Evolution and adaptedness in a facultatively apomictic grass, Poa pratensis L.

Abstract

Facultative apomixis confers great adaptedness and evolutive potential on biotypes belonging to the Poa pratensis L. agamic complex . Pioneering and recent research have dealt with and sometimes elucidated different aspects of apomictic expression, such as cytological mechanisms, distribution patterns, genetic control and environmental effects, in this species . We carried out an investigation on the mode of reproduction expressed in Italian natural populations, cultivars and selected genotypes together with an extensive time (56 years) and space (six countries) review in order to obtain a comprehensive picture of apomixis expression in P. pratensis . Histograms of the estimations were prepared . They showed that, due to breeder and natural selection, both cultivars and natural populations very frequently expressed a high degree of apomixis . Variations in the degree of apomixis across generations, different pollen donors, environments and estimation levels were generally low . It would, therefore, seem that the tenet which holds that apomixis in P. pratensis is strongly influenced by external factors should be reconsidered . Despite the fact that little is known of the genetic, physiological and molecular control underlying apomixis, the overall picture that emerges from our study helps to explain how the balance between sexual and asexual reproduction confers extreme versatility, adaptedness and evolutive capacity on this remarkable grass .

Effect of plantation age on plant and soil C:N:P stoichiometry in Kentucky bluegrass pastures

“…In agricultural practices, perennial grasses are promising candidates for the establishment of artificial pastures with good quality and higher productivity for grazing livestock (Jones et al, 2015) or for the regeneration of vegetation populations in degraded grasslands with their high reproductivity. Many previous studies have found that the aboveground biomass of perennial grass pastures often differs during different plantation ages (Folck et al, 2023), and this difference is related to soil nitrogen availability and supplies because grass is nitrophile (Mazzucato et al, 1996). Kentucky bluegrass (Poa pratensis), a perennial rhizomatous grass with high tolerance to environments, has become increasingly important (Pi et al, 2015;Wu et al, 2023) because of its ability to be productive in cool temperatures and high soil moisture conditions (DeKeyser et al, 2015;Zhu et al, 2023).…”

Cyto-Embryological Analysis of Wild Kentucky Bluegrass Germplasm in Gansu Province, China

“…Supernumerary embryo production allows plants to mitigate the effects of genetic load on fertility by producing more or higher quality offspring, which is akin to reproductive compensation in plant evolution [5]. From an adaptive perspective, apomixis is a method of multiplying gene combinations that are currently adapted, while sexuality provides a reservoir of variation that can be selected in the process of evolution [6]. Therefore, P. pratensis is considered as one of the most variable, buffered, and tolerant species.…”