Nuclear genes affecting percentage of green plants in barley (Hordeum vulgare L.) anther culture

Summary The genetics behind response in barley anther culture was studied with 22 reciprocal and one single: cross between three varieties with high and four varieties with low capacity for green plant formation. Effects of genotypes dominated embryo formation and percentages of green plants, accounting for 62 and 76% of total variation, respectively, with almost no genetic effect on the ability to regenerate plants from pollen embryos. Nuclear genes could explain all genotype effects in this plant material, since no reciprocal effects were indicated. The three parents with high and the four parents with low capacity for green plant formation formed two phenotypically homogeneous groups, producing 27–52% and 0–7% green plants, respectively. Genetic variation within hybrids for both embryo and green plant formation could be explained completely by general combining ability (GCA). The results are discussed with respect to a previous similar study in hexaploid wheat and the reported existence of DNA deletions in the plastid genomes in albino plants from anther culture of wheat and barley.     

The anther-culture response of triticale line x tester progenies

Seven triticale cultivars (Ampiac, Aubrac, Trinidad, Ticino, Lamberto, Pronto and Prado) and their F1 hybrids obtained after crossing in a line x tester scheme were examined with respect to their androgenetic effectiveness. The embryo induction rate (number of embryos per 100 anthers), green plant regeneration rate (number of green plantlets per 100 embryos), plant yield (number of green and albino plantlets per 100 anthers) and green plant yield (number of green plantlets per 100 anthers) were assessed. The multivariate and univariate effects of general (GCA) and specific (SCA) combining abilities for the studied traits were estimated and tested. Significant differences between the genotypes were found for individual traits as well as for all the traits treated jointly. Hybrids generally showed a better response in anther culture than their parental genotypes. Heterosis effects were observed in some hybrids for embryo induction rate and green plant yield. GCA and SCA variances were significant and a dominance of the GCA over the SCA variation was found. Among the examined cultivars, Ticino and Pronto were characterised by positive and significant GCA for embryo induction and green plant yield, and these cultivars may be recommended for the improvement of anther culture responsiveness in triticale.     

Effect of the 1B/1R translocation on anther culture ability in wheat (Triticum aestivum L.)

Using two varieties, their reciprocal hybrids, F₈ lines and doubled haploids, results confirmed that three genetic components are involved in wheat anther culture ability, viz embryo induction frequency, regeneration ability and the frequency of albinism. In these experiments, no significant maternal effects were noticed. For embryo yields, transgressive lines were obtained from hybrids between distant genotypes. Regeneration of green plants depended upon two independent traits: regeneration ability and the frequency of albinos. F₈ lines and two doubled haploids equaled the 50% regeneration rate of the hybrids, but they only regenerated green plants. Based upon cytological examination and gliadin patterns, it is suggested that genes favoring regeneration ability could be linked to the 1BL-1RS translocated chromosome from Aurora.Abbreviations DH doubled haploids - MS Murashige and Skoog - MPG multicellular pollen grains     

Reciprocal effects in anther cultures of wheat hybrids

This study was conducted to determine the reciprocal effects for anther culture response in wheat (Triticum aestivum L.) using a set of 4 × 4 full diallel crosses. Both reciprocal and nuclear genetic effects were highly significant for anther culture response and useful for selection and breeding purposes. General combining ability (GCA) effects were predominant for all investigated anther culture traits. Also, significant differences for specific combining ability (SCA) effects were detected between reciprocal crosses. Although significant reciprocal differences for responding anther, callus number and green plant regeneration were recorded in some reciprocal crosses, there were no significant reciprocal differences for albino plant regeneration. The use of one parent as male or female could lead to change at the production of green plants from the F₁ hybrids and screening of inbred lines for response to anther culture, without reciprocal effects, could decrease the utilization of breeding material.     

Effect of plant growth conditions, plating density, and genotype on the anther culture response of soft white spring wheat hybrids

Ten soft white spring wheat (Triticum aestivum L.) F₁ hybrids were grown under three temperature regimes, and anthers were cultured at two plating densities to investigate the effect of plant growth conditions, plating density, and genotype on embryo induction and plant regeneration. Anthers from plants grown at high temperature (25 °/18 °C) or from plants transferred from low (15 °/12 °C) to high temperature generally produced more embryos and green shoots, with a lower frequency of albinos, than did anthers from plants grown at low temperature. However, plating densities of 10 versus 20 anthers per milliliter, had little effect on anther response. Four of the five hybrids with `Fielder' as the female parent produced more embryos and green shoots than did hybrids with `AC Reed' as the female parent. Received: 12 July 1996 / Revision received: 1 April 1997 / Accepted: 30 April 1997     

Genetic analysis of anther culture response in wheat using aneuploid,chromosome substitution and translocation lines

Summary Marked effects of genotype on wheat anther culture response have been observed. Genetic factors have been recognised to be one of the major contributors to in vitro responses of cultured wheat tissues. In wheat anther culture, embryo induction, plant regeneration and albina/green ratio have been determined to be heritable traits. Using Chinese Spring (CS) monosomic 1D, single chromosome substitution lines of chromosome 5B or chromosome arm 5BL from Chinese Spring into six varieties, and F₁ hybrids heterozygous for the 1B chromosome structure (1BL-1BS/1BL-1RS), the anther culture response was studied: genes on CS1D chromosome and 5BL chromosome arm increases the embryo frequency; gene(s) involved in regeneration ability are located on the 1RS chromosome arm; a gene increasing albina frequency is located on Chinese Spring 5B chromosome. Our results support the fact that without gametic selection, a differential development occurred from the particular classes of microspores carrying genes for higher regeneration ability. Moreover, in some crosses, a few genes with major effects were involved in determination of anther culture response.     

Influence of 2,4-D, IAA, and duration of callus induction in anther cultures of spring wheat

Culture media and environmental factors may significantly influence the yield of haploid plants from anther cultures. Our objectives were to identify a combination of 2,4-dichlorophenoxyacetic acid (2,4-D) and indoleacetic acid (IAA) concentrations which produce the maximum number of haploid plants, and to evaluate the effects of duration in induction medium on calli induction, plant regeneration, and green plant production from anther cultures in spring wheat. Significant (P ≤ 0.01) plant growth regulator concentration effects (2,4-D and IAA) were observed on the number of calli, green plants and albino plants produced, and on direct plant regeneration. Addition of 2,4-D to the induction medium resulted in significantly (P ≤ 0.01) higher means for all anther culture components compared to IAA> While addition of 2,4-D significantly (P ≤ 0.01) reduced plant regeneration, it substantially increased green plant percentage at a 0.3-mg l⁻¹ concentration of IAA. Use of response functions to estimate the maximum effective 2,4-D × IAA combination implied that higher 2,4-D levels in the induction medium should be investigated, and that the optimum hormone combination differs for plant regeneration and green plant percentage. Significant (P ≤ 0.01) effects of duration on callus induction medium were observed for plant regeneration and green plant percentage.     

Chlorophyllian durum wheat plants obtained by isolated microspores culture: importance of the pre-treatments

In Triticum turgidum subsp. durum (Desf.) Husn., the utilization of in vitro anther culture is hampered by the very high frequency of albinism of the regenerated plants reaching in most cases 100%. Only in vitro ovary culture or intergeneric crosses with maize produce gynogenetic green haploid and doubled haploid plants. This paper is concerned with another very interesting method of androgenetic doubled haploid plant production, the in vitro isolated microspore culture. It is shown that this method, associated with cold alone or cold plus mannitol pre-treatments, of the spikes kept within their sheath leaves, during different times, have significant positive effects, not only on embryo production, but also on chlorophyllian plant regeneration. All pre-treatments and control taken together, a total of 16 490 embryos was obtained from 17.4 x 10(6) microspores of two T. durum varieties, among which 9320 embryos were transferred to regeneration medium and developed 150 chlorophyllian plants. Thus a long-term (five weeks) 4 degrees C cold pre-treatment of the microspores could be promising for green regeneration in durum wheat.     

Immature embryo and anther culture of chromosome addition lines of rye in chinese spring wheat

Significant variation among Chinese Spring wheat (Triticum aestivum L.) and a set of seven addition lines in which chromosomes from rye (Secale cereale L.) were incorporated into the Chinese Spring background was observed for callus formation and plant regeneration from anther cultures and for plant regeneration from immature embryo cultures. Callus initiation from immature embryo cultures was uniformly high. Rye chromosome 4 contains factors which significantly increase both anther culture responses relative to Chinese Spring. Rye chromosomes 6 and 7 both contain positive factors for regeneration from immature embryo culture. While no correlation was found between anther culture and embryo culture responses, a positive correlation was observed between the two anther culture response variables.     

Genetic analysis of plant regeneration in rice (Oryza sativa L.)

Summary A diallel study involving reciprocal crosses of four genotypes (IR8, 36, 54, and 64) was carried out to understand the genetic mechanism of plant regeneration from immature embryo-calli in rice. Regeneration frequency (% of calli that produced plants) varied from a high of 86% for IR54 to a low of 0% for IR36, while regenerated plants per embryo numbered from 0 to 7 when these same IR lines and the F₁ hybrids were compared. Combining ability analysis revealed that both nuclear (with both additive and dominant effects) and cytoplasmic genes are important in controlling regeneration in rice. Parental lines and F1 hybrids with high ability to regenerate were identified.     

Inheritance of anther culture derived green plantlet regeneration in wheat (Triticum aestivum L.)

A study was set up to determine the inheritance and combining ability of the factors anther culture response and green plant regeneration. Reciprocal crosses were made between cultivar Ringo Sztar, showing high anther culture response and the cultivars Ciano 067 and Benoist H77022, showing a high level of green plant regeneration. Averaged over all genotypes, 23.0% of the anthers responded and a callus induction frequency of 77.8% was observed. Of all the embryos, 43.0% developed into plantlets, 25.6% of the regenerants being green, the result being that 3.3 green plants per 100 anthers were formed. Genotypic effects accounted for 57.7%, 86.3% and 77.5% of the total variance of anther culture response, callus induction frequency and embryo induction frequency, respectively. Additive and dominant gene action was detected for all characteristics, including green plant regeneration. No reciprocal differences were found for anther culture response, embryo induction frequency and green plant regeneration, indicating no cytoplasmic effects. A small but significant reciprocal difference was found for callus induction frequency. Embryo production was primarily correlated with anther culture response and not with the number of embryos produced per plated anther or per responding anther. Possible mechanisms for the inheritance of green plant regeneration are discussed.Abbreviations CIRA callus induction frequency per responding anther - ERA embryo induction frequency per responding anther - FHB fusarium head blight - MS-medium Murashige & Skoog (1962) medium - REML residual maximum likelihood     

Genetic and non-genetic factors affecting anther culture of Brussels sprouts (Brassica oleracea var. gemmifera)

Summary Eight inbred lines of Brussels sprouts and ten F₁ hybrids derived from them were tested for their response to anther culture. From 5–19 plants per genotype were tested, and each plant was tested on 3–6 separate occasions. Results from the inbred lines were broadly similar to those from the F₁ hybrids, despite the inbreds producing fewer buds and having a higher frequency of anther deformities. The maximum embryo yield from an inbred line was 215 embryos per 100 anthers, and from a hybrid was 275. From estimation of the variance components it was calculated that, for both inbreds and hybrids, about half the total variation was genetic whereas variation due to plants within genotypes and to occasions within plants were each about 13% of the total. The narrow sense heritability of responsiveness to anther culture (estimated by the proportion of variation between inbred lines which was genetic) was 0.48, and there was partial dominance for this character. In three cases the hybrid outyielded the better inbred, and this heterosis may well be due to dispersed dominant genes.     

Protein markers for anther culturability in barley

Two-dimensional electrophoresis of proteins from a recombinant population of anther culture-derived doubled haploid lines identified 4 loci or linkage groups showing a deviation from an expected 11 segregation. It was hypothesized that these markers are linked to genes involved in the process of haploid plant production and that the deviation was due to a selection for alleles conferring higher anther culture response. To check this hypothesis, the anther culturability of 50 of the doubled haploid lines and their two inbred parents was assessed. It was found that 2 of the loci which had a distortion of segregation showed a significant effect on anther culture response, the most efficient allele being the most frequent in both loci. In addition, 2 more markers associated with anther culturability were found. One of the first mentioned 2 loci and one of the latter 2 were found to be linked to genes involved in both embryoid production and subsequent green plant regeneration. The remaining two were linked to genes involved only in green plant regeneration. Of the 4 favorable alleles 3 were inherited from one parent.     

Anther Culture Response of Barley Genotypes to Cold Pretreatments and Culture Media

The embryoid formation and plant regeneration in anther cultures of three barley (Hordeum vulgare L.) cultivars (Niki, Karina, Thermi), one F₁ hybrid (Niki × Thermi), two F₂ populations (Niki × Thermi, Niki × Karina), and two F₃ populations (Niki × Thermi, Niki × Karina) were investigated in two solid induction media after cold pretreatment for 14 and 28 days at 4°C . The media used (N6 and FHG) differed in their composition and source of energy (maltose in FHG vs. sucrose in N6). Embryoid frequency and green plant regeneration depended on both the induction medium composition and cold pretreatment. The combination of the FHG induction medium with 28-day-long cold pretreatment was the most efficient in haploid embryoid formation and green plant production. In addition, the green plant production was genotype-dependent. Cv. Thermi and F₁ hybrid Niki × Thermi exhibited the highest frequency of green plant production. The parent with high or even moderate frequency of embryoid formation in anther culture could lead to the effective production of green plants from the F₁ hybrid or the F₂ generation for breeding purposes.     

芍药花药愈伤组织诱导及体细胞胚发生

以芍药(Paeonia lactiflora)品种粉玉奴花药为外植体,研究不同浓度2,4-D对愈伤组织诱导、体胚发生及植株再生的影响,采用组织细胞学方法观察愈伤组织以及体细胞胚发育过程,采用根尖染色体法鉴定再生植株倍性。结果表明,芍药花药愈伤组织诱导的最适培养基为MS+1 mg·L–1 2,4-D+1 mg·L–1 N...     

不同组织培养途径对小麦再生能力的研究

从现在推广的小麦优良品种和有苗头的新品系中选用10个小麦基因型品种进行组织培养,从愈伤组织诱导率、绿苗分化率等方面比较了幼穗培养、花药培养、幼胚培养三种培养方式的培养效果。结果表明,幼胚培养效果最好,基因型间差异小,都能获得足够数量的再生植株。幼穗的培养效果最差,愈伤组织分化生根和绿芽十分容易,但分化成完整植株则较为困难。花药培养在基因型间差异非常明显而且有较多白化苗。此外,本研究还分析了影响小麦再生能力的因素,建立了一套高效、可靠的小麦组培再生系统,为小麦的转基因技术提供优良的受体材料。     

大白菜与结球甘蓝异源三倍体小孢子植株的获得与鉴定

以6个不同基因型的大白菜四倍体(AAAA,2n=4x=40)品系9401、9402、9403、9404、9405、9406为母本,结球甘蓝二倍体(CC,2n=2x=18)自交系9501为父本配制杂交组合得到的6个杂种一代为试材,进行了游离小孢子培养研究,成功诱导出胚状体,获得了再生植株,并对部分再生株进行了染色体数鉴定和性状调查。结果表明:不同组合小孢子胚胎发生能力不同,各组合产胚率均较低;小孢子再生植株中,染色体数为18的个体所占比例最大,达46.7%;小孢子植株减数分裂行为复杂,终变期除二价体和单价体外,还有三价体等联会形式;小孢子植株性状表现各异。     

Genetic studies of anther culture ability in rice (Oryza sativa)

Inheritance of three anther and culture characters, callus induction, green plant regeneration and culture efficiency was studied using incomplete diallel crosses with a gamete model. It was suggested that callus induction was mainly controlled by gametic additive effects and with less effect of the maternal effects. Green plant regeneration was mainly determined by maternal effects with less influence of gametic additive effects. Culture efficiency was controlled by gametic additive, maternal and cytoplasmic effects. Cultivar Lunhui 422 showed positive genetic effects for all three traits and was a very good parent for rice anther culture breeding. Significant positive heterosis was observed for callus induction. Both gametic additive and maternal correlations contributed to the significant genotypic and phenotypic correlations between callus induction and green plant regeneration suggesting these two traits to be linked.Abbreviations 2,4-d 2,4-dichlorphenoxyacetic acid - NAA -napthaleneacetic acid     

In Vitro Culture of Different Explants from Hubei Photoperiod Sensitive Genic Male-Sterile Rice

Young panicles, immature embryos, stem nodes, stem tips, leaf segments, root tips and anthers from Hubei Photoperiod Sensitive Genie Male-Sterile Rice (Oryza sativa subsp, japonica) “Nongken 58” (abbr. 58s) and fertile “Nongken 58” (abbr. 58f) were examined for callus induction, plant regeneration and direct plantlet formation on differentiation medium. 58s and 58f had equal ability in all explants cultures except anther cultures. The induction frequency of the anther callus and the regeneration frequency of the green plant in 58s were much lower than those in 58f, and such differences were not affected markedly by the change of fertility of 58s donor plants. Young panicle, immature embryo, stem node, stem tips showed direct plantlet formation when cultured on differentiation medium containing NAA and kinetin. Different explants produced various types of responses. Young panicles could produce callus and then regenerate plantlets. Evidences from histological observation showed that the plant regeneration in direct plaatlet formation of young panicles were mainly organogenetic, bowever, somatic embryogenesis was also possible.