Inbred and hybrid sweet corn genotype performance in diverse organic environments

Abstract

The value of selection in conventional breeding trials of cultivars destined for organic systems depends on the correlation between systems and relative heritability of key traits. Genotype by environment interactions is a common phenomenon in plant breeding trials. Thus, multienvironment testing to identify stable genotypes is a high priority for organic systems. In addition, This article is protected by copyright. All rights reserved. because organic systems have limited inputs to buffer the environment, they may have greater spatial heterogeneity which may be better accounted for by additional spatial blocking terms beyond traditional randomized complete block design. Over two years, we evaluated 100 hybrid and 40 inbred sweet corn genotypes in 11 trials in organic systems across 6 locations and evaluated the addition of augmented incomplete block and row-column design to estimate the performance of sweet corn genotypes. Hybrids differed in their performance for all tested traits. Inbred parents differed in per se performance and general combining ability for all traits. For the hybrid entries, modelling spatial factors beyond the replicated complete blocks improved the model fit for days to anthesis, plant height, ear height, husk protection, ear width and ear length. For inbred entries, modelling spatial factors beyond the replicated complete blocks improved \ model fit for plant height, ear height, tenderness, and ear width. Wricke's ecovalence (W 2 i) was a useful measure of stability, correlating reasonably well with two of the three stability statistics considered in this analysis. Based on Wricke's ecovalence, some inbred parents were more stable than others across tested environments in their combining ability for all traits.

Classical and genomic prediction of synthetic open‐pollinated sweet corn performance in organic environments

“…The material tested in this project was based on 40 high‐quality sugary enhancer1 sweet corn inbreds from the University of Wisconsin sweet corn program or on progeny derived from them. These inbred represent a substantial fraction of the diversity of the most elite sugary enhancer1 material from the program (Zystro et al., 2020b).…”

“…Hybrids were developed based on four disconnected North Carolina Design II (NC DII) mating blocks, each with five males and five females (Zystro et al., 2020a). Crosses were made such that (a) inbreds with shared pedigrees (Zystro et al., 2020b) were not crossed to each other, (b) each mating block contained no inbreds with shared pedigrees, and (c) each mating block had inbreds that shared a common pedigree with at least one other inbred in each of the other three blocks.…”

“…Arlington, WI; Shively, CA; Camp Grant, CA; Upper Lake, CA; and Corvallis, OR (Zystro et al, 2020a). These trials were arranged in randomized complete block design with two replications, with each complete block divided into four augmented incomplete blocks.…”

“…These trials were arranged in randomized complete block design with two replications, with each complete block divided into four augmented incomplete blocks. Each of the eight incomplete blocks were augmented with five commercial checks (Zystro et al, 2020a). Each plot was a single row 3.5 meters long and had single-row guard rows between plots planted with a short statured sweet corn population.…”

Classical and genomic prediction of hybrid sweet corn performance in organic environments

“…Second, the results of this study are unique to this set of germplasm. Many of the inbred entries used to create both the hybrids in the NC DII training sets and the hybrids in the validation set share common ancestors (Zystro et al, 2020). When studying population structure and accuracy of genomic selection in wheat (Triticum aestivum L.), Isidro et al (2015) found that accuracy was highest when the training and test populations are highly related.…”