储存温度对单瓣和重瓣紫斑牡丹花粉活力及生理特性的影响北大核心CSCD

以紫斑牡丹‘象牙白’单瓣和重瓣花的花粉为材料,对其超微结构及生理生化特性进行观察和分析,探讨单瓣和重瓣花花粉超微结构以及不同温度储存花粉活力与其可溶性蛋白含量、MDA含量和3种保护酶活性(POD、SOD、CAT)的关系,以确定紫斑牡丹单瓣和重瓣花花粉最佳储存温度。结果表明:(1)紫斑牡丹重瓣花花粉平均极轴长、平均赤道轴长、极轴长/赤道轴长均小于单瓣花花粉;室温(25℃)条件下,单瓣花花粉萌发率(83.62%)高于重瓣花(72.06%),单瓣花和重瓣花花粉的半衰期分别为40 d和60 d;随着储存温度降低和储存时间的延长,单瓣花和重瓣花的花粉萌发率较室温均显著提高,且单瓣花花粉萌发率始终高于重瓣花花粉。(2)紫斑牡丹单瓣和重瓣花花粉在短期储存(1~120 d)、较长时间储存和长期储存的适宜温度分别为4℃、-20℃,-80℃。(3)与室温相比,低温可提高储存期间紫斑牡丹花粉的可溶性蛋白质含量和保护酶活性,并降低MDA含量,从而有效延缓花粉萌发率的下降。(4)低温胁迫对紫斑牡丹单瓣花花粉的影响低于重瓣花花粉,在相同储存温度条件下,重瓣花花粉细胞受损程度更高、萌发率下降速率更快。研究认为,紫斑牡丹花粉在-80℃储存条件下基本处于代谢平衡状态,故低温能有效延长其花粉储存寿命;储存期间花粉萌发率下降的主要原因是细胞膜脂过氧化程度加剧,细胞损伤加重;紫斑牡丹重瓣花花粉粒小、瘪粒和畸形是导致其较单瓣花花粉萌发率低的主要原因。     

同株紫斑牡丹中单瓣与重瓣花芽分化及内源激素含量比较北大核心CSCD

该研究以紫斑牡丹‘关公红’为试验材料,通过调查‘关公红’的开花情况,采用光学显微镜、扫描电镜技术考察花芽分化和花瓣发育过程的结构特征,并测定同株‘关公红’单、重瓣花朵的花芽在不同分化阶段内源激素含量,分析单、重瓣花朵的花芽分化及内源激素含量的变化特征,为紫斑牡丹不同花型的培育奠定理论基础。结果表明:(1)‘关公红’单瓣花朵比重瓣花朵花期长,单瓣花朵花瓣表皮细胞光滑平整无明显褶皱,而重瓣花朵花瓣的表皮有明显的褶皱;重瓣花的花芽分化时间明显早于单瓣,花瓣原基的体积也明显增大,这可能与重瓣花中雄蕊瓣化有关系。(2)低浓度GA_(3)有利于‘关公红’单瓣花朵和重瓣花朵的花芽分化;高浓度的ABA促进重瓣花原基的形成;ZR含量增加有助于紫斑牡丹的花芽分化。(3)较高ZR/IAA、ZR/GA_(3)、ABA/GA_(3)、ABA/IAA比值有利于‘关公红’重瓣花朵的花芽分化;ABA/IAA、ZR/IAA比值的增加有利于‘关公红’单瓣花朵花芽分化;(GA_(3)+IAA+ZR)/ABA与(IAA+ZR)/GA_(3)比值减小分别促进重瓣花朵花瓣原基和雄蕊原基的形成。     

22个木槿品种花粉形态与分类研究

为研究木槿(Hibiscus syriacus)不同品种花粉形态的多样性及其亲缘关系,该研究以22个木槿品种的花粉为材料,通过扫描电镜进行形态特征及外壁纹饰观测,然后使用R型聚类分析法和主成分分析法提取合适的指标进行UPGMA聚类分析。结果表明:(1)木槿的花粉均为单粒近球形,直径为148.98~111.65μm;表面具有刺状纹饰,长度为27.42~14.79μm,刺先端较尖,细刺周围均匀分布散孔;花粉表面分布有颗粒状突起,萌发孔性状不规则。(2)对测量指标提取主成分后进行UPGMA聚类分析,当欧氏平均距离阈值为6时,22个木槿品种被分为6大类,单瓣蓝紫色品种‘蓝鸟’、‘单瓣紫粉’、‘细叶’等亲缘关系较近,半重瓣品种‘薰衣草雪纺’、‘中国雪纺’、‘粉色雪纺’等亲缘关系较近,而‘木桥’、‘汉帛’等粉白色单瓣木槿品种亲缘关系相对较近。该研究认为木槿种内蓝紫色品种相对较为原始,白色半重瓣品种次之,紫色半重瓣品种相对较为进化,白色单瓣品种进化程度更高。该研究结果为木槿种内遗传演化、分类地位以及亲缘关系的鉴定提供了依据。     

大花红山茶花粉形态特征和培养条件及其储藏过程的生理动态分析

以大花红山茶花粉为材料,用扫描电子显微镜观察花粉表观形态,采用离体培养法研究花粉的萌发特性,并就不同贮藏温度与时间对花粉萌发率、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响进行了分析。结果表明:(1)大花红山茶花粉极面观呈正三角形,沟界极区较宽;花粉粒纹饰为穴状、小沟状雕饰纹;花粉粒平均极轴长为71.05μm;说明大花红山茶在山茶属中具有较为特殊的分类地位和系统进化地位。(2)大花红山茶花粉萌发的最适宜培养基为:150g·L-1蔗糖+20mg·L-1硼酸+100mg·L-1 KNO3+50mg·L-1MgSO4+300mg·L-1 Ca(NO3)2,花粉萌发率可达68.10%。(3)大花红山茶花粉最佳贮藏条件为-80℃;-80℃下贮藏360d后,萌发率仍可达到39.40%。(4)-20℃、-80℃贮藏条件下,大花红山茶花粉3种保护酶(SOD、POD、CAT)的活性较高,花粉抗氧化、抗衰老的能力较强;且在花粉贮藏过程中,3种酶活性高峰值前后花粉萌发率出现大幅度下降。(5)不同贮藏温度下,3种保护酶的作用不同,常温下,SOD为敏感性保护酶;4℃、-20℃下,POD为敏感性保护酶;-80℃下CAT为敏感性保护酶;3种酶活性对花粉萌发率的影响依次为:过氧化氢酶超氧化物歧化酶过氧化物酶。     

梅花花粉离体萌发和花粉管生长研究

(南京农业大学园艺学院,南京210095)摘要:研究培养基成分、pH值和培养方式对梅花花粉离体萌发和花粉管生长的影响。结果表明:不同品种梅花花粉离体萌发的最适培养基为ME3+200g.L-1PEG4000(pH5.0),品种‘淡丰后’、‘久观绿萼’、‘喧妍宫粉’和‘月光玉蝶’最高萌发率可分别达到58.6%、60.6%、85.6%和50.7%。PEG4000能显著促进梅花花粉萌发,在培养基各成分中作用最大,不可替代。低浓度(50g.L-1)蔗糖对梅花品种花粉萌发作用不显著,而高浓度(≥100g.L-1)蔗糖明显抑制花粉萌发和花粉管生长。固体和液体培养对梅花花粉离体萌发的影响差异不显著。     

贮藏时间对银杏花粉保护酶活性和萌发率的影响

研究了室温贮藏对银杏花粉萌发率及超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化物酶(Peroxi-dase,POD)、过氧化氢酶(Catalase,CAT)活性的影响。结果表明,随着贮藏时间的延长,花粉萌发率由88．89％降到15．76％;贮藏15d之后超氧化物歧化酶活性降低了80％;过氧化物酶活性减少到原来的10％;过氧化氢酶活性也减少了70％。在室温贮藏条件下萌发率随保护酶活性的下降而降低。POD酶对花粉萌发率的影响比SOD、CAT酶显著。     

梨远缘花粉原位萌发及生长特性

应用荧光标记方法对梨远缘花粉在‘丰水’和‘噢嗄二十世纪’柱头上萌发及花粉管生长特性进行观察,结果表明:(1)梨远缘花粉均能在柱头上萌发,但其萌发率不同,授粉后24 h,在‘丰水’柱头上‘红叶桃’花粉萌发率最高,达62.8%,而‘盖县大李’花粉萌发率仅为12.0%,各种远缘花粉在‘丰水’柱头萌发率均高于‘噢嗄二十世纪’柱头。(2)各种远缘花粉管在梨柱头或花柱内生长情况也有差异,‘红叶桃’等核果类花粉管在梨柱头上均表现为扭曲、盘绕等现象,不能穿过柱头;‘红星’和‘红富士’花粉管虽然有少量穿过柱头,但不能进一步在花柱内生长,表现为扭曲变形、先端膨大等不亲和性现象。因此,梨与远缘果树杂交不亲和在柱头上就已发生,这与梨自交不亲和反应发生在花柱内的现象不同。     

蔷薇属植物与现代月季品种杂交亲和性研究

为培育抗寒、抗病性强、芳香的月季品种,以单瓣黄刺玫(Rosa xanthinaf.normalis)、黄刺玫(R.xanthina)、报春刺玫(R.primula)、美蔷薇(R.bella)、腺果大叶蔷薇(R.macrophylla var.glandulifera)、荷花蔷薇(R.multifloraf.carnea)等6个蔷薇属种、变种及变型和5个玫瑰品种为父本,以11个现代月季品种和香水月季(R.odorata)为母本设计72个授粉组合进行远缘杂交,统计杂交结实率及杂交种子萌发率,并采用扫描电镜技术观察了杂交亲本的花粉与柱头形态,测定花粉萌发率。结果显示:(1)除黄刺玫外,所试其他蔷薇属植物均适合作为父本材料与现代月季品种和香水月季杂交,但不同杂交组合的结实率及出苗率差异显著。(2)花粉、柱头形态对杂交亲和性无显著影响,花粉生活力对杂交亲和性有显著影响,且与杂交结实率成正相关关系。通过试验,筛选出14个亲和性较好的杂交组合、4个适宜的母本材料(香水月季、‘橘红潮’、‘金玛丽’、‘粉和平’)和6个适宜的父本材料(单瓣黄刺玫、报春刺玫、美蔷薇、腺果大叶蔷薇、荷花蔷薇、玫瑰‘大红紫枝’)。     

秋水仙素诱导月季品种‘月月粉’2n花粉的研究

为获得二倍体古老月季品种‘月月粉’人工诱导2n花粉用于现代月季杂交育种,该研究在了解‘月月粉’花粉母细胞发育过程的基础上,使用秋水仙素注射结合包裹法处理幼嫩花蕾,成功获得了可正常萌发的2n花粉,并通过观察诱导获得的花粉离体及其在雌蕊上的萌发特征,初步评估2n花粉用于杂交育种的性能。结果表明:(1)秋水仙素药棉包裹造成部分花蕾在采粉前死亡,花蕾存活率随秋水仙素浓度提高和处理时间延长均极显著降低。(2)2n花粉诱导率在秋水仙素浓度为2.5、5.0、7.5和10.0 g/L间存在显著差异,但在处理时间为24、48和72 h间无显著差异;最佳诱导处理为5.0 g/L秋水仙素处理24 h,诱导率可达15.83%,该处理获得的2n花粉经亚历山大染色检验活力为27.2%。(3)‘月月粉’花粉母细胞在减数分裂时存在异常落后染色体和平行纺锤体,在四分体时期形成染色体数目加倍的二分体和三分体,最终产生2n花粉。(4)所诱导的2n花粉的体外萌发率和花粉管长度与天然花粉无显著差异,且都可以在母本柱头上萌发并长出花粉管进入子房,表明可用于进一步的杂交育种。     

斑叶堇菜花粉形态、贮藏条件及其保护酶活性的变化

以斑叶堇菜花粉为材料,使用扫描电子显微镜观察花粉表观形态,采用离体培养法研究花粉的萌发特性,并探讨了不同贮藏温度和时间对花粉萌发率、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的影响。结果表明:初步判断斑叶堇菜在堇菜属中具有较为特殊的分类地位;花粉萌发的最适宜培养基为:280 g·L~(-1)蔗糖+250 mg·L~(-1)硼酸+50 mg·L~(-1) GA_3+200 mg·L~(-1) Ca(NO_3)_2。花粉最佳贮藏条件为-80°C;-80°C贮藏360 d后,花粉萌发率仍达到40.50%,3种保护酶活性较高,花粉抗氧化、衰老能力较强。贮藏过程中,在3种酶出现高峰值前后,室温和4°C的花粉萌发率出现大幅度下降。不同贮藏温度下,3种保护酶的作用不同,室温下,CAT为敏感性保护酶;4°C下,POD为敏感性保护酶,SOD为非敏感性保护酶;-20和-80°C下,POD为零下低温敏感性保护酶。花粉萌发率与SOD呈极显著正相关。     

Morphology of the petal inAconitum

The petals ofAconitum were classified into six types. Type I: the labium tubular at the base and no appendage inside. Type II: a lambda (A)-shaped enation present inside the limb. The upper part of the enation is situated at the lower edge of the spur mouth and both wings of the enation extend to margins of the labium. Type III resembles type II but both wings do not extend to the margins. Type IV: a small flap attached at the lower edge of the spur mouth. Type V: two auriculate appendages present on both lateral walls of the labium. Type VI: without inside appendage. Most species of sect.Lycoctonum have type I petal and those of sect.Aconitum have type V petal. Type I is distinctly cup-shaped or peltate with a well developed cross zone or adaxial wall and type II is a modification of type I. Type VI is distinctly flat or epeltate without the cross zone. Others are intermediate between cup-shaped and flat or peltate and epeltate types. Based on the observation of petal ontogeny onA. pterocaule var.glabrescens, A. vulparia andA. japonicum var.eizanense, the relation among these types was explained by the partial or total reduction of the adaxial meristematic regions.     

Molecular analysis of hormone-regulated petal regeneration in Petunia

The petal is an important floral organ of higher plants. To study the mechanism of petal development, the in vitro regeneration system of petals was established in Petunia. High-frequency induction of petals occurred directly from explants on the media containing the combination of N6-benzyladenine (6-BA) and indole-3-acetic acid (IAA). Expression analysis of genes involved in flower development indicated that these genes were classified into three types. ABERRANT LEAF AND FLOWER (ALF) gene was induced during petal regeneration. Whereas, B-class and E-class genes, and genes involved in cell division were constitutively upregulated. In contrast, C-class and D-class genes were not expressed in explants and regenerated tissues. Further, in situ hybridization analysis showed that both ALF and GREEN PETAL (GP) expression were spatially regulated. The results suggest that differential regulation of gene expression occurs in the presence of hormones during petal regeneration, and hormone-regulated gene expression might be required for petal regeneration. This study provides the preliminary information to understand the mechanism of petal regeneration.     

Plant regeneration from petal protoplast culture ofPetunia hybrida

Morphologically normal plants have been regenerated from petal protoplasts of petunia (Petunia hybrida) flower. Maximum protoplast yields from petal tissues were obtained within 2 days after anthesis. Protoplasts were cultured on modified Murashige and Skoog's medium in which NH₄NO₃ and Fe·EDTA concentrations were reduced to 1/3 (7mM) and 1/10 (10 M), respectively. After plating, protoplasts gradually reduced pigment density, and plastids developed near the nucleus. In premitotic petunia petal cells, the nucleus moved from the periphery to the central region of the cell. The first cell divisions were detected after 6–10 days of culture initiation, and the average division frequency was 15% in the best culture condition. The results indicated that the time of the first cell division and cell division frequency were closely related to flower age after anthesis. More than a hundred plants with morphologically normal shoots and roots have been obtained. Those plants grew vigorously in soil.Abbreviations BA benzylaminopurine - DAPI 4, 6-diamidino-2-phenylindole - 2, 4-d dichlorophenoxyacetic acid - Fe·EDTA Fe·ethylenediaminetetraacetate - IAA indole-3-acetic acid - MtSB microtubule stabilizing buffer - NAA -naphthaleneacetic acid - PIPES piperazine-N,N-bis(2-ethanesulfonic acid) - EGTA ethylene glycol-bis(-aminoethyl ether) N,N,N,N-tetraacetic acid     

Adventitious shoot regeneration from cultured petal explants of carnation

Adventitious shoot regeneration was compared among leaf, stem and petal explants of carnation (Dianthus caryophyllus L.) cv. Scania on MS medium containing different concentrations of 6-benzyladenine (BA) and -naphthaleneacetic acid (NAA). High frequency regeneration was obtained only from petal explants on the media containing 5 to 10 M BA with or without 5 M NAA. Among the cytokinins tested, N-2-chloro-4-pyridyl-N-phenylurea and N-1,2,3-thiadiazol-5-yl-N-N-phenylurea were more effective than BA, kinetin, N⁶-2-isopentenyl adenine and zeatin on regeneration from petal explants. Although, high frequency shoot regeneration was obtained from all petal explants harvested from various developmental stages of buds, a significant decrease in regeneration capacity was observed in the explants obtained from fully-opened flowers. High frequency shoot regeneration was also obtained from the petal explants of cvs. Coral. Lena, Nora and White Sim, and an interspecific cultivar Eolo using the method developed in this study.Abbreviations NAA -naphthaleneacetic acid - BA 6-benzyladenine - GA₃ gibberellic acid - 2iP N⁶-2-isopentenyl adenine - KT-30 N-2-chloro-4-pyridyl-N-phenylurea (also called 4PU) - TDZ N-1,2,3-thiadiazol-5-yl-N-phenylurea (also called thidiazuron)     

Induction of adventitious buds in cultured petal explants ofChelidonium majus L.

Petal explants ofChelidonium majus L. (Papaveraceae) formed noteworthy adventitious buds without any intermediate callus when cultured under appropriate conditions. Bud formation was favored by combinations of 1–2 mg/l indoleacetic acid (IAA) and/or 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.1–0.5 mg/l kinetin (K). In the present study, neither bud formation nor callus formation occurred in cultures of excised leaves. A histological study revealed that adventitious bud formation occurred only in single epidermal layers of petals, while several subepidermal parenchyma layers did not join in its formation. Activation zones arising from the epidermis underwent intense cell divisions to initiate buds on the epidermal surface. These buds later turned green in color, developing into shoots which eventually grew into plantlets after root formation.     

Both the adaxial and abaxial epidermal layers of the rose petal emit volatile scent compounds

The localization and timing of production and emission of scent was studied in different Rosa × hybrida cultivars, focusing on three particular topics. First, it was found that petals represent the major source of scent in R. × hybrida. In heavily scented cultivars, the spectrum and levels of volatiles emitted by the flower broadly correlated with the spectrum and levels of volatiles contained within the petal, throughout petal development. Secondly, analysis of rose cultivars that lacked a detectable scent indicated that the absence of fragrance was due to a reduction in both the biosynthesis and emission of scent volatiles. A cytological study, conducted on scented and non-scented rose cultivars showed that no major difference was visible in the anatomy of the petals either at small magnification in optical sections or in ultrathin sections observed by TEM. In particular, the cuticle of epidermal cells was not thicker in scentless cultivars. Thirdly, using two different techniques, solid/liquid phase extraction and headspace collection of volatiles, we showed that in roses, both epidermal layers are capable of producing and emitting scent volatiles, despite the different morphologies of the cells of these two tissues. Moreover, OOMT, an enzyme involved in scent molecule biosynthesis was localized in both epidermal layers.     

鱼腥草花粉母细胞减数分裂特征及其育性研究

为深入了解鱼腥草花粉母细胞的减数分裂特征与花粉育性的关系,该研究采用卡宝品红染色法对2个鱼腥草居群花粉母细胞的减数分裂过程进行观察,并采用氯化三苯基四氮唑(TTC)染色法、I2-KI染色法、B-K培养基培养法及荧光显微镜观察法来检测鱼腥草花粉的活力及萌发率。结果发现:(1)鱼腥草减数分裂的进程与花序大小、花药颜色、花药长度均有密切的关系。(2)2个居群的鱼腥草中花粉母细胞减数分裂过程正常占88.2%,有11.8%的花粉母细胞减数分裂异常。(3)减数分裂异常表现在减数分裂过程中出现微核、落后染色体、染色体桥、不均等分离、多分体等现象,并发现在二分体阶段及单核花粉发育过程中存在细胞融合。(4)2个居群的鱼腥草花粉活力均不超过1.5%,花粉几乎不萌发。研究认为,鱼腥草花粉育性低的主要原因是单核花粉的发育过程异常,而非鱼腥草花粉母细胞减数分裂异常所致。