After a short introduction, the cytogenetics of plant cell and tissue cultures and their regenerates will be discussed. In the first section discussion will focus on cytogenetic conditions “in vivo”, i.e., in the original explant: (I) widespread ocurrence of polysomaty as a consequence of endoreduplication; (2) aneusomaty, an important, though rare, cause of chromosome number variation in vivo; (3) occurrence of chromosome structural changes in differentiated tissues, especially in association with aging; (4) mixoploidy and/or gene mutations, either nuclear or organellar, present as mosaics or periclinal chimeras, especially in vegetatively propagated plants. In section two the discussion will follow with nuclear processes at and during callus induction: (1) mitosis induction in diploid (haploid) and endoreduplicated cells and initiation of cell lines with different ploidy levels; (2) chromosome endoreduplication prior to mitosis induction as a mechanism of polyploidization; (3) nuclear fragmentation (ami...

Cytogenetics of plant cell and tissue cultures and their regenerates

Since the successful induction of haploids from anthers cultured in vitro in 1964, a great deal of attention has been given to this problem by those interested in obtaining pure lines and mutants for crop improvement and biochemical genetics. In the last 16 years the anther culture technique has been refined and extended to over one hundred and fifty different species. More recently, isolated pollen culture - which is a refinement of the original anther culture technique - has also been developed. In this review we have made an effort to critically examine existing reports with the objective of analysing the effects of various factors - e.g. culture medium, the cultural conditions, and the effect of genotype and physiological state of the parent plant on pollen induction - and to speculate on the mechanism of action of different factors in order to throw some light on the process of haploid induction.

Induction of haploidy from pollen grains in angiosperms — the current status

36 – pollen, ovule and embryo culture as tools in plant breeding

In vitro induction of pollen embryos and plantlets in Brassica juncea through anther culture

Chapter 7 – haploids in plant improvement

Anther culture ofPhysalis minima L. (2 n=48) was successful and embryos and plantlets could be obtained 5–6 weeks after culture. MS medium containing CM was essential for pollen division. 16.7% of the cultured anthers produced plantlets. All the pollen plantlets were triploid (3 n=72). Regeneration of multiple shoot buds was obtained from cultured leaf and stem expiants of pollen plantlets.

P. S. Rao

Papers

Experimental induction of triploid plants ofPhysalis through anther culture