TITLE:
Negative Association between Seed Dormancy and Seed Longevity in Bread Wheat
AUTHORS:
Jing Zhang, Shijie Xiang, Hongshen Wan
KEYWORDS:
Wheat Seed, Germination Test, Artificial Aging, Longevity and Dormancy, Negative Relationship
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.12 No.3,
March
29,
2021
ABSTRACT: Many organisms have dormant stages with an extension
of their life span to increase longevity, and deeper dormancy is usually
related to greater longevity. In cereal crops, seed dormancy is significantly
associated with pre-harvest sprouting tolerance during seed development, as
seed longevity is a valuable trait for seed banks and providing reliable crop
seeds to farmers. In this study, we evaluated both seed dormancy and longevity
in bread wheat based on germination and artificial aging tests. According to
phenotypic clustering analysis, relative germination rate/potential and
relative seedling vigor index were more effective to indicate seed longevity
than relative electrical conductivity in wheat, while all the four investigated
phenotypes of relative germination potential, relative germination rate,
germination index and degree of seed dormancy fit well as a reflex of wheat
seed dormancy. In the correlation analysis, the germination level of newly
harvested grain negatively reflected its degree of seed dormancy, while the
germination ability of grain after artificial aging reflected its seed
longevity. However, in contrast to the current opinion in plant, seed dormancy
was significantly negatively correlated to seed longevity in our study, and it
was not an accidental phenomenon, for that the majority of accessions with high
degree of seed dormancy had short seed longevity. To our knowledge, this is the
first to report the negative association between seed dormancy and longevity in
cereal crops. It would lead to further concerns about how to breed wheat with
both prolonged seed longevity and deep dormancy to avoid pre-harvest sprouting.