Growth under cold conditions in a wide perennial ryegrass panel is under tight physiological control

Abstract

BackgroundPerennial ryegrass is a cool-season grass species from the family Poaceae and is widely cultivated in temperate regions because it exhibits rapid growth and establishment, and possesses high forage quality. The extension of the growing season in Ireland in spring and autumn is a breeding target to make farming more profitable since a grass-fed diet based on grazing is the cheapest way of nutrition for ruminants.MethodsFifty-seven perennial ryegrass accessions were screened for their ability to grow under typical Irish spring conditions as taken from long term temperature records in controlled climate chambers. They were grown in low temperature (8 °C/2 °C day/night) and control conditions (15 °C/8 °C day/night) in three consecutive independent experiments. Fresh weight, height, chlorophyll content and electrolyte leakage were measured, and these parameters were used to rank plant performance under low temperature growth conditions.ResultsThe results showed that height, yield and electrolyte leakage are excellent measures for the impact of cold stress tolerance. Little variation in growth was seen under cold stress, but a wide variety of responses were observed under control conditions.DiscussionOur results suggest that cold stress is under tight physiological control. Interestingly, the various genotypes responded differentially to more amenable control conditions, indicating that a quick response to more amenable growth conditions is a better target for breeding programmes.

Atmospheric transport reveals grass pollen dispersion distances

“…Previous studies are generally in agreement that temperature, precipitation, and local grass areas are important factors in this dynamic (García-Mozo et al, 2010Jung et al, 2021;Recio et al, 2010;Ščevková et al, 2020;Skjøth et al, 2013;Werchan et al, 2017). This is due both to the growth and maturity of the plants (Charles-Edwards et al, 1971;Förster et al, 2018;Hurtado-Uria et al, 2013) but also the impact on flowering and the release of pollen (Cebrino et al, 2016;Emecz, 1962;Romero-Morte et al, 2020). However, it is uncertain to what degree all of these factors contribute to the absolute levels and the movement of the grass pollen seen in the atmosphere, with one new modelling study suggesting that temperature and CO2 have important positive and enhancing effects, not only on grass pollen levels now but also in the future (Kurganskiy et al, 2021).…”

Development and Validation of a Phenotyping Computational Workflow to Predict the Biomass Yield of a Large Perennial Ryegrass Breeding Field Trial

“…The distribution of NDVI values was wider in the winter2018 than late spring2018_1 and late spring2018_2. This indicates the various genotypes responded differently to cold season conditions (Förster et al, 2018). However, plant height and DMY predictions in the late spring2018_1 indicated higher values in which ryegrass appeared to have rapid growth and faster accumulation of dry matter in the spring season (Wang et al, 2019).…”

Mechanisms of Grazing Management in Heterogeneous Swards

“…Sward height distribution is updated every 10 min using an integral projection matrix model (a modeling approach that uses transition matrices to calculate the change in state of a population structured by a continuous variable) adapted from Ellner et al [24]. Sward areas increase in height according to a temperature-dependent logistic growth process [25] and decrease in height by grazing and trampling with rates that depend on sward height and animal density. Using the original population dynamics view of the integral projection method, the process can be viewed as discrete areas growing into adjacent bins of taller height, or "dying" due to being grazed and trampled and being instantly "reborn" in a bin with a shorter height equal to the remaining stubble.…”