Photosynthesis and Dry Matter Accumulation in Different Chlorophyll-Deficient Rice Lines

Three different chlorophyll-deficient rice isogenic lines chl,fgl and pgl,and their recurrent parent zhefu802 （zf802） were used to study effects of leaf color on photosynthesis,dry matter accumulation,yield,and quality in early season indica rice.Analysis showed that the chlorophyll （Chl.） a/b ratio of isogenic lines chl-8,pgl and fgl was 5.35,10.00 and 15.46,respectively,among them,line fgl had higher leaf area index （LAI）,higher net photosynthetic rate and higher grain-filling rate than its recurrent parent zf802 at the later period of grain filling stage;while LAI,net photosynthetic rate and dry matter accumulated in lines chl-8 and pgl were lower than in zf802.Differences were found in the grain yield and quality among chlorophyll deficient isogenic lines,lines fgl,chl-8 and zf802 had similar grain yield,which was significantly higher than that of pgl;the highest milling quality was observed in isogenic line fgl,with relatively high protein content.This study showed that isogenic line fgl would become a unique material for the development of high yield rice with high grain quality because of its slow aging process and relative steady grain-filling rate.

Characterization of a Novel Chlorophyll-Deficient Mutant Mt6172 in Wheat

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 1 000-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. changes of electron transport rate, photochemical dissipation, Under different photosynthetic active radiation conditions, 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 chloroDhvll deficiency.