(芥蓝×羽衣甘蓝)×白菜型油菜人工合成甘蓝型油菜研究初报

以芥蓝和黄籽羽衣甘蓝的杂种 F1 作母本与黄籽白菜型油菜材料杂交.开展了甘蓝与白菜间多变种复合杂交人工合成甘蓝型油菜初步研究.在4个种间杂交组合中,授粉后20天统计,发育子房率在31.5%～60.1%;每100蕾发育胚珠数为 1.1～60.8;借助胚珠培养获得了1个人工合成甘蓝型油菜新材料,其形态上综合了3个亲本的特征.该人工合成甘蓝型油菜自交高度不亲和,蕾期自交结籽也仅 1.8粒/花蕾;与天然甘蓝型油菜杂交表现较高的亲和性,杂交亲和性表现与天然甘蓝型油菜基因型有关.     

利用人工合成甘蓝型油菜建立白菜—甘蓝附加系

采用白菜子房培养和甘蓝胚培养方法得到了带有标记性状的白菜和甘蓝种间杂种，并将这些人工合成甘蓝型油菜回交于白菜，得到３１个白菜－甘蓝单体附加系（２ｎ＝２１），和１８个双体附加系（２ｎ＝２２），为进一步对附加染色体上的所载基因定位奠定了基础。此外，还研究了附加甘蓝染色体对雄笥和雌性育性的影响，结果表明，白菜中附加甘蓝染色体可明显降低育性，特别是可显著降低附加系的自交和杂交结实率。     

人工合成甘蓝型油菜及其亲本的甲基化变异模式分析

甘蓝型油菜作为多倍体起源和发生的历史较短, 遗传背景较为狭窄, 人工合成甘蓝型油菜可作为植物多倍化研究的优选模型, 本文以人工合成的甘蓝型油菜为材料, 通过HPLC分析发现白菜型油菜和甘蓝的甲基化率分别为8.33%和15.88%, 2个杂种株系的全基因组甲基化水平介于双亲之间(分别为10.29%和12.83%)。MSAP分析发现杂种F₁代及其亲本的甲基化水平存在明显差异(白菜型油菜<杂种F₁<甘蓝), 杂种F1代的甲基化变异(23.71%)中来自A、C基因组的变异分别占6.60%和10.16%。MSAP差异性条带的序列分析发现多倍化过程中与甲基化变化相关的基因参与了多种生物学过程, 且差异甲基化基因在人工合成甘蓝型油菜及其亲本间的表达差异与甲基化修饰模式是一致的。本研究为了解甘蓝型油菜多倍化过程中发生的表观变异奠定了基础。     

白菜型油菜黄籽沙逊和芥蓝种间杂交合成甘蓝型油菜研究

人工合成甘蓝型油菜是拓宽油菜遗传育种种质资源的有效途径,也是研究芸薹属物种起源与演化的重要手段之一。为了把黄籽沙逊的黄籽性状同芥蓝的优良特性相结合,本研究利用白菜型油菜黄籽沙逊(Brassica. campestris var. Yellow Sarson Pain, 2n=AA=20)与芥蓝(Brassica albograbra, 2n=CC=18)开展了芸薹属种间杂交研究,在MS+6-BA 1.0 mg/L+NAA 0.1 mg/L+7%蔗糖+活性炭1.0 mg/L的培养基上,通过胚珠培养从授粉7 d的140个胚珠中得到6个远缘杂交胚发育而成的植株,其中1个自然加倍成为双二倍体,随后应用形态学、细胞学和分子标记的方法对双二倍体种间杂种植株进行了鉴定,结果表明杂种植株生长势较强,形态属于中间类型;根尖染色体压片观察显示杂种植株具有父母本的染色体数量之和;SSR分子标记分析表明,杂种植株包含了双亲的遗传信息,由此证明了所获杂种的真实性,这为最后自交分离获得黄籽甘蓝型油菜提供了科学依据。     

芥菜型油菜与白菜种间杂种的获得与鉴定

以芸薹属植物芥菜型油菜和白菜为研究对象，对其进行常规正反杂交后子房的离体培养，通过离体子房培养获得的杂种种子经MS培养基诱导成苗，获得了芥菜型油菜与白菜的杂种F1代植株，表现出杂种优势；通过细胞学的方法，鉴定了杂种F1幼蕾体的细胞染色体数为2n=28，为母本芥菜型油菜（2n=36）和父本白菜（2n=20）的单倍体染色体数之和；芥菜型油菜与白菜常规杂交后，经离体子房培养获得了“胚性芽”，确立了植物胚挽救的另一种形式。     

白菜—甘蓝染色体附加系的性状遗传

以白菜和甘蓝种间对应性状作为遗传标记性状，人工合成甘蓝型油菜，建立白菜—甘蓝附加系，并用附加系研究种皮颜色、花色和雄性不育等三个质量性状的遗传。结果表明，在甘蓝的染色体组和甘蓝型油菜所含的甘蓝染色体组中，控制种皮颜色和控制花色的基因分别载于不同染色体上，控制所用白菜雄性不育的育性恢复基因与控制种皮颜色和花色的基因也分别载于不同的染色体上；选择种间对应质量性状有显隐性差异的白菜和甘蓝材料合成的甘蓝型油菜附加系，可用所选择性状作遗传标记对其进行区分和利用。     

人工合成甘蓝型油菜高频率再生研究初报

资源材料保存在作物遗传资源的研究与利用中起到非常重要的作用。该实验以不同来源的人工合成甘蓝型油菜KH106，KH109，KH111D为材料，以花序轴，子房，果柄为外植体研究其再生情况，结果表明，由芥蓝和小白菜人工合成的甘蓝型油菜KH106的再生频率极显著高于由羽衣甘蓝和白菜型油菜人工合成的甘蓝型油菜KH109和KH111；与花序轴和子房为外植体再生频率相比，以果柄为外植体平均再生频率最高，差异达到极显著水平；利用不同预处理培养基处理不同时间，结果显示不经过预处理直接接种到分化培养基上再生频率最高。     

甘蓝型油菜与青花菜种间杂种子房离体培养研究

利用子房离体培养的方法克服了甘蓝型油菜与青花菜杂种后代杂种胚的衰亡,并通过组织培养技术获得了杂交后代。试验结果表明：授粉后15d的子房离体培养效果最好,获得7粒饱满种籽,其中2粒发芽,发芽率为0.29;1/2MS+B5有机+IAA1.5mg/L+蔗糖50g/L为最佳的子房离体培养基,平均每个角果可得到杂种0.17粒,杂种发芽率可达66.7%;通过比较父母本和杂交后代性状,发现杂交后代的生物学性状偏向父本。     

甘蓝型油菜小孢子培养中基因型及处理条件对成苗的影响

为进一步提高甘蓝型油菜小孢子培养效率,研究了基因型对甘蓝型油菜小孢子胚产量和再生植株自然加倍率的影响,以及小孢子振荡培养过程中光照与后期低温处理对胚状体一次成苗率和再生植株自然加倍率的影响。结果表明,基因型对小孢子培养胚产量和再生植株自然加倍率影响较大,D 393的胚产量和自然加倍率很高,分别高达119.87胚·蕾~(-1)和79.87%,D 393的自然加倍率是D 524的2～3倍;光照对一次成苗率和再生植株自然加倍率没有影响,4℃低温处理15 d能提高小孢子一次成苗率0.8～3倍。本研究获得了一个胚产量和自然加倍率都很高的甘蓝型油菜DH系D 393;综合考虑一次成苗率和加倍效率,在甘蓝型油菜小孢子培养进程中振荡培养阶段可能不需要光照,而在转入B 5固体培养基前应该对胚状体进行适当低温和时长的处理,可提高小孢子培养效率。     

甘蓝型油菜两类同核异质杂交种遗传效应的比较分析

探究甘蓝型油菜化学诱导型雄性不育(CIMS)和细胞质雄性不育(CMS)杂交种间遗传效应的差异,为利用CIMS和CMS途径进行油菜超高产育种提供依据。以3个甘蓝型油菜CMS和同核CIMS与4个恢复系按照ACII不完全双列杂交(3×4)配制2套同核异质杂交种及其亲本为试验材料,进行了连续2年的田间试验,将29个性状指标划分为农艺、产量、品质3类性状,利用QGA Station Microsoft分析软件中的加-显性(AD)模型进行了统计分析,结果表明:与同核CIMS杂种比较,CMS杂种农艺、产量和品质性状的加性方差分别高21.85%,72.11%,13.48%,显性方差分别高3.58%,94.44%,56.90%,加性方差比率分别高39.29%,8.94%,-7.05%;显性方差比率分别高15.83%,4.30%,89.97%。CIMS杂种与同核CMS杂种间在F1的差异大小为农艺性状产量性状品质性状,在F2为产量性状农艺性状品质性状;在F1、F2,与同核CIMS杂种比较,CMS杂种的群体平均优势农艺性状分别低31.61%,32.74%,产量性状高72.82%,76.95%,品质性状指标则低58.81%,22.63%;在F1、F2,CMS杂种的群体超亲优势为农艺性状分别低75.35%,76.33%,产量性状低47.53%,32.90%,品质性状高14.09%,20.53%。CMS杂种的农艺性状、产量性状的狭义遗传率则分别比CIMS杂种高47.77%,54.31%。CMS不育细胞质对油菜杂种的性状产生了影响,且不同性状受到的影响程度不同;即CMS杂种的性状受亲本基因型的控制程度高于CIMS杂种;对CMS杂种的亲本应在早期世代加强选择,主要利用亲本的一般配合力(加性效应)进行选择,而CIMS杂种的亲本则应在高世代加强选择;亲本的性状和亲本的特殊配合力(显性效应)对2类杂交种的表现都有较大影响,因而亲本的选配对杂种的表现有很大的决定性。     

Production of intergeneric hybrids between Brassica and Sinapis species by means of embryo rescue techniques

Reciprocal crosses were made to produce intergeneric hybrids among seven species of Brassica and three species of Sinapis with the aid of embryo rescue techniques. Ovule culture showed better responses in terms of hybrid plant development. Altogether, hybrids from 8 different combinations were obtained from the crosses between B. campestris var. trilocularis × S. turgida, B. campestris var. pekinensis × S. arvensis, S. arvensis × B. campestris var. pekinensis, B. oleracea var. alboglabra × S. alba, B. oleracea var. alboglabra × S. turgida, B. carinata × S. alba, B. carinata × S. arvensis, and B. carinata × S. turgida. Reciprocal crosses yielded no hybrid except in the combination of S. arvensis × B. campestris var. pekinensis. Among them hybrids from 6 combinations were established in the glass house. The hybridity of the plants was confirmed by morphological characters, pollen stainability, chromosome number and by isozyme analysis. Hybrids of four combinations out of six turned out as true hybrids, one as sesquidiploids and the another one as false hybrid plant. This revised version was published online in August 2006 with corrections to the Cover Date.     

Sexual hybridisation in crosses of cultivated Brassica species with the crucifers Erucastrum gallicum and Raphanus raphanistrum: Potential for gene introgression

Studies were conducted to investigate the crossability of the cultivated Brassica species, Brassica napus (oilseed rape), B. rapa (turnip rape), and B. juncea (brown and oriental mustard), with two related cruciferous weeds that are abundant in certain regions of Canada, Erucastrum gallicum (dog mustard) and Raphanus raphanistrum ssp. raphanistrum (wild radish). Seed was produced without recourse to embryo rescue from all reciprocal crosses except R. raphanistrum × B. juncea. Four hybrid plants were recovered, namely B. napus × E. gallicum, B. napus × R. raphanistrum (two plants), and B. rapa × E. gallicum. The hybrids were characterized by their morphology, RAPD analysis, and cytological examination. The B. rapa × E. gallicum hybrid was extremely vigourous and fertile, and would likely grow in natural habitats. This hybrid produced self-seed and backcrossed readily with the B. rapa parent and, to a lesser extent, with the E. gallicum parent. The B. napus × E. gallicum hybrid was a weak plant, but produced fertile backcross progeny with the E. gallicum parent. The B. napus × R. raphanistrum hybrids were vigourous but mostly sterile. Because of their low vigour and/or sterility, hybrids produced from crosses of B. napus with the cruciferous weeds would not likely be an environmental concern. However, the potential of the B. napus × E. gallicum and B. rapa × E. gallicum hybrids to backcross with E. gallicum may be of concern. This revised version was published online in July 2006 with corrections to the Cover Date.     

甘蓝型油菜与花椰菜种间杂种子房离体培养研究初报

甘蓝型油菜与花椰菜种间杂种子房离体培养研究初报     

芸芥(Eruca sativa Mill.)与芸薹属(Brassica L.) 3个油用种的远缘杂交

采用芸芥(Eruca sativa Mill.)与芸薹属3个油用种（Brassica napus, Brassica juncea, Brassica rapa）进行杂交，共授粉15 990朵花，获得1 257个角果，711粒杂交种子，结角率为7.86%，亲和指数0.045。经形态学鉴定，无论芸芥作母本还是芸薹属的三个油用种作母本，F1植株均为偏母植株。杂交所获得角果的角粒数很低，许多角果     

In-vitro Fertilization of Ovules of Some Species of Brassicaceae*

The method of in-vitro fertilization of ovules can be successfully applied to various species of Brassincaceae. Mature embryos and plants were obtained after in-vitro pollinating the ovules of Arabis caucasica, Brassica napus, B. oleracea var. sabellica (kale), B. oleracea var. italica (broccoli), Diplotaxis tenuifolia, Moricandia arvensis and Sisymbrium Loeselli. In the case of Sinapis alba fertilization and embryo development did not occur. The same method has been successfully used for obtaining hybrid immature embryos at different stages of development from crosses between B. napus X D. tenuifolia, B. napus X M. arvensis, B. oleracea var. italica X D. tenuifolia, D. tenuifolia x B. napus, D. tenuifolia. X M. arvensis and D. tenuifolia X S. Loeselli. The present findings show that in-vitro pollination of ovules of various species of Brassicaceae makes it possible to (a) perform the whole process of fertilization and embryogenesis; and (b) obtain intergeneric hybrid embryos.     

Resynthesis of Brassica napus L. for self-incompatibility: self-incompatibility reaction, inheritance and breeding potential

Self-incompatibility (SI) in Brassica has been considered as a pollination control mechanism for commercial hybrid seed production, and so far has been extensively used in vegetable types of Brassicas. Oilseed rape Brassica napus (AACC) is naturally self-compatible in contrast to its parental species that are generally self-incompatible. Introduction of S-alleles from its parental species into oilseed rape is therefore needed to use this pollination control mechanism in commercial hybrid seed production. Self-incompatible lines of B. napus , carrying SI alleles in both A and C genomes, were resynthesized from self-incompatible B. oleracea var. italica (CC) cv.'Green Duke' and self-incompatible B. rapa ssp. oleifera (AA) cv. 'Horizon', 'Colt' and 'AC Parkland'. All resynthesized B. napus lines exhibited strong dominant SI phenotype. Reciprocal cross-compatibility was found between some of these self-incompatible lines. The inheritance of S-alleles in these resynthesized B. napus was digenic confirming that each of the parental genomes contributed one S-locus in the resynthesized B. napus lines. However, the presence of two S-loci in the two genomes was found not to be essential for imparting a strong SI phenotype. Possible use of these dominant self-incompatible resynthesized B. napus lines in hybrid breeding is discussed.     

Transfer of powdery mildew resistance from Brassica carinata to Brassica oleracea through embryo rescue

Interspecific hybrid plants and backcross 1 (BC₁) progeny were produced through sexual crosses and embryo rescue between Brassica carinata accession PI 360883 and B. oleracea cvs Titleist’and‘Cecile’to transfer resistance to powdery mildew to B. oleracea. Four interspecific hybrids were obtained through application of embryo rescue from crosses with B. carinata as the maternal parent, and their interspecific nature confirmed through plant morphology and random amplified polymorphic DNA (RAPD) analysis. Twenty‐one BC₁ plants were obtained through sexual crosses and embryo rescue although embryo rescue was not necessary to produce first backcross generation plants between interspecific hybrids and B. oleracea. All interspecific hybrids and eight of the BC₁ plants were resistant to powdery mildew.