甘薯花粉—柱头乳突细胞间相互作用的细胞学研究

以甘薯鸟吃种和高自一号为亲本进行人工自花授粉;以甘薯鸟吃种和高自一号为母本,河北351为父本进行杂交授粉.观察了花粉在柱头上的行为,柱头乳突细胞表面糖蛋白的定位分布,授粉前后乳突细胞超微结构的变化.结果表明,不育组合首先表现出花粉在柱头上粘附和水合能力很弱,花粉不萌发.能育组合授粉后花粉在柱头上的粘附水合能力很强,多数花粉萌发.但有的花粉管不进入柱头,仅在乳突细胞表面爬行,或提前破裂,释放内容物;以及在花粉管接触的柱头乳突细胞中沉积胼胝质.糖蛋白(钉红着色物质)在能育与不育组合的柱头乳突细胞壁上的分布有明显的差异,作者用细胞化学定位法验证了糖蛋白与自交不育可能存在的相关性.鸟吃种柱头乳突细胞杂交授粉后12h其超微结构明显退化;而自花授粉后3h就已明显退化.柱头乳突细胞退化的早晚可能与所授花粉是否能育相关.     

沙田柚柱头表面结构及花粉管进入柱头细胞的研究

采用光学显微镜、扫描电镜及透射电技术对沙田柚柱头表面结构及其花粉萌发后花粉管进入柱头细胞途径的观察，结果如下：１）沙田柚的柱头突细胞为棒状，柱头表面正中有一大型开口的柱头结构，当柱头发序成熟后分泌出大量的粘液，故属湿型柱头。２）不论自交或异交，沙田柚的花粉落到花柱头上都能萌发，通过柱头乳突细胞间隙进入柱头，且沿着柱头区薄壁细胞间隙进入花柱，其自交不亲和性反应发生在花粉管通过花柱时，故沙田柚自交不亲     

部分野生杜鹃杂交授粉后花粉管生长状况分析

以映山红(Rhododendron simsii)及锦绣杜鹃(Rhododendron pulchrum)为母本,分别与杜鹃属15种杜鹃进行杂交授粉试验,观察授粉后花粉在柱头上萌发与花粉管生长状况,分析杜鹃远缘杂交组合的亲和性.结果显示,所有父本花粉都能在映山红及锦绣杜鹃柱头表面附着并萌发,花粉管生长情况和异常花粉管的比率因父本不同而情况各异.与锦绣杜鹃组合相比,映山红组合花粉管到达花柱底部速度快、数量多,异常花粉管比率低,部分锦绣杜鹃杂交组合,花粉管在花柱中、上部生长受阻,表明映山红组合种间杂交亲和性较高.亲和性较差的杂交组合,花粉管生长易出现扭曲、螺旋、膨大、破裂以及胼胝质过多沉积等现象,但自交与种内杂交组合也存在各种花粉管生长异常状况.结果表明,花粉管异常的类型与杂交亲和性无直接联系,但异常花粉管出现的比率与杂交亲和性相关.     

楸树自交及种内、种间杂交亲和性的细胞学观察

运用荧光显微技术、整体透明法和石蜡切片法,对楸树自交及种内、种间杂交亲和性进行了显微观察.结果表明:无论自交或种内、种间杂交花粉均可在柱头萌发,但萌发时间和萌发率存在显著差异.花粉管在柱头分泌物中生长或穿透乳突细胞沿柱头中部维管束生长,之后进入花柱引导组织胞间隙.大量种内和种间杂交花粉管于授粉后12～24 h迅速生长至花柱基部；48 ～72 h进入子房；96～120 h前后发生双受精,肉眼可见子房发红膨大.自交授粉后约36％的花粉管在柱头和花柱上端终止生长；42％的花粉管于授粉后72～96 h进入子房；直到授粉后120 h花冠脱落为止,少数花粉管能够穿透胚囊,但未见双受精发生,子房无膨大.研究认为:楸树具有自交不亲和性,而种内和种间杂交是亲和的；其不亲和反应发生的最终位置在子房,时间在合子形成前,为合子前晚期自交不亲和类型.     

大白菜的自交和杂交亲和性

大白菜（ＢｒａｓｉｃａｃａｍｐｅｓｔｒｉｓｓｓｐｐｅｋｉｎｅｎｓｉｓＯｌｓｓｏｎ）冠－２９１花期自交授粉后，花粉管在柱头乳突细胞表面盘曲，乳突细胞中出现胼胝质反应。蕾期自交授粉能克服自交不亲和性，但受精作用，胚胎发育较冠－２９１×石－８５１迟缓，单果鲜重及种子数仅为后者的一半。电助授粉未见明显效果。     

自交不亲和甘蓝的花粉萌发与花柱内保护酶活性变化

研究了柱头提取液对自交不亲和甘蓝花粉萌发、花粉管生长以及自花、异花授粉过程中花柱内过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性动态变化.结果表明:自花柱头提取液能显著抑制花粉萌发和花粉管的生长,而异花柱头提取液能提高花粉萌发率和花粉管的生长;授粉过程中花柱内SOD,POD和CAT活性都显著上升,而自花授粉上升幅度明显低于异花授粉.花柱内蛋白质含量在授粉过程中都会上升,但自花授粉在授粉后最初3～5min出现一个含量峰值.     

鼠尾草属植物杂交亲和性探究

为研究鼠尾草(Salvia)不同品种间杂交亲和性,选取3种7个品种的鼠尾草作为试验材料,检测花粉活力及柱头可授性强弱,进而通过荧光观察杂交后花粉萌发和花粉管生长情况.结果表明,鼠尾草的花粉活力及柱头可授性均在开花后1～2 d内达到最大;不同种间相互授粉杂交亲和性普遍低于种内杂交,正反交结果也存在差异,出现萌发缓慢、花粉管畸形生长等现象,只有少量的花粉管进入花柱基部使子房膨大;种内杂交比种间杂交更容易得到有胚种子.为了更好地完成杂交育种工作,需选择正确的杂交亲本,在适宜时期进行人工授粉,能够有效提高杂交成功率.     

烟草花粉与雌蕊互作调控机制研究进展

授粉是植物生活史周期中的一个重要过程.茄科植物属于湿柱头,实心花柱.成功授粉起始于花粉粘附在成熟的柱头表面,接着水合、萌发,花粉管穿过柱头后沿着花柱传导组织细胞间隙朝着胚囊的方向生长,经过助细胞后释放精子完成双受精.在这个过程中,花粉外壁决定因子与花粉管生长通道中的各种成分相互作用,激活花粉管细胞内部的一系列生理生化反应.存在于烟草柱头、花柱传导组织细胞、子房和助细胞中的各种分泌物对于花粉细胞粘附、花粉管生长营养供给、信号传导、方向引导具有重要作用;另外,某些花粉决定因子与雌蕊成分的相互作用也可能导致自交不亲和与杂交不亲和.文章总结了烟草授粉后花粉与雌蕊相互作用涉及的物质及机理,这些物质主要包括蛋白质、多糖、脂类、激素、酶类和黄酮类等.     

慈姑雌花在自然居群中的受粉过程：花粉粒落置,萌芽？…

用荧光显微术观察了慈姑不同时期的雌花柱头上花粉粒的落置１、萌发及花粉管的生长过程与途径。结果表明：该种雌花开花２ｈ柱头受粉率为０，开花４ｈ和８ｈ受偻率分别为５３．８％和９８．３％，柱头上花粉萌发这１００％；花粉管沿雌蕊之向心一侧的组织中穿行至子房基部后部分花粉管转向胚球，由珠孔进入珠心。本研究发现 花粉管常过子房基部至花托组织，并可进入其他蕊中，作者认为这种行为可能对保证雌花的结实率有一定意义。     

苜蓿雄性不育系花柱与柱头形态结构观察研究

对草原1号杂花苜蓿雄性不育系与可育系的花柱与柱头形态结构进行了对比观察研究，结果表明。苜蓿雄性不育系的花柱与柱头的形态结构与可育系有很大差别，不育系花柱细，柱头小且下陷，柱头的毛状体细胞相对少并紧包乳突状细胞，分泌物少．这些形态特征影响着苜蓿雄性不育系受粉和受精，是导致杂交制种结实率低的原因之一。     

Primary measurement of pollen flow inLiriodendron chinense using RAPD markers

Techniques of tracking movements of pollen grains are essential for many topics in pollination biology. Pollen transfer ofLiriodendron chinense (Hemsl.) Sarg., a hermaphroditic plant, may be both interfloral and intrafloral pollination. Observations on pollinator movements and flower emasculated experiments in natural populations showed that most of pollen grains deposited on stigmas in a flower are foreign. But it is not certain whether cross pollination or long distance pollen transfer occurs in this insect-pollinated plant. The authors attempt to use random amplified polymorphic DNA (RAPD) loci for paternity analysis to mark pollen dispersal. The results indicated pollen via gene transportation reached at least 100 m away from the pollen source in a selected population. The primary study suggests a larger effective population size in this endangered plant. With its rapid and simple characters, RAPD methods can be a suitable technique for marking pollen flow and able to be widely used in various taxa.     

慈姑雌花在自然居群中的受粉过程--花粉粒落置、萌芽及花粉管生长的荧光显微观察

用荧光显微术观察了慈姑（Ｓａｇｉｔｔａｒｉａ ｔｒｉｆｏｌｉａ Ｌｉｎｎ）不同时期的雌花柱头上花粉粒的落置、萌发及花粉管的生长过程与途径。结果表明：该种雌花开花２ｈ 柱头受粉率为０,开花４ｈ 和８ｈ受粉率分别为５３８％ 和９８３％ ,柱头上花粉萌发率达１００％ ;花粉管沿雌蕊之向心一侧的组织中穿行,至子房基部后部分花粉管转向胚珠,由珠孔进入珠心。本研究发现该种花粉管常穿过子房基部至花托组织,并可进入其他雌蕊中,作者认为这种行为可能对保证雌花的结实率有一定意义     

不同授粉方式对祝光苹果受精过程的影响

祝光苹果自花授粉后2小时,花粉粒在柱头上萌发。授粉当日和次日,花粉管在花柱中生长。授粉后第三日,花粉管停止生长,最长花粉管平均长至花柱全长的26％。此时,花粉管先端明显膨大。而后,未见到有抵达花柱基部的花粉管,也未见到受精过程的发生。 异花授粉后4—6小时,大量花粉粒在柱头上萌发。授粉后1—2日,花粉管径直向花柱基部生长。授粉后50小时,花粉管穿过花柱基部,进入子室内。授粉后3—4日,观察到进入胚囊的花粉管将内含物释放到一个已退化的助细胞中。授粉后5—6日,观察到双受精过程。     

Gene flow from genetically modified herbicide-resistant rapeseed to cruciferous weeds

The sexual compatibility between genetically modified (GM) glyphosate-resistant rapeseed variety Q3 (Brassica napus L.) and 5 cruciferous weeds is studied through the observation of fluorescence microscopy and cross-fertility after manual pollination. The results indicated that Q3 (as male) was highly incompatible with Thlaspi arvense L., Capsella bursa?pastoris (L.) Medic, Cardamine hirsuta L. and Rorippa palustris (L.) Besser (as female). Fluorescence microscopic observation showed that growing of pollen tubes terminated on the stigma surface or at the upper 1/3 part of the style. However, B. juncea×Q3 was compatible, and the compatibility index was 1.65. Under the neighboring growth and natural pollination conditions, the rates of gene flow from Q3 to T. arvense, C. bursa-pastoris, C. hirsute and R. palustris were all 0, while it was 0.86% for B. juncea. These results indicate that there is difference in the rate of gene flow between GM rapeseed and cruciferous wild weeds, and frequency of gene flow is highly correlated with sexual compatibility.     

Cytogenetics of intergeneric hybrids between Brassica species and Orychophragmus violaceus

In the sexual intergeneric hybrids between the cultivated Brassica species and Orychophragmus violaceus, both complete separation and partial separation of the parental genomes were found to occur during mitosis and meiosis under genetic control. The cytogenetics of these hybrids was species-specific for Brassica parents. The different chromosome behavior of hybrids with three Brassica diploids ( B. campestris , B. nigra and B. oleracea ) might contribute to the different cytogenetics of hybrids with three tetraploids ( B. napus, B. juncea and B. carinata). Owing to the parental genome separation, Brassica homozygous plants and aneuploids with various chromosome constitutions were identifiable in the progenies of these hybrids, which were valuable for the study of the structure and evolution of Brassica genome and for the breeding of Brassica crops.     

Assessment on alien herbicide-resistant gene flow among crucifers by sexual compatibility

Cross-pollination and high cross-compatibility are frequently found in many cruciferous plants, which implies that there might be potential risk of alien gene flow among crucifers. In this work, the alien glyphosate-resistant gene flow between GM （Genetically modified） rapeseed variety Q3 （Brassica napus） and 6 varieties from 5 cruciferous species was assessed by sexual compatibility through aniline blue fluorescence observation, manual cross, mentor pollination with the mixture pollen and DNA identification. The results indicated that the compatibility indices of two B. napus varieties, B. juncea vat. multiceps Tsen et Lee and Chinese cabbage （B. chinensis） （as female） with Q3 （as male） were 16.15, 12.77, 2.345 and 0.85, respectively. FI plants were examined by PCR and all of these samples were confirmed as positive. Crossing between Orychophragmus violaceus, Descurainia sophia （as female） and Q3 （as male） expressed high cross-incompatibility. Fluorescence microscope observation indicated that growing of pollen tube terminated at the upper 1/3 part of the style of O. violaceus and on the stigma surface of D. sophia. The mentor plants were further analyzed by PCR and all were shown to be negative. Under the neighboring growth and natural pollination conditions, the rates of gene flow to two B. napus varieties were 2.3278% and 2.1487%, respectively, B. juncea var. multiceps Tsen et Lee and Chinese cabbage were 1.0157% and 0.9236%, respectively. No gene flow was observed in O. violaceus and D. sophia. Frequency of gene flow was highly correlated with sexual compatibility. Due to possible alien gene flow among crucifers, special consideration and care should be taken to grow GM rapeseed.     

美洲黑杨无性系Ⅰ-63花粉粒的发育和超微结构

<正> 美洲黑杨Ⅰ-63〔Populus deltoides Bartr.var.deltoides cv.“Harvard”(Ⅰ-63/51)〕自引种以来,生长良好,已经作为一种基因资源应用于新无性系的培育工作。Nagaraj在1952年曾对PopuluS deltoides的小孢子发生和花粉形态进行过研究,但选育为无性系并引种至我国的同纬度地区后,其小孢子的发育过程是否发生变化,选育应用时应注意哪些问题,却研究甚少。近年来,学者们对花粉超微结构做了大量工作,可惜至今还局限于少数植物,特别是草本植物。这里,我们试对美洲黑杨Ⅰ-63的小孢子发生、花粉发育和结构用光学显微镜进行了观察研究,并在此基础上观察了二细胞花粉粒的超微结构,希冀为这方面提供一些有益的资料。     

矮慈姑人工授粉后花粉管生长的荧光显微观察

用荧光显微术观察了矮慈姑人工授粉后雌蕊上花粉粒萌发及花粉管的生长过程与途径,结果表明：该种在授粉０．５ｈ后花粉粒全部萌发出花粉管,花粉管在授粉２ｈ后部分到达子房,４ｈ仙进入胚珠;花粉管在雌蕊之向心一侧的组织中行进,至子房基部后部分花部管转向胚珠,由珠孔进入珠心。