Systemic View on Heading and Overwintering: Are They Always Opposed?

Abstract

The study investigated the cultivars of non-obligatorily requiring vernalization plant Festulolium braunii and assessed the influence of non-hardy reproductive and hardy vegetative structures on overwintering effect. The study was conducted taking into account systemic relations between these types of structures. The results show the cultivars differ according to the percentage of headed and overwintered plants, when the cultivars with the most abundant heading -'Felopa' and 'Sulino' -are also better at overwintering. The positive correlation between heading and overwintering characteristics was also observed, what seemed to be a rather new finding. It can be explained by systemic effect: non-hardy later reproductive structures induce the post-generative regrowth of vegetative shoots, which during shorter days halt development and become potentially hardy. More detailed interpretation is also provided including discussion of causal mechanisms of the detected phenomenon. The authors suppose that these mechanisms constitute a survival strategy for such perennial plants. The observed late heading which represents reproductive structures could be applied in plant breeding as a marker of winter-hardiness among perennial grass plants which non-obligatorily demand vernalization.

Vernalization Requirement and the Chromosomal VRN1-Region can Affect Freezing Tolerance and Expression of Cold-Regulated Genes in Festuca pratensis

“…Indeed, a re-examination of the marker data of Alm et al (2003) showed that, in the F 1 population, the maternal marker haplotype of the VRN1 -region associated with the ability to head without vernalization was also the one that was associated with better freezing tolerance after 2 weeks of CA (the paternal haplotypes did not have different effects on these traits in F 1 ). Šimkūnas et al (2013) also found a positive correlation among Festulolium cultivars between heading prior to vernalization and survival in the field during the following winter. They speculated that this might be due to more young tillers in the plants heading prior to vernalization, but had no data supporting this.…”