‘正午’牡丹有性生殖败育的形态学观察

 采用光镜和杂交等方法对牡丹远缘杂交一代品种‘正午’有性生殖败育进行系统形态学观察发现: (1) 雄蕊较雌蕊先成熟, 初花期即散粉, 正常2 - 细胞花粉仅占2.41% , 且花粉在多种培养液中、在自身和其它两种柱头上均不萌发; 柱头在谢花期大量分泌粘液, 进入最佳授粉状态; (2) 同一胚珠中多个大孢子母细胞减数分裂高度不同步, 胚囊发育与受精延迟, 部分胚乳游离核在细胞化时期分裂异常;(3) 自花及品种内异花授粉不结实, 天然授粉结实率为0.053‰～0.130‰。认为‘正午’牡丹有性生殖败育的主要原因是不能形成足够多的有生活力的配子和缺乏有效授粉。     

不同放牧制度大针茅草原植物种群有性繁殖能力研究

放牧制度对锡林郭勒大针茅草原植物种群有性繁殖能力有一定影响,对适口性不同的植物其影响结果不同.大针茅草原适度放牧利用能显著降低植物种群单位面积生殖枝数、种子数及其萌发力.划区轮牧与连续放牧相比,划区轮牧有利于提高适口性好的糙隐子草种群结实生殖枝数、种子雨和种子萌发力;连续放牧有利于提高适口性差的大针茅种群结实生殖枝数、种子雨及其萌发力.     

羊栖菜的研究述评

分布于太平洋西北部的大型褐藻羊栖菜具有较高的营养和药用价值，在过去十几年中，羊栖菜自然资源遭到了过度开发而破坏，由于对该藻还缺乏足够了解，全人工资源目前还没有很好的解决，为促进该生物资源的合理开发利用，本文结合作者研究工作的进展，对国内外在羊栖菜生物学和药学方面的研究、目前开发和利用现状进行了全面概述，并提出了存在的问题，对下一步发展趋势做了分析和展望。     

金坪矮垂栗有性后代性状表现

金坪矮垂栗是从普通实生板栗中选出的变异类型, 其自交后代出现直立和垂枝性状的分离近似3∶1, 直立性与垂枝性呈显、隐性基因关系。金坪矮垂栗自然授粉有性后代矮化性仍有保存, 可利用其作为栗的矮化育种材料。嫁接结果表明, 以金坪矮垂栗实生苗为砧嫁接良种板栗, 可实现板栗的矮化密植与丰产栽培。     

糜子的开花习性和有性杂交技术

该文从糜子的开花习性和有性杂交技术两个方面做了详细的阐述。     

Assessment of Gene Flow Through Detection of Sexual Compatibility Between Transgenic Rice with bar and Echinochloa crusgalli var. mitis

The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 rmin, and 1 -4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn‘t germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.     

小苍兰有性后代商品性状观察

本文主要观察小苍兰(Freesia)有性繁殖后代的外观品质(颜色、状况、大小)及繁殖能力等。用种子播种繁殖,在常规栽培下,第一年能开花,第二年可切花。五年多来,通过对花茎长与粗、主花穗长与小花数、花径、侧花穗数以及繁殖能力等性状的观察分析比较,说明有性后代有明显的复壮效果。通过有性繁殖提供的丰富的遗传变异后代中,初选出了花茎直立性、强健、耐寒性强;新花色、花期长、耐水养和适于盆栽的矮株等新类型,供进一步选育之用。     

The production of 2n pollen in rose

Based on the size differences found between haploid and diploid pollen produced by diploid and tetraploid rose cultivars, respectively, 2n pollen producers were identified in a population of 53 diploid hybrids from a cross between a dihaploid rose, derived from the haploidization of a tetraploid modern cultivar and the diploid species R. wichuraiana. Frequency of 2n pollen producers was estimated in 2002, 2003 and 2004. Highly variable frequencies were found i) within population; ii) during years of observation (between years and between different months in the same year). The variation of 2n pollen production could be related to environmental fluctuations. A cytological analysis of male meiosis was carried out in 10 hybrids randomly chosen. Among meiotic abnormalities leading to 2n pollen formation, triads (containing a 2n microspore at one pole and two n microspores at the other) resulting from abnormal spindle geometry were frequently observed. The mode of 2n pollen formation is genetically equivalent to a First Division Restitution (FDR) mechanism. FDR 2n pollen transmits a high percentage of the heterozygosity from the diploid parent – 2n pollen producer-to the tetraploid offspring.     

上海地区棉蚜生活型的分化及其对为害的影响

本文研究结果表明,本地棉蚜除在木槿等植物上产卵越冬外,还能在大棚内,甚至在露地某些植物上以孤雌胎生方式繁殖为害,并成为第二年的早期虫源。研究中还对性蚜分化的原因提出了新的看法:即性蚜分化的主要原因是寄主种类,其次才是温度和光照周期的改变,性分化主要发生在冬寄主上。     

湖羊的生理生化常值测定

本实验对湖羊的25项常值进行了测定,其中生理常值有呼吸频率、心率、体温、血细胞压积、红细胞总数、血红蛋白、血小板、凝血时、红细胞沉降率,白细胞总数和分类计数等。生化常值有血脂、血糖、非蛋白氮、清蛋白和球蛋白等。此外,本文还报导了一些有关性成熟和产羔率等资料。