植物的自交不亲和性

自交不亲和性(self-incompatibility)也叫自交不育性(self-sterility),指某些植物在自然条件下,虽然两性器官都正常,但以本花、本株或同一品种的异株花粉授粉时,不能受精或不能正常结实的现象.这种不亲和性常见于某些雌雄同株的植物,如黑麦以本穗花粉授粉,苹果和梨的某些品种以本株、本品种的花粉授粉时常不结实.自交不亲和是植物长期进化过程中所形成的有利于异花传粉的一种生殖隔离.它却给作物种子生产上带来了防杂保纯的困难.然而,认识这种特性的特点,采取相应措施,就可以发挥其长处,有利于农业生产.例如,大白菜育种上针对这一特性育成自交不亲和系,可以简化去雄手续,产生杂交种子,利用杂种优势.苹果、梨等果树中自交不结实或结实很少的某些品种,适当配置与主栽树同时开花、花粉发育正常、所结果实的经济价值也较高的品种作授粉树,可使主栽树有良好的授粉、受精条件,增加结果.如茌梨用鸭梨、青香蕉苹果用红香蕉苹果作授粉树等.     

小报春不同授粉组合亲和性研究

利用小报春‘红星’、‘紫霞’、‘罗兰香’3个品种分别设置8种授粉组合,统计了不同授粉组合的结实情况和单果种子数量,并对‘红星’品种部分授粉组合的花粉萌发与花粉管伸长过程进行荧光显微观察。结果显示:(1)3个品种的结实率和单果种子数量均表现为异型植株授粉>长花柱同型异株授粉、长花柱自交>短花柱同型异株授粉、短花柱自交,不同授粉组合间单果种子数量差异极显著,异型植株授粉类型结实率均达到100%,单果种子数量为44～181粒,显著高于自交组合和同型异株杂交组合;以异型致死花粉作为蒙导对短花柱同型异株授粉组合的结实有一定促进作用,但对长花柱同型异株授粉组合的结实没有一致的促进作用;3个品种中‘红星’的结实率和单果种子数量最高。(2)荧光显微观察表明,异型授粉组合花粉在柱头上大量萌发并在花柱中伸长,授粉144h后花粉管开始进入子房;同型授粉组合授粉12h后花粉开始萌发,但直到授粉后144h花粉管还没有进入花柱;自交授粉组合授粉后144h仍无花粉萌发。实验结果说明,小报春存在明显的自交不亲和性,且短花柱类型的自交不亲和性比长花柱类型强。     

观赏海棠品种间的杂交亲和性研究和亲本选择

为筛选出优质亲本及杂交组合,确定最佳授粉时期,探究观赏海棠品种间的杂交亲和性,为观赏海棠的新品种培育提供参考,该研究以15个性状互补的海棠品种为供试材料,用离体培养法测定花粉活力、悬液法测定花粉含量并对其雄性育性进行评价;联苯胺-过氧化氢法测定其不同开花时期的柱头可授性;荧光显微观察法观察授粉后花粉管的生长及受精情况;人工控制授粉法研究5个杂交组合的坐果动态变化情况。结果显示,(1)根据花粉活力可将15个海棠品种的雄性育性分为不育型、较低型、中等型、优质型4类,其中‘印第安之夏’、‘冬红’等6个品种为优质父本。(2)海棠从开花前1 d至第6天的柱头可授性呈现“弱—强—弱”的变化规律,开花第3天时的柱头可授性最强。(3)授粉后4～8 h花粉开始萌发,48～96 h完成受精。(4)花粉育性和柱头可授性与杂交坐果率、种子饱满率间均存在显著的正相关性。授粉后2个月内是落果集中期,此后至果实成熟坐果率基本趋于稳定。‘冬红’ב印第安之夏’、‘草莓果冻’ב印第安之夏’为高坐果率杂交组合。研究表明,海棠雌雄蕊存在发育不同步现象,选择育性优质的亲本是杂交取得成功的关键,而受精后障碍是本研究中海棠杂交...     

巴旦杏授粉试验及花粉管生长的荧光显微观察

对巴旦杏4个主栽品种的授粉试验结果表明：自花授粉试验中“鹰嘴”、“双果”坐果率分别为19．74％和4．29％,“纸皮”和“麻壳”坐果率为零;自然授粉状态下4个主栽品种坐果率在9．37％－20．13％之间;人工异花授粉试验中4个品种9个授粉组合坐果率绝大多数都在40％以上,其中混合花粉授粉试验结果最好;人工养蜂条件下的坐果率明显高于无蜂自然授粉的坐果率,昆虫传粉可达到人工混合花粉授粉的效果。授粉试验还表现出巴旦杏雌蕊柱头的有效授粉时间为开花后花期的前4d,授粉越早,越有利于坐果。荧光显微观察表明,巴旦杏花粉管最早约于授粉第7天通过花柱基部到达子房室,第8天前后到达胚珠。     

基于SRAP分析的梨授粉品种亲缘关系对砀山酥梨石细胞含量的影响

利用SRAP分子标记,从88对引物中筛选出34对引物组合,分析砀山酥梨母本与授粉品种之间的亲缘关系,探讨梨授粉品种亲缘关系对砀山酥梨石细胞含量的影响。结果表明:授粉品种紫酥、鸭梨和马蹄黄与砀山酥梨亲缘关系较远,授粉品种华山、幸水和圆黄与砀山酥梨亲缘关系较近;砀山酥梨自然授粉果实石细胞含量为0.61%;选用紫酥、鸭梨和马蹄黄作授粉树时,果实石细胞含量分别为0.34%、0.33%、0.36%,低于自然授粉的砀山酥梨;选用华山、幸水和圆黄作授粉树时,果实石细胞含量分别为0.84%、0.70%、0.66%,高于自然授粉的砀山酥梨。选用与砀山酥梨亲缘关系较远的梨品种作授粉树可减少砀山酥梨石细胞含量,改善口感     

栽培菊花与矶菊属间杂交亲和性及F1结实特性研究

研究菊属栽培小菊‘奥运火炬’、‘意大利红’与亚菊属矶菊的杂交亲和性和结实性,以及杂种F1自交、回交和开放授粉的结实特性。结果表明:无论是以栽培菊花还是矶菊为母本,父本花粉在柱头上均能很好萌发,但结实率较低,‘奥运火炬’和矶菊杂交结实率为每花序3.72粒,‘意大利红’和矶菊正反交结实率分别为每花序1.20粒和0.87粒。回交组合(‘奥运火炬’×矶菊)F1ב奥运火炬’结实率为0～1.24粒;‘意大利红’与矶菊正反交F1无论是以‘意大利红’还是以矶菊为回交父本,结实率均较低,为0～1.37粒;‘早意大利红’和矶菊正反交F1自交不结实,‘奥运火炬’×矶菊杂种F1自交仅有少数单株有一定结实性,但在开放授粉条件下结实率均较高,最高达每花序47.5粒,说明F1雌配子发育良好,回交结实率低的原因可能在于远缘杂交障碍,而自交结实率低可能由自交不亲和机制决定。     

猕猴桃种间及种内杂交亲和性研究

以3个种的9个猕猴桃品种为试材,通过培养法比较它们的花粉活力,用荧光显微镜观察猕猴桃种间与种内杂交亲和性,并统计其亲和指数及坐果率,为猕猴桃的杂交育种以及最佳授粉树的选配提供依据.结果表明:猕猴桃花粉活力在种间表现为美味猕猴桃＞中华猕猴桃＞狗枣猕猴桃;中华猕猴桃和美味猕猴桃种间和种内杂交组合的柱头识别反应快,花粉在柱头粘附多、生长快且萌发率高、亲和性较强且坐果率较高,而用狗枣猕猴桃与中华猕猴桃和美味猕猴桃种间杂交的花粉在柱头上萌发生长发育缓慢,其亲和性弱,平均坐果率仅为19.81%;30个杂交组合中亲和指数最高的是'金阳'×'金阳'雄株,亲和指数为960.33,坐果率为95.56%,最低的是'狗枣'×'金阳'雄株,亲和指数201.60,坐果率为12.22%.研究发现,猕猴桃的种间亲和性小于种内亲和性,同种内不同品种间的亲和性与坐果率也不同.     

欧报春二型花柱的繁育特性研究

二型花柱植物通常具有自交不亲和性,在不同植物中所表现的可育性不同。欧报春(Primula vulgaris)是典型的二型花柱植物,为了探究欧报春的繁育特性,通过温室栽培,对欧报春的长花柱和短花柱的花部特征、花粉和花柱形态、花粉活力、柱头可授性、花粉/胚珠比、杂交指数、杂交亲和性、花粉管观察进行研究。结果表明,(1)长花柱和短花柱的花冠直径、花冠筒长度、柱头高度、花药高度和花筒中部直径均表现出两型性;(2)花粉和柱头观察发现花粉极轴长、花粉赤道轴长、花柱直径、柱头乳突细胞和花粉数量均有差异;(3)长花柱的花粉/胚珠比为384.20,短花柱为369.70,属于兼性异交类型;长花柱和短花柱的花粉活力和柱头可授性能在较长时间内维持较高活力;(4)长花柱杂交指数值为5,短花柱为4,表明繁育系统类型为异交,部分自交亲和,需要传粉者;6种授粉组合均能结实,异型花间授粉的结实数明显高于同型自花授粉和异株同型授粉;短花柱为母本的异型花间授粉组合亲和性优于其他组合;欧报春存在自交不亲和性,长花柱的自交不亲和性低于短花柱。     

中国‘苦水’玫瑰杂交育性的初步研究

油用玫瑰主栽品种‘苦水’玫瑰的栽培园区总见千花无果现象,为此,本研究对‘苦水’玫瑰的杂交育性进行了遗传学研究。授粉试验发现,自然授粉和人工辅助授粉时‘苦水’玫瑰自交不结实;异交时,‘苦水’玫瑰作为母本与‘丰花’玫瑰、‘四季’玫瑰、‘艳霞’玫瑰、重瓣黄刺玫之间具有亲和性,而作为父本与杂交母本都无法成功授粉结实。在雄蕊花瓣化、P/O值、花粉异型性和花粉萌发率等生殖特征中发现‘苦水’玫瑰的花粉畸形现象严重,萌发率近似为零。进而,显微观察小孢子母细胞减数分裂各时相发现‘苦水’玫瑰中存在染色体分配行为不协调,胞质分裂不均一,四分体中有三分体等异常现象。由此可见‘苦水’玫瑰的异常减数分裂行为致花粉败育妨碍其做父本时的受精结实,故雄性不育而非蔷薇科常见的自交不亲和性,是‘苦水’玫瑰自交不结实的主要原因,也表明作为母本通过杂交育种方法改良‘苦水’玫瑰的种质是可行的。     

''京白梨''结实与雌雄配子体发育的解剖学研究

以‘京白梨’、‘鸭梨’、‘雪花梨’为材料,用石蜡切片技术对其雌雄配子体发育过程进行了观察研究,并对其花粉育性、自然授粉结实率进行统计分析。结果表明:(1)‘京白梨’自然授粉结实率和花粉发芽率明显低于‘鸭梨’和‘雪花梨’;(2)京白梨从小孢子母细胞形成到成熟花粉的各个发育阶段观察到未形成小孢子或形成后很快退化、花粉囊中的花粉极少、花粉发育阶段细胞发生退化等不同类型的雄性败育个体,而且在花粉成熟阶段有部分花药中的绒毡层细胞不发生退化,花粉难以散出造成雄性败育;(3)雌配子体在大孢子母细胞发育阶段发现不能形成大孢子和大孢子形成后退化或发育不良等多种发育异常的雌配子体败育类型,而且败育频率高达36.7%。研究表明,‘京白梨’雌、雄配子体在其形成发育过程中的各种异常使其不能正常受精,最终导致坐果低下。     

野菊与菊花杂交中花粉活力和柱头可授性及胚胎发育研究

应用石蜡制片、活体压片、光学显微镜及扫描电子显微镜观察等方法,研究了四倍体河南云台山野菊(Dendranthema indicum)与栽培菊花'钟山金山'(D.grandiflorum 'Zhongshanjinshan')种间杂交中父本花粉活力、花粉在柱头萌发、花粉管生长及胚胎发育情况等.结果发现,父本云台山野菊的花粉活力在授粉时为12%左右.人工授粉后的不同时间,在柱头上都观察到正常萌发的花粉粒,且花粉管都能进入柱头,其中,在授粉后0.5 h时,平均每柱头有5.9粒花粉萌发;12 h时,为59.9粒;而24和48 h时,则分别降为47.1和35.7粒.此外,在授粉后8、10、12和15 d时,分别在49.1%、40.8%、39.7%和38.5%子房内观察到正常发育的胚胎,最终杂交结实率为44.8%,而母本自然开放结实率为52.3%.研究表明,授粉前其多数母本雌蕊发育良好、授粉后多数花粉能在柱头正常萌发和花粉管正常生长,在受精后大部分胚胎发育正常是野菊与栽培菊种间杂交较高结实率的重要保证,而授粉前父本较低的花粉活力对杂交结实率影响不大.     

杂种卡特兰花粉萌发和花粉贮藏性研究

以杂种卡特兰品种‘绿世界’(Rhyncholaeliocattleya Sung Ya Green‘Green World’)的新鲜花粉为试材,采用正交试验比较了蔗糖、H3BO3、CaCl2对花粉萌发的影响。结果表明,适宜的花粉培养基为:蔗糖100 gL-1+H3BO3 40 mgL-1+CaCl2 150 mgL-1。不同贮藏方法对杂种卡特兰花粉萌发率的影响较大,4℃低温湿润贮藏30 d后,花粉萌发率仅为3.5%,而4℃低温干燥贮藏、-20℃冷冻湿润和干燥贮藏720 d后,花粉仍然具有较高的活力,花粉萌发率均达32.5%以上,且对授粉结实率没有明显影响。杂种卡特兰的授粉最佳时期为开花后0-8 d,花粉块在整个花期均保持较高的活性。     

Electrophysiological and behavioral responses of Asian and European honeybees to pear flower volatiles

Honeybee pollination behavior is influenced by flower volatiles, which honeybees sense via olfactory receptors. Honeybees are only weakly attracted to pear flowers. To investigate the potential reasons, we extracted and determined the floral volatile compounds from three pear cultivars (Su, Ya, and Xuehua) using headspace solid-phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC–MS). The effects of pear flower volatiles on the Asian honeybee (Apis cerana cerana Fabricius) and the European honeybee (Apis mellifera ligustica Spinola) were determined by electroantennogram (EAG) assays and behavioral tests in a three-arm olfactometer. Among the 76 flower volatiles detected with GC–MS, 21 were found in all three pear cultivars, accounting for approximately 70% of the total volatile content. 3-Methyl-1-butanol and (+)-limonene volatiles had the highest relative content. Five compounds elicited strong EAG responses in both bee species: 2-methylbutyraldehyde, 1-nonanal, 6-methyl-5-hepten-2-one, 3-methyl-1-butanol, and (+)-limonene. Neither bee species showed positive taxis to these volatiles. In behavioral tests, A. mellifera ligustica showed a low preference for 6-methyl-5-hepten-2-one (20%, 400 µg/µL) and 2-phenethyl alcohol (16.7%, 400 µg/µL). Apis cerana cerana showed a low preference for 6-methyl-5-hepten-2-one (6.7%, 400 µg/µL) and 1-nonanal (10%, 400 µg/µL), whereas its preferences for 3-methyl-1-butanol (43.3%, 400 µg/µL) and α-farnesene (40%, 400 µg/µL) were similar to that for the control. Therefore, a lack of attractive volatile compounds could explain why honeybees are only weakly attracted to pear flowers. Therefore, to achieve acceptable pollination in pear orchards, we suggest using flower-scent sugar syrup feeding and a saturation pollination strategy.     

Effects of varying pollen load on fruit set,seed set and seedling performance in apple and pear

Two apple crosses and one pear cross were carried out using three different pollen densities. In one of the apple crosses, both fruit and seed set decreased when a mixture of pollen and powder (diluted pollen treatment) was used for pollination. Also, seedlings from the undiluted treatment were more vigorous than those originating from pollination with diluted pollen. In the other apple cross, however, no effect on fruit set, seed set or growth in the first year was found. Mean diameter after the second year differed among treatments, but did not seem to be related to pollen density. For pear, the number of good seeds decreased and the number of deaf, probably unfertilized, seeds increased with decreasing pollen density. However, there was no apparent significant effect of pollen density on seedling growth. With respect to scab resistance and mildew attack in both apple crosses, no differences among treatments were found. The results indicate that gametophytic competition may occur in apple crosses, but that it is probably weaker in pear.     

Xenia and metaxenia in grapes: differences in berry and seed characteristics of maternal grape cv. ‘Narince’ (Vitis vinifera L.) as influenced by different pollen sources

Literature investigations indicate that the grapes have quite complex fertilisation biology. This complexity necessitates extensive investigations to obtain reliable knowledge for both well‐organised hybridisation studies and maximising grape yield. Therefore, this study was conducted to investigate the influences of self‐, free‐ and cross‐pollination on berry and seed characteristics in grape. Five different pollination treatments were applied to ‘Narince’, the most widely known and popular white wine grape in Turkey. Pollen tests indicated that all the cultivars had satisfactory in vitro pollen viability percentages. Free‐pollination produced a significantly higher percentage berry set. Among the pollinizers, the use of pollen of ‘Thompson Seedless’ and ‘Cardinal’ varieties resulted in higher berry set percentage in ‘Narince’. The free‐pollination was also superior in giving the highest weight, length and width of the berry, as well as number of seeds per berry. These findings revealed that there were strong xenial and metaxenial effects in the studied grape cultivars. Among the pollinizer cultivars, the most effective pollinator was ‘Thompson Seedless’. Hence, for better berry set and quality, the use of ‘Thompson Seedless’ as a pollinizer may be an attractive option in both grape production and breeding studies.     

The evolution of distyly in Primula vulgaris

Experiments on pollen flow and seed production were performed in populations of P. vulgaris in order to examine the roles of selection for reduced self-pollination in a partially self-fertile morph, selection for reduced stigma clogging, selection for a pollen saving effect, and selection for disassortative pollination in the evolution of morphological distyly (reciprocal herkogamy). Selection for reduced self-pollination and disassortative pollination were shown to have a plausible role in the evolution of this dimorphism. Selection for reduced stigma clogging and pollen saving appeared to have no obvious role in the evolution of morphological distyly.     

Extensive citrus triploid hybrid production by 2x?×?4x sexual hybridizations and parent-effect on the length of the juvenile phase

The citrus fresh market demands the production of seedless citrus fruits, as seedy fruits are not accepted by consumers. The recovery of triploid plants has proven to be the most promising approach to achieve this goal, since triploids have very low fertility, are generally seedless and do not induce seeds in other cultivars by cross pollination. Triploid plants can be recovered by 2x?×?4x sexual hybridization. In this work, we present an effective methodology to recover triploid plants from 2x?×?4x hybridizations based on in vitro embryo rescue, ploidy level analysis by flow cytometry and genetic origin of triploid plants. The pollen viability of diploid and tetraploid citrus genotypes was analyzed by comparing the pollen germination rate in vitro. The pollen viability of tetraploid (doubled-diploid) genotypes is generally reduced but sufficient for successful pollination. Triploid embryos were identified in normal and undeveloped seeds that did not germinate under greenhouse conditions. The influence of parents and environmental conditions on obtaining triploid plants was analyzed and a strong interaction was noted between the parents and environmental conditions. The parental effect on the length of the juvenile phase was also demonstrated through observations of a large number of progeny over the last 15?years. The juvenile phase length of the triploid hybrids obtained with 'Fortune' mandarin as female parent and tetraploid 'Orlando' tangelo as male parent was shorter than the juvenile phase obtained with a clementine as female parent and tetraploids of 'Nova', 'W. Leaf' and 'Pineapple' male parents. Key message Effective methodology to recover citrus triploid plants from 2x?×?4x sexual hybridizations and the parental effect on the length of the juvenile phase.     

RAPD Detection of Pollen Contamination in Cross Breeding of Liriodendron (in English)

Based on the biology peculiarity of Liriodendron L., the non-bagged pollination technique was used widely in cross breeding of the genus. Theoretical analysis and indirect detection indicated that the pollen contamination rate of this pollination technique was no higher than 1%. But there is no evidence from direct detection by now. The pollen contamination rate produced in this pollination technique, for the first time, was detected by means of RAPD markers in this study. The results revealed that all the 93 progenies detected, derived from the non-bagged pollination technique, were progenies of the purpose male tree of the cross. No pollen contamination was found. Because the frequency of the 4 paternal marker fragments selected for the detection were relatively low in the population, the reliability of the pollen contamination rate detected was very high (>99%). Therefore, the non-bagged pollination technique is viable in Liriodendron . The authors also considered that RAPD markers had higher potential of use in other fields of botanic study such as pollen competition, pollen flow, pollen contamination of forest seed orchard, etc.