Evaluation of Public Sweet Sorghum A-Lines for Use in Hybrid Production

Abstract

A fundamental need for commercialization of sweet sorghum [Sorghum bicolor (L.) Moench] as a bioenergy crop is an adequate seed supply, which will require development of hybrid varieties using dwarf seed-parent lines.

Heterosis and Combining Ability of F1 Hybrid Sweet Sorghum in Thailand

“…Grain yields averaged 4.74 Mg ha -1 for inbreds and checks and 5.74 Mg ha -1 for hybrids. Pedersen et al (2013) also reported heterosis for grain yield in hybrid sweet sorghum in Nebraska, and yields among hybrids were similar to those observed in this study. On the basis of a conversion factor of 402 L Mg -1 grain (USDA, 2006), some of the hybrids in this study could potentially produce over 3000 L ha -1 ethanol from grain alone.…”

“…Overall, males showed greater GCA effects than the females for most traits, but as in other studies, SCA effects were of greater significance. Pedersen et al (2013) created hybrids using six A-lines and six sweet sorghum cultivars as pollen parents, and then evaluated them for sugar, biomass, and grain production in Nebraska. The results showed that five of the A-lines could be used as seed parents (A-Dwarf Kansas Sourless, AKS9, A-N36, A-N39, and A-N4692) to produce hybrids with sugar yields that were usually comparable to those of the inbred male parents.…”

Sorghum

“…Firstly, hybrids allow producers to increase yield by maximizing heterosis. Heterosis for grain yield is usually between 150 and 200%; heterosis for biomass yield is typically 20-50% [45,46]. Secondly, seed production for many of the biomass sorghum cultivars is only feasible using hybrid systems.…”

“…Studies of these hybrids are superior to seed parents and numerically equal if not superior to pollen parents (i.e., sweet sorghum varieties) [45,46]. While first generation hybrids did not always outperform their respective pollinator parents, hybrid seed production capacity was four to six times greater than for a pure-line sweet variety and it was much easier to harvest.…”

Dedicated Herbaceous Biomass Feedstock Genetics and Development

“…Pedersen et al [71] determined that a large portion of variation in ethanol yields of sweet sorghum lines and hybrids was due to cellulosic fiber. Genes responsible for increased saccharification via enzymes have been mapped and were identified from a sorghum core collection [127].…”