English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Three distinct sequential stages comprise the microsporogenesis . These are: the pre meiosis, meiosis and post-meiosis. Pre-meiosis is the preparatory stage of a meiocyte to undergo meiosis. During this stage, the cells separate from one another attaining thereby the genetic autonomy, secretes a callose wall and synthesises about 96% DNA (Kaul 1988). This is followed by meiosis that involves a series of sensitive, specific and specialized events leading to microspore production. Once the microspores are liberated from PMCs, they enter post-meiosis-a preparatory stage for gamete production. During this stage, the micro spores separate from each other, secrete a callose wall and prepare for a mitotic division. All these events in the microspore comprise post-meiosis. Of all these three distinct development stages, the meiosis is a long duration, time and energy consuming cellular event. It is con trolled and co-ordinated by a large number of genes majority of which are dominant (Gottschalk and Kaul 1974, Kaul and Murthy 1985). Compared to the meiotic events, both pre and post meiotic events are controlled by a relatively fewer number of genes. Despite this fewer number of gene control, majority of the mutant genes inducing male sterility are post-meiotic (Kaul 1988, Kaul and Nirmala 1989). Whereas reasons of this preferential mutant gene action are not known, the net effect of all the ms genes is induction of male sterility accompanied by unimpaired female fertility.

Male Sterility in Pea I. Genes disrupting pre- and post-meiosis.