Strategies of grain number determination differentiate barely row-types

Gaining knowledge on intrinsic interactions of various yield components is
crucial to improve the yield potential in small grain cereals. It is well
known in barley that increasing the grain number (GN) preponderantly
improves their yield potential; however, the yield components determining
GN and their association in barley row-types are less explored. In this
study, we assessed different yield components like potential spikelet
number (PSN), spikelet survival (SSL), spikelet number (SN), grain set
(GS), and grain survival (GSL), as well as their interactions with GN by
using a selected panel of two- and six-rowed barley types. Also, to
analyze the stability of these interactions, we performed the study in two
growth conditions, greenhouse and field. From this study, we found that in
two-rowed, GN determination is strongly influenced by PSN rather than SSL
and/or GS in both growth conditions. Conversely, in six-rowed, GN is
associated with SSL instead of PSN and/or GS. Thus, our study exemplified
that increasing GN might be possible by augmenting PSN in two-rowed
genotypes, while for six-rowed genotypes, the ability of SSL needs to be
improved. We speculate that this disparity of GN determination in barley
row-types might be due to the fertility of lateral spikelets.
Collectively, this study revealed that the GN of two-rowed largely depends
on the developmental trait, PSN, while in six-rowed, it mainly follows the
ability of SSL.