小麦×长穗偃麦草的受精和早期胚胎发育

用石蜡切片法,对小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ）和长穗偃麦草（Ｅｌｙｔｒｉｇｉａｅｌｏｎｇａｔａ）杂交的受精和早期胚胎发育进行了观察。结果表明,长穗偃麦草花粉在小麦柱头上萌发良好,花粉管可顺利长入花柱和胚囊。观察的１７０个小麦子房中,１７６５％发生了双受精,产生了胚和胚乳;９４１％发生了单卵受精,只产生胚而无胚乳;４７１％发生了单极核受精,只产生胚乳而无胚;总受精率为３１７７％;成胚率为２７０６％。由于胚乳的缺乏或发育异常及败育,最终难以获得有生活力的种子。为小麦与长穗偃麦草远缘杂交提供了细胞胚胎学证据。     

硬粒小麦与珍珠栗远缘杂交的受精作用和胚胎发育

对硬粒小麦(Triticum durum Desf.)和珍珠栗(Pennisetum glaucum syn.P. americanum)远缘杂交的受精作用和胚胎发育进行了研究。对授粉后的192个硬粒小麦子房进行制片观察,7.81％发生双受精,具胚和胚乳,但胚乳发育往往落后于胚的发育;3.13％只发生了单卵受精,只产生胚而无胚乳;1.04％发生了单极核受精,只产生胚乳而无胚。总受精率为11.98％,成胚率为10.94％。由于胚乳的缺乏或发育异常及败育,最终难以获得有生活力的种子。     

小麦×节节麦杂种发育的胚胎学研究

用石蜡切片法,对小麦经节节麦花粉授粉后不同时间固定的子房进行了细胞胚胎学观察。结果表明,节节麦花粉在小麦柱头上萌发良好,花粉管可顺利长入花柱和胚囊。观察的２３８个小麦子房中,１０５０％发生了双受精,产生了胚和胚乳;４６２％发生了单卵受精,只产生胚而无胚乳;３７８％发生了单极核受精,只产生胚乳而无胚;总受精率为１８９０％;成胚率为１５１２％。本文还报道了小麦与节节麦远缘杂交时雌雄性核的结合及杂种胚和胚乳的发育情况,探讨了小麦与节节麦杂交结实率低在胚胎学方面的原因     

硬粒小麦与珍珠栗远缘杂交的受精作用和胚胎发育

对硬粒小麦（ＴｒｉｔｉｃｕｎｄｕｒｕｍＤｅｓｆ．）和珍珠栗（Ｐｅｎｎｉｓｅｔｕｍｇｌａｕｃｕｍｓｙｎ．Ｐ．ａｍｅｒｉｃａｎｕｍ）远缘杂交的受精作用和胚胎发育进行了研究。对授粉后的１９２个硬粒小麦子房进行制片观察,７．８１％发生双受精,具胚和胚乳,但胚乳发育往往落后于胚的发育;３．１３％只发生了单卵受精,只产生胚而无胚乳;１．０４％发生了单极核受精,只产生胚乳而无胚。总受精率为１１．９８％,成胚率为１０．９４％。由于胚乳的缺乏或发育异常及败育,最终难以获得有生活力的种子     

小麦与赖草远缘杂交的受精和胚胎发育

对小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．）和赖草（Ｌｅｙｍ ｕｓｓｅｃａｌｉｎｕｓＴｚｒｅｌ．）杂交的受精和胚胎发育进行了观察．赖草花粉在小麦柱头上萌发良好,花粉管可顺利长入花柱和胚囊,在检查过的３１９个小麦子房中,６２个（１９．４４％ ）发生了双受精,产生了胚和胚乳,但胚乳的发育往往落后于胚的发育;４９个（１５．３６％ ）发生了单卵受精,只产生胚而无胚乳;７个（２．１９％ ）发生了单极核受精,只产生胚乳而无胚．小麦×赖草虽然总受精率可高达３６．９９％ ,然而由于胚乳的缺乏或发育不完全,致使最后结实率很低．从１５０朵授过赖草花粉的小麦颖花中,只得到１粒种子．表明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     

长穗偃麦草优异基因的染色体定位及应用

长穗偃麦草比较公认的有2个种,即二倍体长穗偃麦草(Thinopyrum elongatum,2n=2X)和十倍体长穗偃麦草(Thinopyrum ponticum,2n=10X),是重要的小麦近缘种,具有抗病、抗寒、抗旱、耐盐碱等优良性状。因其基因组中蕴含许多对小麦品种改良极为有用的基因,且易与小麦杂交等优势,多年来长穗偃麦草一直作为小麦遗传改良的优良种质资源而备受关注。本文对长穗偃麦草的基因组研究及其在小麦的抗逆、抗病和提高光合能力、产量及高分子量谷蛋白(HMW-GS)含量等方面的应用做了综述,为其基因组中优异基因的进一步开发和利用提供了理论依据。     

四倍体大燕麦与六倍体裸燕麦的受精作用和胚胎发育

用石蜡切片法,对四倍体大燕麦(Avena magna L.)和六倍体裸燕麦(Avena nuda L.)杂交的受精作用和胚胎发育进行了观察。结果表明,六倍体裸燕麦花粉在四倍体大燕麦柱头上萌发良好,花粉管可顺利长入花柱和胚囊。观察的168个四倍体大燕麦子房中,238%发生了双受精,产生了胚和胚乳;179%发生了单卵受精,只产生胚乳而无胚;总受精率为536%;成胚率为417%。由于胚乳的缺乏或发育异常及败育,最终难以获得有生活力的种子。为四倍体大燕麦和六倍体裸燕麦杂交提供了细胞胚胎学证据。     

小麦与彭梯卡偃麦草杂种及其衍生后代的细胞遗传学研究──Ⅱ．来自小麦和彭梯卡（长穗）偃麦草及中间偃麦草杂种后代11个八倍体小偃麦的比较研究

利用染色体配对分析和酯酶及种子醇溶蛋白电泳分析研究了我国育成的１１个八倍体小偃麦,结果表明：（ａ）来源于小麦和中间偃麦草杂交后代的６个部分双二倍体中,中１和中２的偃麦草染色体组不同于中３、中４、中５和小偃７８８２９的偃麦草染色体组;（ｂ）来源于小麦和长穗偃麦草杂交后代的５个部分双二倍体中,小偃７８４的偃麦草染色体组不同于小偃６９３和小偃７６３１中的偃麦草染色体组,表明在长穗偃麦草中有两个互不相同又不同于小麦的染色体组Ｅ和Ｆ,而小偃７４３０和小偃６８中的偃麦草染色体组很可能是Ｅ和Ｆ染色体组的重组体;（ｃ）小偃７８４中的长穗偃麦草染色体组和中５及小偃７８８２９中的中间偃麦草染色体组基本相同,而中２的中间偃麦草染色体组不同于小偃６９３和小偃７６３１中的长穗偃麦草染色体组Ｆ,这意味着在长穗偃麦草和中间偃麦草中可能只有一个共同的染色体组Ｅ。部分双二倍体中酯酶及醇溶蛋白偃麦草染色体特征带的存在和发现,为这些染色体或其片段导入小麦后的鉴定提供了方便。     

普通小麦与长穗偃麦草杂种及其衍生材料的细胞遗传学特性

对十倍体长穗偃麦草(Thinopyrum ponticum)与普通小麦杂交F1及其与普通小麦回交BC1F1的形态学和细胞学特性进行了分析。结果表明,长穗偃麦草与普通小麦‘兰考矮早八’衍生F1(‘兰考小偃麦’)的根尖细胞染色体数为56条;花粉母细胞减数分裂中期Ⅰ染色体构型平均值为19.81Ⅰ+15.78Ⅱ+0.75Ⅲ+0.59Ⅳ;基因组荧光原位杂交(GISH)显示,兰考小偃麦中含有35条完整的长穗偃麦草和21条小麦染色体。‘兰考小偃麦’/‘科育818’和‘兰考小偃麦’/‘Cp02-3-5-5’杂交F1的根尖细胞染色体数及其所遗传的长穗偃麦草染色体数分别为50~52和16~22条,且存在染色体易位;花粉母细胞减数分裂中期Ⅰ平均染色体构型为14.54Ⅰ+17.40Ⅱ+0.55Ⅲ+0.14Ⅳ,平均49.4%的细胞出现多价体(三价体或四价体)。这些材料为创造小麦-长穗偃麦草新种质奠定了基础。     

四倍体大燕麦与六倍体裸燕麦的受精作用和胚胎发育

用石蜡切片法,对四倍体大燕麦（Avena magna L.）和六倍体裸燕麦（Avena nuda L.）杂交的受精作用和胚胎发育进行了观察。结果表明,六倍体裸燕麦花偻在四倍体大燕麦柱头上萌发良好,花粉管可顺利长入花柱和胚囊,观察的168个四倍体大燕麦子房中,2.38%发生了双受精,产生了胚和胚乳;1.79%发生了单卵受精,只产生胚乳而无胚;总受精率为5.36%;成胚率为4.17%。由于胚乳的缺管或发育异常及败育,最终难以获得有生活力的种子,为四倍体大燕麦和六倍体裸燕麦杂交提供了细胞胚胎学证据。     

Fertilization and Embryo Development in Hybridization Between Wheat and Leymus

Observations were made of the fertilization and embryo development in intergeneric cross between Triticum aestivum L. cv. Chinese Spring and Leyrnus secalinus Tzrel. The pollen germination of Leymus secalinus appeared normal on the stigma of Triticum aestivum and the pollen tubes grew into the style and entered the embryo sacs. Double and simple fertilization were observed in the pollinated florets. Of the 319 ovaries examed 62 (19.44%) had double fertilization and had embryo and endosperm, but endosperm development was slower than that of the embryos, 49 (15.36%) had only embryo and 7 (2.19%) had only endosperm. The total percentage of fertilization was as high as 36.99%. However, only I seed was obtained from 150 wheat ftorets pollinated with Leymus secalinus. This was obviously due to the absence or poor development of the endosperm. It may be suggested that the potential of increasing the frequency of hybrid plant obtainment was great in the cross between wheat and leymus, if embryo culture technique is employed at the early stage of hybrid embryo development.     

On the Fertilization of Oryza sativa L. × Sorghum vulgare Pets.

1.The pollen germination of Sorghum vulgate appeared normal on the stigma of the Oryza sativa, but the pollen tubes grew slowly in the style. Some of the pollen tubes may become enlarged in their tips or sometimes bursting, while others have continued to grow and entered the embryo sacs. 2. The growth rate of the pollen tubes varied widely. A few pollen tubes were observed in the embryo sacs of the materials 2 hours after pollination, but most of them entered the embryo sacs much later. 3. The zygote associated with a paucity of endosperm nuclei was observed in the materials 1 day after pollination. The double fertilization and 8–12-celled proembryo associated with a number of the free nuclei of the endosperm appeared with a rather high frequency (10.3%) in the materials 3 days after pollination. Some of them are normal in appearance and others may show more or less abnormalities. 4. No division figure was found except in one single case in which mitoses have occurred in both the proembryo and the endosperm. It is most likely that in such case the proembryo and the endosperm if left intact might develop further. 5. A 80-celled embryo was the biggest one which appeared in the materials 5 days after pollination. In general, no cells were ever formed in the endosperm, except in one instance among the 7 days materials the endosperm became cellular in micropylar end. In all other cases the endosperm either ceased to develop early or disorganized. The disorganized endosperm materials are considered to be utilized by the embryo. 6. In certain instances the free nuclei of the endosperm were not distributed at random. They were not equal in size and might fuse into giant nuclelei. 7. The most striking feature is that in the embryo sacs, in which double fertilization or proembryo and endosperm have occurred, a dark stained pollen tube was commonly present. This fact leads us to the conviction that in general only if a healthy pollen tube entered the embryo sac, double fertilization can take place and further development can proceed. 8. In certain cases the protoplasm of the embryo cells appeared scanty. It is apparently that the normal metabolism of the embryo was disturbed owing to the lack of nutrient, and the death of the embryo ensued. 9. No differentiated embryo was observed and no mature seeds were produced. The materials fixed 12 days after pollination showed a variety of abnormalities and collapses. The authors believe that the failure of seed production of rice X kaoliang was primarily due to the fact that the pollen tubes in the style grew too slowly to reach the embryo sacs in time. The consequence is that the double fertilization took place only in a late stage while the male and female gametes may have already become unhealthy. In addition, in this late stage the stored starch in the maternal tissues having gradually disappeared, the nutrient supply to the embryo sac was therefore limited and the young embryo and endosperm were finally in starvation.     

小麦×高粱的受精率和小麦单倍体的诱导(简报)

远缘杂交无论在植物遗传学理论的建立还是在新品种的培育上都是一项十分有用的技术,特别在小麦上成绩更为突出。近来发现小麦不但和其亲缘属(如山羊草属、偃麦草属,赖草属等)植物可以杂交,而且和亲缘关系较远的植物种属如玉米、珍珠栗、大刍草、摩擦禾等杂交也有很高的成胚率,并且通过杂种胚发育过程中父本染色体的消失,可以获得小麦单倍体。Laurie和Bennett以高粱属的