Specific features of meiosis in the Siberian Fir (Abies sibirica) in the forest Arboretum of the V. N. Sukachev Institute, Russia

Abstract

Investigating the tolerance of plant reproductive systems to environmental changes has become a research priority under current climate change scenarios. Successful plant conservation requires knowledge of plant reproductive biology, particularly the meiotic characteristics of planted species. Meiosis, as part of microsporogenesis, is a critical plant developmental stage controlling future pollen quality. Meiosis in a Siberian fir (Abies sibirica) plantation, established in the Forest Arboretum of the Sukachev Institute, Russia, was studied from 2002 to 2004. The microsporogenesis pattern found for the Siberian fir appeared to be largely similar to that exhibited by other conifer species. Meiosis in the Siberian fir has the following characteristics: asynchrony, rapid progression of telophases I and II, and parallel and linear spindle arrangements at different meiosis II stages. General and specific meiosis irregularities were recorded at each stage. Some specific features of meiosis and the specific development of some irregularities were revealed. Pollen development analysis showed that irregular pollen grains made up less than 1% of all grains. The specific features of meiosis identified in fir trees growing in the Arboretum indicated low resistance of male reproductive structures to climatic changes and might account for high fir pollen sterility in this new environment.

Fossilized pollen malformations as indicators of past environmental stress and meiotic disruption: insights from modern conifers

“…2), we summarize possible developmental origins of pollen malformation types observed in this study that are applicable to the fossil record by drawing upon historical observations in the cytological literature of extant conifers and seed plants. In studies to date, the developmental origins of certain malformation traits have not explicitly been discussed, given that cytological studies on conifer microsporogenesis mentioning them focus on genotypic rather than phenotypic implications of meiotic deviations (Andersson 1947; Runquist 1968; Bazhina et al 2007a,b, 2011; Noskova et al 2009), while morphological studies addressing malformations do not evaluate their developmental origins (Lakhanpal and Nair 1956; Srivastava 1961; Mehra and Dogra 1965). However, there are inferences that can be made about malformation origins based on what is known about microsporogenesis in saccate conifers and the nature of some morphological deviations.…”

“…Although certain morphological deviations in both fossil and modern pollen walls can be inferred to result directly from certain types of developmental disruptions, traceable to specific stages in meiosis I and II (Chira 1967; Bazhina et al 2007a,b, 2011; Noskova et al 2009) (Fig. 2), it can be difficult to infer presence of a specific environmental stress using higher frequencies of developmental deviations alone, as they arise from numerous genotype by environment interactions (Veilleux and Lauer 1981).…”

“…Additionally, Siberian A. sibirica growing under industrial pollution (Presnukhina and Kalashnik 2003) and under near-ambient conditions in an arboretum (Bazhina et al 2007b) have also displayed a wider spectrum of structural deviations during meiosis, including chromosome fragmentations, chromosome bridges, and ring chromosomes, as well as chromosome ejection and agglutination. Bazhina et al (2011) suggested that chromatin agglutination may have accounted for heterogeneity in sizes and shapes of pollen grains observed in studies of A. sibirica under changing climate in Siberia. Unreduced malformed grains such as giant grains (Fig. 2A,B) or conjoined grains (Fig.…”

“…2:13) (Bazhina et al 2019). In some cases, Bazhina et al (2011) documented instances of five-pole separation in anaphase II of A. sibirica . When these genes are completely damaged, chromosomes become either concentrated at the center of the cell or randomly distributed throughout (Bazhina et al 2019).…”

<i>Abies sibirica</i> Male Reproductive Cones Developmental Shift at Introduction

“…Although meiosis proceeded in a fairly regular way in most cells, irregularities of general and specific types were found nearly throughout meiosis and pollen formation (the irregularities occured in 11.7%, 13.3%, and 17.9% of the cells in low mountains, middle mountains and in the arboretum (Figures 2(e)-(f)). In the Arboretum, irregularities frequency of occurence increased at all meiotic stages and reached 48.2% at anaphase I [27]. Regular Siberian fir pollen grains have, as a rule, two large symmetrical air sacs.…”