S‐locus diversity and cross‐compatibility of wild Prunus avium for timber breeding

Prunus avium is primarily cultivated for its fruit, sweet cherries. However, it is also used to produce high‐quality timber. In a P. avium seed orchard, gametophytic self‐incompatibility is a restriction for free pollen flow and should be considered when establishing basic forest materials. In this study, S‐locus diversity and cross‐incompatibility of wild cherry individuals in clonal banks established for breeding for timber production were investigated. Wild cherry trees (140) with outstanding forest growth habit, collected in northern Spain, grafted and planted in two clonal banks, were genotyped at the S‐locus. The self‐incompatibility S‐locus genes, S‐RNase and SFB, were analysed by PCR. Twenty‐two S‐haplotypes, resulting in 72 different S‐genotypes, were identified. The genotypes were grouped into 33 incompatibility groups and 39 unique genotypes. This initial S‐locus analysis revealed large genetic diversity of wild cherry trees from the Spanish northern deciduous forest, and provides useful information for seed orchard design. Wild P. avium displays significantly more genetic diversity than what is detected in local cultivars, revealing a narrowing of genetic diversity during local domestication.     

林木远缘杂交育种现状及研究进展

远缘杂交是拓宽种内遗传资源、扩大基因库和弥补近源杂交局限性的重要手段, 目前在林业生产上已取得了重要成果。然而, 由于生殖隔离的存在, 远缘杂交往往具有一定的不亲和性, 对育种进程造成了较大的阻碍。文中对远缘杂交育种的发展历史、原理、育种策略及在林业上的研究成果进行了综述, 并对远缘杂交育种过程中存在的困难及解决办法进行了分析, 以期为远缘杂交育种在林业上的应用提供参考。     

Linkage Between the Incompatibility Locus Z and a β-Glucosidase Locus in Rye

Crosses of plants from the same I_0.1 line can be used for studying linkage relations between incompatibility loci and marker genes. Only one of the two incompatibility loci of rye has so far been localized, on chromosome 1R. In order to locate the second locus, crosses were performed with plants possessing known isozyme markers of the rye genome. Linkage was found with the β-glucosidase locus on chromosome 2R. By combined analysis a recombination value of C.144 was determined.     

硼酸对萝卜成花生理代谢与亲和性的影响

采用不同浓度的硼酸分别喷洒萝卜叶片和花蕾,调查硼对自交不亲和萝卜成花生理代谢与亲和性的影响。结果显示:叶面喷施硼酸对萝卜生理代谢有显著影响:硼酸浓度越高,抽薹前期萝卜叶片的可溶性糖含量越高,但是从抽薹开始,硼效应已经不明显;硼处理下的叶绿素含量始终高于对照;0.6%硼酸处理下萝卜POD活性最高;从现蕾开始,硼处理下的脯氨酸含量始终高于对照。蕾期喷施硼酸可以在一定程度上促进花粉管伸长,提高亲和指数,尤以双核期喷施0.4%硼酸的效果最好,其亲和指数达到3.08。总体看来,在萝卜成花过程中,硼酸处理无论是对萝卜成花过程的生理代谢还是亲和性都存在显著影响。     

用荧光显微镜技术观察药用野生稻(Oryza officinalis Wall)和转基因水稻的不亲和性

 采用荧光显微镜技术观察转基因水稻花粉在药用野生稻柱头上的萌发及在花柱内的生长过程,以明确两者之间不亲和性发生的阶段,为判断其能否发生基因漂流提供依据。结果表明,两种转基因栽培稻(Y003和99t)的花粉在药用野生稻柱头上的萌发率均比药用野生稻自花授粉的低,花粉管在花柱中的生长速度较慢,且分别在到达花柱中部(Y003)或花柱基部(99t)时停止生长,顶端异常膨大,杂交子房逐渐萎缩,结实率为0。药用野生稻与栽培稻杂交不亲和的原因是花粉管在花柱中停止生长、不能进入胚囊完成受精,在自然条件下转基因栽培稻中的外源基因     

Influence of Abscisic Acid and the Abscisic Acid Biosynthesis Inhibitor, Norflurazon, on Interactions Between Phytophthora sojae and Soybean (Glycine max)

A comparison was made of the effects of abscisic acid (ABA) and the ABA biosynthesis inhibitor, norflurazon on the interaction between soybean leaves and Phytophthora sojae. Inoculation of leaves of cv. Harosoy resulted in a compatible interaction typified by the presence of spreading, water soaked lesions with ill-defined margins while inoculation of cv. Haro 1272 resulted in an incompatible interaction with lesions restricted to the inoculation site. Activity of phenylalanine ammonia lyase (PAL) slowly increased in the compatible interaction but in the incompatible interaction there was a rapid rise in activity within 8h after inoculation. When Haro 1272 plants were treated with ABA the normally incompatible interaction with race 1 was changed to what resembled a compatible interaction and activity of PAL was reduced to control levels. There was no visible effect on the compatible combination. In contrast when plants of cv. Harosoy were treated with norflurazon the normally compatible interaction with race 1 was changed to that which resembled an incompatible interaction and PAL activity increased to high levels rapidly. There was no effect of norflurazon on the incompatible interaction of cv. Haro 1272 with race 1. Stomata on leaves of cv. Harosoy treated with norflurazon closed within 2h of inoculation resembling the response of stomata in normal incompatible interactions but not compatible interactions where stomata remained open. On leaves of cv. Harosoy treated with norflurazon at sites 3 and 20mm from the inoculation point stomata also closed. These results extend and confirm the idea that ABA is a molecule that may regulate the outcome of the interaction between soybeans and P. sojae.     

新疆野生油菜与甘蓝型油菜属间杂种分子鉴定

采用蕾期剥蕾授粉的方法,成功获得了新疆野生油菜和甘蓝型油菜属间杂种.杂种F1植株之间形态表现一致,介于双亲之间,并且具有明显的杂种优势.从F1群体中随机选取9株进行RAPD分析,扩增出的带型完全一致,并且是父母本随机扩增DNA片段的综合,说明这9株全为真杂种.试验结果表明,蕾期授粉可以克服新疆野生油菜和甘蓝型油菜属间杂交的不亲和性,利用RAPD分子标记技术可以快速有效地鉴定远缘杂种.     

Variation of prezygotic barriers in the interspecific hybridization between oilseed rape and wild radish

Escape of transgenes from genetically modified oilseed rape, Brassica napus, into wild radish, Raphanus raphanistrum, depends on sexual compatibility. The variation in prezygotic barriers of two different cultivars for interspecific hybridization with a population of wild radish was investigated by hand crossing and fluorescence microscopy of pistils. Significant differences were observed between oil seed rape cultivars in their ability to accept wild radish pollen germinating onto their stigma and the rate of fertilization of ovules. Some differences among the pollen donor plants were also detected. These results suggest that the rate of interspecific hybridization in the field would depend upon the oilseed rape cultivar and the genotype composition of the local wild populations. The implication of S-related genes, as revealed through identification by pistil tissue prints of class I and II S-types of SLG (S-Locus Glycoprotein) and SLR1 (S-Locus Related),and immuno-IEF, was not significant. This revised version was published online in August 2006 with corrections to the Cover Date.     

S-allele identification by PCR analysis in sweet cherry cultivars

Gametophytic self‐incompatibility, governed by the S‐locus, operates in sweet cherry. The knowledge of the S‐genotype of sweet cherry cultivars is therefore essential to establish productive orchards by defining compatible combinations. The isolation of sweet cherry S‐R Nases has allowed the use of different molecular techniques to characterize the S‐genotypes of sweet cherry cultivars. Previously, incompatibility group assignment could only be carried out on mature trees through pollination tests. In this work, PCR analysis with primers designed on the conserved sequences of sweet cherry S‐R Nases has been used to characterize the S‐genotype of 71 sweet cherry cultivars, including 26 cultivars whose S‐allele constitution had not been previously described. This approach has allowed the detection of alleles that had not been amplified by PCR before, to identify six putative new S‐alleles, to define three new self‐incompatibility groups and to compile the standards for a PCR‐based S‐allele typing method in sweet cherry.     

The role of pollen and stigma in determining the level of partial self-compatibility in brussels sprouts

Summary Brussels sprouts inbred plants, homozygous for the same recessive S-allele, were intercrossed in all combinations and the number of pollen tubes penetrating the stigmas of such crosses measured. The results of five such experiments showed that pollen as well as stigma is significant in determining the number of pollen tubes counted. It was also found that the capacity of a plant's stigmas to permit pollen tube penetration was independent of the capacity of its pollen to penetrate other plants' stigmas. Variation in pollen tube production between pollens of the plants tested was often greater than that between their stigmas.