荧光显微技术在梨自交不亲和性检测中的应用

以梨为材料,介绍了荧光显微技术在自交不亲和性快速检测中的主要操作步骤．并对试验中的关键技术及注意事项进行了说明。     

普通小麦与鸭茅状摩擦禾的远缘杂交──Ⅰ．胚形成频率

本文在国内首次报道普通小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ,２ｎ＝６ｘ＝４２）和鸭茅状摩擦禾（Ｔｒｉｐｓａｃｕｍｄａｃｔｙｌｏｉｄｅｓ,２ｎ＝４ｘ＝７２）杂交成功。用３３个春小麦品种（系）为母本,与鸭茅状摩擦禾杂交,授粉６６３６朵花,获得３０８３个颖果。颖果分为有胚和无胚两类。有胚颖果８０６个,占总颖果数的２６．１４％。３３个母本中３０个都能和鸭茅状摩擦禾杂交,１４个母本的杂交亲和性（胚数／授粉花数×１００）超过１０％。４个最高的分别达到５９．００％,３９．００％,２９．５０％和２２．６６％与小麦和玉米（Ｚｅａｍａｙｓ,２ｎ＝２ｘ＝２０）的杂交相比,鸭茅状摩擦禾同样对小麦Ｋｒ基因的作用不敏感,且与小麦的杂交亲和性要比与玉米杂交时高。加之鸭茅状摩擦禾为野生型,具有多年生、多分枝、花期长等特点,可以克服小麦和玉米杂交时花期不遇的困难。讨论了用它作为花粉给体的优越性及在小麦改良和产生小麦单倍体上的前景。     

小麦条锈病罹病植株对水分胁迫的响应

水分胁迫时,小麦条锈病病叶的叶片扩散阻力（ＬＤＲ）明显增大,蒸腾速率（Ｔｐ）、相对含水量（ＲＷＣ）、水势（Ψｗ）、渗透势（Ψπ）和压力势（Ψｐ）明显降低。亲和与不亲和性反应寄主病叶对水分胁迫的反应明显不同。亲和性反应寄主叶片在水分胁迫时表现出较低的反应型,产孢期推迟;Ｔｐ、ＬＤＲ、ＲＷＣ、Ψｗ、Ψｐ和Ψπ在产孢前轻微下降或高;在开始产孢后病叶Ｔｐ急剧升高,ＬＤＲ、Ｔｐ、ＲＷＣ、Ψｗ、Ψπ和Ψｐ大幅     

单芽狗脊蕨的生境观测及其芽胞发育初步研究

初步观察了单芽狗脊蕨的生长环境及其芽胞的发育过程。结果表明,单芽狗脊蕨喜阴湿环境和偏酸性土壤。5月的复叶上开始分化出芽胞,7月成熟的芽胞可在母体上萌发,长出不定须根,芽胞脱离母体后即能在土壤中萌发生长。芽胞越大,其萌芽率和生长速度越大。单芽狗脊蕨一年可产生两代芽胞。进行胎生的单芽狗脊蕨的孢子囊缺失或数目减少。     

高山杜鹃与大喇叭杜鹃种间杂交过程的观察研究

以高山杜鹃‘Nova Zembla’为母本,大喇叭杜鹃为父本进行人工杂交授粉,利用荧光显微镜对杂交组合花粉萌发及花粉管生长过程进行观察,并统计其杂交的田间坐果率。结果显示:(1)授粉后1d花粉开始萌发形成花粉管,其萌发率在授粉后1～5d内显著增长,其后增长缓慢,到第12天萌发率最高达37.36%。(2)花粉萌发后花粉管生长速度由慢变快,授粉后2d花粉管进入花柱,7d进入子房,10d进入胚珠;实验中杂交花粉管与胚珠虽有结合,但与胚珠结合率低,授粉后12d仅7.42条花粉管进入胚珠。(3)在花粉管生长过程中,伴有大量异常现象,表现为授粉后柱头细胞、花粉管、花柱引导组织、子房组织、胚珠中的胚囊等部位依次出现胼胝质沉积反应,花粉管生长中出现的膨大、先端沉积胼胝塞而中途停止生长、螺旋扭曲、粗细不均、杂乱生长或螺旋膨大且逆向生长等异常。(4)该实验杂交的田间坐果率为零。研究表明,高山杜鹃‘Nova Zembla’与大喇叭杜鹃杂交不亲和,杂交后花粉管生长的异常行为可能是种间杂交不亲和的主要原因,且受精前障碍与受精后障碍可能同时存在。     

Characterization of the promoter of phosphate transporter TaPHT1.2 differentially expressed in wheat varieties

TaPHT1.2 is a functional, root predominantly expressed and low phosphate （Pi） inducible high-affinity Pi transporter in wheat, which is more abundant in the roots of P-efficient wheat genotypes （e.g., Xiaoyan 54） than in P-inefficient genotypes （e.g., Jing 411） under both Pi-deficient and Pi-sufficient conditions. To characterize TaPHT1.2 further, we genetically mapped a TaPHT1.2 transporter, TaPHT1.2-D1, on the long arm of chromosome 4D using a recombinant inbred line population derived from Xiaoyan 54 and Jing 411, and isolated a 1,302 bp fragment of the TaPHT1.2-D1 promoter （PrTaPHT1.2-D1） from Xiaoyan 54. TaPHT1.2-D1 shows collinearity with OsPHT1.2 that has previously been reported to mediate the translocation of Pi from roots to shoots. PrTaPHT1.2-D contains a number of Pi-starvation responsive elements, including P1BS, WRKY-binding W-box, and helix-loop-helix-binding elements. PrTaPHT1.2-D1 was then used to drive expression of 13-glucuronidase （GUS） reporter gene in Arabidopsis through Agrobacterium-mediated transformation. Histochemical analysis of transgenic Arabidopsis plants showed that the reporter gene was specifically induced by Pi-starvation and predominantly expressed in the roots. As there is only one SNP between the TaPHT1.2-D1 promoters of Xiaoyan 54 and Jing 411, and this SNP does not exist within the Pi-starvation responsive elements, the differential expression of TaPHT1.2 in Xiaoyan 54 and Jing 411 may not be caused by this SNP.     

Subcellular Localization of the S Locus F-box Protein AhSLF-S2 in Pollen and Pollen Tubes of Self-Incompatible Antirrhinum

The distribution of the S locus F-box (SLF) protein was examined by immunocytochemistry and Western blot techniques using an antibody against the C-terminal part of AhSLF-S2 in self-incompatible Iines of Antirrhinum. Abundant gold particles were found where pollen tubes emerge in vitro. With the elongation of pollen tubes, binding sites for the antibody were found in the cytoplasm of the pollen tubes,including the peripheral part of the endoplasmic reticulum. After germination in vitro for 16 h, the product of AhSLF-S2 and possibly its allelic products could still be detectable, implying that the SLF protein has a role in the elongating process of pollen tubes. The present study provides evidence at the protein level that the SLF protein is present in pollen cytoplasm during pollen tube growth. These findings are discussed, as is their potential role in the self-incompatible response in Antirrhinum.     

簇枝补血草花的二态性及繁育系统研究

白花丹科被列为异型花柱较多的科,该文以补血草属簇枝补血草为材料,通过对野外居群的花部特征、花期物候和繁育系统等研究,探讨花部形态多态性及其对生殖的影响。簇枝补血草具有两种类型植株,具玉米状柱头和A型花粉的植株称为C型植株;具乳头状柱头和B型花粉的植株称为P型植株,且A/B型花粉的大小、外壁纹饰不同。单花发育过程中两型植株的花萼、雌蕊大小差异明显,随着花的成熟差异逐渐消失。两型植株都为雌蕊高于雄蕊,柱头探出式雌雄异位;C型植株的花期较P型植株长约2 d。一天当中,A型花粉活力高峰期为13:00,B型花粉在11:00和15:00都表现为高峰期;玉米状柱头可授性最强时期在13:00～15:00,乳头状柱头则在15:00。两型花粉可育性在盛花期最高,终花期时B型花粉可育性明显高于A型。荧光染色观察发现花粉萌发和花粉管的生长速度都为:异型授粉＞同型授粉,B型花粉在乳头状柱头上不能完成受精。此外,人工授粉实验也表明异型授粉结实率显著高于同型,P型植株经同型授粉结实现象并不明显,存在少量无融合生殖。研究表明簇枝补血草花部具二态性,繁育系统为兼性异交,其中乳头状柱头对A型花粉亲和,对B型花粉不亲和,但玉米状柱头却对A/B型花粉都亲和,这打破了该科的异型自交不亲和的例证。     

苦苣苔科植物远缘杂交亲和性初探

该研究对苦苣苔科的蛛毛苣苔属[Paraboea(C.B.Clarke)Ridley]、马铃苣苔属(Oreocharis Bentham)、报春苣苔属(Primulina Hance)、吊石苣苔属(Lysionotus D.Don)、台闽苣苔属(Titanotrichum Solereder)、半蒴苣苔属(Hemiboea C.B.Clarke)、长蒴苣苔属(Didymocarpus Wallich)、光叶苣苔属(Glabrella Mich.MollerW.H.Chen)进行属间远缘杂交,对马铃苣苔属的马铃苣苔组、川滇马铃苣苔组、大叶石上莲组进行组间远缘杂交,统计不同杂交组合的结实情况及播种后的种子萌发情况,以明确不同属(组)间远缘杂交亲和性,为通过远缘杂交进行苦苣苔科种质资源的创新奠定基础。结果表明:(1)不同属作为父本,与同一母本进行杂交,以及同一属内不同种作为父本,与同一母本进行杂交,结实情况差异显著。(2)不同属作为母本,与同一父本进行杂交,以及同一属内不同种作为母本,与同一父本进行杂交,结实情况同样存在显著差异。(3)相同两个种正反交杂交成功率也并不一致。(4)马铃苣苔属与半蒴苣苔属,报春苣苔属与吊石苣苔属,吊石苣苔属与报春苣苔属和半蒴苣苔属,光叶苣苔属与报春苣苔属和吊石苣苔属之间部分种进行远缘杂交能够正常结实,且杂交种子能够正常萌发。(5)马铃苣苔属内组间杂交无明显生殖隔离的现象。     

香菇自然群体中个体间的空间分布及其遗传联系*

应用体细胞不亲和性反应、交配型因子分析和基因组ＤＮＡ的ＲＡＰＤ分析,研究了一个分布于方圆约１ｋｍ的６根倒木上的１８个香菇野生菌株间的遗传差异。结果表明,该群体大多数菌株间配对（８０．４％）体细胞不亲和,而同一倒木菌株间配对的体细胞亲和率达 ６２．５％。不同倒木菌株间未发现体细胞亲和的配对。该群体存在 １１个特异的Ａ因子和７个特异的Ｂ因子。同一倒木的菌株有的交配型因子相同,有的则不同。不同倒木的菌株大多数交配型因子不同,未发现交配型因子完全相同的菌株。ＲＡＰＤ分析显示,体细胞亲和的菌株,交配型因子完全相同的菌株,在基于ＤＮＡ相似系数的遗传相关聚类中,首先聚为小类。总起来看,在自然群体中,香菇个体间的遗传差异与其空间分布之间存在一定的联系,随着空间距离的增大,菌株间的异质性相应增高。