Characterization of a Novel Chlorophyll-Deficient Mutant Mt6172 in Wheat

Abstract

Identification of new chlorophyll-deficient mutants will provide materials for studying signaling components and pathways between plastid and nucleus. A novel chlorophyll-deficient mutant, named Mt6172, was obtained by spaceflight environment induction. Genetic analysis showed that its inheritance was controlled by nuclear and cytoplamic genes. Leaf color of its self-fertilized progenies was albino, narrow-white striped, or green. Only a few cells with abnormal chloroplasts were observed in albino plants and white section of narrow-white striped plants. These chloroplasts had obvious flaws in inner structure, and granum lamellae was extremely disordered. The narrow-white striped plants were characterized with green-and-narrow-white striped leaves, and the width of stripes between different plants was even, their plant height, number of productive tillers, and 1000-grain weight were lower than those of the wild type. The narrow-white striped plants and the wild type had significant difference in the value of potential activity of photosystem II at all tested stages. At elongation stage, which was impacted the most seriously, effective quantum yield significantly decreased, whereas the energy for photoprotection and photodamage significantly increased. Under different photosynthetic active radiation conditions, changes of electron transport rate, photochemical dissipation, and effective quantum yield were different, electron transport rate was more impacted than other parameters. Therefore, the leaf morphology and inheritance of mutant Mt6172 was different from the other reported mutants in wheat, and it was a novel mutant of chlorophyll deficiency.

Keywords

• Triticum aestivum L.
• space mutagenesis
• chlorophyll-deficient mutant
• agronomic traits
• chloroplast ultrastructure