Wyniki wyszukiwania - Biblioteka Nauki

1

Observations on embryogenesis of Notothenia neglecta Nybelin in Admiralty Bay (King George Island, South Shetland Islands, Antarctica)

100%

Sapota M. R.

Oceanological Studies

|

1993

|

nr 64/3

283-289

2

Present status of Gentiana taxa biotechnology

100%

Mikula A. , Rybczynski J. J.

|

nr 4

76-91

EN

Data on the tissue culture and genetic manipulation of several species of the genus Gentiana in support on the review of literature are presented.

3

Consequences of transformation of embryogenic Triticale cell

100%

Zimny J. , Czaplicki A. , Menke-Milczarek I. , Oleszczuk S. , Sowa S.

|

nr 2

64-72

EN

Plants carrying foreign genes have been obtained for many crops including wheat, rice, maize, barley and Triticale. The most important aspect for practical breeding is the regeneration of whole plants from a specific cell possessing the desired agronomic properties. Particle bombardment provided the necessary breakthrough for the efficient transformation of cereals. Efficient regeneration is a prerequisite for all transformation techniques. The aim of the presented work was to study the progeny of transgenic plants of the allohexaploid cereal species Triticale. By combining an efficient regeneration system with the successful particle bombardment method we were able to obtain transgenic Triticale plants. Transgene expression was sometimes unstable and generally resulted in the decline of the expression, although some lines showing stable expression were also selected. In our laboratory several generations of androgenic doublehaploid transgenic lines have been regenerated and multiplicated. The integrated transgenes were detected in Triticale lines by in situ hybridisation method. The stability of trangenes has been studied on ten generations. A regeneration system from single cell to plant combined with microprojectile bombardment appeared to be the most efficient transformation method for Triticale. Numerous chimeric genes are now available for research. Some of these genes may appear useful in the future breeding of Triticale.

4

Isolated microspores as a source doubled haploids of barley

100%

Oleszczuk S. , Zimny J.

Biotechnologia

|

2001

|

nr 1

139-142

EN

In vitro techniques for doubled haploids (DH) production allow for obtaining homozygous lines in a single generation. This is connected with shorter breeding cycle of the new variety. DH lines have a potential for being used in the selection of recombinants, stabilising of transformed lines and molecular mapping. DH lines are produced from isolated microspores through haploid embryogenesis. Microspore culture has several advantages over anther culture: it reduces the time of cultures, enables monitoring of the earliest phase of embryogenesis, allows for direct development embryos, facilitates the in vitro selection and mutation, allows for avoiding regeneration from somatic anther tissues. Moreover, microspore culture appears to be a promising tool in genetic manipulations (transformation, mutagenesis) and it can be used as a source of protoplasts and suspensions. Here we report on how to induce microspore embryogenesis, resulting in plant formation. The switch of microspore development from gametophytic to sporophytic pathway has been stimulated by various stress factors like cold and heat shock, starvation. Stress treatment not only stops pollen development but also re-programmes the microspore towards embryo formation. The effects of various parameters including pretreatment, carbohydrates and nurse culture have been investigated. After optimising the culture conditions we were able to regenerate high number of fertile plants.

5

In vitro culture of cereal microspores

100%

Oleszczuk S. , Zimny J.

|

nr 2

142-160

EN

The development of microspore culture methods in the Poaceae family has received considerable attention in recent years. Isolated microspore culture can be induced in vitro to switch their development from gametophytic to a sporophytic patway, resulting in embryoid or callus formation. Different stresses like cold or heat shock and nitrogen starvation have been identified as the major trigger in inducing microspore embryogenesis. Microspore culture appears to be a promising toll for future production of double haploids in cereals. Isolated microspore culture has several advantages over anther culture in genetic manipulation and haploid study, such as: direct observation of microspore development, unique possibility to study plant embryogenesis, easier in vitro selection and mutation, easier transformation of single cells. Moreover, isolated microspores are the most efficient way of double haploid regeneration. Many factors such as genotypes, physiological status of donor plants, stage of microspores development, pretreatment of anthers or spikes, method of microspores isolation, culture media, nurse culture and culture conditions, have a great influence on microspore culture. These and other problems concerning in vitro culture of isolated microspore are discussed in this review.

6

Obtaining homozygous carrot plants with the aid of androgenesis in anther cultures

75%

Gorecka K. , Krzyzanowska D. , Kiszczak W. , Kowalska U. , Gorecki R.

Biotechnologia

|

2008

|

nr 2

142-152

EN

Experiments with anther cultures of 22 carrot cultivars were carried out to study the effect of various factors on the effectiveness of embryogenesis in these cultures. The factors included: the stage of microsporogenesis, genotype, training of donor plants and their growth conditions. A modified B5 medium (Gamborg, et al. 1968) containing 500 mg L-1 glutamine, 100 mg L-1 serine, 0.1 mg L-1 of 2,4D, 0.1 mg L-1 NAA, 100 g L-1 sucrose and 6.5 g L-1 agar were used to induce androgenesis. Regeneration was carried out on MS media and B5 with reduced concentration of sucrose at 20 g L-1 without aminoacids and hormones or with small amount of hormones. Substrates that were a mixture of various components, such as peat, sand, mineral wool and charcoal, were used for adaptation. Ploidy of the obtained plants was determined by cytometry method. Homozygosity of the plants was established using two isoenzymatic systems: PGI ? phosphoglucose isomerase, and AAT ? aspartate aminotransferase. Anatomical studies of embryogenesis during anther cultures were also carried out to confirm the androgenetic origin of embryos. It was found that the uninucleate stage was the most suitable time to stimulate microspores to produce embryos, and that bud length was a good external indicator of the stage of microsporogenesis. The studied cultivars differed in their ability to undergo androgenesis in vitro. It was shown that it was not necessary to remove all shoots and umbels except the main one. Generally, the embryos were obtained regardless of the way the donor plants were trained, even when the plants were not trained at all. The donor plants grown in a greenhouse produced more embryos than the plants grown in the field. On MS and B5 media without hormones, used to regenerate plants from embryos, secondary embryogenesis was found to take place followed by a conversion of embryos to complete plants, which subsequently resulted in better adaptation (more than 80% of plants became adapted). Cytometric studies revealed that more than 90% of the obtained androgenetic plants had a doubled chromosome complement. By analyzing the AAT and PGI isoenzymes, it was found that the obtained carrot androgenetic plants were homozygotes. Anatomical studies confirmed that embryos were formed from microspores.

7

Participation of jasmonates in differentiation processes in plants

63%

Saniewski M. , Urbanek H.

|

2003

|

nr 3

75-86

EN

Jasmonic acid (JA), methyl jasmonate (JA-Me) and their related compounds which are designated as jasmonates, are widely distributed in the plant kingdom and show various important biological activities in the regulation of plant growth and development, resulting in a consideration that they are putative new plant hormones. Endogenous levels of jasmonates, mainly JA, increase rapidly and transiently in plants or their organs under both abiotic and biotic stress conditions. Jasmonates consist of an integral part of the signal transduction chain between stress signal(s) and stress response(s). In this article, we focused on and reviewed the role of jasmonates in control of differentiation processes in tissue cultures, regeneration and micropropagation, somatic embryo formation, tuber initiation and formation. The involvement of jasmonates in tuberization, tuberous root formation and bulb formation was inferred from their ability to induce the processes in vitro, and from changes in the levels of endogenous jasmonates during the growth of the plants which can account for the initiation of tuberization. The tuberization and the expansion of cells induced by jasmonates always involve the reorientation of cortical microtubules. Differential effect of jasmonic acid on cell cycle progression is also presented. It is still an open question about interactions between jasmonates and other hormones (auxin, ethylene, cytokinins, abscisic acid) in the regulation of meristem activities, cell cycle and other physiological processes.