Heterosis studies in sweet sorghum [Sorghum bicolor (L.) Moench]

An investigation was carried out in Sweet sorghum [Sorghum bicolor (L.) Moench] to evaluate 18 new hybrids developed by using 3 lines and 6 testers for heterosis in respect of ethanol yield and its attributing characters. Analysis of variance for the genotypes including parents and hybrids differed significantly for all the characters studied. Similarly, significant differences were observed among the parents and hybrids for all the characters except brix per cent. The mean squares of hybrids Vs parents were significant for most of the characters except juice pH and ethanol yield. Among the seven characters studied, cane height, stem girth, cane weight, juice volume, ethanol yield exhibited significant heterosis over mid parent as well as better parent in majority of the crosses indicating predominance of non-additive gene action in the genetic control of these traits. The standard heterosis was significant in desirable direction only in two hybrids in respects of juice pH and brix per cent, while 5 to 13 hybrids exhibited significant standard heterosis in respect of other five characters. Out of 18 hybrids, eight exhibited high overall (H) heterotic status across the characters. The hybrids RSSV 76 x ICSV 93046, RSSV 104 x ICSV 700, ICSR 93034 x ICSV 93046, RSSV 76 x ICSV 700, ICSR 93034 x ICSV 700 and RSSV 76 x NSSV 254 were the top five promising high ethanol yielding hybrids identified from the study.