甘蔗开花生物学特性及花粉活力研究

在温室内观察甘蔗开花动态,用TTC法测定甘蔗花粉活力,联苯胺-过氧化氢法测定柱头可授性。结果表明：花穗上小蠡花开放顺序,一般是自上而下,由外至内;ROC22和科五花粉活力于开花第1 天达到80%以上,第2 天有小幅度上升,之后迅速降低,第7 天仅采到少许花粉,但活力仍在32%左右。甘蔗雌蕊柱头开花前1天具有可授性,自交授粉后的1～2 d内保持强可授性,之后柱头迅速变黑枯萎;未授粉柱头花开后的9 d内一直保持靓丽的艳红色,具强可授性。柱头可授性的最佳时期为开花后第1～9 天,甘蔗的最佳授粉期为母本开花2 d后再授以父本花粉,4 d内即可完成杂交过程。     

3种果壳类型油棕花粉活力及柱头可授性的比较

采用花粉离体萌发法测定3种不同果壳类型油棕花粉在散粉后不同天数和一天内不同时间点的花粉活力,联苯胺-过氧化氢法测定不同花期及一天内不同时间点的柱头可授性。结果表明:3种类型油棕的花粉活力呈现先升高后下降的趋势,在散粉第1 d即具有活力,薄壳种、厚壳种和无壳种的花粉活力分别在散粉后第2、3、4 d达到最大值,随后下降;日变化特点:在同一开放状态下,除12:00和18:00时,3种类型油棕的花粉活力排序为:薄壳种>厚壳种>无壳种。柱头可授性的变化特点为:雌花开放的早期,具有较弱的柱头可授性,薄壳种和无壳种在第Ⅲ期可授性最强,第Ⅳ期开始减弱,厚壳种则是在第Ⅳ期达最强,柱头的可授性日变化排序为:8:00~10:00,无壳种>薄壳种>厚壳种,12:00~18:00则是厚壳种>薄壳种>无壳种。综上可知,3种果壳类型油棕的花粉应于散粉后的第2~4 d采集;无壳种和薄壳种的雌花在开花后第Ⅲ期的10:00授粉效果最佳,厚壳种则是开花后第Ⅳ期的16:00授粉效果最佳。      

防风花粉活力测定方法的比较及柱头可授性的研究

研究并确定防风花粉生活力及柱头可授性的快速有效测定方法。使用I2-KI、TCC、亚甲基蓝及无机盐培养法测定花粉活力。用联苯胺-过氧化氢法测定柱头可授性。亚甲基蓝染色法最适于检测花粉活力,结果与无机盐观测法符合度高。防风刚开花时花粉活力不高,开花后第三天花粉活力最高,可达96%,第五天花粉活力开始下降,且下降幅度较大。防风开花2d后柱头分泌黏液,第3d分泌量最大,但此时柱头不具有可授性。待花药脱落后,柱头可授性逐渐增强,第6-8d达到最大值。亚甲基蓝染色法简便、快捷,适于防风花粉活力的观测。花药脱落后第6-8d柱头可授性最强。     

多花指甲兰花粉活力及柱头可授性研究

花粉和柱头特性的研究是兰花杂交育种的重要基础。本研究以多花指甲兰（Aerides rosea）为实验材料,利用扫描电子显微镜观察多花指甲不同开花时期的花粉微观形态用TTC（氯化三苯基四氮唑）、I2-KI和醋酸洋红染液并结合花粉离体培养检测不同开花时期的花粉活力,利用联苯胺-过氧化氢法测定柱头的可授性。结果表明, 多花指甲兰花粉随着开花时间的延长,花粉表面颜色变深,质地更硬,花粉粒结合更加紧密,花粉团体积变小,表面变得更加平滑致密。 多花指甲兰花蕾期花粉染色为粉红色,盛花期的花粉染色最明显,染色率最高,而衰败期的花粉几乎无法被染色,在整个开花过程中,花粉活力呈先上升后下降的趋势。柱头可授性的结果显示,盛花期柱头气泡最多最迅速,可授性最强。该研究结果为多花指甲兰的引种栽培、迁地保护提供理论基础,在花卉资源利用和产业发展上具有重要指导意义。     

龙眼2个品种花部特征比较研究

研究龙眼石硖和储良2个品种的花部形态、开花生物学特性、花粉形态特征及萌发率、花粉量、P/O值、柱头可授性及其黏液分泌情况。结果显示，二者花部特征相似，储良花期较石硖长；二者的花粉形态相似，储良的花粉较石硖稍大，萌发率较石硖高；P/O值说明龙眼为专性异交植物；石硖和储良花粉活力和柱头可授性是同步变化的，尤其在盛花期花粉活力趋于最大，柱头分泌黏液与柱头可授性变化也一致，都在柱头展开成水平，开花约48 h达到最大。     

杏李新品种‘风味玫瑰’生殖特性的初步研究

为了探究‘风味玫瑰’自然结果率偏低的原因,运用花部形态、花粉活力及柱头可授性测定、花粉-胚珠比(P/O)以及人工授粉试验相结合的方法,对‘风味玫瑰’生殖特性进行了初步研究.研究表明:(1)‘风味玫瑰’的花有两种类型,一种花柱高于雄蕊,另一种花柱萎缩,很短；(2)花粉活力持续3d,柱头可授性持续5d,主要访花昆虫为蜂类；(3)平均单花花粉量/单花胚珠数(P/O)值为(605.7±25.1)；(4)人工异花授粉坐果率最高可达30.19％,自花授粉坐果率为7.8％,明显比异花授粉坐果率低,表明‘风味玫瑰’交配系统类型是兼性异交、需要传粉者.研究结果认为,传粉效率低是其自然结果率低的重要原因.     

棉花胚胎学基础知识(四) 第四章 棉花花粉、胚胎、幼胚和花药的人工培养

一、花粉的人工培养1.花粉的培养利用。棉花花粉的自然萌发,是指开花后花药开裂,花粉散落在柱头上的萌发,这在第三章已经谈到。一般在正常开花的情况下,若不遇雨、高温或低温等异常条件,花粉散落到柱头后便可很快萌发,长出花粉管,棉花的花粉也可进行人工培养萌发。花粉经过贮藏保存以后,或者为了杂交的需要进行远距离运送后,需检定花     

水稻光温敏核不育系‘亮S’异交特性研究

为合理利用两系新不育系‘亮S’,以‘750S’为对照,探究了‘亮S’的抽穗历期、开花习性、柱头活力、张颖历期和张颖角度等。结果表明,‘亮S’抽穗历时8 d;见穗第2天始花,历时10 d,第5~8天为盛花期,盛花期开花数占开花总数的75.96%,花期集中,盛花期较盛穗期迟3 d;日开花高峰期在9:00~11:30,午前开花率为86.48%;柱头外露率为88.46%,柱头活力强,开花当天最高,为56.82%;张颖历时90~390 min,平均张颖角度33°2';大面积制种‘亮S’赤霉素用量225 g/hm2较适宜。     

观果玫瑰花粉活力及柱头可授性研究

[目的]探讨观果玫瑰花粉活力和柱头可授性变化规律,为观果玫瑰的有性繁殖和人工杂交育种提供理论依据。[方法]采用醋酸洋红染色法测定花粉活力,用联苯胺—过氧化氢法测定柱头可授性。[结果]同一品种的花粉活力在花朵开放后4天内差异明显,12个品种花后1天花粉活力最高,其中8个品种在花朵露色时即表现有活力,不同品种间的花粉活力差异表现明显。[结论]观果玫瑰人工授粉最佳时期为开花后1至3天,且选作母本材料需在花朵露色时即去除雄蕊;     

杂交棉新陆早43号亲本花粉及柱头生活力的研究

以新陆早43号的2个亲本为试验材料,在9:00—20:00的10个时间段,分别给母本柱头授以自然花粉和冰箱保存花粉。结果表明,在新疆自然条件下,棉花盛花期柱头的生活力为1.5d(开花当天及开花第2天上午)。开花当天柱头生活力较高,呈"不对称双峰"特征,11:00-12:00及16:00-17:00为柱头活力旺盛时段。棉花花粉生活力可维持1d,以9:00-10:00生活力较强,随时间推移,花粉活力逐渐下降,下午丧失生活力。     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

先玉335、郑单958和京科968抗虫能力的比较研究

以先玉335、郑单958、京科968为材料,以玉米螟(Ostrinia furnacalis)、黏虫(Mythimna separata)和禾谷缢管蚜(Rhopalosiphum padi)为供试昆虫,探究玉米品系大喇叭口期对玉米螟和黏虫及抽雄期对禾谷缢管蚜抗性差异,测定其主要抗虫化合物丁布类物质的含量。结果发现,京科968对玉米螟及禾谷缢管蚜抗性均高于另外两个品系;对黏虫的抗性,郑单958和京科968高于先玉335。大喇叭口期京科968中丁布类物质含量最高,抽雄期郑单958和京科968中主要丁布成分含量均高于先玉335,上述组织中丁布合成相关基因在郑单958及京科968中的表达量也均高于先玉335。本研究揭示杂交玉米抗虫性与抗性相关化合物含量及其相关基因表达间存在正向相关关系,为抗虫玉米分子育种提供理论参考。     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Effect of a continuous hot water treatment of potato tubers on seed-borne fungal pathogens

Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive. Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk. Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d.     

Evaluation of fungicides to control Petri disease pathogens in the grapevine propagation process

The efficacy of fourteen selected fungicides against Phaeomoniella chlamydospora and Phaeoacremonium aleophilum was evaluated in vitro by mycelial growth and conidial germination assays. Azoxystrobin, carbendazim and tebuconazole were the most effective fungicides against P. chlamydospora, while carbendazim and didecyldimethylammonium chloride were the most effective against P. aleophilum. An assay was also conducted with cubiet, hydroxyquinoline sulphate and didecyldimethylammonium chloride to determine their potential to prevent infections caused by these pathogens during the hydration stage in grapevine propagation. The results of this experiment demonstrated that P. chlamydospora and P. aleophilum were able to infect healthy cuttings during the hydration stage and showed that didecyldimethylammonium chloride was consistently the best treatment as a disinfectant soak for grapevine cuttings. Additionally, semi-commercial trials were conducted in two grapevine nurseries to evaluate the effectiveness of several strategies with carbendazim, flusilazole and hydroxyquinoline sulphate at different nursery stages. Soaking planting material in carbendazim during the hydration stage was the most effective treatment since neither P. chlamydospora nor P. aleophilum were isolated from planting material in either nursery.     

Screening for resistance to early blight (Alternaria solani) in potato (Solanum tuberosum L.) using toxic metabolites produced by the fungus

Summary The phytotoxic components of the culture filtrate of the fungusAlternaria solani Sor, which causes early blight in potato, were used in this study to differentiate between resistant and susceptible genotypes selected to represent a range of reactions when screened in the field. Detached leaflet assays, using spores and toxic metabolites from the culture filtrate, were compared with field ratings and a whole-plant glasshouse test. Rank correlations between several detached leaflet tests were highly significant (P<0.01) but the correlations between these tests and the glasshouse and field tests were poor. The disease ratings obtained in the various tests were clustered into four groups and assigned to resistance classes. For many of the genotypes there was a good correspondence between resistance classes for all test methods. Divergent results between tests were associated with foliage maturity characteristics of the genotypes. Contribution no. 3879050 of the Lethbridge Research Station.     

B9601-Y2溶磷解钾固氮能力及促玉米生长效果研究

为了明确淀粉芽孢杆菌B9601-Y2(Y2)的促生长机制,通过摇瓶培养,检测其溶磷解钾固氮活性;通过盆栽试验,探索Y2对玉米生长量和溶磷解钾量的影响。结果表明,在第7天时,Y2固氮量为2.9 mg/L,解钾量为13.5μg/mL;在第4天时,溶磷量达732μg/mL。与空白对照相比,Y2发酵液能增加玉米株高28.29%,根长27.21%,叶宽18.56%,鲜重80.93%,干重66.67%;提高土壤中速效氮、速效磷和速效钾含量分别为20.42%、111.01%和17.24%,提高植株氮、磷、钾含量45.46%、120.17%、68.45%。研究结果表明,Y2活化土壤中难溶性磷、钾和具有固氮能力,并能促进植株对氮、磷、钾营养的吸收利用。     

Evaluation of diploid potato clones for resistance to tuber soft rot induced by strains ofErwinia carotovora subsp.atroseptica,E. carotovora subsp.carotovora andE. chrysanthemi

Summary Tubers of clones from a diploid hybrid population ofSolanum phureja andS. stenotomum were screened for resistance to tuber soft rot caused by strains ofErwinia carotovora subsp.atroseptica (Eca),E. carotovora subsp.carotovora (Ecc) andE. chrysanthemi (Ech). Significant, positive correlations between resistance to the different strains and species were observed, indicating that screening for resistance to tuber soft rot could be accomplished by using just one of the three pathogens. Strains of Ecc and Ech were found to be much more virulent than strains of Eca. Inoculating with Ecc and Ech resulted in more distinct differences among susceptible, moderately resistant and resistant clones than inoculating with Eca.