玉米单倍体诱导系诱导双生苗的观察

以不同玉米杂交种与单倍体诱导系为材料,对从杂交种中诱导双生苗的情况进行了观察。结果表明,在农大108、高油5598、郑单958与CAUHOI-1的杂交当代籽粒中,双生苗的平均频率为0.15%,显著低于单倍体的平均诱导频率3.38%,而在自交籽粒中没有发现双生苗。利用45个双列杂交组合为母本分别与两个诱导率不同的诱导系(CAUHOI01和CAU79)进一步杂交,在杂交籽粒中发现26对双生苗,其中有23对来自于CAUHOI-1的杂交后代。本研究结果表明双生苗诱导与单倍体诱导一样,不仅与诱导系有关,在一定程度上也受母本基因型影响,而二者诱导能力表现趋势不一致。对双生苗类型的观察结果表明,双生苗主要为二倍体-二倍体类型,少数为单倍体-单倍体类型,没有发现单倍体-二倍体类型。SSR分析表明每个双生苗两个体间基因型一致,但部分双生单苗田间生长存在着差异。双生苗的发生与单倍体诱导机理的关系有待于进一步研究。     

小孢子培养获得松花型花椰菜DH再生植株

对5个松花型花椰菜(Brassica oleraceavar.botrytisL.)杂种一代的小孢子培养研究表明,小孢子胎胚发生主要依赖于基因型,庆农65天的每花蕾胚状体产量最高,平均达15.5个。松花菜的胚状体萌发率一般在30%左右,并有效地获得了大量的DH再生植株。冷激预处理能显著地影响花椰菜小孢子的胚胎发生,但供体材料间存在不同的结果。结球期和开花结角期再生植株的生育期与育性出现较大分离,可育且能正常结角的比例约占全部小孢子再生植株的50%以上,因而不再需要加倍处理。     

利用小麦×玉米诱导小麦单倍体的研究

将10个小麦杂交组合的F1作母本与2个玉米品种(沈糯1号和沈甜1号)进行远缘杂交,用不同浓度的2,4-D溶液处理杂交穗,以获得小麦单倍体幼胚。结果表明,2,4-D溶液对杂交穗产生单倍体胚是必须的;不同小麦杂交组合的得胚率差异显著;沈糯1号和沈甜1号的得胚率分别为5.4%和3.7%,沈糯1号玉米高于沈甜1号玉米;不同浓度的2,4-D溶液处理按得胚率高低排序为150mg.L-1>100mg.L-1>200mg.L-1>50mg.L-1,对应的得胚率分别为8.0%,5.3%,2.0%和1.4%。     

棉花半配合材料VSg在遗传育种中的应用

以VSg作母本与其它材料杂交可以培育父性单倍体,但不同材料作父本与VSg杂文F₁所产生的父姓单倍体的比率不同.以海岛棉或海岛棉品种间杂交F₁作父本时较高(2.5%),海陆种间杂交F₁作父本时次之(1.3%),陆地棉或陆地棉品种间杂交F₁作父本时较低(0.7%).用秋水仙素水溶液处理父性单倍体植株后获得13个加倍单倍体株系.以VSg单倍体植株作母本与正常异源四倍体棉花杂交可以获得非整倍体.     

两个水稻DH群体茎蘖消长的发育QTL分析

利用分别来源于窄叶青8号(ZYQ8)和京系17(JX17)及春江06(CJ06)和台中本地1号(TNI)2个组合的DH群体(分别称为DH-1和DH-2群体),采用非条件及发育QTL分析方法研究水稻茎蘖消长的遗传控制.其中,DH-1群体定位到条件与非条件QTL共44个,分布于第3、12染色体以外的其他10条染色体上;DH-2群体定位到条件和非条件QTL共70个,分布于第7染色体外其他11条染色体上.通过全基因组比较QTL定位,在2个群体间共确定了10对26个处于相似物理位置的QTL位点,其中有6对14个位点均在相同时期内被检测到,很可能包含有控制茎蘖数的主效数量基因,这些QTL位点在显著性、效应值和贡献率均存在较大差异,对其基因本质仍需进一步深入研究.     

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。     

Retrospect on in vitro androgenesis of sorghum (Sorghum bicolor)

Development of sorghum hybrids can immensely benefit from an enhanced anther culture protocol since the resultant doubled haploids would accelerate, as in other major cereal crops, the attainment of homozygosity and fixation of alleles. Production of the hybrids that have got high yielding, stress tolerance and other traits of industrial significance in a shorter time as compared to the current trend can hence be realized. This review presents the advances that have been made in the development of such a protocol, with closer attention to androgenic induction components of pre-treatment, culture media composition and conditions as well as ploidy determination and eventual chromosome doubling. From the findings of this review, it is clear that further work is desired to ensure a protocol, that to a large degree, breaks the genotype dependency trend that has been widely cited to impede the usability of the tested protocols.     

Effect of incubation temperature regimes and culture medium on broccoli microspore culture embryogenesis

Conditions for reliable induction of embryogenesis from isolated microspores were studied in ten genotypes of broccoli. Embryo yields were significantly increased in almost all of the broccoli genotypes by the incubation at 32.5 ^°C for 1 day, than when the standard incubation at 30 ^°C for 2 days was used. Treatments of 48 hours at 32.5 ^°C produced less than optimal results suggesting that broccoli microspores are more sensitive to high temperatures than those of B. napus. The use of the ¹/₂ NLN-13 medium yielded greater number of embryos than the standard NLN-13. The magnitude of the response to the redution of the concentration of major salts by half in the NLN medium varied with the different genotypes. High embryogenic broccoli cultivars, such as ‘Shogun’, ‘SDB9’, and ‘Green Valiant’, presented a better response to the reduction of the concentration of major salts by half in NLN-13. Reduction never produced a detrimental effect on embryo yield and seems not to have any effect in the subsequent development of embryos in plants. This revised version was published online in July 2006 with corrections to the Cover Date.     

The evaluation of superior Hordeum bulbosum L. genotypes for use in a doubled haploid barley breeding programme

Summary Eight Hordeum bulbosum selections were produced from a cross between Cb 2920/4 and Cb 2929/1, two genotypes widely used in doubled haploid breeding programmes. The selections were hybridized with barley to evaluate their ability to produce high proportions of well-differentiated haploid embryos compared with Cb 2929/1 as control. We report here an initial small-scale investigation followed by a larger-scale test in two different environments to assess seed setting, haploid embryo differentiation rates and VB hybrid formation. These VB embryos contain both parental sets of chromosomes and occur more frequently in the glasshouse during the winter. Two of the eight selections were identified as combining the desirable characteristics of both parents, namely high seed setting on cv. Vada which is partially incompatible with H. bulbosum, large numbers of well-differentiated haploid embryos and a low incidence of VB hybrids. The selections are available for release to interested research workers and plant breedersAbbreviations DH doubled haploid - VB a hybrid from H. vulgare x H. bulbosum which contains both parental sets of chromosomes     

基于双单倍体牙鲆挖掘与生长性状连锁的微卫星标记

利用中国水产科学研究院北戴河中心实验站2007年制备的双单倍体牙鲆为材料,根据生长性状表型值分成快速生长组(Fast growth group,FGG)和慢速生长组(Slow growth group,SGG),进行微卫星标记与生长性状的连锁分析.从牙鲆遗传连锁图谱选择40个高多态性的微卫星标记,覆盖了24个连锁群中的...