甘蓝型油菜小孢子培养技术及其单倍体应用研究进展

油菜小孢子培养已经成为油菜育种和生物技术的一项重要内容.由于影响小孢子成胚和成苗的因素较多,低诱导频率及成苗率严重限制了该技术在育种中的应用.为了全面了解小孢子胚状体发生能力及影响再生体系的各项因素,掌握该技术的研究动态和发展方向,总结了近20年来国内外影响小孢子培养的主要因素:供体植株基因型、供体植株生长条件及生理状态、小孢子发育时期、培养基组成、培养条件,及其在双单倍体育种、诱变育种、转基因育种等领域中的应用.     

小麦游离小孢子培养的研究

在游离小孢子培养过程中认为子房共培养可显著地提高游离小孢子胚状体愈伤率和再生率 ,子房共培养以 2 0个子房为宜。低温子房共培养胚状体发生和愈伤率低 ,但绿苗分化率较高 ,施加PAA、谷氨酰胺对游离小孢子形成的胚状体有促进作用。麦芽糖是游离小孢子培养最好的碳源 ,以蔗糖、葡萄糖以及葡萄糖和果糖搭配作碳源均未获得胚状体。检查培养 3d后的小孢子活力发现 ,唯有麦芽糖作碳源培养的小孢子有活力 ;认为高浓度的蔗糖、葡萄糖以及葡萄糖加果糖对小孢子有毒害作用。当葡萄糖浓度达到 2 0mmol/L时就对小孢子有毒害作用且致死。当在麦芽糖培养基中培养 1d后加入高浓度的葡萄糖发现小孢子存有活力 ,而且随着起始培养天数的增加活力也增加。对Y77品系来讲 ,适宜小孢子培养的麦芽糖浓度为 0 12mol/L。饥饿和热激 (33℃ )预处理对游离小孢子培养有促进胚状体和愈伤形成的作用     

通过花药漂浮培养提高花椰菜小孢子胚胎发生率

通过花药漂浮培养,成功地诱导两个秋花椰菜基因型的小孢子胚胎发生.在液体培养基与固、液体双层培养基上,小孢子胚胎产量相仿,但后者褐色胚产生较多.在液体培养基中加入62.5mg/L的硝酸银对诱导小孢子胚胎发生效果较好.试验结果表明,采用花药漂浮培养方法可以明显提高花椰菜小孢子胚产量.     

芸薹属蔬菜游离小孢子成胚影响因素研究进展

游离小孢子培养也称花粉培养,是以植物细胞全能性为基础,植物组织培养发展的一个分支。利用此项技术,可获得纯合体植株,缩短常规育种年限,为基因工程、细胞工程等学科提供载体或目的基因。笔者综述了近年来国内研究中的关于芸薹属蔬菜游离小孢子培养中的成胚影响因素,主要包括：供试材料的基因型、生长环境、小孢子的发育时期、分离方法、预处理、激素及活性炭的添加等,并结合实际提出了小孢子培养研究中存在的一些问题和对其未来发展的期望。     

花椰菜游离小孢子培养及植株再生研究

以186个花椰菜杂交品种及组合为试材,进行了游离小孢子培养研究。结果表明:基因型是胚状体发生的决定因素;24 h 32℃的高温前处理是胚状体发生的必须条件;单核靠边期到双核期的小孢子是进行胚状体诱导的最佳时期,胚状体发生频率最高;培养基中添加6-BA 0.1 mg/L,NAA 0.005 mg/L可以促进胚状体发育。将20 d的胚状体进行脱分化处理,可以大幅度提高胚状体的成活率,植株再生率为53%,再生植株中双单倍体占83.5%。     

玉米小孢子高频再生培养技术程序研究

以大田种植的玉米供体植株为实验材料,以提高游离小孢子存活率及成胚率为重点进行了技术优化研究。摸索出了一些行之有效的技术措施,提高了游离小孢子的离体培养反应,获得了一批再生植株。通过技术优化,建立玉米小孢子离体培养高频再生技术程序,在此基础上构建了玉米DH育种技术平台。应用这一技术平台,可以在当年获得玉米DH纯系的种子,第二年即可安排大田纯系鉴定。     

玉米小孢子培养高频再生技术程序的研究

以大田种植的玉米供体植株为实验材料，以提高游离小孢子存活率及成胚率为重点进行了技术优化研究。摸索出了一些行之有效的技术措施，提高了游离小孢子的离体培养反应，获得了一批再生植株。通过技术优化，建立玉米小孢子离体培养高频再生技术程序，在此基础上构建了玉米DH育种技术平台。应用这一技术平台，可以在当年获得玉米DH纯系的种子，第二年即可安排大田纯系鉴定。     

影响油菜游离小孢子培养再生因素的研究进展

游离小孢子培养已经成为油菜遗传育种和生物工程的重要内容。由于影响游离小孢子形态发生的因素较多，尤其是生长在大田环境下的植株，小孢子发育不一致，游离小孢子形态发生产生频率低，因此形态发生诱导率低仍然是限制该技术广泛应用的一个问题。为此，深入和全面了解影响小孢子形态发生能力及再生体系的各种因素，掌握这一领域的研究动态和今后发展的方向，有助于优化油菜小孢子的再生体系、促进油菜育种。本文总结了油菜游离小孢子形态发生的研究进展，并认为应用分子技术克服小孢子离体形态发生障碍有极大的发展潜力。     

活性炭对甘蓝型油菜(Brassica napus L.)小孢子胚胎发生的影响

试验以大田环境下的多份甘蓝型油菜的品种或品系为材料,研究了活性炭对游离小孢子胚胎发生的影响.结果表明:活性炭对甘蓝型油菜游离小孢子培养胚状体发生有很好的促进作用,不仅提高了胚产量,而且有利于小孢子胚的正常发育,添加活性炭的固液双层培养基效果尤为显著.     

活性炭对甘蓝型油菜（Brossica napus L．）小孢子胚胎发生的影响

试验以大田环境下的多份甘蓝型油菜的品种或品系为材料，研究了活性炭对游离小孢子胚胎发生的影响。结果表明：活性炭对甘蓝型油菜游离小孢子培养胚状体发生有很好的促进作用，不仅提高了胚产量，而且有利于小孢子胚的正常发育，添加活性炭的固液双层培养基效果尤为显著。     

Ploidy of broccoli regenerated from microspore culture versus anther culture

The use of microspore or anther culture to generate doubled-haploids (DH) is an important adjunct to broccoli breeding) Regenerated populations from broccoli anther culture are usually mixtures of ploidy. However, ploidy composition of populations derived from microspore culture has not been reported. The purpose of the present study was to characterize regenerants derived from microspore culture, to evaluate factors influencing these characteristics and to compare results with those from anther culture. Eight populations, four from each culture method, were generated simultaneously using the same four F₁ hybrids as donor parents. The ploidy level of all regenerants was determined by DNA flow cytometry: the majority of them were diploid. As in anther culture, a mixture of ploidy was observed in all populations derived from microspore culture. Ploidy variation was more frequent among clonal families from anther culture (10%) than microspore culture (5%)‘Everest’ was the most productive donor parent with both methods, while ‘Greenbelt’ and ‘Major’ were least productive in anther and microspore culture, respectively. Genotype specificity for the total number of regenerated plants and ploidy composition occurred in both culture methods.     

青花菜小孢子发育时期与花器形态的相关性

对青花菜小孢子发育时期细胞学特征及其与花器外部形态的相关性展开研究,试图从花器的外部形态特征来推断小孢子的发育时期,最终目的是为花药或游离小孢子培养研究提供科学依据。结果表明,青花菜小孢子发育经历四分体时期、单核早中期、单核靠边期和双核期共4个时期,供试3个青花菜各时期细胞学特征存在明显差异。青花菜小孢子发育时期与花蕾大小和花药颜色等指标密切相关。供试青花菜花蕾纵径为10.52~11.05 mm,花蕾横径为3.64~4.25 mm,花药长度为2.85~2.87 mm,花药宽度为0.95~0.96 mm,且花瓣微露出花萼,花瓣和花药均为淡黄色时,80%以上的小孢子发育至单核靠边期。     

Microspore culture is successful in most crop types of Brassica oleracea L.

Summary Microspore culture was shown to be applicable to a broad range of accessions belonging to six horticulturally important crop types of Brassica oleracea: broccoli, white cabbage, cauliflower, savoy cabbage, Brussels sprouts and curly kale. Of 64 accessions tested 86% were responsive. Large genotypic differences were found in number of embryos produced per flower bud, and in frequency and mode of regeneration of plants from embryos. B. oleracea was characterized by a strong asynchrony of microspore development within single buds. Microspore populations optimal for culture contained a large proportion (10–40%) of binucleate pollen. An initial high temperature treatment was essential for microspore embryogenesis. Growth conditions of the donor plants during inflorescence formation were less critical.     

Effect of thidiazuron on microspore embryogenesis and plantlet regeneration in Chinese flowering cabbage (Brassica rapa. var. parachinenis)

Traditional breeding methods require more than 6 years to obtain homozygous inbred lines, while isolated microspore culture (IMC) is an effective way to cultivate double haploid homozygous lines in only 2 years. However, low embryogenesis induction frequency in Chinese flowering cabbage remains a key obstacle to the practical application of this technique. Thidiazuron was added at different concentrations to NLN‐13 medium to estimate its effects on microspore embryogenesis and plantlet regeneration. Results showed that three genotypes responded positively. Optimum thidiazuron concentrations produced embryo yields of up to 14.67 embryos per bud and increased microspore embryogenesis frequency with up to 100% survival. Plantlet regeneration rates were up to 81.67%, and the treatment groups showed lower callus formation. We obtained up to 552 diploid plants from the tested genotypes, and the percentage of doubled haploid at different TDZ concentrations showed slight differences, and doubled haploid rates in the three genotypes were above 70%. They showed a high uniformity and can be directly used for hybrid breeding. This method accelerates microspore application in Chinese flowering cabbage hybrid breeding.     

Efficient doubled haploid production in microspore culture of loose-curd cauliflower (Brassica oleracea var. botrytis)

We present an improved protocol for highly efficient production of doubled haploid loose-curd cauliflower plants (Brassica oleracea var. botrytis) via microspore culture. Our experiment explored factors such as donor plant treatment, flower bud pretreatment, embryo germination medium, and ploidy characterization of regenerated plants. Our technique efficiently produced embryos from both tight- and loose-curd donor plants, although the embryo yields were genotype dependent. We achieved a germination rate of around 30 % by employing a hormone combination of zeatin, indole-3-acetic acid, and 6-benzylaminopurine pretreatment culture. We also used 1–4 days of cold pretreatment of the flower buds, which were submerged into NLN-13 medium, to induce microspore embryogenesis. Analysis using an FCM Ploidy Analyzer showed that more than 50 % of regenerated plants were spontaneously doubled haploids, more than 25 % were tetraploids, and fewer than 7 % were haploid. Visual examination of plants in the field revealed that they had distinct phenotypic characteristics relating to their ploidy level. The efficient production of double haploids using our improved microspore culture technique is a promising approach that can be applied in loose-curd cauliflower breeding programmes and genetic research.     

不同光照条件对几种类型蔬菜呼吸强度变化的影响

为探明光照条件对番茄、西兰花、花椰菜和芦笋4种类型蔬菜呼吸代谢的影响,采用近室温（15℃）、亚低温（8℃）和适宜贮温（0～2℃）3种温度,分别对该4种蔬菜在黑暗和光照条件下的呼吸强度进行了对比研究。结果表明,光照对采后离体蔬菜的呼吸代谢作用有较大影响。在同一贮藏温度下,番茄、西兰花和芦笋置于光照条件下比黑暗条件下的呼吸强度低,光照降低呼吸代谢的效果明显;而花椰菜则受光照的影响较小,光照抑制呼吸强度的效果不显著;同时,光照对呼吸代谢的影响还与温度有关,一般情况下,贮藏温度越低,光照对呼吸强度的影响越小。