结球甘蓝小孢子培养条件优化及高代自交系胚状体诱导研究

以25份不同类型的结球甘蓝为试验材料,研究游离小孢子培养过程中影响胚状体产生的因素并进行了优化;同时对结球甘蓝高代自交系的诱导出胚情况进行了研究。结果表明:基因型是影响结球甘蓝胚状体产生的关键因素,参试材料中有11份(2份一代杂种和9份高代自交系)出胚,其中一代杂种中中甘628出胚率(19.8个·蕾~(-1))最高,高代自交系中01-88出胚率(47.5个·蕾~(-1))最高,极显著高于其他参试材料;花蕾长度3.0~3.5 mm、花药长度∶花瓣长度为3∶2至2∶1时,处于单核靠边期的小孢子比例最高,是适合小孢子培养的最佳取样时期;初花期和盛花期是理想的取蕾时期;添加适量活性炭可以极显著提高胚诱导率。     

胡萝卜游离小孢子胚状体诱导技术优化

以10种基因型胡萝卜品种为试材,采用游离小孢子离体培养的方法,对影响胡萝卜小孢子诱导的因素进行了研究,以期为胡萝卜小孢子培养过程中的相关环节提供参考。结果表明:有3个基因型诱导出胚状体,不同基因型之间胚诱导率差异明显,表明基因型是影响小孢子胚诱导的重要因素;盛花期取材进行诱导的出胚率显著高于其它2个时期,表明盛花期为最佳取材时期;33℃处理2 d的出胚率最高,为胡萝卜小孢子胚诱导的最佳热激条件;激素最佳配比为0.5 mg·L^-1 2,4-D;培养基中添加一定量的活性炭有利于小孢子诱导产生胚状体,最佳浓度为0.2 g·L^-1。     

球茎甘蓝小孢子培养中影响胚诱导的几个因素

以10份球茎甘蓝品种(系)为试材,采用游离小孢子培养方法,研究影响胚状体发生的因素。结果表明:基因型是影响胚状体发生的关键因素,不同基因型间胚诱导率存在显著差异;初花期为最理想的取蕾时期;添加适量激素能够提高胚诱导率,6-BA的适宜浓度为0.2mg·L-1,NAA的作用因基因型而异;4℃低温预处理24h可以明显提高胚诱导率;添加0.25mg·mL-1活性炭不仅可以显著提高胚诱导率,而且能够改善胚状体发育状态。     

菜心小孢子培养体系优化

为了优化菜心小孢子培养体系,以10个菜心品种为试材进行小孢子培养,研究基因型、不同培养基配方和植物生长调节剂对小孢子胚诱导率的影响。结果表明,基因型是决定菜心品种能否出胚的一个重要因素,且不同基因型试材间小孢子胚诱导率具有明显差异,其中'Cx1'Cx6'Cx8'经过小孢子培养后较易获得胚状体,而其他材料则没有获得胚状体,基因型的不同导致胚状体诱导率在0～2.10胚·蕾~(-1)之间;同一基因型,在不同培养基成分诱导条件下,添加活性炭对小孢子胚状体诱导率的影响较大,胚诱导率在0.03～2.10胚·蕾~(-1)之间;培养基中蔗糖质量浓度为130 g·L~(-1)时',Cx1'的胚诱导率最高;此外,在培养基中添加0.05 mg·L~(-1)6-BA和0.5 mg·L~(-1)NAA可以显著提高菜心'Cx1'胚状体诱导率。     

活性炭和振荡培养对提高大白菜胚诱导率的影响

以11个大白菜品种(品系)为材料,采用NLN培养基进行游离小孢子培养,研究了活性炭和振荡培养对小孢子胚诱导和形成的影响。结果表明:11个大白菜品种有9个诱导出胚,每花蕾诱导胚数0.056～12.67个。在NLN-13培养基中添加活性炭(0.5g/L),有利于小孢子胚的诱导和形成,Y536和Y585胚诱导率分别提高了16.1和4.8倍,极难诱导出胚的材料Y516也诱导出胚;采用振荡培养方式(65r/min),Y531和Y445胚诱导率较静置培养分别提高了18.23%和30.91%,出胚时间提早2～4d。     

花粉发育时期与取样时期对白菜小孢子胚诱导的影响

以上海青、精选长梗白菜和高华青梗白菜为试材，对花粉发育时期与取样时期对白菜小孢子胚诱导的影响进行了研究。结果表明，当花瓣与花药长度比长为1／2～2／3，花蕾长范围在2．2-2．8mm时，供试白菜小孢子胚诱导率最高，与此对应的最佳白菜小孢子培养时期为单核中期至单核靠边期。蕾期末和初花期的花蕾取样，小孢子培养胚诱导率最高。     

不同基因型大白菜小孢子胚状体诱导及植株再生

以9个大白菜品种的花蕾为试材,研究了基因型、6-BA以及不同固体培养基对大白菜小孢子胚发生的影响,以期为其它十字花科蔬菜小孢子培养体系的建立提供技术参考。结果表明:不同基因型大白菜的小孢子胚诱导率具有明显差异,9个大白菜品种中有6个诱导出胚状体,‘北京特好吃火锅菜’出胚率最高,达到每蕾12.38胚;添加0.3mg/L的6-BA可以促进小孢子胚状体的形成,以‘北京特好吃火锅菜’提升效果最显著;添加0.01g/L活性炭的MS固体培养基比B5培养基更适于成熟胚状体发育成苗。     

影响白菜游离小孢子培养关键因素分析

对影响白菜游离小孢子培养的关键因素进行分析研究。单因素研究结果表明: 54个基因型之间的小孢子胚诱导率差异显著; 对供体材料低温处理, 在0～5 d范围内小孢子胚诱导率差异不大, 超过5 d则明显降低; 高温诱导在12～60 h范围内差异不大, 超过此范围则小孢子胚诱导率明显降低; NLN培养基中添加生长素(NAA) 和细胞分裂素(6-BA) 对小孢子胚诱导率影响不大, 添加的浓度过大时小孢子胚诱导率反而降低; 活性炭的有无和浓度大小对小孢子胚诱导率影响极大。通过基因型、生长素、细胞分裂素、活性炭4因素分析表明: 基因型之间差异显著, 活性炭不同浓度之间差异显著; 基因型与活性炭不同浓度之间的互作差异显著; 其它的5个一级互作、4个二级互作和1个三级互作差异均不显著。     

芥菜游离小孢子培养技术研究

以12 份不同基因型的芥菜栽培种为试材,用NLN-13 培养基进行游离小孢子培养,并进行不同的热激诱导处理,研究基因型、热激条件以及供体植株生长条件（主要是温度）对芥菜游离小孢子培养的影响。结果表明：芥菜小孢子培养的适宜花蕾长度为2～3 mm,此时小孢子主要处于单核靠边期,显微观察小孢子有3 条明显的萌发沟;35 ℃热激处理3 d 有利于芥菜小孢子诱导成胚;基因型是影响芥菜小孢子培养的关键因素,不同基因型芥菜的出胚能力差异很大,供试12 份材料中有9 份诱导出胚,其中V03B0097 和A12959 出胚率最高,分别达5.87 胚·蕾^-1 和5.54 胚·蕾^-1;供体植株在 较低的温度环境下生长有利于芥菜小孢子的胚胎发生。     

抗生素对耐抽薹大白菜小孢子胚胎发生的影响

为克服耐抽薹大白菜游离小孢子培养中出胚难的问题，以23个耐抽薹大白菜品种为试材，探究不同基因型间小孢子胚胎发生的差异以及两性霉素-B、灰黄霉素对小孢子胚诱导的影响。结果表明：采用NLN-13培养基，23份耐抽薹大白菜材料中仅有3份诱导出胚，胚诱导成功率为13.0%，且不同基因型间小孢子出胚率存在显著差异，表明基因型是影响大白菜小孢子胚胎发生的重要因素。添加适宜浓度的两性霉素-B和灰黄霉素，23份耐抽薹大白菜材料的胚诱导成功率分别达到60.9%和82.6%，添加1.0～2.0 mg·L^-1两性霉素-B和0.5 mg·L^-1灰黄霉素时诱导出胚材料数量最多，胚诱导率最高可达0.467胚·蕾^-1和0.733胚·蕾^-1，表明培养基中加入抗生素能够在一定程度上促进耐抽薹大白菜小孢子胚胎形成。     

菠萝叶基愈伤组织诱导体细胞胚

以菠萝[Ananascomosus(L.)Merr.]吸芽上的叶基部组织为材料,研究了2,4-D、NAA、BA、TDZ在菠萝愈伤组织诱导体细胞胚过程中的影响。结果表明,2,4-D在体细胞胚诱导过程中起着极为重要的作用,其适宜浓度为5mg/L,适当浓度(1mg/L)的BA在降低畸形胚比例和增加体细胞胚发生率方面有重要作用,但BA也会促进愈伤组织分化不定芽;低浓度的TDZ与BA效果相似,在不同生长调节物质处理组合中,MS+0.01mg/LTDZ+5mg/L2,4-D培养基的体细胞胚发生率最高(97%)。低浓度NAA(2￣5mg/L)利于非胚性愈伤组织的增殖,而高浓度的NAA虽能促进体细胞胚发生,但这种体细胞胚很难继续增殖,在萌发时只生根不发芽。成熟体细胞胚在MS+0.2%活性炭上30d时的转株率为22.7%。     

Effect of artificial chilling on the depth of endodormancy and vegetative and flower budbreak of peach and nectarine cultivars using excised shoots

Stem cuttings were obtained from 12 peach and nectarine cultivars during leaf fall, placed in plastic bags at 3.0 ± 0.1 °C to simulate 0–800 h of chilling and forced to budbreak at 20.0 ± 1.0 °C for a period of 6 weeks. Some cultivars showed high blooming and leafing without exposure to chilling; chilling enhances leafing and blooming but the percentage increment was higher in leaf buds. In general, maximum budbreak was reached with less chilling accumulation (<100–200 h) in flower buds compared with leaf buds; excessive chilling caused a reduction of the percentage budbreak in flower but not in leaf buds. Additionally, chilling modified the proportion of blooming that occurred before leafing. In non-chilled shoots, blooming occurred earlier than leafing, except in cv. ‘San Pedro 16–33’ but the proportion of blooming before leafing decreased significantly with chilling in most cases. By studying the mean time to budbreak, we conclude that the flower bud generally has a lower intensity of rest; the intensity of rest declines at a slower rate in flower than in leaf buds with chilling; flower buds had greater heat requirements than leaf buds when the chilling requirement had been covered, so that each peach cultivar had a point of critical chilling accumulation below which blooming tended to occur earlier, and above which leafing tends to occur first. Flower and leaf buds had different depths of endodormancy but similar chilling requirements in the majority of peach and nectarine cultivars studied. Finally, different varieties with similar chilling requirements showed different responses to chilling. Therefore, the cutting test measuring the response of vegetative and floral buds provides considerable information on the characterisation of the variety, compared with the sole and traditional data of chilling requirements.     

桃离体组织分化再生植株的研究

  以奉化‘玉露’桃叶片、幼茎、下胚轴、子房、胚珠、胚乳及花后45～50 d 和75 d 的未成熟胚、完全成熟的种胚为外植体, 进行离体培养再分化试验。结果表明只有花后45～50 d 和75 d 的未成熟胚产生白色致密节球状的愈伤组织, 并可诱导出不定芽, 不定芽分化率分别为73. 8 %和15. 5 %; 62BA 诱导愈伤组织不定芽的效果优于KT。不定梢转移生根成苗获得了完整的再生植株。探讨了不同激素和碳源等对不定芽诱导的影响。     

Strawberry fruit yield and quality responses to flower bud removal: A simulation of damage by strawberry blossom weevil (Anthonomus rubi)

Summary

The effect of flower bud severing (with scissors) on the yield and fruit quality of strawberry (cv. Elsanta) grown on raised, polythene-mulched beds varied with plant size and numbers of flower buds per plant. On very small plants (with an average of seven flower buds and yielding 105 g of fruit per plant) severing reduced yield in direct proportion to the proportion of flower buds severed, irrespective of whether severing included or did not include removal of the primary (first node) flower bud. There was no evidence of crop compensation. On larger plants (with 24, 70 and 117 flower buds and yielding 0.34 kg, 0.73 kg and 1.16 kg of fruit per plant respectively) severing up to 12 buds per plant did not significantly affect yield: mean berry weight increased by up to 11% and the percentage fruit (by number) in quality class I increased from 67% to 72% in response to severing. Two mechanisms of yield compensation were, apparent i) an increase in mean berry weight, and ii) the maturing of alternative replacement flower buds. Severing slightly delayed by 1–2 d the date by when 10% and 25% of fruit was picked. Implications for the economic damage threshold for flower bud severing by the strawberry blossom weevil are discussed.     

Simultaneous down-regulation of DORMANCY-ASSOCIATED MADS-box6 and SOC1 during dormancy release in Japanese apricot (Prunus mume) flower buds

In temperate deciduous fruit crops such as Prunus spp., bud endodormancy is an important physiological phase affecting the timing of blooming and subsequent fruit development. Japanese apricot (Prunus mume) bears unmixed flower buds, separate from vegetative buds, that bloom slightly more than a month before vegetative bud burst. Seasonal expression of Prunus mume DORMANCY ASSOCIATED MADS-box genes (PmDAMs) has previously been analyzed only in vegetative buds, with an association between these genes and flower bud endodormancy release not yet confirmed. In this study, we performed a seasonal expression analysis of PmDAM1–6 genes in flower buds of two Japanese apricot genotypes – namely, high-chill and low-chill cultivars. The analysis revealed that PmDAM3, PmDAM5, and PmDAM6 expressions are closely associated with dormancy release in both flower and vegetative buds. In addition, a yeast two-hybrid screening demonstrated that PmDAM6 can interact in yeast with the homolog of Arabidopsis SOC1 (PmSOC1). Synchronized expression patterns were detected in PmDAM6 and PmSOC1 during dormancy release in flower buds of the two genotypes. Taken together, these results suggest that the dimer of PmDAM6 and PmSOC1 may play a role in the regulation of dormancy transition and blooming time in Japanese apricot flower buds.     

贮藏温度对黄瓜花粉活力的影响

研究了不同贮藏温度对黄瓜新鲜雄花和花蕾花粉活力的影响。结果表明:5～25℃范围内,随着贮藏温度的降低黄瓜花粉寿命延长,5、10、15℃分别较常温(25℃)的花粉寿命长60、44、34h;低温贮藏花蕾能有效地延长花粉寿命,以在傍晚(约18:00)采摘第2天将开放的大花蕾为贮藏材料较好;5℃低温下花粉活力持续时间最长,但因低温不利于雄花开放和散粉,所以在授粉前将5℃低温贮藏的花蕾放在常温(25℃)下1～2h以加速雄花的开放和散粉。     

Anatomical and morphological study of apple (Malus × domesticaBorkh.) flower buds growing under inadequate winter chilling

Summary

Some apples cultivars produce low yields when grown in regions with inadequate winter chilling. Their unsatisfactory development is attributed to the lack of climatic adaptation which causes some abnormalities in bud differentiation. The development of reproductive spurs is erratic, leading to vegetative shoots, and the flower index is very low. The purpose of this work is to understand the flower differentiation problem. An assessment was made through morphological and histological studies, also an analysis of climatic data was performed in an attempt to identify the responsible factors. The number of chilling hours recorded was about 695. Defoliation was delayed and happened during the second week of January. Bud break was advanced by 10 d in comparison with the average period. The spurs density (12 and 23 spurs per m of twigs) was similar to the values observed in normal situation. The buds carried by these spurs evolved into vegetative shoots for all variety × rootstock combination used in this study. The average of this transformation was 47 and 50% for ‘Golden Delicious’ and ‘Starking Delicious’, respectively. A flowering index obtained was very low (1.3 kg per tree). Anatomical observations carried out on buds collected in October showed that differentiation was undertaken and the floral primordium was already formed with some abnormalities in flower development in later stage. At anthesis, internal structures of the buds showed primordia disorganized. Reproductive organs presented pistil abortion with low microsporogenesis. Xylem vessel elements were not observed at the base of the bud and vascular connection was not established. This problem in flower development occurred at this stage which was affected by external factors. The winter was characterized by periods of high temperatures which affect negatively the accumulation of chilling units. The mode of action of temperature, notably of chilling on the formation of flowering organs and vessels, remains to be determined.     

提高大白菜小孢子植株获得率的研究

 大白菜小孢子胚发生过程中胚胎发育不同步, 以子叶形胚数量最多。发育较好的胚状体成苗率较高, 子叶形胚和萌发胚成苗率分别为20%和90.5%; 较干燥的培养基更利于小孢子胚成苗, 最适的琼脂含量是1.2%。培养基中添加200 mg·L ^{- 1}活性炭可以大幅度提高小孢子胚成苗率, 及时地将成熟的子叶形胚转移至再生培养基上, 对提高植株获得率至关重要。