Heterosis and Specific Combining Ability in Sweet Corn and Its Correlation with Genetic Similarity of Inbred Lines

Abstract

The heterosis phenomena has been exploited in hybrid maize field production. Theoretically, heterosis was depending on genetic distance of inbred lines. Meanwhile, different from field corn breeding, sweet corn does not have well defined heterotic group. The objective of this study was to determine genetic similarity (GS) of eight selected inbred lines of sweet corn based on morphological traits and its correlation with specific combining ability (SCA) and heterosis. The eight inbred lines were characterized and crossed in full diallel design. Then, the lines, F1 and its reciprocal, were evaluated by using the Randomized Complete Block Design in three replications. The result showed positive heterosis and SCA effect in most of the hybrids which indicated the heterosis effect in the hybrids performance. Based on the morphological traits, the genetic similarity between the inbred lines was 62.2-82.4%. The inbred lines with 70% similarity coefficient were grouped into three. There was significant correlation between the genetic similarity and heterosis in all traits, except in the plant height. Meanwhile, only SCA of days to maturity and TSS showed significant correlation to genetic similarity. This indicated the usefullness of genetic similarity to identify the potential inbred lines for parental hybrid.

Diversity of twenty-three sweet corn (Zea mays L. saccharata) varieties in Indonesia

“…Meanwhile, cluster 3 consisted of five varieties with a similarity level of 30.07 to 57.26%. The diversity of sweet corn in this study was higher than the diversity reported by Stansluos et al (2019), who divided 11 hybrid and non-hybrid varieties into four clusters with a similarity level of 75 to 97%, and Yuwono et al (2017), who divided eight inbred lines into three clusters with a similarity level of 62.5%. Stansluos et al (2019) and Yuwono et al (2017) used agronomic traits for clustering.…”

“…The diversity of sweet corn in this study was higher than the diversity reported by Stansluos et al (2019), who divided 11 hybrid and non-hybrid varieties into four clusters with a similarity level of 75 to 97%, and Yuwono et al (2017), who divided eight inbred lines into three clusters with a similarity level of 62.5%. Stansluos et al (2019) and Yuwono et al (2017) used agronomic traits for clustering. The diversity of sweet corn in this study is similar to Roy et al (2015), who divided 30 genotypes into several clusters with 25 to 66% similarity using molecular markers.…”

Partial diallel and potential of super sweet corn inbred lines bt 2 to obtain hybrids

“…Similar results for ear yield, grain yield, plant height and total soluble solids were obtained by Lemos et al (2002); Bordallo et al (2005), Solomon et al (2012, Rice & Tracy (2013) and Suzukawa et al (2018). However, for ear height and ear diameter, Solomon et al (2012) reported that additive gene action had greater importance in relation to non-additive effects, and for TSS, the authors verified no significant difference for GCA and SCA in diallel crosses evaluated, whereas Yuwono et al (2017) verified significant difference of SCA for TSS.…”

Selecting experimental super sweet corn hybrids based on selection index

“…Sweet and super sweet corn breeding programs do not have well-defined heterotic patterns, unlike what occurs in common corn breeding programs. Heterosis effects are significant for the main traits related to productivity (Solomom et al, 2011;Kuki et al, 2017;Yuwono et al, 2017); however, almost always they are not sufficient for obtaining commercially successful sweet corn hybrids. This is due to the fact that traits such as ear diameter, ear length and soluble solids contents in grains, as well as high productivity, are essential to launch hybrids on the market (Souza Neto, 2019).…”