草莓‘甜查理’和‘章姬’花药培养及单倍体植株的获得

为筛选草莓花药培养及单倍体植株最适宜的培养条件,以草莓栽培品种‘甜查理’和‘章姬’为材料,研究不同预处理方式、花序以及激素种类和配比对草莓花药愈伤组织诱导和分化效率的影响。结果表明:在4℃低温预处理过程中,始终保持花蕾表面湿润状态较自然状态下更能提高草莓花药愈伤的诱导率,最佳处理时间为72h;北京地区越冬栽培的草莓第1、2花序的花药较第3、4花序花药具有更好的培养效果;筛选出最佳愈伤诱导培养基,其中‘甜查理’愈伤诱导效率最高达到91.67%,‘章姬’为87.28%;筛选出最佳分化培养基,其中‘甜查理’最高分化率达到19.10%,‘章姬’为10.59%。共获得花药培养植株688株,其中‘甜查理’445株,‘章姬’243株。‘甜查理’再生植株中八倍体(2n=8x=56)、四倍体(2n=4x=28)植株所占百分比分别为90.43%和7.62%,其他为非整倍体植株。‘章姬’再生植株中八倍体和四倍体植株所占百分比分别为93.42%和4.32%,其他为非整倍体植株。建立了草莓花药培养高频诱导体系并获得了单倍体植株。     

茄子新品种海丰长茄1 号的选育

海丰长茄1 号是以双单倍体（DH）株系02-QP-19 为母本，优良自交系A-40 为父本配制而成的长茄一代杂种。平
均始花节位为第9 节，植株生长势强，叶片绿色，叶脉、叶柄和主茎的颜色为紫色，植株半开张类型。果实平均纵径31.5
cm，横径4.5 cm，果皮紫黑色，有光泽，果实顶部尖，平均单果质量220 g，VC 和VP 的含量分别为23.2 mg·kg^-1 和0.035%。
一般每667 m² 产量5 000 kg 左右。适宜北京、吉林和黑龙江等地区露地种植。     

甘蓝型油菜DH群体抗倒伏相关性状遗传分析

为明确油菜抗倒伏性的遗传规律，本文利用抗倒伏性差异显著的2个甘蓝型油菜品系配制杂交组合，构建含280个株系的DH群体，采用作物茎秆强度抗倒测量仪等考种工具对该群体进行连续两年的抗倒伏性鉴定，并利用植物数量性状的主基因 + 多基因混合遗传模型及偏度和峰度分析对抗倒伏性进行遗传分析。结果表明，茎秆抗折力和茎秆抗折强度都受到0对主基因 + 9对微效多基因控制，茎秆抗折力和单株生物量的基因间无互作，茎秆抗折强度的基因间有互补作用，茎秆抗折力和茎秆抗折强度两年的平均遗传率在50%左右，而茎秆直径两年的平均遗传率为69.338 %，单株生物量两年的遗传率分别为52.198%和69.284%，遗传率都较低，性状受环境影响都较大，因此对于茎秆抗折力、茎秆抗折强度、茎秆直径和单株生物量，在育种选择的早期阶段都不宜太严格。同时茎秆抗折强度相比茎秆抗折力更能说明作物的抗倒伏能力，因而在抗倒伏选择育种时应更加关注。     

一个辣椒杂交种的加倍单倍体（DH）群体果实性状的遗传分析

 以一个牛角椒组合（‘97403’ב97410’ 杂交而成）作为供体,通过花药培养技术构建了103个加倍单倍体(DH)系组成的DH群体,再以此DH群体为试验材料,对该群体果实性状进行遗传分析。结果表明：果实横径、果肉厚、果形指数、单果质量、果实纵径等5个性状的遗传力分别是 82.3%、80.8%、80.5%、75.7%、70.9%,最少基因对数分别为20.6、8.4、6.1、33.9、10.0。估算各性状的偏度和峰度系数,分析影响各性状的基因作用方式,结果表明：影响单果质量和果实横径的多基因间存在互补作用,控制果肉厚的多基因间可能存在互补,果实纵径、果形指数各自的基因间无互作关系。     

Morphological evaluation of olive germplasm present in Tuscany region

Undesirable characteristic of rapeseed oil is a relatively high level of linolenic acid (18:3), which is easily oxidized leading to rancidity and a shortened shelf life of the oil. Previous attempts to reduce linolenic acid levels in rapeseed oil through breeding have been impaired by complex genetics and strong environmental sensitivity of this trait. Therefore, our objective was to develop molecular markers for low linolenic acid that could facilitate the breeding of low linolenic rapeseed. Bulked segregant analysis was employed to identify two RAPD markers associated with 18:3 in a doubled haploid population segregating for linolenic and erucic acid levels. Based on analysis of individual DH lines, the markers RM350 and RM574, representing two independent loci, accounted for a total of 39% of the genetic variability in this population. This marker RM350 alone accounted for 25% genetic variation for this trait with no evidence of recombination. Significant interlocus interaction found between the markers RM350 and RM574 suggested that epistasis was involved in the genetic control of 18:3 level in this population. Another marker designated as RM322, which was independent of the other two, was found significantly associated with the erucic acid level and oil content. RAPD markers identified in this study should be a useful tool for the early detection of low linolenic, or low or high erucic acid genotypes in rapeseed breeding programs based on doubled haploids. This revised version was published online in July 2006 with corrections to the Cover Date.     

Quantity production of anther-derived haploids from a multiple disease resistant tobacco hybrid. I. Frequency of plants with resistance or susceptibility to tobacco mosaic virus (TMV), potato virus Y (PVY), and root knot (RK)

Summary Methods are described for producing large numbers of haploid plantlets from anthers of a flue-cured tobacco hybrid with monogenic resistance to tobacco mosaic virus, (TMV), potato virus Y (PVY) and root knot (RK), respectively. Additional details are given on colchicine treatment for converting haploids to doubled haploids (DH's) and on the frequency of spontaneous DH's among untreated plantlets. Disparate genetic ratios of TMV-resistant to TMV-susceptible plants were obtained among colchicine-treated haploid plantlets, induced DH's and untreated haploids when compared with F₂ and BC₁ progenies. Haploids (gametes) with the gene for TMV resistance occurred more frequently than expected and plantlets with the gene for RK resistance occurred less frequenctly than expected. Transmission of the gene for PVY resistance differed only slightly from Mendelian expectations. These unexpected ratios, in addition to the frequent occurrence of plastid chimeras among anther-derived plantlets, strengthened our conviction that haploidy is somehow associated with mutation.Joint contribution from the Departments of Genetics, Crop Science and Plant Pathology, North Carolina State University, and the Tobacco Research Laboratory, Agricultural Research, Science and Education Administration, U.S. Department of Agriculture, Oxford, North Carolina. Paper No. 5576 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, North Carolina.     

条斑紫菜双单倍体群体主要经济性状的遗传分析

条斑紫菜叶状体主要经济性状的遗传参数及相互间的遗传关系,是开展分子育种的基础。实验以条斑紫菜野生型品系(Py-WT2,父本)和红色突变型品系(Py-HT,母本)杂交后产生的杂合丝状体为材料,构建由152个品系组成的条斑紫菜双单倍体(DH)群体。该群体叶状体的6个经济性状(L50、W50、FW50、SGR-L、SGR-W、SGR-FW)的表型值用单样本Kolmogorov-Smirnov检验。结果发现,各性状均为数量性状。L50和SGR-W为超亲遗传性状,其余4个性状的变异介于双亲之间,其中W50偏向于母本,FW50、SGRL和SGR-FW偏向于父本。6个性状的变异系数介于21.11%~56.68%,均属中等强度变异。相关性分析表明,L50、W50和FW50相互之间均存在极显著正相关性,SGR-L、SGRW和SGR-FW相互之间也存在极显著正相关性。利用单因素方差分析法估算出L50、W50和FW50的遗传力分别为58.17%、64.00%和57.64%,控制3个性状的基因对数分别为6.61、12.63和8.09,遗传力(y)与基因对数(x)的二次回归方程为y=0.2922x~2–4.6533x+76.162(R~2=1)。基因间互作方式的检测结果显示,控制L50和控制FW50的多基因间均分别不存在互作;控制W50和控制SGR-W的多基因间均分别存在互补作用;控制SGR-L和控制SGR-FW的多基因间均分别存在重叠作用。研究表明,条斑紫菜叶状体L50和FW50的遗传力高、基因对数少且基因间无互作,可进行早代选择。另外,L50、W50和FW50之间的相关性高,可进行间接选择以提高育种效率。     

牙鲆雌核发育研究进展

牙鲆(Paralichthys olivaceus)是一种重要的海水经济鱼类,其雌性生长速度显著快于雄性。因此,生产全雌牙鲆对提高养殖产量和经济效益具有重要意义。雌核发育是一种特殊的有性生殖方式,在这种生殖方式中,灭活的精子进入卵子,激活胚胎发育,但精核不与卵核融合形成合子,所以雌核发育的个体只具有母本的遗传信息。目前,牙鲆已成为雌核发育技术应用于产业的代表性鱼类。本文对牙鲆人工诱导雌核发育的研究进展进行综述,介绍牙鲆减数分裂雌核发育和有丝分裂雌核发育的诱导方法,以及雌核发育技术在性别控制、克隆制备等育种研究中的应用。最后,作者提出"雌核发育育种体系"构想,并对其在鱼类育种和遗传研究中的应用前景进行展望。     

Molecular identification of Pm12-carrying introgression lines in wheat using genomic and EST-SSR markers

The traditional process of obtaining maize hybrids involves the generation of inbred lines through successive generations of selfing and subsequent testcrosses in order to identify the best combining ability by allelic complementation. A fast alternative to obtain inbred lines is to induce the formation of haploids followed by chromosome doubling. However, even with the aid of haploid-inducing genetic sources, this strategy has not been widely used in maize breeding programs, partly due to difficulties inherent to haploid generation and identification. In order to evaluate the possibility of using dihaploids to generate homozygous maize tropical lines, we used the androgenetic haploid inducer line W23 as a female parent in crosses with the tropical single-cross hybrid BRS1010. Within the progeny of these crosses, 462 seeds were phenotypically selected as putative haploids by the purple-colored endosperm and colorless embryo conditioned by the R1-nj gene. Among these, only four individuals were confirmed as being haploids using SSR markers, chromosome counting and flow cytometry, showing that the phenotypic marker was not efficient in detecting haploids in the tropical maize genotype used. All four haploids as well as some diploid plants presented reduced size, corroborating the difficulties for haploid identification by phenotypic evaluation. Genetic diversity analysis revealed by SSR markers divided the haploids in two groups represented by flint and dent maize inbred lines, which could be helpful in identifying complementary dihaploid lines. The present article demonstrates that a combination of haploid production and SSR fingerprinting is a feasible strategy for maize hybrid development in tropical germplasm.     

玉米诱导系遗传多样性及诱导率与母本遗传背景的关系

【目的】研究玉米单倍体诱导率与遗传背景的关系及诱导系的遗传多样性。【方法】选用东北地区主要的玉米杂种优势模式下骨干自交系所组配的F1代为母本进行单倍体诱导,统计诱导率;利用SSR标记对诱导系遗传多样性进行分析和类群划分。【结果】母本不同的材料间单倍体诱导率变异幅度较大,相同杂交模式下的基础材料间诱导率变化也较大,杂交模式间诱导率无显著差异;同一亲本组配的诱导基础材料的诱导率变化范围较大,不同亲本的组合间差异不显著。SSR标记分析表明,35对SSR引物共检测出152个等位基因变异,每对引物检测出2~7个等位基因,平均4.342 9个,每对引物多态性信息量(PIC)为0.113 7~0.676 5,平均为0.442 0。聚类分析结果表明,供试玉米诱导系分为4个大群,第2类群可以被划分为6个亚群。【结论】单倍体诱导率与母本基础材料的基因型有一定的相关性;供试诱导系可划分为4个大群;在对诱导系评价或父本诱导系改良时,应考虑测定母本基因型等综合因素。