The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
János Pauk - One of the best experts on this subject based on the ideXlab platform.
-
improvement of isolated microspore culture of pepper capsicum annuum l via co culture with ovary tissues of pepper or wheat
Plant Cell Tissue and Organ Culture, 2009Co-Authors: Csaba Lantos, R Mihaly, Aniko Gemes Juhasz, Gyorgy Somogyi, Krisztina Otvos, Pal Vagi, Zoltan Kristof, Norbert Somogyi, János PaukAbstract:The influence of the developmental stage of Microspores on establishing isolated microspore cultures of three Hungarian (‘Szegedi 80’, ‘Szegedi 178’, and ‘Remeny’) and three Spanish (‘Jeromin’, ‘Jariza’, and ‘Jaranda’) pepper genotypes was investigated. Donor anthers containing 80% uninucleated and 20% binucleated Microspores yielded the highest frequency of successful microspore cultures. Co-cultures with wheat, line ‘CY-45’, ovaries exhibited enhanced frequency of embryoid production than those with pepper ovaries. Differences in efficiency of isolated pepper microspore culture establishment were observed among different pepper genotypes. Green plantlets were regenerated from microspore-derived embryoids, but some were exhibited abnormal growth habits, such as leaf rosetting. A total of seven fertile microspore-derived plants were obtained, including three ‘Jariza’, three ‘Jaranda’, and a single ‘Szegedi 80’ plant.
-
protocol of triticale x triticosecale wittmack microspore culture
2003Co-Authors: János Pauk, R Mihaly, T Monostori, M PuolimatkaAbstract:Triticale (x Triticosecale Wittmack) is a spontaneous synthetic amphiploid cereal that has been considerably improved through breeding. Triticale is currently grown on about 2 million hectares worldwide. After the initial period, intensive breeding research on triticale was started in the early 1950s by Arpad Kiss in Hungary. Nowadays, the centre of European triticale breeding is in Poland. Polish breeders released excellent varieties that have had a good performance, especially in Europe. Since the induction of the first triticale anther culture derived haploid plantlets by Wang et al. (1973), the method of anther culture has been essentially modified and improved. Theoretically, two in vitro cell and tissue culture methods are used to induce androgenesis: anther and microspore culture. The anther culture method seems to be more laborious. The blender isolation protocol provides a sufficient number of Microspores to avoid the necessity for anther isolation. In cereals, microblending isolation was earlier established for barley (Olsen, 1991) and wheat (Ziauddin et al.,1992), confirming its potential. The present protocol describes an in vitro process for blender-isolated triticale Microspores leading to doubled haploid lines from microspore derived embryo-like structures (ELS). Embryogenesis was observed in isolated triticale Microspores. This phenomenon also occurs in microspore culture of other cereals. From the ELS green plants can be regenerated, but albinism is still a typical problem of triticale microspore culture. Depending on the genotype, more than half of the regenerants may be albino.
-
protocol of triticale x triticosecale wittmack microspore culture
2003Co-Authors: János Pauk, R Mihaly, T Monostori, M PuolimatkaAbstract:Triticale (x Triticosecale Wittmack) is a spontaneous synthetic amphiploid cereal that has been considerably improved through breeding. Triticale is currently grown on about 2 million hectares worldwide. After the initial period, intensive breeding research on triticale was started in the early 1950s by Arpad Kiss in Hungary. Nowadays, the centre of European triticale breeding is in Poland. Polish breeders released excellent varieties that have had a good performance, especially in Europe. Since the induction of the first triticale anther culture derived haploid plantlets by Wang et al. (1973), the method of anther culture has been essentially modified and improved. Theoretically, two in vitro cell and tissue culture methods are used to induce androgenesis: anther and microspore culture. The anther culture method seems to be more laborious. The blender isolation protocol provides a sufficient number of Microspores to avoid the necessity for anther isolation. In cereals, microblending isolation was earlier established for barley (Olsen, 1991) and wheat (Ziauddin et al.,1992), confirming its potential. The present protocol describes an in vitro process for blender-isolated triticale Microspores leading to doubled haploid lines from microspore derived embryo-like structures (ELS). Embryogenesis was observed in isolated triticale Microspores. This phenomenon also occurs in microspore culture of other cereals. From the ELS green plants can be regenerated, but albinism is still a typical problem of triticale microspore culture. Depending on the genotype, more than half of the regenerants may be albino.
-
In vitro androgenesis of triticale in isolated microspore culture
Plant Cell Tissue and Organ Culture, 2000Co-Authors: János Pauk, M Puolimatka, K. Lökös Tóth, T MonostoriAbstract:Culture conditions for triticale (X Triticosecale Wittmack) androgenesis were studied using microspore culture. Sporophytic development of isolated triticale Microspores in culture is described in five winter hexaploid triticale genotypes. Microspores were isolated using a microblendor, and embryogenesis was induced in modified 190-2 medium both in the presence and absence of growth regulators. The highest induction of microspore embryogenesis was obtained in a growth regulator-free medium. Adventitious embryogenesis was observed during in vitro development of triticale Microspores. Albino and green plantlets were regenerated from embryo-like structures. More than 50% of regenerants were albino. In total, 126 green plantlets were produced, transplanted and established in soil. Cytological evidence revealed that 90% of the transplanted regenerants were haploid.
Alison M R Ferrie - One of the best experts on this subject based on the ideXlab platform.
-
crispr cas9 mediated targeted mutagenesis in wheat doubled haploids
Methods of Molecular Biology, 2020Co-Authors: Alison M R Ferrie, Pankaj Kumar Bhowmik, Nandhakishore Rajagopalan, Sateesh KagaleAbstract:CRISPR/Cas9-based genome editing technology has the potential to revolutionize agriculture, but many plant species and/or genotypes are recalcitrant to conventional transformation methods. Additionally, the long generation time of crop plants poses a significant obstacle to effective application of gene editing technology, as it takes a long time to produce modified homozygous genotypes. The haploid single-celled Microspores are an attractive target for gene editing experiments, as they enable generation of homozygous doubled haploid mutants in one generation. Here, we describe optimized methods for genome editing of haploid wheat Microspores and production of doubled haploid plants by microspore culture.
-
isolated microspore culture of oat avena sativa l for the production of doubled haploids effect of pre culture and post culture conditions
Plant Cell Tissue and Organ Culture, 2014Co-Authors: Alison M R Ferrie, K I Irmen, Aaron D Beattie, B G RossnagelAbstract:The production of doubled haploid (DH) plants from Microspores is an important technique used in plant breeding programs and basic research. Although doubled haploidy efficiencies in wheat and barley are sufficient for breeding purposes, oat (Avena sativa L.) is considered recalcitrant. The objective of this project was to develop a protocol for the production of microspore-derived embryos of oat and further develop these embryos into fertile DH plants. A number of experiments were conducted evaluating the factors influencing microspore embryogenesis, i.e. donor plant conditions, pretreatments, media composition, and culture conditions. The initial studies yielded little response, and it was not until high microspore densities (106 Microspores/mL and greater) were used that embryogenesis was achieved. Depending on the treatment, yields of over 5,000 embryos/106 Microspores were obtained for breeding line 2000QiON43. The doubled haploidy protocol includes: a 0.3 M mannitol pretreatment of the tillers for 7 days, culture in W14 basal medium with a pH of 6.5–7.5, a microspore density of 106 Microspores/mL, and continuous incubation at 28 °C incubation. The resulting embryos observed after 28 days were plated onto solidified W14 medium with 0.8 or 1.0 g/L activated charcoal. A colchicine treatment of 0.2 % colchicine for 4 h resulted in conversion of 80 % of the plants from haploid to DH. This protocol was successful for the production of oat microspore-derived embryos and DH green plants with minimal albinism. DH seed was produced and planted for evaluation in a field nursery.
-
haploids and doubled haploids in brassica spp for genetic and genomic research
Plant Cell Tissue and Organ Culture, 2011Co-Authors: Alison M R Ferrie, Christian MollersAbstract:The availability of a highly efficient and reliable microspore culture protocol for many Brassica species makes this system useful for studying basic and applied research questions. Microspores and microspore-derived embryos are ideal targets for modification by mutagenesis and transformation. Regenerated doubled haploid plants are widely used in breeding programs and in genetic studies. Furthermore, the Brassica microspore culture system allows the identification of genomic regions and genes involved in the microspore embryogenic response, spontaneous diploidization and direct embryo to plant conversion. This review summarizes current achievements and discusses future perspectives.
-
a high throughput brassica napus microspore culture system influence of percoll gradient separation and bud selection on embryogenesis
Plant Cell Tissue and Organ Culture, 2011Co-Authors: Pankaj Kumar Bhowmik, Joan M Dirpaul, Patricia L Polowick, Alison M R FerrieAbstract:Microspore culture for the purpose of developing doubled haploid plants is routine for numerous plant species; however, the embryo yield is still very low compared with the total available microspore population. The ability to select and isolate highly embryogenic Microspores would be desirable for high embryo yield in microspore culture. To maximize the efficiency of canola microspore culture, a combination of bud size selection and microspore fractionation using a Percoll gradient was followed. This approach has consistently given high embryo yields and uniform embryo development. Microspores isolated from buds 1.5 to 4.4 mm in length of Brassica napus genotypes Topas 4079, DH12075, Westar and 0025 formed embryos at different frequencies. The most embryogenic bud size range varied with each cultivar: Topas 4079 3.5–3.9 mm, DH12075 2.0–2.4 mm, and Westar and 0025 2.5–2.9 mm. When the Microspores from 2.0 to 2.4 mm buds of DH12075 were carefully layered on top of a discontinuous Percoll gradient of 10, 20 and 40%, and subsequently spun through the Percoll layers by centrifugation, bands were formed containing populations of Microspores of uniform developmental stage. The middle layer of the gradient contained the late uninucleate and early binucleate Microspores that were the most embryogenic. In addition, the relationship between the bud size, developmental stage of isolated Microspores, Percoll gradient concentration and the embryogenic frequency of each cultivar were studied. Optimization of these factors is required for each genotype evaluated.
-
transcript profiling and identification of molecular markers for early microspore embryogenesis in brassica napus
Plant Physiology, 2007Co-Authors: Meghna Malik, Joan M Dirpaul, Patricia L Polowick, Alison M R Ferrie, Feng Wang, Ning Zhou, Joan E KrochkoAbstract:Isolated Microspores of Brassica napus are developmentally programmed to form gametes; however, Microspores can be reprogrammed through stress treatments to undergo appropriate divisions and form embryos. We are interested in the identification and isolation of factors and genes associated with the induction and establishment of embryogenesis in isolated Microspores. Standard and normalized cDNA libraries, as well as subtractive cDNA libraries, were constructed from freshly isolated Microspores (0 h) and Microspores cultured for 3, 5, or 7 d under embryogenesis-inducing conditions. Library comparison tools were used to identify shifts in metabolism across this time course. Detailed expressed sequence tag analyses of 3 and 5 d cultures indicate that most sequences are related to pollen-specific genes. However, semiquantitative and real-time reverse transcription-polymerase chain reaction analyses at the initial stages of embryo induction also reveal expression of embryogenesis-related genes such as BABYBOOM1, LEAFY COTYLEDON1 (LEC1), and LEC2 as early as 2 to 3 d of microspore culture. Sequencing results suggest that embryogenesis is clearly established in a subset of the Microspores by 7 d of culture and that this time point is optimal for isolation of embryo-specific expressed sequence tags such as ABSCISIC ACID INSENSITIVE3, ATS1, LEC1, LEC2, and FUSCA3. Following extensive polymerase chain reaction-based expression profiling, 16 genes were identified as unequivocal molecular markers for microspore embryogenesis in B. napus. These molecular marker genes also show expression during zygotic embryogenesis, underscoring the common developmental pathways that function in zygotic and gametic embryogenesis. The quantitative expression values of several of these molecular marker genes are shown to be predictive of embryogenic potential in B. napus cultivars (e.g. ‘Topas’ DH4079, ‘Allons,’ ‘Westar,’ ‘Garrison’).
P S Testillano - One of the best experts on this subject based on the ideXlab platform.
-
autophagy is activated and involved in cell death with participation of cathepsins during stress induced microspore embryogenesis in barley
Journal of Experimental Botany, 2018Co-Authors: Ivett Barany, Mariateresa Solis, Mariacarmen Risueno, Eduardo Berenguer, Yolanda Perezperez, Estrella M Santamaria, Jose L Crespo, Isabel Diaz, P S TestillanoAbstract:Microspores are reprogrammed towards embryogenesis by stress. Many Microspores die after this stress, limiting the efficiency of microspore embryogenesis. Autophagy is a degradation pathway that plays critical roles in stress response and cell death. In animals, cathepsins have an integral role in autophagy by degrading autophagic material; less is known in plants. Plant cathepsins are papain-like C1A cysteine proteases involved in many physiological processes, including programmed cell death. We have analysed the involvement of autophagy in cell death, in relation to cathepsin activation, during stress-induced microspore embryogenesis in Hordeum vulgare. After stress, reactive oxygen species (ROS) and cell death increased and autophagy was activated, including HvATG5 and HvATG6 up-regulation and increase of ATG5, ATG8, and autophagosomes. Concomitantly, cathepsin L/F-, B-, and H-like activities were induced, cathepsin-like genes HvPap-1 and HvPap-6 were up-regulated, and HvPap-1, HvPap-6, and HvPap-19 proteins increased and localized in the cytoplasm, resembling autophagy structures. Inhibitors of autophagy and cysteine proteases reduced cell death and promoted embryogenesis. The findings reveal a role for autophagy in stress-induced cell death during microspore embryogenesis, and the participation of cathepsins. Similar patterns of activation, expression, and localization suggest a possible connection between cathepsins and autophagy. The results open up new possibilities to enhance microspore embryogenesis efficiency with autophagy and/or cysteine protease modulators.
-
early embryo achievement through isolated microspore culture in citrus clementina hort ex tan cvs monreal rosso and nules
Frontiers in Plant Science, 2015Co-Authors: Benedetta Chiancone, P S Testillano, Ivett Barany, Valeria Gianguzzi, Marines Marli Gniech Karasawa, A Abdelgalel, Daniela Torello Marinoni, Roberto Botta, Maria GermanaAbstract:Microspore embryogenesis is a method of achieving complete homozygosity from plants. It is particularly useful for woody species, like Citrus, characterized by long juvenility, a high degree of heterozygosity and often self-incompatibility. Anther culture is currently the method of choice for microspore embryogenesis in many crops. However, isolated microspore culture is a better way to investigate the processes at the cellular, physiological, biochemical and molecular levels as it avoids the influence of somatic anther tissue. To exploit the potential of this technique, it is important to separate the key factors affecting the process and, among them, culture medium composition and particularly the plant growth regulators and their concentration, as they can greatly enhance regeneration efficiency. To our knowledge, the ability of meta-Topolin, a naturally occurring aromatic cytokinin, to induce gametic embryogenesis in isolated Microspores of Citrus has never been investigated. In this study, the effect of two concentrations of meta-Topolin instead of benzyladenine or zeatin in the culture medium was investigated in isolated microspore culture of two genotypes of Citrus. After eleven months of isolated microspore culture, for both genotypes and for all the four tested media, the microspore reprogramming and their sporophytic development was observed by the presence of multinucleated calli and microspore-derived embryos at different stages. Microsatellite analysis of parental and embryo samples was performed to determine the embryo alleles constitution of early embryos produced in all tested media, confirming their origin from Microspores. To our knowledge, this is the first successful report of Citrus microspore embryogenesis with isolated microspore culture in Citrus, and in particular in Citrus clementina Hort. ex Tan, cvs. ‘Monreal Rosso’ and ‘Nules’.
-
a new microspore embryogenesis system under low temperature which mimics zygotic embryogenesis initials expresses auxin and efficiently regenerates doubled haploid plants in brassica napus
BMC Plant Biology, 2012Co-Authors: Deepak Prem, Mariateresa Solis, Mariacarmen Risueno, Ivett Barany, Hector Rodriguezsanz, P S TestillanoAbstract:Background Microspore embryogenesis represents a unique system of single cell reprogramming in plants wherein a highly specialized cell, the microspore, by specific stress treatment, switches its fate towards an embryogenesis pathway. In Brassica napus, a model species for this phenomenon, incubation of isolated Microspores at 32°C is considered to be a pre-requisite for embryogenesis induction.
-
no ros and cell death associated with caspase like activity increase in stress induced microspore embryogenesis of barley
Journal of Experimental Botany, 2012Co-Authors: Maria Rodriguezserrano, Mariacarmen Risueno, Ivett Barany, Deepak Prem, Maria Jose Coronado, P S TestillanoAbstract:Under specific stress treatments (cold, starvation), in vitro Microspores can be induced to deviate from their gametophytic development and switch to embryogenesis, forming haploid embryos and homozygous breeding lines in a short period of time. The inductive stress produces reactive oxygen species (ROS) and nitric oxide (NO), signalling molecules mediating cellular responses, and cell death, modifying the embryogenic microspore response and therefore, the efficiency of the process. This work analysed cell death, caspase 3-like activity, and ROS and NO production (using fluorescence probes and confocal analysis) after inductive stress in barley microspore cultures and embryogenic suspension cultures, as an in vitro system which permitted easy handling for comparison. There was an increase in caspase 3-like activity and cell death after stress treatment in microspore and suspension cultures, while ROS increased in non-induced Microspores and suspension cultures. Treatments of the cultures with a caspase 3 inhibitor, DEVD-CHO, significantly reduced the cell death percentages. Stress-treated embryogenic suspension cultures exhibited high NO signals and cell death, while treatment with S-nitrosoglutathione (NO donor) in control suspension cultures resulted in even higher cell death. In contrast, in microspore cultures, NO production was detected after stress, and, in the case of 4-day microspore cultures, in embryogenic Microspores accompanying the initiation of cell divisions. Subsequent treatments of stress-treated microspore cultures with ROS and NO scavengers resulted in a decreasing cell death during the early stages, but later they produced a delay in embryo development as well as a decrease in the percentage of embryogenesis in Microspores. Results showed that the ROS increase was involved in the stress-induced programmed cell death occurring at early stages in both non-induced Microspores and embryogenic suspension cultures; whereas NO played a dual role after stress in the two in vitro systems, one involved in programmed cell death in embryogenic suspension cultures and the other in the initiation of cell division leading to embryogenesis in reprogrammed Microspores.
-
early markers of in vitro microspore reprogramming to embryogenesis in olive olea europaea l
Plant Science, 2008Co-Authors: Mariateresa Solis, Beatriz Pintos, Mariajesus Prado, Mariaangeles Bueno, Ivan Raska, Mariacarmen Risueno, P S TestillanoAbstract:Microspore embryogenesis to form haploid and double-haploid embryos and regenerated plants is an efficient method of producing homozygous lines for crop breeding. In trees, the process is of special interest since classical methods are impractical in many cases, as in Olea europaea L. Recently, a convenient method has been developed for microspore embryogenesis induction by stress in olive isolated Microspores in vitro cultures. In the present work, the switch of the microspore developmental pathway and the formation of microspore-derived multicellular proembryos have been achieved and a cytochemical and immunocytochemical analysis was performed in the early stages. The young microspore proembryos displayed defined features different to both, the in vivo gametophytic, and the in vitro non-responsive Microspores. Reprogrammed Microspores showed an absence of starch, the occurrence of a first symmetrical division and cytokinesis, the presence of an abundant ribosomal population, and changes in cellulosic and pectic cell wall components which constituted early markers of the embryogenic microspore process. They provided new insights on the molecular and cellular events associated with the microspore reprogramming of woody plants, and specifically in olive, providing interesting knowledge which could guide future selection and regeneration strategies in this fruit tree of high economic interest.
K. J. Kasha - One of the best experts on this subject based on the ideXlab platform.
-
the influence of pretreatment on cell stage progression and the time of dna synthesis in barley hordeum vulgare l uninucleate Microspores
Plant Cell Reports, 2003Co-Authors: Y S Shim, K. J. KashaAbstract:The objective of this study was to correlate the time that DNA synthesis first occurs in haploid Microspores of barley with cell cycle and plant morphological stages and to subsequently assess the influence of pretreatments on DNA synthesis at different stages of microspore development. Spikes with Microspores in early, mid, and late uninucleate stages of the two-rowed barley cultivars Manley and Igri were subjected to two commonly used pretreatments. First, during cold pretreatment for 28 days there was a slow increase in relative DNA values as well as asymmetric nuclear divisions in some Microspores. Second, during a 4-day cold plus 0.3 M mannitol pretreatment, there was very little change in the microspore stage or DNA values indicating that for the duration of this pretreatment the progression of the cell cycle was essentially suspended at all stages, both in Igri and Manley. The results are discussed relative to the potential for genetic transformation of Microspores.
-
characterization of cdnas expressed in the early stages of microspore embryogenesis in barley hordeum vulgare l
Plant Molecular Biology, 1999Co-Authors: P L Vrinten, T Nakamura, K. J. KashaAbstract:To gain insight into the molecular events occurring in the very early stages of barley microspore embryogenesis, cDNA clones corresponding to genes differentially expressed during the early stages of microspore culture were isolated and characterized. A cDNA library established from barley Microspores cultured for three days was differentially screened against probes generated from freshly isolated Microspores. Three cDNAs representing genes not previously identified in barley were isolated. ECA1 (early culture abundant 1) lacked significant homology to known genes or proteins, and the transcript was only expressed during the early stages of culture. Expression was also reduced in low-density control cultures, therefore this gene may play a role in the early stages of barley microspore embryogenesis. ECGST (early culture glutathione S-transferase) had homology to parA-like genes, which are members of a newly discovered group of glutathione S-transferases (GSTs). The protein corresponding to ECGST may be important in protecting cells from oxidative stress during the culture process. ECLTP (early culture lipid transfer protein) had homology to lipid transfer proteins (LTPs), and had an expression pattern similar to that of an LTP known to be a marker of the early stages of embryogenesis in the carrot somatic embryogenesis system. The identification and characterization of the clones isolated in this study provides new information on the events involved in barley microspore embryogenesis.
Calvin F Konzak - One of the best experts on this subject based on the ideXlab platform.
-
production of doubled haploids in wheat triticum aestivum l through microspore embryogenesis triggered by inducer chemicals
2003Co-Authors: M Y Zheng, Y Weng, W Liu, E Polle, Calvin F KonzakAbstract:Production of doubled haploids (DH) from Microspores by androgenesis is a proven method to obtain homozygous individuals in a single step, thus the method is very useful in plant breeding. Since homozygosity is achieved in one generation, the breeder can avoid the numerous cycles of inbreeding required by conventional breeding systems and at the same time substantially reduce the population sizes required for effective selection of superior trait combinations. An efficient doubled haploid production system is also a preferred technique to produce homozygous transgenic plants. Dominant or recessive target gene(s) to be incorporated into gametic cells by genetic transformation can be fixed in homozygous form in a single generation. Doubled haploids are also important tools in plant genome mapping and studies of embryogenesis. In this chapter, there are described two unique and efficient systems — “flask” and “fresh microspore” systems for the production of doubled haploids, effective for a wide spectrum of genotypes in common wheat (Triticum aestivum L.). These systems rely upon three key steps. First, the Microspores are switched from their naturally programmed pathway for gametophytic development (Fig. 2.13-la) to sporophytic development (Fig. 2.13-1b) by an inducer chemical treatment under proper physical conditions. Second, optimal culture conditions are provided, which include adequate nutrition and a favorable physical environment to help Microspores elaborate their altered developmental programme leading to embryoid production, once a large population of reprogrammed Microspores is obtained. Third, embryoids are germinated on solid, hormone-free medium to form doubled haploid plants. Cell divisions in treated Microspores follow a well-organized and predictable pattern that leads to the formation of true “embryoids” rather than calli, ensuring success in plant regeneration. Cell divisions within the first 7 days in culture lead to the formation of a clearly defined multi-cellular structure, whose size is only 10–15 µm (diameter) larger than a microspore (Fig. 2.13-5a).
-
highly efficient doubled haploid production in wheat triticum aestivum l via induced microspore embryogenesis
Crop Science, 2002Co-Authors: W Liu, Ming Y Zheng, E Polle, Calvin F KonzakAbstract:An efficient doubled-haploid production technology that induces homozygosity can greatly reduce the time and cost of cultivar development. Low efficiency of doubled-haploid production previously has limited exploitation of this method for crop improvement. This study aimed to develop a more efficient and effective isolated microspore culture system for generating doubled-haploid wheat (Triticum aestivum L.) plants. We report here the development and testing of a new chemical formulation for its efficiency to induce microspore embryogenesis, and the development of a system for double haploid production, in which the induction of embryogenesis in Microspores was followed by isolating embryogenic Microspores, and culturing them under optimized growth conditions to produce high embryoid yields. Up to 50% of the total treated Microspores in the whole spike were converted from their preprogrammed gametophytic to a sporophytic pathway by a chemical inducer formulation consisting of 0.1 g L -1 of 2-hydroxynicotinic acid, 10 -6 mol L -1 2,4-dichlorophenoxy-acetic acid, and 10 -6 mol L -1 6-benzylaminopurine. The isolated embryogenic Microspores were cocultivated with live wheat ovaries in a liquid NPB 99 media with an osmolality of about 300 mOsmol kg -1 1 H 2 O, resulting in the regeneration of 50 to 5500 green plants per single spike of eight wheat genotypes. The high efficiency and simplicity make the system practical for biological research and for accelerating cultivar development in wheat breeding programs.
-
the effect of ovary conditioned medium on microspore embryogenesis in common wheat triticum aestivum l
Plant Cell Reports, 2002Co-Authors: Ming Y Zheng, Y Weng, W Liu, Calvin F KonzakAbstract:Microspores were isolated from wheat (Triticum aestivum L.) spikes of various genotypes following an effective pretreatment that induced microspore embryogenesis. The isolated Microspores were cultured with or without live ovaries, and with or without medium pre-conditioned by ovaries for varying periods of time. Live ovaries alone increased androgenic embryoid yields up to 4.5-fold over the control for Microspores isolated from responsive genotypes. While live ovary co-culture alone was not effective for Microspores isolated from recalcitrant genotypes, the addition of medium preconditioned by ovaries to microspore cultures increased embryoid yield by more than 100-fold. Without ovary-conditioned medium, no embryoids could be obtained from some recalcitrant genotypes. Ovary-conditioned medium apparently functions to increase embryoid yields by providing essential substance(s) for elaboration of the embryogenic program already triggered during pretreatment.
