甘蓝自交不亲和系柱头和花粉粒不亲 和互作的电镜扫描研究

扫描电镜观察到甘蓝(Brassica oleracea L.)自交不亲和系02-E1柱头上不能萌发的花粉在授粉后18小时内就会萎缩变小直至干瘪。能够萌发的花粉从一个萌发沟萌发后，另外两个萌发沟就自动萎缩，其花粉管有的扭曲不能伸入乳突细胞，仅少量花粉管能伸长进入花柱。经过5%NaCl溶液处理后的甘蓝自交不亲和系的柱头表膜乳突细胞或皱缩或破裂，花粉粒很容易萌发并长出花粉管，然后花粉管穿破乳突细胞壁而伸入花柱完成受精作用。     

甘薯与低倍体种间杂种杂交低结实性的克服

通过观察花粉萌发、 花粉管生长、 受精、 胚发育等过程, 发现甘薯与低倍体(3 x, 5 x)种间杂种杂交低结实性的原因： 一是花粉附着量少、 花粉萌发量少、 花粉管生长缓慢导致子房受精不足, 使子房出现第一次大量脱落; 二是胚发育异常导致子房出现第二次大量脱落。 这种胚发育异常对甘薯×5 x杂种来说是受精卵发育缓慢; 对     

阔叶杨桐花粉离体萌发和花粉管生长特性的研究

研究了不同浓度的蔗糖和硼酸,在不同温度和培养时间内对阔叶杨桐花粉萌发率和花粉管生长的影响,以期为阔叶杨桐的繁殖育种研究提供依据.结果表明:1)不同浓度的蔗糖和硼酸处理组之间存在显著性差异,蔗糖和硼酸都能促进杨桐花粉萌发和花粉管的生长,但超过一定浓度则会起到抑制作用;2)随着培养温度的升高,花粉萌发率和花粉管长度呈先升后降的趋势;3)随着培养时间的延长,花粉萌发率和花粉管长度逐渐增加,但最初的前12h内花粉萌发快,在培养的前9h内花粉管生长较快.4)实验显示:阔叶杨桐花粉培养的最适培养基是15％蔗糖和0.02％硼酸,最适培养温度为25℃,培养24 h后花粉萌发率为84.32％,花粉管长达2 003.51 μm.     

石竹种间杂交障碍研究

研究栽培种香石竹与野生种瞿麦种间杂交障碍,为获得抗逆性好且花色花型独特的种间杂交新品种奠定基础。以瞿麦为父本,春之歌、四季红和Promesa为母本进行种间杂交,统计其膨大率和结实率;并采用压片法对亲本的染色体倍性进行测定;利用荧光显微镜观察石竹种间杂交花粉萌发情况、花粉管伸长及受精情况,探讨种间杂交不亲合性的原因。3个种间杂交组合的杂交结实率为0,揭示石竹种间杂交存在杂交障碍。染色体倍性鉴定发现,瞿麦为二倍体(2n=2x=30),春之歌为二倍体(2n=2x=30)、四季红为三倍体(2n=3x=45)、香石竹栽培品种Promesa为二倍体(2n=2x=30);花粉活力测定发现瞿麦花粉活力高,为92.8%,且显微镜观察表明花粉能在柱头上萌发,花粉管能伸入柱头及子房并与胚珠结合,但胚珠与花粉管结合率低。胚珠与花粉管结合率低可能是影响石竹种间杂交障碍的因素之一。结果揭示石竹种间杂交障碍的原因,为石竹杂交育种提供理论依据。     

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。     

美国梾木(Cornus spp.)花粉活力及萌发特性

为了了解美国梾木花粉活力及萌发特性,采用扫描电镜技术对13个美国梾木无性系花粉形态进行观测与方差分析,并采用荧光显微技术和TTC染色法对无性系2号花粉萌发特性及花粉活力进行观察。结果显示:(1)不同无性系间花粉大小差异不显著,但外壁纹饰差异较大,极面沟距的变异系数最高且遗传最为稳定。(2)花序开花率为75%时花粉活力最高,整花4℃条件下短期保存花粉活力较高。(3)授粉后,多数花粉可在柱头上正常萌发,72 h后花粉管即可进入子房。研究认为,花粉外壁及极面沟距可作为鉴定美国梾木无性系的形态指标,美国梾木花粉活力及萌发特性是抗逆及丰产杂交组合的重要保证。     

植物生长调节物质对黄金梨花粉萌发和花粉管生长的影响

目的:研究不同质量浓度的6-BA、NAA、2,4-D、多效唑等4种植物生长调节物质对黄金梨花粉萌发和花粉管生长的影响。方法:配制含有不同浓度的生长调节物质的花粉液体培养基,对采集的黄金梨花粉进行培养,研究不同浓度植物生长调节物质对花粉萌发和花粉管生长的影响。结果:在所使用的植物生长调节物质的浓度范围内:(1)较低浓度的6-BA和2,4-D能促进花粉萌发和花粉管生长,但超过一定浓度时起抑制作用;(2)NAA和多效唑均对花粉萌发和花粉管的生长表现出抑制作用。结论:6-BA和2,4-D促进黄金梨花粉萌发与花粉管生长的最适宜浓度分别为10mg/L和5mg/L。     

美蔷薇花粉离体萌发条件及贮藏特性研究

以美蔷薇花粉为试验材料,研究不同营养组分配比对花粉萌发及不同贮藏条件对花粉活力的影响。结果表明,蔗糖、H_3BO_3、CaCl_2、MgSO_4·7 H_2O、KNO_3等5因子均对美蔷薇花粉萌发率及花粉管伸长有显著影响;美蔷薇花粉最佳萌发培养基为100 g·L~(-1)蔗糖+0.1 g·L~(-1) H_3BO_3+0.3 g·L~(-1) MgSO_4·7 H_2O+0.2 g·L~(-1) KNO_3,萌发率可达40.26%,花粉管平均长度为166.77μm。贮藏过程中,干燥剂(无水氯化钙或硅胶)不能显著延缓花粉活力的降低。不同温度贮藏的花粉寿命不同,贮藏360 d时,4℃冷藏花粉萌发率为0,-20℃冷冻花粉萌发率为19.88%,-20℃更利于花粉长期保存。将不添加干燥剂于-20℃贮藏330 d的美蔷薇花粉用于月季杂交育种,结实率超过50%,验证了该条件下贮藏一年左右的美蔷薇花粉具有活力,可应用于月季杂交育种。     

果梅花粉离体萌发及花粉管生长影响因子的研究

研究了果梅 (PrunusmumeSieb etZucc)花粉在不同温度、湿度条件下贮藏后以及在不同培养基组分、pH值和湿度条件下花粉萌发和花粉管生长特性。结果表明 ,花粉萌发及花粉管生长最适宜的液体培养基为 10 %蔗糖 ,0 0 1%硼酸 ,15 %PEG - 40 0 0 ,0 0 7?(NO3 ) 2 ·4H2 O ,0 0 2 %MgSO4·7H2 O ,pH值以 6 0～ 6 5为宜 ;在该培养基上果梅花粉萌发率为 6 2 % ,花粉管生长长度为 4 2 9μm。适宜于花粉萌发和花粉管生长的空气相对湿度约为 80 %。随着贮藏时间的延长 ,花粉活力逐渐下降 ,但下降的速度因贮藏温度及湿度不同而异 ,如在 2 5℃条件下贮藏 1个月的花粉就已完全丧失萌芽力 ,在 5℃条件下贮藏 1个月的花粉的萌芽率仍有 2 0 % ,而在 - 2 0℃条件下贮藏 2个月后 ,其萌发率也几乎不降低 ,此外 ,贮藏空间的相对湿度越小 ,越有利于花粉的长期贮藏。     

玉米与摩擦禾、薏苡的杂交不亲和性

采用荧光显微技术, 对摩擦禾、薏苡花粉在玉米柱头上的萌发和生长过程进行了观察。摩擦禾花粉粒在玉米柱头上均能萌发, 花粉管在柱头中伸长并到达花柱基部, 且可将雄配子送入胚囊内, 玉米果穗顶端有受精结实痕迹, 说明摩擦禾与玉米的杂交障碍不是杂交不亲和, 而是胚囊不亲和或杂种衰亡。薏苡花粉粒在玉米柱头也能萌发, 花粉管能伸入花柱, 但玉米与薏苡杂交生殖隔离较摩擦禾严格, 杂交极其困难, 杂交障碍为胚囊不亲和或花柱不亲和。玉米与薏苡杂交时, 薏米花粉管能到达玉米花柱基部, 而川谷花粉管却在花柱中停止生长, 杂交障碍与薏苡种类有关。玉米与薏苡杂交的花粉管异常率高于玉米与摩擦禾杂交花粉管异常率, 反映了玉米与摩擦禾的亲缘关系较与薏苡近。     

甘蓝型油菜与近缘种、属杂交时花粉-雌蕊相互作用的研究

甘蓝型油菜作母本与白菜、甘蓝、黑芥、芥菜型油菜和埃塞俄比亚芥杂交时,花粉粘合程度减弱。花粉管常常不能穿入柱头,与花粉管接触的柱头乳突细胞内普遍产生胼胝质。少数异源花粉管能穿过柱头进入花柱,但时有异常胼胝质沉积在花粉管中。海甘蓝的花粉很难粘合在甘蓝型油菜柱头上。异种花粉与甘蓝型油菜雌蕊的亲和性按大小依次     

The progamic phase in Cichorium intybus L. Pollen tube growth in the style,incompatibility reaction and gametophytic competition

Summary Pollen germination and tube growth were studied following compatible, incompatible and pseudo-compatible pollinations in chicory. Pollen germination begins 3 minutes after compatible pollinations. The earliest pollen tubes reach the ovary 17 minutes later. Many of the later germinating pollen tubes are arrested and burst at the stigma papillae. In the transmitting tissue inhibitional effects due to negative interactions between pollen tubes are frequently observed. Complete self-incompatibility results in total inhibition of germination. In case of pseudo-self-compatibility, some pollen germinate but germination and stigma penetration are delayed and often result in pollen bursting. There is no self-incompatibility reaction in the transmitting tract but if the pollen tubes reaching this tissue are relatively numerous, negative interactions between them occur as after compatible pollinations. An hypothesis is presented which attributes the negative interactions between pollen tubes to the diffusion of a substance from the growing pollen tubes. This substance would also provoke pollen bursting on the stigma.     

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。     

Self-incompatibility in Spanish clones of apricot (Prunus armeniaca L.) tree

The present study is about some aspects of the reproduction physiology of twenty apricot clones ( Prunus armeniaca L.) grown in Abarán (Murcia, Spain). Self incompatibility of these clones was determined not only in field conditions in terms of the fruit set by means of self fertilization and free pollination, but also in laboratory conditions, by means of fluorescence microscopy of pollen germination on the stigma and of the growth of the pollen tube towards the egg. The only clone with signs of self incompatibility was ‘Moniquí Azaraque’. The clone with the lowest fertilization time was ‘Chicanos Archena’. This revised version was published online in July 2006 with corrections to the Cover Date.     

Prezygotic interspecific hybridization barriers between kenaf (Hibiscus cannabinus L.) and four wild relatives

Use of interspecific hybridization in genetic improvement of kenaf (Hibiscus cannabinus), a multipurpose crop, is limited by low cross‐compatibility. Previous hybridization studies suggest that part of incompatibility barrier is prezygotic. Pollen germination, stigma receptivity and growth of alien pollen on kenaf pistil were studied using wild relatives of kenaf. Four wild and semi‐domesticated species, H. surattensis, H. acetosella, H. radiatus and H. vitifolius, were used as pollen donors in the present experiment. H. radiatus exhibited highest pollen germination (65.89%) on H. cannabinus stigma. For closely related species (H. surattensis, H. acetosella, H. radiatus), stylar incompatibility was noticed, while for distantly related species H. vitifolius, the incompatibility was stigmatic. Number of pollen tubes entering ovule of H. cannabinus pistil was higher for H. radiatus (1.30). Alien pollen growth and penetration of pollen tube through ovule were higher in species sharing same genome of H. cannabinus. High callose deposition was observed in incompatible crosses, suggesting a general mechanism for prezygotic incompatibility in Hibiscus section Furcaria. Callose deposition in incompatible crosses increased with time.     

小麦×羊草远缘杂交的受精和胚胎发育

对小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｎＬ）和羊草（ＬｅｙｍｕｓｃｈｉｎｅｎｓｉｓＴ．）杂交的受精和胚胎发育进行了研究。羊草花粉在小麦柱头上萌发较好，花粉管能顺利穿过柱头，进入胚囊。在检查过的３１０个子房中，１７个（５．５％）发生了双受精，产生了胚和胚乳；２个（０．６５％）发生了单卵受精，只产生胚而无胚乳；７个（２．２６％）发生了单极核受精，只产生胚乳而无胚。小麦×羊草虽然受精率为８．４１％，但最后结实率很低，若利用胚培养技术对杂种胚进行早期离体培养，可望提高杂种植株的获得率     

Association between sporophytic reaction to Alternaria helianthi and gametophytic tolerance to pathogen culture filtrate in sunflower (Helianthus annuus L.)

Seven sunflower genotypes comprising of populations and hybrids showing differential sporophytic reaction to Alternaria leaf and stem blight were studied for their gametophytic reaction to pathogen culture filtrate. The sunflower pollen grains germinate well in the liquid medium and give good pollen tube growth in the absence of the culture filtrate. The addition of increasing concentrations of culture filtrate to medium significantly reduced the pollen germination and tube growth in all the genotypes. The reduction in pollen germination and tube growth in vitro due to culture filtrate was more in highly susceptible genotypes L-101 and Morden than the moderately resistant genotypes Acc. nos. 1229, 180 and ISFH-306. Pretreating the stigma and style with the culture filtrate before pollination reduced the number of pollen grains germinating compared to untreated control suggesting toxin stress can be created on the stigmatic surface before pollination. There was correspondence between pollen germination on stressed stigma (in vitro) and sporophytic reaction of the genotype suggesting pollen grain having resistance would germinate on the stressed stigma and fertilise the ovule achieving selective fertilisation. The correlation analysis indicated that there is a negative relation between sporophytic per cent disease index value and gametophytic parameters such as in vitro and in vivo pollen germination, culture filtrate required to inhibit 50% pollen germination and pollen tube growth. The association between pollen and the sporophytic reaction to the disease indicate the possibility of rapid screening of a large number of genotypes by means of pollen assay as an alternate technique with regard to sporophytic disease index in sunflower. The study also indicate the possibility of pollen selection before fertilisation to achieve rapid improvement in disease resistance. This revised version was published online in August 2006 with corrections to the Cover Date.     

The ovular incompatibility system in Gasteria verrucosa (Mill.) H. Duval

Summary The nature and process of ovular incompatibility in Gasteria verrucosa was studied. Using different crossing programs and following the pollen germination and ovule penetration histochemically, an ovular gametophitic incompatibility system based on two or more loci is affirmed. Pollen tubes after self-and cross-pollination penetrate the micropyle. Although the percentage of seed setting reached about 60% after cross pollination no clear differences could be seen between the germination and ovule penetration of cross and self pollen.In the ovules, multiple penetration of micropyles and a preference for the first position ovules was observed. Results of semi-compatible crossings and mixed crossings indicated a gametophytic two or more loci incompatibility system. Ovular incompatibility was manifested by the degeneration of the sporophytic ovular tissues. In Gasteria verrucosa the system of ovular incompatibility does not seem to be restricted to the ovule.     

芸芥(Eruca sativa Mill.)与芸薹属(Brassica L.) 3个油用种的远缘杂交

采用芸芥(Eruca sativa Mill.)与芸薹属3个油用种（Brassica napus, Brassica juncea, Brassica rapa）进行杂交，共授粉15 990朵花，获得1 257个角果，711粒杂交种子，结角率为7.86%，亲和指数0.045。经形态学鉴定，无论芸芥作母本还是芸薹属的三个油用种作母本，F1植株均为偏母植株。杂交所获得角果的角粒数很低，许多角果     

Barriers to interspecific hybridization in Ulmus americana

Summary Crossability barriers between the tetraploid Ulmus americana and five other diploid elm species were investigated using both fluorescence and scanning electron microscopy. Both pollen germination and pollen tube development were inhibited in all interspecific crosses. Pollen tube behavior on the stigma of U. americana was unchanged when pollen of a colchicine-induced U. pumila tetraploid was substituted for diploid U. pumila pollen.Self-incompatibility was observed in one of two American elms studied and manifested itself via reduced pollen germination and inhibited pollen tube growth on the stigma surface.The results indicate that crossing barrier(s) between U. americana and other elm species occur at the stigma surface and operate independently of ploidy level. This conclusion is discussed in relation to current breeding efforts to transfer Dutch elm disease resistance into the American elm via interspecific hybridization with Eurasian elms.