Meiotic mutations in rye Secale cereale L

Area of Science:

• Plant genetics
• Molecular biology
• Cytology

Background:

• Spontaneous meiotic mutations can arise in crop plants.
• Understanding these mutations is crucial for breeding programs and genetic research.
• Winter rye (Secale cereale L.) is an important crop with a diploid chromosome number of 2n=14.

Purpose of the Study:

• To identify and characterize spontaneous meiotic mutations in winter rye.
• To analyze the cytological and genetic basis of these mutations.
• To investigate the interactions and epistatic relationships between different meiotic mutations.

Main Methods:

• Induction of mutations through self-pollination of F1 hybrids from crosses between cultivar Vyatka/weedy rye and inbred lines.
• Cytological analysis of meiosis (Metaphase I, Prophase I).
• Genetic analysis of mutant phenotypes and interactions (double mutants).

Main Results:

• Six distinct types of meiotic mutations were identified, including asynapsis, nonhomologous synapsis, synaptonemal complex defects, irregular chromatin condensation, and chromosome supercondensation.
• Mutations affected synaptonemal complex (SC) formation, bivalent formation, chiasma frequency, and meiotic spindle assembly.
• Recessive epistatic interactions were observed, indicating a sequential genetic control of meiotic events (sy9 > sy1 > sy3 > sy19).
• Some mutations showed modified expression due to additional genes, and most identified mutations have analogs in other plant species.

Conclusions:

• Spontaneous meiotic mutations in winter rye provide valuable genetic resources for studying meiosis.
• The identified mutations disrupt key meiotic processes, leading to partial or complete sterility.
• Comparative analysis suggests conserved mechanisms of meiotic regulation across plant species.