). The extinctioncoefficient for PAR decreased with plant size reaching a valueof 0.55 in cauliflower and 0.45 in broccoli at plant leaf areasof 0.235 m² and 0.227 m², respectively. The leaf area expansionrate was unaffected by irradiance when compared at identicalleaf surface temperatures. The response of expansion rate tosurface temperature was fitted to a broken stick model witha base temperature of –0.7C and an optimum temperatureof 21.0C. The radiation conversion coefficient increased withair temperature below 13.8C and remained constant above this.The estimated radiation conversion coefficient above 13.8Cand for a PPFD of 20 mol m^–2 d^–1 was 0.77 g mol^–1in cauliflower and 0.87 g mol^–1 in broccoli. The radiationconversion coefficient declined with increasing irradiance levelfrom a maximum of 1.89 g mol^–1 at near nil irradiancein cauliflower. Key words: Leaf area, dry matter, radiation use efficiency, extinction coefficient     

2-D zymographic analysis of Broccoli (Brassica oleracea L. var. Italica) florets proteases: follow up of cysteine protease isotypes in the course of post-harvest senescence

Zymographic analysis of Broccoli florets (Brassica oleracea L. var. Italica) revealed the presence of acidic metallo-proteases, serine proteases and cysteine proteases. Under conditions which were denaturing for the other proteases, the study was restricted to cysteine proteases. 2-D zymography, a technique that combines IEF and zymography was used to show the presence of 11 different cysteine protease spots with molecular mass of 44 and 47-48 kDa and pIs ranging between 4.1 and 4.7. pI differences could be ascribed to different degrees of phosphorylation that partly disappeared in the presence of alkaline phosphatase. Post-harvest senescence of Broccoli florets was characterized by decrease in protein and chlorophyll contents and increase of protease activity. In particular, as determined by 2-D zymography, the presence of cysteine protease clearly increased during senescence, a finding that may represent a useful tool for the control of the aging process.     

Heat shock response during anther culture of broccoli (Brassica oleracea var italica)

Embryo formation from microspores of Brassica oleracea var Italica (Broccoli) and other Brassica species is greatly enhanced by an initial incubation at elevated temperatures (eg 35°C) followed by continued incubation of 25°C. In the present study we observed that a three hour high temperature treatment induced the formation of heat shock proteins in cultured anthers. These were identified in two dimensional gels by silver staining, and labelled heat shock proteins were synthesised in vitro from isolated anther RNA. The appearance of heat shock proteins in anthers followed a similar pattern and displayed similar characteristics to that from leaves. Comparison of the heat shock proteins induced in isolated cultured anthers of known highly embryogenic and less embryogenic plans did not reveal obvious qualitative differences.     

Vernalization in calabrese (Brassica oleracea var. italica) - a model for apex development

Using data from an experiment in controlled environment cabinets,with temperatures between 7 C and 23 C, a model of vernalizationwas developed which predicts the change in apex diameter ofcalabrese with temperature. The model does not include a juvenilephase and the rate of diameter growth is maximal at 15.8 C.When tested on field-grown crops of two cultivars, the modeldescribed apex expansion well. Key words: Model, cardinal temperatures, juvenility, vernalization, initiation