BA对大麦花药培养中药壁的衰退和植株再生频率的影响

用含20ppm 6-BA的0.1％吐温-80溶液喷施花粉为单核前期的大麦上部叶片和穗部,明显影响大麦花药培养效率。实验结果表明:1)BA处理可明显延缓培养花药的药壁衰退进程。2)BA处理后的花药,在培养期间,其死亡的花粉数比对照大大减少,相反其双核或多核的花粉数比对照明显增加。3)BA处理虽然没有促进大麦花粉愈伤组织的诱导率,但显著地促进愈伤组织的生长。提高愈伤组织成长率,增加可转入分化培养的愈伤组织块数。4)BA处理促进愈伤组织的再分化,尤其是绿苗的分化。     

香果树组织培养过程中遗传变异的RAPD分析

用RAPD分子标记方法,从DNA水平上分析野生型香果树以及通过器官发生途径和体细胞胚胎发生途径得到的香果树再生植株以及体细胞胚胎发生过程中不同继代次数的培养物之间的遗传变异。筛选了100个随机引物,其中有75条随机引物能够扩增出条带,从中选取11个引物进行PCR扩增的结果显示：香果树体细胞胚胎无性系中有RAPD多态性位点,在胚性愈伤组织中也检测到少数RAPD变异位点。表明RAPD分子标记方法可以鉴定香果树组织培养过程中的遗传变异。     

甘露糖对大麦品种不同外植体生长的影响

以大麦栽培品种的茎尖、成熟胚为外植体,研究了不同甘露糖浓度对这些外植体愈伤组织诱导和生长的影响。结果表明:甘露糖浓度为20 g/L时,茎尖的叶片伸长和生根受到明显抑制;甘露糖浓度为10 g/L或15 g/L时,成熟胚的愈伤组织诱导率降低50%,甘露糖浓度为20 g/L或25 g/L时,成熟胚愈伤诱导和生长完全受到抑制,因此在以大麦茎尖和成熟胚为外植体的磷酸甘露糖异构酶(PM I)/甘露糖筛选中,可分别以20 g/L、25 g/L甘露糖作筛选压。另外,在培养早期阶段筛选比较适宜。     

陆地棉花药愈伤组织的诱导和继代培养

花药培养是自６０年代以来发展起来的一项生物技术,旨在诱导出单倍体花粉植株,应用于育种实践和基础研究〔１〕。以单倍体植株为基础的单倍体育种被认为在以下几个方面具有优越性：第一,缩短育种年限;第二,排除杂种优势对后代选择的干扰〔２,３〕。此外,花药培养在...     

基因型和培养条件对大麦花药培养的影响

不同基因型大麦(Hordeum vulgare)的花粉愈伤组织诱导率不同。带大麦黄花叶病抗性基因的品种、品系或F_1杂种的诱导率(8.83—14.21％)高于不带抗性基因的材料(1.04～6.25％)。MS基本培养基舔加2,4-D,1 mg/l,Kt0.1 mg/l,BA0.2 mg/l,生物素0.1 mg,其诱导率(平均11.0995)高于MS添加2,4-D3 mg/l和Kt0.1 mg/l的诱导率(6.33％)及MS添加2,4-D 1 mg/l和Kt0.1 mg/l的诱导率(8.21％)。接种后先15℃暗培养5天,再转入25℃暗培养,其产生愈伤组织的高峰期推迟2—4天,但诱导率却从对照的5.84％提高到11.59％;25℃暗培养与25℃光-暗交替培养,诱导率无显著差异。     

大麦与小麦属间杂种的形态学和细胞遗传学研究

通过幼胚培养技术分别获得了大麦(Hordeum vulgare L., 2n=2x=14)与普通小麦(Triticum aestivum L., 2n=6x=42)、硬粒小麦(T. durum d. sf., 2n=4x=28)以及栽培二粒小麦(T. dicoccum Schrank 2n=4x=28)之间的属间杂种,平均杂交结实率分别为3.0％、1.2％和0.8％。杂种在形态上偏向小麦,自交不孕,用父本作回交亲本获得了大麦×普通小麦杂种的回交一代。所有杂种均表现细胞学上的不稳定性。杂种减数分裂中期1 PMC染色体平均配对频率和交叉结频率分别为27.31Ⅰ 0.33Ⅱ 0.011Ⅲ,0.45;20.571 0.20Ⅱ 0.008Ⅲ,0.25和20.41Ⅰ 0.28Ⅱ 0.005Ⅲ,0.32,表明双亲染色体组间不存在同源关系。大麦×四倍体小麦杂种小孢子的染色体计数表明,杂种中未减数雄配子的频率在60％以上。     

Intergeneric somatic hybridization of rice (Oryza sativa L.) and barley (Hordeum vulgare L.) by protoplast fusion

An intergeneric somatic hybrid was obtained upon fusion of protoplasts of rice and barley. Protoplasts isolated from suspension cultures of rice cells were fused by electrofusion with protoplasts that had been isolated from young barley leaves. Some of the resultant calli formed green spots and shoots. Only one shoot formed roots, and it was subsequently successfully transferred to soil in a greenhouse. Its morphology closely resembled that of the parental rice plant. Cytological analysis indicated that the plant had both small chromosomes from rice and large chromosomes from barley. Southern hybridization analysis with a fragment of the tryptophan B (trpB) gene revealed both a rice-specific band and a barley-specific band. Mitochondrial (mt) and chloroplast (cp) DNAs were also analyzed using the same method. The plant was shown to contain novel mitochondrial and chloroplast sequence rearrangements that were not detected in either of the parents. Received: 5 March 1997 / Revision received: 4 September 1997 / Accepted: 13 September 1997     

Proteolytic degradation of barley ribulose-1,5-bisphosphate carboxylase/oxygenase and recognition of the fragments by monoclonal antibodies

Limited proteolysis of barley ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) was effected by treatments with trypsin and Staphylococcus aureus strain V8 protease. Treatment of native RuBPCO with proteases resulted in the degradation of the large subunit (LS) of the enzyme. Trypsin cleaved three fragments from the LS but the S. aureus strain V8 protease cleaved only one. The small subunit (SS) was not affected. In the presence of 0.5 % sodium dodecyl sulfate, RuBPCO degraded into several fragments; some of them were fairly stable. Monoclonal antibodies (Mabs) against barley RuBPCO were applied in immunoblotting analysis to distinguish which of the fragments were recognized. All the Mabs recognized the fragments with molecular masses close to those of the LS. Differences among Mabs were observed in the fragments with low molecular mass. This revised version was published online in June 2006 with corrections to the Cover Date.     

Production and analysis of plants that are somatic hybrids of barley (Hordeum vulgare L.) and carrot (Daucus carota L.)

In order to obtain plants that were somatic hybrids of barley (Hordeum vulgare L.) and carrot (Daucus carota L.), we fused protoplasts that had been isolated from 6-month-old suspension cultures of carrot cells with protoplasts isolated from barley mesophyll by electrofusion. After culture for 1 month at 25°C , the cells were cultured for 5 weeks at 4°C , and were then returned to 25°C for culture on a shoot-inducing medium. Three plants (nos. 1, 2 and 3) were regenerated from the cells. The morphology of the regenerated plants closely resembled that of the parental carrot plants. A cytological analysis of callus cultures induced from these plants indicated that most of the cells had about 24 chromosomes, fewer than the sum of the numbers of parent chromosomes which was 32. Southern hybridization analysis with fragments of the rgp1 gene used as probe showed that the regenerated plants contained both barley and carrot genomic DNA. Chloroplast (ct) and mitochondrial (mt) DNAs were also analyzed with several probes. The ctDNA of the regenerated plants yielded hybridization bands specific for both barley and carrot when one fragment of rice ctDNA was used as probe. Furthermore, the regenerated plants yielded a barley specific band and a novel band with another fragment of rice ct DNA as a probe. One of the regenerated plants (no. 1) yielded a novel pattern of hybridized bands of mt DNA (with an atp6 probe) that was not detected with either of the parents. These results indicated that the regenerated plants were somatic hybrids of barley and carrot and that recombination of both the chloroplast genomes and the mitochondrial genomes might have occurred. Received: 28 May 1996 / Accepted: 2 August 1996     

A comparison of barley isolated microspore and anther culture and the influence of cell culture density

Comparisons were made between the efficiency of barley plant regeneration from anther culture (AC) and isolated microspore culture (IMC) for the European winter cultivar `Igri' and the spring F<sub>1</sub> Australian breeder's hybrid Amagi Nijo×WI2585. In both cases, IMC produced a higher number of green regenerant plantlets per anther than AC. For `Igri' there was a 100- to 200-fold improvement and for Amagi Nijo×WI2585 there was a five- to ninefold improvement of IMC over AC. To improve the consistency and reliability of the IMC method, we investigated several parameters, including maltose concentration, subculture protocol, microspore plating density and colony plating density. Subculturing during the liquid culture phase produced no significant improvement in the number of microspores developing into colonies. The optimal concentration of maltose in the liquid induction medium was found to be 90 g l^–1. Both microspore plating density and colony plating density were found to influence plant regeneration. Microspores produced the highest numbers of colonies when plated at densities greater than 5×10⁴ ml^–1, and colonies produced optimal numbers of green plantlets when plated at 12.5–25 colonies/cm². Received: 23 March 1997 / Revision received: 29 May 1997 / Accepted: 25 June 1997