Corn Journal
  • Corn Journal
  • Author
  • Stalk Rot Booklet
  • Seed Testing
  • Corn Genetics
  • Pathology
  • Sponsors
  • Contact
"You can see a lot by just looking"-Yogi Berra

Germination

3/16/2021

 
 ​Corn seed planting time is approaching in the northern hemisphere. The processes of successful producing and storage of the seed will soon come to fruition.  The selection of seed parents, care in the seed field of the last season and then the drying, shelling and storage all have an affect on reaching the goal of getting a uniform emergence in this next stage of growing corn.
 
Cells in a developing embryo are sufficiently mature to germinate in only 15 days after pollination if separated from the endosperm.  Early germination (vipipary) is inhibited by the presence of the plant hormone, abscisic acid, in the endosperm which negates the growth stimulant hormone, gibberellic acid, in the embryo.  This allows normal seed desiccation as water is replaced with starch deposits and eventual seed germination inhibition because of low water content.  Seed producers know that each genotype differs in the percent moisture to be used to harvest for optimum seed quality.  Generally, for most corn dent hybrids, that moisture is higher (+/-36%) than normal black layer moisture of 32%.  From there the moisture level must be rapidly decreased to less than 13 % to prevent excessive aging caused by damage to the cell membranes.  It is the art and science of the seed producer to bring the moisture down rapidly without using excess heat which also could damage the membranes.
 
Intactness of the pericarp affects the speed of imbibition of water in the soil.  Allowing the membranes surrounding each cell as well as the cell internal membranes to swell back to normal size with minimum injury is essential to their functions.  Cell membranes being the main structural component of embryo cells needed for energy conversion from starch in the mitochondria and translation of DNA to proteins, have a major effect on the germination quality of seeds.  Genetics of mitochondrial membranes, at least partly affected by the mitochondrial DNA, are probably one of the major reasons that seed quality varies between hybrid parents.  Mitochondria of the seed are replications of those in the female parent.  This is the major reason why choice of which hybrid parent becomes the seed parent.
 
Another major factor affecting on seed quality is the growing environment in the seed production field.  Stress, from drought or disease during the seed maturation period shows later in seed germination quality.  Such seed often becomes evident in germination tests done 4-5 months after seed harvest, sometimes in contrast to tests done only a few months earlier.  It is as if these seed had some membrane pre-harvest injury that when added to normal aging during these 4-5 months surpassed the minimum for normal germination.  These individual seeds either fail to germinate or are slower to emerge than other seed in the same seedlot.

Comments are closed.

    About Corn Journal

    The purpose of this blog is to share perspectives of the biology of corn, its seed and diseases in a mix of technical and not so technical terms with all who are interested in this major crop. With more technical references to any of the topics easily available on the web with a search of key words, the blog will rarely cite references but will attempt to be accurate. Comments are welcome but will be screened before publishing. Comments and questions directed to the author by emails are encouraged.

    Archives

    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015

    Categories

    All

    RSS Feed

© COPYRIGHT 2023. ALL RIGHTS RESERVED
  • Corn Journal
  • Author
  • Stalk Rot Booklet
  • Seed Testing
  • Corn Genetics
  • Pathology
  • Sponsors
  • Contact