General and specific combining ability in sweet sorghum

Abstract In breeding of sweet sorghum hybrids, non-additive genetic effects are important in phenotypic expression of the traits of interest. The aim of this study was to evaluate the general combining ability (GCA) of sweet sorghum lines and the specific combining ability (SCA) of the hybrids for agronomic and technological traits. Five fertility restorer lines, four male-sterile lines, and their hybrids from partial diallel crosses were evaluated in experiments laid out in a 5 x 6 triple rectangular lattice design in the municipalities of Lavras, MG and Sete Lagoas, MG, Brazil. Diallel analysis was performed using the Griffing model adapted to partial diallel crosses. There was a significant effect of GCA and SCA for most of the traits evaluated, indicating the participation of additive or dominant genes in inheritance. The restorer lines CMSX508, BRS 511, CMSXS643, and CMSXS646 show potential for use as parents in sorghum breeding programs.

摘要 在甜高粱杂交品种选育过程中，非加性遗传效应在目标性状的表型表达中占据重要地位。本研究旨在评估甜高粱育性恢复系的一般配合力（general combining ability, GCA），以及各杂交组合针对农艺与工艺性状的特殊配合力（specific combining ability, SCA）。试验选取5个育性恢复系、4个雄性不育系，及其通过部分双列杂交（partial diallel crosses）获得的杂交后代，于巴西米纳斯吉拉斯州拉弗拉斯市（Lavras）与塞特 Lagoas市（Sete Lagoas），采用5×6三重矩形格子设计（triple rectangular lattice design）开展田间试验。采用适配部分双列杂交的格里芬模型（Griffing model）进行双列杂交分析。结果表明，多数被测性状的一般配合力与特殊配合力效应均达到显著水平，证实加性或显性基因参与了该类性状的遗传调控。恢复系CMSX508、BRS 511、CMSXS643及CMSXS646具备作为高粱育种项目亲本的应用潜力。