Effect of sterile cytoplasms on photosynthetic activity and biomass yield in sorghum F1 hybrids

Abstract

Indicators of photosynthetic potential (PP), net photosynthesis productivity (NPP), and biomass yield were studied during 3 years in F1 sorghum hybrids obtained with using two sets of isonuclear cytoplasmic male sterility (CMS) lines with different types of sterile cytoplasms: A3, A4, 9E carrying Zheltozernoe 10 (Z10) genome and M35-1A and 9E carrying Pishchevoe 614 (P614) genome when crossing with Merkurii (M) and Pishchevoe 35 (P35) cultivars. It was demonstrated that the type of sterile cytoplasm affects the PP and NPP value, and the cytoplasm effects differ in different years. The sterile cytoplasm 9E stimulated the PP value in extremely hot and droughty 2010. According to the results of 3-year studies, the A3 cytoplasm (unlike 9E and A4 cytoplasms) decreased PP indicators in the tillering–heading stage. The effect of sterile cytoplasms on NPP depended on the hybrid genotype and ontogenesis stage: the 9E cytoplasm promoted an increase in NPP in the tillering–heading stage as compared with the A3 and A4 cytoplasms (in hybrid combinations Z10/P35) and M35-1A (in combinations with CMS lines with P614 genome); in combination with Z10/M, the A4 cytoplasm significantly stimulated NPP in the tillering–heading stage and decreased it in the stage of heading–complete maturity. On average over 3 years, higher biomass yield was registered in hybrids with 9E cytoplasm than in hybrids with A3 and A4 cytoplasms, and the strongest differences were observed in hot 2010.