萝卜与芸薹属物种间的远缘杂交研究进展

萝卜是十字花科植物中与芸薹属亲缘关系最近的物种,是芸薹属植物遗传改良的宝贵种质资源,可提供细胞质雄性不育基因、恢复基因、自交不亲和基因以及多种抗逆基因。笔者概述了近1个世纪以来萝卜与芸薹属物种间远缘杂交的研究进展,包括萝卜属与芸薹属植物的亲缘关系、杂交不亲和性机理、改良杂交效率的技术和手段、萝卜优异基因在近缘种中的应用、新型遗传材料的创制及人工合成新物种,并对萝卜属与芸薹属远缘杂交育种的前景进行了展望。     

芸薹属栽培种与近缘种的远缘杂交及进展

芸薹属栽培种的众多近缘种是其遗传改良的宝贵种质资源,可提供许多有用的性状及基因。在过去的几十年中,研究者通过有性杂交和原生质体融合的方法,合成了许多远缘杂种及后代材料、异源胞质雄性不育系,极大地促进和丰富了芸薹属栽培种的遗传研究与育种工作。     

萝卜与芸薹属远缘杂交不亲和性克服及DNA甲基化的研究进展

通过远缘杂交可以获得种内杂交难以得到的变异类型,创造许多新的种质资源,为品种改良提供原材料。从20世纪20年代开始,人们就已经开展了萝卜属与芸薹属植物远缘杂交的研究,并有不少属间杂交成功的报道。本文综述了当前萝卜与芸薹属属间不亲和性的机制,总结了不亲和性的克服方法,并概括了不同属间远缘杂种的育性和DNA甲基化的研究进展,以期为今后萝卜与芸薹属蔬菜品种的遗传育种工作提供参考。     

芸薹属植物远缘杂交研究现状

着重论述了芸薹属植物远缘杂交不亲和机理及克服不亲和的方法 ,并提出了几个问题与展望     

芸薹属植物的远缘杂交

芸薹属(Brassica)植物是一个种类繁多、用途广泛的物种。由于长期的人工选择和品种间杂交选择,用于栽培种品种选育的亲本资源日渐狭窄。以有性杂交、原生质体融合为基础的远缘杂交是解决芸薹属中栽培种基因资源亏乏的重要手段。通过远缘杂交可以将新的优良特异基因从异种或异属植物中导入到目标栽培种中,提高栽培种的品质、产量及抗逆性,创造新的蔬菜类型。转移萝卜的不育性基因、高效利用杂种优势是芸薹属远缘杂交成功的典型例证。种、属间远缘杂交尤其属以上的杂交不亲和,可通过混合、多次重复授粉、化学药剂处理、幼胚拯救等提高结实性。染色体加倍、回交法、延长培育世代等可克服远缘杂种不育性。本文综述了芸薹属植物远缘杂交中存在的问题及克服方法,预测了未来芸薹属植物远缘杂交育种的发展方向。     

芸薹属作物根肿病抗性遗传研究进展

对芸薹属作物上发生的根肿病致病机理、抗性遗传基础以及病害防控进行了综述,为根肿病的抗性遗传规律研究及抗病育种提供了依据。     

芸薹属作物雄性不育研究进展

综述了芸薹属作物雄性不育系的花器的形态特征,以及芸苔属作物雄性不育系花粉败育的细胞学与生理生化研究进展,同时对两种不育类型的遗传机制研究进展进行了概述。     

芸薹属作物体细胞杂交研究

自Cocking(1960)首创原生质体技术以来,目前植物原生质体培养和体细胞杂交技术已进入实际应用阶段。已有大量的植物甚至包括单子叶的禾谷类作物如玉米、水稻(Webb,1988)均可由原生质体再生植株,并在分类上不同程度趋异的植物种、属间     

芸薹属蔬菜分子育种研究进展

综述了近年来芸薹属蔬菜的分子育种研究进展,包括种质资源研究、分子遗传图谱构建及重要农艺性状的分子标记,重点综述了抗病性、抗逆性和品质等方面的主要研究进展,并讨论了我国今后芸薹属蔬菜分子育种的主要研究方向。     

萝卜与芥菜远缘杂交新品种的选育研究

以萝卜不育系为母本,雪里蕻、大头菜和多裂叶芥为父本,在温室通过蜜蜂进行远缘杂交,并获得杂交种。经过田间种植淘汰掉假杂种,获得一株叶形明显变异的品种,对其自交,其分离成7个类型品系。选取较稳定的"萝芥4号"品系观察了其生长形态、下扎趋势以及根系分布特性,分析了早期生长过程中品种间的相似性,同时针对"萝芥4号"及对照品种进行营养成分分析。采用"武A"雄性不育系与"萝芥4号"配制杂交组合,获得叶片性状遗传稳定、肉质根杂交优势明显的组合,该组合十分适合腌制加工。     

从萝卜下胚轴再生完整植株

以萝卜无菌幼苗下胚轴为外植体,研究了不同基因型萝卜品种,不同浓度的NAA、BA、蔗糖、AgNO3对植株再生的影响。基本培养基(BM)为MS无机盐 Gly2mgL 肌醇2mgL 烟酸05mgL VB101mgL 琼脂68gL。试验证明萝卜离体再生主要受基因型和BA、NAA浓度影响。从自交系小红头下胚轴愈伤组织产生的绿色子叶状团块在提高BA、NAA浓度的培养基中大量增殖;降低激素浓度,尤其是BA浓度后,这些子叶状簇生团块发育成大量无根苗,叶片正常。无根苗在添加不同种类的生长素的培养基中生根,并成功地移植入田间。本实验也对AgNO3的作用进行了研究和讨论。     

萝卜组培苗与实生苗若干生理生化性状的比较研究

对萝卜组培苗与实生苗生长过程中若干生理生化性状进行了研究，结果表明，组培苗叶片中可溶性糖含量高于实生苗，而根部可溶性糖含量低于实生苗；组培苗叶片中过氧化物酶(POD)活性在定植后42d内低于实生苗，56d时显著增加并高于实生苗，之后又回落，70d时低于实生苗；而组培苗根部POD活性始终高于实生苗；组培苗叶片和根中超氧化物酶(SOD)活性均高于实生苗。组培苗和实生苗的酯酶(EST)、POD及淀粉酶同工酶酶谱在叶片与根部之间有差异，但相同部位均没有出现特征带。     

萝卜硫苷生物合成相关基因RsFMO_(GS-OXs)的预测及分析

以控制拟南芥硫苷生物合成相关基因家族FMO GS-OXs全长cds为参考序列,在萝卜ESTs数据库中进行blastn检索,得到具备Score≥100、E-value≤10-10和coverage≥70%条件的24条萝卜ESTs作为候选的拟南芥FMO GS-OXs基因的同源ESTs,并进行序列聚类拼接、注释及分析。结果显示:在萝卜中发现两个旁系同源基因(RsFMO GS-OXa和RsFMO GS-OXb)。RsFMO GS-OXs与拟南芥FMO GS-OXs间在核酸水平上的一致性为68.0%⁸3.2%;RsFMO GS-OXs旁系同源基因间的一致性仅为67.3%;RsFMO GS-OXs与白菜FMO GS-OXs同源基因间的一致性为67.3%83.2%;RsFMO GS-OXs旁系同源基因间的一致性仅为67.3%;RsFMO GS-OXs与白菜FMO GS-OXs同源基因间的一致性为67.3%⁹2.9%。系统进化分析发现,RsFMO GS-OXa和白菜FMO GS-OX2基因亲缘关系最近,而RsFMO GS-OXb和白菜FMO GS-OX5a亲缘关系更近一些,同时认为,RsFMO GS-OXa和RsFMO GS-OXb的直系同源基因分别为FMO GS-OX2和FMO GS-OX5。     

油菜与蔊菜远缘杂交亲和性研究初报

用油菜与菜进行了远缘杂交。以甘蓝型油菜为母本时 ,直接去雄授粉的有两个花序结实 ,共收获种子 3 9粒 ,其F1 有较大的分离。以菜为母本时 ,仅子房膨大 ,角果生长中途停止 ,但一直未枯死。试验结果表明油菜与菜的远缘杂交有一定的亲和性。     

Analysis and Evaluation of Nutritional Quality in Chinese Radish (Raphanus sativus L.)

Radish (Raphanus sativus L.) is an important vegetable crop worldwide. High nutritional quality was critical in its genetic improvement and production. The nutritional quality of 42 Chinese radish cultivars was analyzed in this study. The contents of six nutritional facts, dry matter (DM), crude fiber (CF), total soluble sugar (TSS), vitamin C (Vc), protein, and nitrate, ranged from 29.7 to 88.2, 4.507 to 18.546, 2.233 to 15.457, 0.1416 to 0.3341, 0.34 to 1.15, and 1.81 to 5.89 g kg-1 flesh weight (FW), respectively. Significant differences among the 42 radish cultivars were detected in the contents of nutritional facts. The data were subjected to cross-correlation analysis and principal component analysis (PCA). It was found that DM content was positively correlated with the content of TSS (r=0.7104), Vc (r=0.4011) and protein (r=0.4120). Vitamin C (Vc) content of radish showed a positive correlation (r= 0.3300) with the protein content. According to the principal component analysis, out of the 42 radish cultivars, Nau-17, Nau-28, Nau-6, Nau-11, Nau-10, Nau-27, and Nau-31 were detected with very high scores in comprehensive evaluation. It could be concluded that abundant diversity of nutritional fact content occurred in different radish genotypes, and PCA analysis was effective for selecting radish germplasm with high quality. The results could contribute useful knowledge of nutritional quality, and provide important germplasms for the elite cultivar development and the inheritance study of nutritional facts in radish.     

不同颜色肉质萝卜核型分析研究

以红皮红心、绿皮红心、红皮白心和白皮白心4种不同肉质颜色的32份萝卜品种为材料,室内检测红色肉质萝卜的色素含量及镜检观测不同颜色肉质萝卜的核型.结果表明,供试红色肉质萝卜色素含量变幅为3.4‰～28.8％,基因型间存在显著差异.不同颜色肉质萝卜品种的染色体数目均为2n=2x=18,且未见随体,红皮红心萝卜核型公式为2n...     

Molecular Characterization and Expression Profiles of Myrosinase Gene (RsMyr2) in Radish (Raphanus sativus L.)

Myrosinase is a defense-related enzyme and is capable of hydrolyzing glucosinolates into a variety of compounds, some of which are toxic to pathogens and herbivores. Many studies revealed that a number of important vegetables or oil crops contain the myrosinase-glucosinolate system. However, the related promoter and genomic DNA sequences as well as expression profiles of myrosinase gene remain largely unexplored in radish (Raphanus sativus). In this study, the 2 798 bp genomic DNA sequence, designated as RsMyr2, was isolated and analyzed in radish. The RsMyr2 consisting of 12 exons and 11 introns reflected the common gene structure of myrosinases. Using the genomic DNA walking approach, the 5′-flanking region upstream of RsMyr2 with length of 1 711 bp was successfully isolated. PLACE and PlantCARE analyses revealed that this upstream region could be the promoter of RsMyr2, which contained several basic cis-regulatory elements including TATA-box, CAAT-box and regulatory motifs responsive to defense and stresses. Furthermore, recombinant pET-RsMyr2 protein separated by SDS-PAGE was identified as myrosinase with mass spectrometry. Real-time PCR analysis showed differential expression profiles of RsMyr2 in leaf, stem and root at different developmental stages (e.g., higher expression in leaf at cotyledon stage and lower in flesh root at mature stage). Additionally, the RsMyr2 gene exhibited up-regulated expression when treated with abscisic acid (ABA), methyl jasmonate (MeJA) and hydrogen peroxide (H₂O₂), whereas it was down-regulated by wounding (WO) treatment. The findings indicated that the expression of RsMyr2 gene was differentially regulated by these stress treatments. These results could provide new insight into elucidating the molecular characterization and biological function of myrosinase in radish.