蒙药植物蓝盆花的授粉亲和性

利用显微镜观察花粉和柱头形态,采用离体萌发法对花粉活力进行测定,采用压片法对自交授粉后花粉管生长动态进行观察,以探明蓝盆花自交是否存在授粉障碍,为今后蓝盆花人工栽培和杂交育种工作提供理论依据。结果表明:蓝盆花花粉饱满,具有1~3个萌发孔,二裂柱头,花柱细长通直,培养10 h花粉萌发率达86.06%,花粉活力高。授粉后4 h多数花粉萌发后花粉管进入花柱;授粉后10 h花粉管进入花柱中上部;授粉后12 h多条花粉管进入花柱并到达中部;授粉后48 h花粉管到达花柱基部进入子房,但通过观察发现花柱顶端有胼胝质及花柱内的花粉管交叉缠绕停止生长的异常现象,从而花粉管不能进入子房完成受精过程,这可能是导致果实空瘪的一个原因。由此推测,蓝盆花自交授粉存在受精前障碍,属于配子体自交不亲和类型。     

‘砀山酥梨’花柱可授性及蜜蜂授粉特性的研究

采用半离体培养法和联苯胺-过氧化氢法研究了‘砀山酥梨’花粉萌发特性和柱头可授性。通过对‘酥梨’的最适授粉时间以及7种授粉处理坐果率的研究,探讨其授粉特性。结果表明：开花后每天酥梨柱头活性最佳的时间是11时至15时,柱头最佳授粉时间为开花后第4~5天;‘酥梨’花粉最适萌发温度为25℃,花粉管生长最有利的温度为22~25℃,在相同温度下,花粉萌发率和花粉管长度随时间增加而增加。7种授粉处理‘酥梨’的花朵坐果率中,没有昆虫授粉的‘酥梨’坐果率为0.48%和0.44%,自然授粉和人工授粉坐果率分别为2.83%和13.05%,‘酥梨’ב雪花梨’组蜜蜂授粉的坐果率为32.95%,新鲜花粉和商品花粉坐果率分别为70.2%和13.05%。由此可见,‘酥梨’是异花虫媒果树,蜜蜂可以在‘酥梨’柱头活性最高时进行授粉,从而提高‘酥梨’的坐果率,同时通过对‘酥梨’花器官生理活性和坐果习性的研究,为‘酥梨’的授粉和生产提供基础资料。     

开花期低温胁迫对四川攀西稻区水稻开花结实的影响

以3种籼稻品种和3种粳稻品种为试验材料, 利用人工气候室在开花期进行低温胁迫处理, 研究了低温胁迫对攀西稻区籼、粳稻开花和结实及两者间关系的影响。结果表明, 开花期低温胁迫下籼稻和粳稻的开花习性、花药和花粉特性和结实表现不同。常规粳稻开花对低温有较高的耐冷性。低温胁迫下籼稻品种(组合)花药体积、花药开裂率、可育花粉率、柱头着花粉数和柱头花粉萌发率较对照降低幅度均比粳稻品种(组合)大; 籼稻品种(组合)各产量构成因素较对照降低幅度比粳稻品种(组合)大。相关分析表明, 结实与水稻花药和花粉主要性状有密切关系。开花期低温胁迫影响花药和花粉发育成熟, 使花药不能正常开裂、散粉不足, 可育花粉率和柱头花粉萌发率降低, 直接影响受精结实, 成为结实率降低的主要原因之一。     

枣不同品种开花结实及花粉发芽特性研究

对枣22个品种开花类型,12个品种的花粉发芽率,5个品种的花粉萌发动态,9个品种的花粉贮藏和10个品种自花结实率进行了研究。结果表明,脆枣、辣椒枣、葫芦枣、福枣、扁核酸、骏枣、赞皇大枣、红颜、无等、稷山圆枣、晋枣、绵枣、尖枣、临猗梨枣、长红、酥枣是昼开型;湖南鸡蛋枣、冬枣、束鹿糖枣、月出、尖头灰、屯屯枣是夜开型。其中脆枣、辣椒枣、葫芦枣、福枣、骏枣、赞皇大枣、红颜、无等、稷山圆枣、晋枣、绵枣、尖枣、酥枣、湖南鸡蛋枣、束鹿糖枣、月出、尖头灰、屯屯枣皆为首次报道。供试枣品种间花粉发芽率有很大差异,为1.52%~74.95%,平均发芽率为34.28%,变异系数为14.74%,其中冬枣最低,辣椒枣最高;花粉在散射光下培养与黑暗条件下培养对花粉发芽率没有显著差异。花粉-12℃干燥器贮藏极显著地好于2℃干燥器贮藏和室温干燥器贮藏;-12℃干燥器贮藏条件下,贮藏6d、10d的花粉发芽率分别是新鲜花粉的88.04%、59.88%。花粉发芽动态试验表明,花粉发芽率和花粉管生长曲线呈单S型,培养5.5h花粉发芽率不再变化,7.5h花粉管停止生长。供试枣品种的自花结实坐果率几乎为零。     

高山杜鹃‘XXL’与蓝果杜鹃的杂交亲和性

利用高山杜鹃优异品种与野生种质进行杂交是培育自主观叶新品种的有效途径。本研究开展以高山杜鹃‘XXL’(Rhododendron’XXL’)为母本,蓝果杜鹃(R. cyanocarpum)为父本进行杂交授粉,用荧光显微镜观察授粉花粉萌发及花粉管的生长过程,调查其子房膨大率和结实率。结果显示,在授粉后1～8 d,蓝果杜鹃的花粉萌发率呈缓慢上升趋势,‘XXL’花粉管在花柱中呈显著伸长趋势,期间无受精情况发生;在授粉后11～17 d,花粉管进入‘XXL’子房并发生受精;在授粉后17 d,其花粉萌发率和受精胚珠数达最大值,分别为(31.67±8.50)%和(13.67±3.79)个。在花粉管生长过程中,在柱头细胞、花粉管、花柱、子房和胚珠等多处出现异常胼胝质沉积反应;其杂交子房膨大率为18.75%,结籽率为零。研究表明,高山杜鹃‘XXL’与蓝果杜鹃的杂交不亲和性明显且可能存在较强的杂交障碍。     

万寿菊花粉活力及柱头可授性研究

为探明造成万寿菊雄性不育系结实率低的原因,对万寿菊花粉活力及柱头可授性进行了研究。采用花粉离体萌发法研究万寿菊自交系V-01花粉萌发适宜温度、花粉活力日变化和适宜贮存条件;用联苯胺-过氧化氢法检测万寿菊雄性不育系S-261、S-17-06-29、S-0191不育株柱头的可授性;水溶性苯胺蓝染色法检测花粉在柱头的萌发情况。结果表明：（1）万寿菊V-01适宜萌发温度介于25~30℃之间;V-01花粉活力日变化趋势为先升高后降低,11-13时采集的花粉萌发率最高;4℃干燥贮存是最适宜的花粉贮存条件。（2）万寿菊柱头形态呈‘γ’状时有可授性,可授性可持续3天。（3）万寿菊花粉授粉到柱头上1 h内即可萌发,授粉后2 h,花粉细胞达到花粉管内。     

小麦花粉管生长途径及受精过程经历时间的研究

应用常规石蜡切片和荧光显微镜技术对小麦花粉管生长途径及受精过程相应时间进行研究。结果表明，授粉后，花粉随即萌发，2个精子进入花粉管，营养核留在花粉粒内，不久解体。花粉管进入羽毛状柱头分支结构的细胞间隙，继续生长于花柱基部至子房顶部的引导组织的细胞间隙内。随后穿过子房壁，在子房壁与外珠被之间的缝隙中向珠孔方向生长。自花粉萌发至花粉管长入珠孔大约需要1 h。自花粉萌发并到达柱头分支结构中，花粉管均具明显的绿色荧光；但在引导组织区以及子房壁与外珠被之间生长的花粉管几乎看不到荧光。授粉后1 h花粉管经珠孔及珠心表皮细胞间隙进入1个助细胞，并释放精子。授粉后2～6 h精卵融合，授粉后16 h合子第一次分裂。授粉后2～3 h精子与极核融合，授粉后4 h初生胚乳核第一次分裂。授粉后2～16 h，即精卵融合至合子分裂前为花粉管通道法转化合适的时间，采用花柱横切滴加法转入外源DNA。     

大花萱草不同品种间杂交亲和性及结实特性研究

本试验以不同品种大花萱草为试材,研究了其品种间的杂交亲和性和结实状况。结果表明：大花萱草自交亲和性很低,杂交亲和性也普遍偏低。在17个杂交组合中,金娃娃与不同品种的杂交坐果率相对较高,其中金娃娃♀?红运♂坐果率最高,为27.9%;其次是黄绣客,红运最低。不同授粉方法对大花萱草杂交亲和性影响效果为：2g/L赤霉素 > 2g/L NaCl >4g/L赤霉素>切割柱头>蕾期授粉>1g/L赤霉素>常规授粉。大花萱草结实率的高低与父本的花粉活力、母本柱头可授性、花粉管萌发生长状态及胚败育等因素相关。     

棉花的花粉

一朵棉花花朵约有近十万个花粉。一个花粉粒为一个单细胞,直径约120微米,肉眼细看能分辨出来。花粉呈球形,表面有细刺,易于附着雌蕊的柱头上,也易于被昆虫粘走。昆虫传送花粉是造成棉花天然杂交的主要原因。当早上花朵开始开放,花药逐渐破裂,成熟花粉随即散出,在二、三小时内花粉萌发率高,柱头接受力也强。授粉后,花粉伸出花粉管,经过     

硼酸、蔗糖和pH值对火龙果花粉离体萌发和花粉管伸长的影响

为明确硼酸、蔗糖和pH值对火龙果花粉离体萌发特性的影响,本研究以新鲜花粉为材料,采用液体培养基离体培养法,结合单因子与正交设计试验,以期优化液体培养基组分。结果表明,蔗糖、硼酸和pH值三因素均对火龙果花粉离体萌发和花粉管伸长产生极显著影响,因素间存在交互作用。其中,对花粉离体萌发率的作用大小表现为硼酸×蔗糖蔗糖蔗糖×pH硼酸硼酸×蔗糖×pHpH硼酸×pH,对花粉管长度影响程度为蔗糖pH硼酸×蔗糖硼酸硼酸×pH蔗糖×pH硼酸×蔗糖×pH。促进花粉萌发的最佳组分为500 mg/L硼酸+25%蔗糖+pH 6.5,促进花粉管伸长的最佳组分为300 mg/L硼酸+20%蔗糖+pH 7.5。本研究为建立最佳火龙果花粉离体萌发的液体培养基配方奠定基础,也为生产中提高辅助授粉效率、加快人工杂交育种进程提供参考。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.