The use of the new types of CMS in the breeding of the heterosis sorghum hybrids needs the study of their effects on the biologic and economic-valuable traits of the plants. During the years of 2010, 2012 and 2013 there were studied the indicators of the photosynthetic potential (PsP) and the net photosynthetic productivity (NPsP) of the grain sorghum hybrids F1 , obtained from two sets of the nuclear CMS-lines with different types of the sterile cytoplasm А3, А4, 9Е (with the genome of the

more »

... hum line 'Zheltozernoe10') and М35-1А and 9Е (with the genome of the sorghum line 'Pishchevoe614'). The grain sorghum varieties 'Merkuriy' and 'Pishchevoe35' have been used as the pollinators. The indicators of PsP and NPsP have been estimated on the stages 'sprouts – tillering', 'tillering – heading stage', 'heading stage – maturity'. It has been determined that the type of the sterile cytoplasm influences upon the PsP and NPsP values of the hybrid F1 . The display of the cytoplasmic differences depends on the environmental conditions and the genotype of the pollinator. On average the hybrids with 'Merkuriy' showed significant effects of the type of cytoplasm during all stages of ontogenesis, but the hybrids with 'Pishchevoe35' showed the effects only on the stage 'tillering – heading stage'. The cytoplasm A3 reduced the PsP value of the hybrids, the cytoplasm 9E increased the PsP and NPsP values, especially in the hot and dry environmental conditions. The cytoplasm М35-1А also reduced the PsP value, but significant differences during three years were seen not on all stages of ontogenesis. The obtained data should be taken into account in the programs of the breeding of the heterosis sorghum hybrids.