巴戟天胚乳诱导愈伤组织及三倍体再生

目的:利用巴戟天种子内胚乳为外植体进行离体培养获得三倍体。方法:选取未成熟巴戟天种子内胚乳,置于不同培养基上诱导愈伤组织和分化再生植株,并对植株倍性进行根尖染色体鉴定。结果:在MS+2,4-D(2,4-二氯苯氧乙酸)2.0 mg/L+6-BA(6-苄基嘌呤)1.0 mg/L培养基上诱导获得愈伤组织,诱导频率达58.9%。愈伤组织在MS+6-BA1.0~2.0 mg/L+IBA 0.1~0.5 mg/L分化培养基上分化出不定芽。不定芽在1/2 MS+IBA 0.5 mg/L上诱导生根,生根率100%。再生植株根尖细胞染色体数目为2 n=3 x=33。结论:利用巴戟天胚乳培养获得三倍体是创造多倍体新种质的有效途径。     

安祖花愈伤组织再生体系的建立及染色体检变

试验以安祖花幼嫩叶片和无菌苗叶柄为外植体,通过愈伤组织诱导途径,建立快速高效的安祖花再生体系。结果表明：最适宜的诱导叶片和叶柄愈伤组织的培养基分别为1/2MS+1.0 mg/L 6-BA+0.2 mg/L 2,4-D和1/2MS+1.0 mg/L 6-BA+0.1 mg/L 2,4-D;诱导出愈伤组织在1/2MS+2.0 mg/L KT+0.1 mg/L NAA培养基上能很好的分化不定芽苗;1/2MS+2.0 mg/L 6-BA+0.2 mg/L NAA培养基可对再生芽实现增殖与复壮;最适宜的生根培养基为1/2MS+0.05 mg/L NAA。试验通过观察安祖花继代过程中愈伤组织细胞染色体变异的情况,发现随着继代次数的增多染色体变异细胞的频率也随之上升,并且染色体变异多为非整倍体变异。     

甘蓝未受精子房离体培养及再生植株倍性的鉴定

甘蓝通过未受精子房离体培养诱导获得的再生植株,对再生植株的倍性进行有效的鉴定是将其进一步应用于优良品种选育的基础。本研究利用3种基因型的甘蓝材料(PMQM、QMF、RMQM)培育再生植株,优化甘蓝未受精子房离体培养体系,并通过形态学鉴定法、根尖染色体计数法、流式细胞仪鉴定法对组培植株进行倍性鉴定。结果表明:在0.4 mg/L ZT的分化培养基中,3种基因型材料的愈伤组织分化率明显高于1.0 mg/L 6-BA培养基中的组培苗,其中基因型RMQM的分化效果最好;最终确定诱导愈伤组织分化不定芽的最适培养基配方为MS+0.4 mg/L ZT+2.0 mg/L 2,4-D+0.1 mg/L NAA,且通过3种鉴定方法,得出再生植株倍性:单倍体3.4%,双倍体49.8%,四倍体15.9%,嵌合体35.3%。     

章丘大葱子叶再生体系建立及再生株倍性鉴定

以章丘大葱子叶为材料,研究了不同激素配比对愈伤组织诱导和继代、芽分化、芽点的伸长及根诱导的影响,并对获得的再生植株进行了鉴定。结果表明,诱导章丘大葱子叶产生愈伤组织、愈伤组织的继代培养、愈伤组织芽分化、芽点的伸长及诱导生根的最佳培养基及激素配比分别为：MS+2,4-D 2.0mg/L+KT 0.5mg/L、MS＋2,4-D 2.5mg/L＋KT 0.5mg/L、MS+2,4-D 0+KT 1.0mg/L、MS+KT 0.5mg/L和MS基本培养基;试管苗经驯化移栽后,共有22株成活,成活率为92%,对成活的再生植株进行形态学、叶片气孔及根尖染色体鉴定表明,共有3株发生变异,其中2株为外部形态上的变异,而另一株为染色体的加倍变异。     

中国水仙花药培养及植株再生体系建立

本研究以中国水仙花药为外植体,通过器官发生途径建立其植株再生体系,并通过染色体计数鉴定筛选变异个体。结果显示:在4℃下预处理3d有利于花药愈伤组织的形成;愈伤组织诱导培养基最适配比为:MS+2,4-D1.0mg/L+BA0.5mg/L+CH500mg/L+AC500mg/L;愈伤组织分化小鳞茎的最适培养基为:MS+BA0.5mg/L+NAA0.1mg/L+CH500mg/L+AC1000mg/L。通过染色体计数对38个再生植株进行倍性鉴定,结果显示其中30个为三倍体(2n=30),8个为非整倍体(2n=10,11,12,14,17,26)。以这些再生苗为外植体,经器官发生途径,建立了不同倍性的再生体系。     

组织培养中大葱染色体倍性变异的研究

采用大葱茎尖分生组织直接成苗及分化丛生苗、茎盘诱导愈伤组织培养再生植株,通过染色体压片,对大葱愈伤组织及幼苗染色体数目变化进行了研究。结果表明,茎尖分生组织培养的幼苗及丛生苗遗传稳定,其染色体未发生倍性变异,均为2n=16;愈伤组织及其再生苗遗传稳定性较差,愈伤组织染色体数变异率为43.4%,其中单倍体占6.7%、三倍体占2.5%、四倍体占10%、五倍体占4.2%、六倍体占3.3%、七倍体占4.2%、八倍体占3.3%、非整倍体占9.2%;愈伤组织分化苗染色体变异率为11.7%,其中单倍体占6.7%,三倍体占1.7%,四倍体占3.3%。     

胡萝卜高效再生体系的建立

以胡萝卜下胚轴为外植体,研究其愈伤组织诱导及植株再生各个时期的影响因素。试验结果表明：0．1mg／L2,4-D或0．1mg／L2,4-D 0．2mg／L KT的激素组合有利于胡萝卜下胚轴的愈伤组织诱导;在0．1mg／L2,4-D的培养基上形成的愈伤组织主要以胚状体的形式再生,而在含0．1mg／L2,4-D 0．2mg／L KT激素组合的培养基上形成的愈伤组织主要以发生不定芽的方式再生;再生过程中,B5基本培养基上的苗子不易生根,需要附加0．1mg／L的IBA,而在MS培养基上苗子可直接形成根。     

水稻原生质体愈伤组织再生植株培养程序的比较

在4种不同的培养程序中应用了几种处理方法, 并对其在诱导水稻原生质体起源的愈伤组织 再生植株中的效果进行了比较。 直接将愈伤组织从含有2,4-D的增殖培养基转移到含有BA 和NAA的植株再生培养基上培养, 只能得到少量的弱苗(第1种程序)。 在增殖培养基中添加 ABA诱导了结节状的愈伤组织形成, 使愈伤组织的植株再生能力明     

培养基及植物激素对烟草原生质体再生植株的影响

本文研究了不同基本培养基、培养方法及培养基中不同激素浓度配比对烟草叶肉细胞细胞原生质体再生植株的影响.结果表明,利用MS基本培养基进行琼脂糖固体平板培养,对烟草叶肉原生质体的发育速度、分裂频率及愈伤组织形成效果最佳;培养基(1/2 MS NAA 0.5 mg/L 2,4-D 1.0mg/L 6-BA0.5 mg/L 1.2%LMA) (1/2MS 2,4-D2.5mg/L KT0.5mg/L)的培养效果最好,再生细胞团的数目及愈伤组织最多;用1/2 MS IAA 2.0 mg/L KT 0.5 mg/L和1/2 MS IAA0.5 mg/L KT 2 mg/L两种培养基对愈伤组织诱导分化时出芽率高;在再生芽诱导生根时直接用不含任何激素的MS基本培养基效果最理想.     

深山草莓花瓣离体培养诱导变异植株及性状稳定变异株系的品种特性

应用均匀设计法研究了影响深山草莓花瓣愈伤组织诱导及愈伤组织再分化变异植株的主要因子和水平。深山草莓花瓣愈伤组织诱导率超过65.0%以上的适宜培养基共有11个,经过组合优化后可知,培养基LS+TDZ2.06 mg?L-1+2,4-D0.60 mg?L-1对深山草莓花瓣愈伤组织诱导效果最好,诱导率为98.0%;其中,以培养基LS+TDZ2.20 mg?L-1 +2,4-D0.40 mg?L-1诱导形成的愈伤组织在10个适宜的分化培养基中培养均分化出再生芽苗,优化后的最佳再分化培养基为1/2LS+TDZ 2.30 mg?L-1+KT 1.38 mg?L-1,分化率为96.3%,田间试验发现变异率高达2.77%。对10个含有不同激素和浓度配比及1个优化后的培养基诱导形成的再生芽苗生根后经5年的田间栽培观察可知,有6个性状稳定的优良变异株系。这说明深山草莓花瓣在适当激素和浓度配比的条件下可产生变异植株,并能趋向稳定性状变异。     

Chromosomal instability in cell- and tissue cultures of tomato haploids and diploids

Summary The effect of the tissue culture system, the genotype and the ploidy level of the plant material used as explant source on the stability of the ploidy level of plants regenerated fromcell and tissue cultures of tomato was investigated. In addition the use of the chloroplast number in guard cells as a measure for ploidy level was evaluated. Haploids of tomato were very instable, which instability was observed already in somatic root tip and leaf cells. The number of regenerated plants that retained the original ploidy level differed significantly between the tested haploids. The plants that were regenerated from leaf explants of diploids were predominantly diploid in contrast to the plants regenerated from established callus cultures and protoplast where the majority was tetraploid.     

Analysis of genetic variability in various tissue culture-derived lemon plant populations using RAPD and flow cytometry

Five populations of lemon plants [Citrus limon (L.) Burm] obtained from undeveloped ovules through different tissue culture procedures were examined for the presence of somaclonal and irradiation-induced genetic variation. Tested groups were: (1) nucellar seedlings; (2) organogenic, regenerated via adventitious buds from nucellar seedling internodes; (3) embryogenic population, regenerated from non-irradiated nucellar callus via somatic embryogenesis; (4) embryogenic population, regenerated from irradiated nucellar callus via somatic embryogenesis; and (5) protoplast-derived, regenerated via somatic embryogenesis. Genomic DNA samples from 360 plants (72 from each group) were screened for polymorphism among RAPD fingerprints amplified by 10 decamer primers. Among all tested plants, genetic variation was detected only within the group of plants recovered from irradiated embryogenic calli. Out of 72 plants from that group, three had RAPD fingerprints different from the rest of the population, and fourth plant was found to be cytochimeric, consisting of diploid and tetraploid cells as revealed by flow cytometry. In all other populations of regenerated plants, we did not come across any plants with changed ploidy level.     

Plant regeneration from embryo-callus culture in barley

Summary Plants were regenerated from callus cultures initiated from immature embryos of barley, Hordeum vulgare L. Immature embryos from seven diverse genotypes were cultured on modified Murashige and Skoog (MS) medium supplemented with 1.5 mg 2,4-D and 6.5 mg IAA/l. Of the 249 embryos cultured, 30% initiated callus within 8 days. Subculture of callus for 80 to 100 days on half-MS medium supplemented with 0.5 mg/l 2,4-D and 1.0 mg/l zeatin resulted in organogenesis. Culture of organogenic calli for 30 days on half-MS medium without growth regulators produced plants which originated mostly via multiple shoot formation. Callusing response of the tested genotypes ranged from zero to 44%; however, only 23% of the calli were regenerative. Regenerated plants included variants for chlorophyll deficiency, plant height, stem thickness, spike shape, pollen fertility, seed set and ploidy.     

低酚陆地棉直接体细胞胚胎发生和植株再生

选用低酚陆地棉无菌苗下胚轴为材料进行全固体组织培养,直接诱导获得了胚性愈伤组织,并进一步分化为再生植株.结果表明,激素是影响棉花直接体细胞胚胎发生的重要因素.MSB培养基中添加2,4-D有利于愈伤组织的形成,却不能直接诱导获得胚性愈伤组织.MSB培养基中添加IBA和BA也不能直接诱导获得胚性愈伤组织.MSB培养基附加适当浓度的IBA和KT能直接诱导出胚性愈伤组织.最适激素组合(1.0 mg/L IBA,0.5 mg/L KT)能使诱导棉花下胚轴产生大量胚性愈伤组织,并且在3个月内就可肉眼观察到不同发育时期的胚.MSB培养基中附加1.0 g/L谷氨酰胺和0.5 g/L天门冬酰胺有利于胚萌发成苗.本研究建立了简便高效的棉花直接体细胞胚胎发生和植株再生培养体系,从胚性愈伤组织诱导到植株再生约需5～6个月时间.     

Regeneration in sugarcane via somatic embryogenesis and genomic instability in regenerated plants

In the present study, embryogenic calli of sugarcane variety BL4 were induced using 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin in different concentrations and combinations. In contrast to earlier studies, embryogenic callus sectors were identified and isolated microscopically within 1–2 weeks. Subsequently, 51 media formulations were used for regeneration of proliferated embryogenic callus, using MS medium supplemented with three different cytokinins [kinetin, 6-Benzylamino purine (BAP), and thidiazuron (TDZ)] and auxins (IAA/NAA and IBA) in different combination and concentrations. After acclimatization, the genomic DNA of regenerated plants was studied to explore the insertion polymorphism of transposable elements in order to ascertain the variation among somaclones. Though low concentration of kinetin with 2,4-D was found supportive to embryogenic callus development, the highest number of regenerated plantlets was observed using BAP (1 μM), however the plantlets had very low fresh weight (2.2 g). Conversely, TDZ alone supported a significant increase in the number of plantlets regenerated (38–40) with higher fresh weight. The somaclones generated during this study showed considerable positional polymorphism of activator-like transposable elements possibly due to the stress associated with in vitro culture. This study provides a procedure to produce regenerated sugarcane plants from embryogenic callus in a relatively short time.     

Diploidization in Haploid Tissue Cultures of Sorghum

Conditions for the effective experimental regulation of ploidy level in regenerants from callus cultures derived from young, undifferentiated leaves and panicles of haploid sorghum were established. Diploidization depended on the ontogenetic age of the explant and the 2,4-D concentration in the medium. With a low 2,4-D concentration (0.5 mg/1) and segments of young panicles (< 35 mm long) the cultures produced only haploid regenerants. Diploid plants were formed from cultures derived from more mature panicles ( 35 mm long) and young leaves (15–65 mm long). Under a high 2,4-D concentration (2.5 mg/1) diploid plants were regenerated from cultures derived from young panicles (less than 35 mm) except the most young ones (5–15 mm). The majority of the diploid regenerants contained mutations, mainly affecting male fertility and plant height.     

Linamarin content and genetic stability of cassava plants derived by somatic embryogenesis

A protocol was established for high frequency cyclic somatic embryogenesis for different varieties of cassava. An efficient plant regeneration system was developed for the high cyanogenic variety PRC60a. Linamarin content and linamarase activity were determined in various tissues of secondary somatic embryos and regenerated plants of PRC 60a. Both linamarin and linamarase activity were not detected in embryogenic callus, roots induced from callus and somatic embryo tissues. The stems and leaves of regenerated plants (in vitro) and storage roots and leaves of mature plants (in vivo), however, contained variable amounts of linamarin and linamarase activity whereas in the non storage root tissues (in vitro) only linamarin was detected. The present study suggested that the linamarin biosynthetic pathway may be absent or not switched on in the embryogenic callus and somatic embryos. The ploidy level and somatic chromosome number of the regenerated plants were found to be same as the source plants. The availability of this regeneration system would be useful not only for investigating cyanogenesis but also for genetic manipulation in cassava. This revised version was published online in July 2006 with corrections to the Cover Date.     

Production of Primary Triticale from Calluses of Immature Abnormal Hybrid Embryos between Triticum durum and Secale cereale

Plant regeneration was attempted in callus induced from the immature abnormal hybrid embryos between T. durum and S. cereale, using 4-Huorophenoxyacetic acid as a growth regulator. In particular, the relationship of numerical variation in chromosomes between the callus tissues and the regenerated plants was investigated. Cytological observation revealed that there was no distinctive numerical difference between the shoot-forming (SF) and the non-shoot-forming calluses and also between the SF calluses and the regenerated plants. The root-tips of regenerated plants consisted of cells having various chromosome numbers, including the expected 2 n = 3 ×= 21 (genomes, ABR) of which the frequency was 69.8 %. The regenerated plants showed partial fertility, notwithstanding that the hybrid plants were expected to be sterile. Since the frequency of abnormal embryos was about 90 % in this cross, the utilization of abnormal embryos was demonstrated by use of callus culture.