Polyploidy in tulips (Tulipa L.). The occurrence of diploid gametes     

G. H. Kroon  J. P. Van Eijk 《Euphytica》1977,26(1):63-66

Summary From data available in the literature and supplemented by information from private tulip breeders, it appeared that triploid and tetraploid varieties raised in the past, resulted from crosses between diploid tulips and between diploids and tetraploids. This can only be explained by the occurrence of diploid gametes in diploid (2n=24) cultivars. This phenomenon which may affect both female and male gametes, appears to be specific for certain varieties. Consequences for practical breeding are discussed.  相似文献   

Alkenyl Glucosinolate Levels in Androgenic Populations of Brassica napus     

Jutta  Sieble K. P. Pauls 《Plant Breeding》1989,103(2):124-132

The levels of individual and total alkenyl glucosinolates in seeds of microspore-derived spontaneous diploid plants from low by high and low by low glucosinolate parent crosses were examined to assess the utility of haploidy in canola breeding. The distributions of lines in the populations supported previous proposals that alkenyl glucosinolate levels are under multigenic control. Levels of all of the individual glucosinolates were positively correlated and were significantly reduced in canola-quality material in comparison to rapeseed-quality material. The populations of microspore-derived lines from low × high crosses were skewed to high glucosinolate levels but the population from a low × low glucosinolate cross had a greater proportion of low glucosinolate lines. The former observations can be explained in terms of the dominance of genes for high glucosinolate levels in Brassica napus. The present findings contradict previous reports that androgenic lines have higher glucosinolate content than the parents and in fact, haploidy may select for low glucosinolate lines when crosses between low glucosinolate parents are used.  相似文献   

Cytological studies of 2n male gamete formation in sugarcane, Saccharum L.     

L.M. Bielig  A. Mariani  N. Berding 《Euphytica》2003,133(1):117-124

The germplasm for modern sugarcane cultivars (Saccharum spp. hybrids)has been derived principally from S. officinarum (2n = 80), and S. spontaneum (2n = 40 to 128). Diploid gamete formation has been significant in developing cultivated sugarcane, but the cytological basis for the processes involved is not clearly understood. This research investigated microsporogenesis in nine clones of Saccharum spp. Hybrids and in S. officinarum and S. spontaneum. Diploid gamete formation occurred in all 11 lines, but was least frequent in S. spontaneum and S. officinarum which produced 0.5% and 0.8%2n gametes, respectively. In the hybrid lines, 2n gametes were formed infrequencies ranging from 0.9% to 4.4%. Cytological evidence was obtained for dyad and triad formation during microsporogenesis. Detailed analysis of chromosome behaviour at meiosis indicated that 2n male gamete formation is probably attributable to the absence of cytokinesis rather than a combination of asynchrony and non-disjunction. The clones were ranked on the basis of the frequencies with which they formed 4 × 1n microspores and the data were analysed using χ ² tests for homogeneity. These established that theSaccharum spp. hybrids could be designated as either ‘high’ or ‘low’ frequency haploid gamete producers. Conversely, the latter group, which formed diploid gametes most frequently (2.2%–4.4%), can be described as high frequency diploid gamete producers. The identification of clones most frequently forming diploid gametes may facilitate the more rapid recovery of desirable sugarcane genotypes because such clones could be selected for preferential use in clonal improvement. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Generation of pathogenic F1 progeny from crosses of Phytophthora infestans isolates differing in ploidy     

B. H. Hamed  U. Gisi 《Plant pathology》2013,62(3):708-718

Ten Phytophthora infestans isolates were analysed for maximal growth rate (μ_max), sporulation capacity (K), ploidy and the ability to produce infective F₁ progeny when combined in different crosses on tomato leaflets. Ploidy was determined using three different methods: simple sequence repeats (SSR, microsatellites), allele quantification at F382Y in the RNA polymerase, and flow cytometry. Eight out of 10 isolates were classified as diploid, the other two as triploid. There was no correlation between ploidy, growth rate and sporulation capacity although the latter was rather low for triploid isolates. Ten crosses were investigated in tomato leaflets (five 2n × 2n; four 2n × 3n; one 3n × 3n). Oospore production was observed in all crosses independent of parental ploidy. Germination and pathogenicity of oospores were investigated by measuring the number of infection sites (pathogenic F₁ progeny) over a time period of 72 days. All crosses containing a triploid parent produced many fewer F₁ isolates than 2n × 2n crosses. The generation of pathogenic F₁ progeny isolates was best for 2n × 2n crosses. A total of 319 F₁ offspring were produced and analysed for mating type and ploidy; a subset was tested for ploidy with all three methods. For 2n × 2n crosses, the majority of offspring were diploid, whereas in crosses containing one or two triploid parents, diploid, triploid and trisomic offspring were observed. The results suggest that less pathogenic F₁ progeny isolates are produced if at least one parent is triploid.  相似文献   

马铃薯类胡萝卜素研究进展     

索海翠  刘计涛  王丽  李成晨  单建伟  李小波 《广东农业科学》2021,48(12):111-119

马铃薯是我国第四大粮食作物,也是重要的粮菜兼用经济作物,对保障国家粮食安全、丰富菜篮子和增加农民收入意义重大.自然界中马铃薯的薯肉颜色呈现出从白色到奶油色、黄色到橙色以及红色到紫色等颜色的变化,而类胡萝卜素物质作为天然着色剂,是形成黄色、橙色、红色的主要色素物质,具有重要的生物学功能,不仅对马铃薯生长发育过程中块茎的颜色变化具有重要作用,而且还会影响其营养品质及商品价值.近几年,马铃薯遗传育种的目标正向着改善块茎的营养品质方向发展,高类胡萝卜素含量马铃薯品种的培育逐渐成为育种的重要方向.概述了马铃薯种质(包括栽培种四倍体和野生种二倍体)中所含类胡萝卜素的种类和含量、类胡萝卜素合成代谢途径中关键基因〔包括β-羟化酶(Chy)、玉米黄质环氧化酶(zep)、番茄红素ε-环化酶基因(LCYe)〕的克隆及其等位基因和单倍型的功能分析、利用常规育种和基因强化等手段提高马铃薯类胡萝卜素含量等方面的研究进展,并从马铃薯类胡萝卜素合成代谢途径调控基因的鉴定和富含高类胡萝卜素含量的野生型二倍体资源的利用方面展望马铃薯类胡萝卜素的研究方向,对今后马铃薯类胡萝卜素合成代谢相关基因调控表达调控、马铃薯高类胡萝卜素品种选育以及马铃薯营养品质改良改善方面的研究具有重要意义.  相似文献   

栉孔扇贝三倍体与二倍体的排泄研究     

刘志鸿  王清印  张岩  杨爱国 《中国水产科学》2000,7(4):10-13

从温度变化、个体大小和昼夜变化等３个角度研究栉孔扇贝（Ｓｃｈｌａｍｙｓ ｆａｒｒｅｉ）三倍体与二倍体的排泄率。结果表明,栉孔扇贝三倍体与二倍体的排泄率均随温度升高而增大;不同壳宽排泄率（Ｎ）与温度（ｔ）的关系为：Ｎ＝７．２０３３ｅ＾０．１２１５ｔ,Ｒ＾２＝０．８４４１（三倍体ｓ组,壳宽约３．２ｃｍ）;Ｎ＝８．８１５３ｅ＾０．１０３１ｔ,Ｒ＾２＝０．９８６３（三倍体ｂ组,壳宽约４．３ｃｍ）;Ｎ＝６．  相似文献   

二、三倍体细鳞鲑幼鱼生长特性的研究     

魏凯  陈春山  郑伟  马龙  耿琰 《水产学杂志》2019,(3):1-4

细鳞鲑Brachymystax lenok成熟卵受精后20min,在26℃下处理20min,获三倍体细鳞鲑幼鱼。将二、三倍体细鳞鲑幼鱼饲养在210cm×50cm×45cm(水深60cm)的玻璃钢水槽内,每槽30尾,每种倍性鱼类设3个平行,水温8~10℃下常规养殖90d后,测定试验鱼体长、体质量和肥满度等生长指标。结果表明,三倍体细鳞鲑幼鱼的日增重、增重率和特定生长率显著高于二倍体幼鱼(P<0.05),但二、三倍体细鳞鲑幼鱼的肥满度、饲料系数和存活率等差异不显著(P>0.05)。二、三倍体细鳞鲑幼鱼的体长(L)与体质量(W)呈幂指数增长相关,均为异速生长。两者的特定生长率随体质量的变化趋势相同,均呈显著负相关。本研究结果表明:三倍体细鳞鲑幼鱼的生长特性优于二倍体,可示范养殖、推广。  相似文献   

四倍体和二倍体泥鳅及大鳞副泥鳅营养成分分析   总被引：2，自引：0，他引：2       下载免费PDF全文

印杰  熊传喜  李圣华  张红云  朱勇夫 《水生态学杂志》2008,29(2):67-70

利用常规肌肉营养分析方法测定了四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅的肌肉营养成分。结果表明: 四倍体泥鳅、二倍体泥鳅和大鳞副泥鳅肌肉中蛋白质含量(鲜重) 分别为18. 68%、18. 69%和18. 20%; 脂肪含量分别为0. 796%、0. 106%和1. 203%; 水分含量分别为79. 81%、79. 52%和78. 40%; 灰分含量分别为0. 951%、11188%和1. 162%。3种泥鳅肌肉中都含有常见的17种氨基酸, 其中包括9种人体必需氨基酸。氨基酸总量(占鲜重)分别为17. 57%、18. 11%和17. 47%; 必需氨基酸总量分别为7. 84%、7. 98% 和7. 76%, 必需氨基酸的构成比例符合FAO /WHO 的标准。鲜味氨基酸含量分别为6. 98%、7. 33%和6. 95%。经比较分析, 四倍体泥鳅和二倍体泥鳅肌肉中蛋白质含量、17种氨基酸含量、氨基酸总量和必需氨基酸总量均很接近, 但都明显高于大鳞副泥鳅。  相似文献   

白榆二倍体及同源四倍体的生理特性及转录组差异分析     

崔露露  宋文龙  葛卉  王力源  刘兴菊  梁海永 《林业与生态科学》2023,38(1):8-15

为了探究白榆二倍体及其同源四倍体的基因表达谱差异情况，以白榆二倍体及其同源四倍体为材料，比较二者成熟叶片的生理特征并采摘幼嫩叶片进行转录组数据分析。结果显示，与二倍体相比，同源四倍体丙二醛含量、可溶性蛋白含量及叶绿素含量增加，可溶性糖含量降低。转录组测序结果共得到2 407个差异表达基因，其中上调基因为1 076个，下调基因为1 331个。在COG蛋白质的同源注释分析得到918个差异表达基因，主要涉及21个方面。共有1 380个差异表达基因被GO注释，主要与细胞组分、代谢功能、催化活性等相关。通过KEGG通路注释发现，共有930个差异表达基因分布到5大类KEGG通路中，其中以代谢机制中差异表达基因被注释到的最多。叶绿素含量的增加使四倍体的叶片颜色变得更加浓绿，丙二醛、可溶性糖、可溶性蛋白的含量的增加与减少与四倍体植物在植物代谢与生长上有一定关系，经过转录组测序分析，糖酵解途径的基因表达为下调，还原性戊糖磷酸循环与光呼吸等与叶绿体有关的基因为上调。  相似文献