埃塞俄比亚芥与诸葛菜属间杂种的基因组原位杂交分析

用幼胚培养方法重新获得的埃塞俄比亚芥(Brassica carinata A.Braun,2n=34)与诸葛菜(Orychophragmus violaceus (L.)O.E.Schulz,2n=24)的属间杂种仍为混倍体(2n=14～34),2n=34细胞的频率最高;绝大多数花粉母细胞(PMCs)表现正常的17个二价体配对和17：17的分离。基因组原位杂交分析结果表明,在所有体细胞和PMCs中不含有整条的诸葛菜染色体,2n=34的体细胞和PMCs中包含了来自黑芥(B．nigra (L．)Koch,2n=16)的16条染色体。这些具有完全或部分埃塞俄比亚芥染色体组成的细胞,可能来源于以前提出的杂种细胞在有丝分裂中完全或部分亲本染色体组分开和染色体复制,并伴随诸葛菜染色体的消除。     

不同细胞质埃塞俄比亚芥的获得及其生物学特性比较研究

以埃塞俄比亚芥(Brassica carinata)为轮回亲本,分别对甘蓝型油菜(Brassica napus)和芥菜型油菜(Brassica juncea)连续回交7代,获得了具有核基因组基本相同而细胞质不同的新材料:N/BBCC和J/BBCC。两个新材料及其轮回亲本C/BBCC在生长发育时期、植株外部形态特征、POD酶活性等方面表现基本一致,但在雄性育性、脯氨酸含量及相对电导率上存在着明显差异,其中N/BBCC雄蕊发育不完善、花药瘦小、药内花粉量很少且多为无生活力的畸形花粉,表现严重败育;J/BBCC和N/BBCC的脯胺酸含量及相对电导率明显低于其轮回亲本C/BBCC。     

新疆昭苏野生油菜与黑芥品种尤嫩斯染色体组型和带型比较研究

大量的细胞学观察表明,昭苏野生油菜与黑芥之间,不论是在染色体数上,还是在染色体组型、带型以及染色体大小、总长上都有较大的差异。昭苏野生油菜的染色体数为2n=18,芥黑则为2n=16;染色体组型,前者为14m+4m(SAT),后者为8m+4sm+4sm(SAT);染色体带型,前者为12C/C+2CN/C+2WN~O/O+2W/O,后者为12C/C+2WN/C+2WN~O/C;染色体长度前者为2.00—4.00μ,后者为6.48—3.75μ,虽然黑芥染色体条数少于野生油菜,但总长度却长于昭苏野生油菜。通过观察测量和分析比较,我们认为,昭苏野生油菜与黑芥在亲缘关系上有着较大的距离,二者为不同的物种。     

荧光原位杂交分析小麦-簇毛麦杂种减数分裂与染色体易位

利用基因组ＤＮＡ荧光原位杂交技术详细地研究了小麦－簇毛麦杂种染色体的减数分裂和配对行为,结果表明,在中期Ⅰ,小麦和簇毛麦染色体多呈两个单价体,在０．３％的ＰＭＣ中小麦与簇毛麦染色体发生配对;在后期Ⅰ时,单价体错分裂频率为３２．７％－３７．５％,另有０．７％的小麦－簇毛麦染色体重组易位出现;后期Ⅱ时,断列染色体的频率为２０．５％－２２．４％,还发现有０．８２％－１．７２％的自发易位染色体形成,此外,     

我国芥菜型油菜品种遗传多样性初探

用ＲＡＰＤ技术对包括春、冬芥菜型采及国外品种在内的３６个芥菜型油菜品种的遗传多样性进行了分析。在扩增得到的１２８条ＤＮＡ带中,多态性ＤＮＡ片段达８８．２８％。分析表明：春 油菜间遗传差异较大,国内冬性芥菜型油菜地方种多样性水平较高,２５份冬性品种分属Ⅰ、Ⅱ和Ⅲ类群,而春性芥菜型 采地方种均归于Ⅳ类;印度的ＲＬＭ１９８与四川的珙县金黄油菜、澳大利亚品种与我国春油菜品种亲缘关系密切。     

芥菜型多室油菜与甘蓝型油菜的种间远缘杂交

通过对芥菜型多室油菜与甘蓝型油菜种间杂交 以下简写为芥×甘或甘×芥 的结实性、交配性以及不同甘蓝型油菜对交配性的影响等研究发现:芥、甘正反交形成的饱满种子数较少,其形成种子的能力弱,但是芥×甘与甘×芥杂交相比,芥×甘形成饱满种子的能力较强,受精能力以及杂种胚胎的发育能力也强,在授粉后的子房发育上二者无显著差异.所以,芥菜型多室油菜与甘蓝型油菜种间杂交创建新资源时宜采用芥×甘杂交方式;不同甘蓝型油菜品种与芥菜型多室油菜正反交的结角率、受精指数、结籽指数和可交配指数均不相同,但可交配指数的变异系数最大.因此,筛选可交配性强的甘蓝型基因型应着眼于可交配指数高的甘蓝型油菜亲本材料,根据本试验结果,芥菜型多室油菜与甘蓝型油菜93-221-1杂交形成的杂种胚具有较强的可发育性.     

芥菜型油菜和白菜型油菜种间杂种遗传分析

种间杂交是一种拓宽栽培作物遗传基础和转移优良性状的重要手段,已经广泛地用于作物品质的改良。本研究通过芥菜型油菜（Brassica juncea L.）和白菜型油菜（Brassica rapa L.）种间杂交,将芥菜型油菜的有利性状转移到白菜型油菜中,创造新型白菜型油菜,以改良白菜型油菜的农艺性状、提高抗逆性和拓宽其遗传基础。研究结果表明：以芥菜型油菜作母本、白菜型油菜作父本的杂交组合较易获得杂交种子,杂种F1植株营养生长具有较明显的杂种优势,但花粉完全不育;以白菜型油菜回交获得的BC1植株间表型差异明显,平均花粉可染率为34.8%,介于 0~84%之间,群体自交不亲和;BC1F1和BC2群体变异广泛,出现自交亲和植株和黄籽植株,平均花粉可染率分别为79.7%和79.1%。     

甘蓝型油菜和芥菜型油菜种间杂交研究

甘蓝型油菜与芥菜型油菜杂交研究结果表明,杂交结实力与杂交组合方式以及参与杂交的亲本材料有关,以芥菜型油菜作母本的杂交结实力高于以甘蓝型作母本的组合：芥×甘杂交组合的平均结实数／花为 ２．６４ 粒,而甘×芥杂交组合的平均结实数／花为 ０．１０ 粒。芥甘杂种一代形态特征和生育期介于双亲之间,甘芥杂种一代不表现整齐的中间类型,株间差异明显;总体来看,芥甘杂种一代与双亲回交的结实力（０．４０,０．２１）低于甘芥杂种一代与双亲回交的结实力（３．３０,１．７４）,无论是芥甘杂种一代还是甘芥杂种一代,用甘蓝型油菜作父本回交的结实力高于用芥菜型油菜作父本回交的结实力,但也有个别回交组合出现例外,不表现上述规律。 Ｂ Ｃ１ 代种子当年播种出苗率低（１８．５％ ）,群体株间性状差异明显,生育期极不一致。芥甘杂种一代与甘蓝型油菜亲本第二次回交,其平均结实数／花较回交一代提高 １．０８ 粒, Ｂ Ｃ２ 代种子当年播种出苗率仍较低,但较对应的 Ｂ Ｃ１ 代稍有提高,群体中出现趋回交父本性状但雄性育性彻底退化的植株。芥甘杂种一代自由授粉所得 Ｆ２ 群体是一个变异极为丰富的遗传群体。     

芥菜型油菜种质资源研究进展

本文从收集保存、鉴定、研究、创新和利用5个方面介绍了芥菜型油菜种质资源研究进展。芥菜型油菜起源于亚洲,印度、中国收集的资源最多。芥菜型油菜可以分为中国-东欧类型和中国-印度类型2大类,每一类中均存在较大的遗传变异,许多具有优良性状的种质已经鉴定出来,并对其进行了生理学、遗传学研究。通过远缘杂交、诱变和遗传转化已创造出芥菜型油菜新种质。已鉴定、培育的芥菜型油菜优异种质资源在油菜育种上得到广泛利用。     

Production and cytogenetics of the intergeneric hybrids Brassica juncea×Orychophragmus violaceus and B. carinata×O. violaceus

 Intergeneric hybrids between Brassica juncea (2n=36), B. carinata (2n=34) and Orychophragmus violaceus (2n=24) were produced when B. juncea and B. carinata cultivars were used as female parents. The hybrids between B. juncea and O. violaceus had an intermediate morphology except for petal colour and were partially fertile. The hybrids between B. carinata and O. violaceus had a matroclinous morphology and were nearly fertile. Cytological analysis of the hybrids and their progenies gave the following results. (1) In the hybrids between B. juncea and O. violaceus, the somatic tissues of the roots, leaves and styles were mixoploid (2n=12–42), and cells with 24, 30 or 36 chromosomes were the most frequent. Based on the recorded numbers and behaviour of the mitotic and meiotic chromosomes, complete and partial separation of the parental genomes was proposed to have occurred during mitosis. This resulted in the occurrence of cells with possibly complete and incomplete complements of the parental species and cells with parental complements and some additional chromosomes from the other parent. (2)  Pollen mother cells (PMCs) possibly with both parental chromosome complements, only B. juncea chromosomes or a complete B. juncea complement with additional O. violaceus chromosomes were more competitive in entering meiosis. The majority of fertile gametes were deduced to have been produced by PMCs with a B. juncea complement with or without additional O. violaceus chromosomes. (3) The progeny plants from selfed hybrids between B. juncea and O. violaceus were morphologically either of a B. juncea, hybrid or variable type. Cytologically they were grouped into six types according to the frequencies of cells with various chromosome numbers. All of the plants except 2 which constituted two types, were mixoploids, composed of cells with various chromosome numbers, mainly in a certain serial range. (4) The hybrid plants between B. carinata and O. violaceus were mixoploids with chromosome numbers in the range of 12–34, and cells with 2n=34 were the most frequent. The main categories of PMCs with 17 bivalents at metaphase I and 17 : 17 segregations at anaphase I contributed to the high fertility of the hybrids and the fact that their progeny after selfing were mainly plants with 2n=34. Somatic and meiotic separation of the parental genomes was proposed to have occurred in the hybrids between B. carinata and O. violaceus. (5) Mitotic and meiotic elimination of what could be O. violaceus chromosomes might also have contributed to the observed mitotic and meiotic cell types in the two kinds of hybrids studied. Finally, the possible mechanisms behind these cytological observations and their potential in the production of Brassica aneuploids were discussed. Received: 4 February 1997/Accepted: 29 July 1997     

Comparison of feeding behaviour of two Brassica pests Brevicoryne brassicae and Myzus persicae on wild and cultivated brassica species

Feeding behaviour of the specialist Brassicae aphid, Brevicoryne brassicae (L) (cabbage aphid) and the generalist, Myzus persicae, (Sulzer) (peach potato aphid) was monitored electronically on the susceptible cauliflower, Brassica oleracea var. botrytis cv Newton Seale, and a range of 17 Brassica species, B. carinata, B. juncea, B. nigra, B. macrocarpa, and B. villosa var. drepanensis and cultivated brassica varieties, B. oleracea, B. campestris and B. napus. Aphids, monitored for 10 h on the underside of leaves, performed recognisable feeding behaviour on all brassica species. The main differences in feeding behaviour, between M. persicae and B. brassicae, on the susceptible cauliflower Newton Seale, were fewer probes, shorter times to initially reach the phloem but longer times to establish sustained phloem ingestion and the longer times spent, by M. persicae, in xylem ingestion.Feeding behaviour on the range of brassica species tested indicated that generalist and specialist aphids are influenced differently by the host plant. A longer time spent in xylem ingestion was again the major difference in the feeding behaviour of the two aphids. In addition, rejection of passive phloem ingestion, by M. persicae, was not related so closely to increased time spent in non probing activities, as for B. brassicae. This observation indicates that M. persicae does not generally accept or reject brassica species due to the presence of phagostimulants, such as glucosinolates at the leaf surface or along the stylet pathway, unless the concentration is very high. Differences in feeding strategies employed by generalist and specialist aphids on the same plants are discussed.     

芥蓝与芸苔属几个常见种花粉形态的比较

本文通过对芸苔属(Brassica L.)几个常见种芥蓝(B. alboglabra Bailey)、芥菜(B.juncea(L. )Coss.)、油菜(B. campestris L.)和花椰菜(B. oleracea var. botrytis L.)等花粉形态的光学显微镜和扫描电镜的观察比较,得知它们的花粉形态特征比较一致。而与杨萍等关于芥蓝的花粉形态特征——无极,具散孔这一报道截然不同;亦与黄增泉(Huang Tseng-chieng)关于芥菜的花粉特征——不具萌发孔的报道不同。作者的研究表明,上述几个种的花粉均具3沟,沟长而明显。外壁具网状纹饰,网眼较粗。但种与种间其花粉大小有所不同。作者不同意杨萍等关于“由于芥蓝的花粉形态与芸苔属其它种的花粉明显区别,说明芥蓝与芸苔属其它种不很亲缘”的观点,而认为,从花粉形态看,芥蓝与芸苔属其它种是基本一致的,把它们置于同一自然类群是合理的。     

初始培养条件对定兴芥小孢子胚胎发生的影响

本文探索了油菜花药培养中小孢子胚早期发育的适宜条件。花药分步悬浮法第一培养基的简化实验表明,小孢子胚在仅含有20%蔗糖的空白培养基上的诱导率(212%)与对照的(202%)无显著差异。这样,第一培养基便从原Keller培养基简化为不含大量、微量和有机元素而仅含有20%蔗糖的水溶液,并且,花药第一阶段的培养时间从原来的3—5天减少到1.5—2天。此外,研究了花药在蔗糖水溶液上的滞留时间对小孢子胚胎早期发育的影响。滞留36～48小时,小孢子胚的诱导率(135%)最佳。考察小孢子胚胎早期发育的状况与不同滞留时间的关系则发现,36—48小时内每100个活细胞里,膨大细胞约占70%。这表明,早期培养时,花粉只要膨大而不需分裂即可转入第二阶段培养,便可获得较高产率的胚状体。     

The relative importance of glucosinolates and amino acids to the development of two aphid pests Brevicoryne brassicae and Myzus persicae on wild and cultivated brassica species

This paper describes an experiment to investigate the relative importance of glucosinolates and the availability of free amino acids in the phloem to the feeding behaviour and development of the specialist brassica aphid, Brevicoryne brassicae (L) (cabbage aphid) and the generalist, Myzus persicae, (Sultzer) (peach potato aphid). Aphid development was determined on brassica species and cultivated brassica varieties. Analysis of individual glucosinolates in the wild brassica species identified significant differences in their profiles and in their concentrations present in freeze dried leaves. Multiple regression analysis showed a significant correlation ( ) between the intrinsic rate of increase of B. brassicae and glucosinolate concentrations; four glucosinolates, 2-OH-3-butenyl, and 2-propenylglucosinolate, 3-methoxyindolyl and 4-pentenylglucosinolates accounted for 79% of the variation. The intrinsic rate of increase of M. persicae was less correlated, though still significant ( ); 3-indolyglucosinolate and 3-butenylglucosinolate accounted for 47% of the variation. Regression analysis also showed a correlation between phloem amino acid concentrations and the intrinsic rate of increase of B. brassicae ( ) but not of M. persicae. The concentration of the important amino acids tyrosine, alanine, leucine and glutamic acid, accounted for 43% of the variation in intrinsic rate of increase. Leaf water potential of the Brassica species showed no relationship with the intrinsic rate of increase of either B. brassicae or M. persicae.     

Random chloroplast segregation and mitochondrial genome recombination in somatic hybrid plants of Diplotaxis catholica+Brassica juncea

Detailed molecular analysis of the somatic hybrid plants of Diplotaxis catholica+B. juncea indicated random chloroplast segregation. One of the five hybrid plants analyzed derived its chloroplasts from D. catholica and two hybrids had chloroplasts of B. juncea origin. Two hybrid plants maintained mixed population of chloroplasts. The mitochondrial (mt) genomes of the fusion partners had undergone recombinations. Occurrence of fragments specific to both the parents in HindIII digestion followed by atp 9 probing, as in hybrid DJ5, provided evidence for intergenomic mitochondrial recombination between D. catholica and B. juncea. Similar mt genome organization in two hybrids (DJ3 and DJ6) suggested that intergenomic recombination may be preferred at specific sites. Hybrid DJ1 had about 70% similarity to D. catholica in mt genome organization. mt genomes of hybrids DJ2, 3, 5, and 6 differed from B. juncea by 14.3–28%. The significance of these novel mt genome organizations in developing novel male sterility systems is discussed. Received: 4 April 1997 / Revision received: 19 December 1997 / Accepted: 28 March 1998