Twenty‐Four Cycles of Phenotypic Recurrent Selection for Percent Oil in Maize. I. Per Se and Test‐Cross Performance

Abstract

Responses and limits to selection are found to differ in various maize (Zea mays L.) populations and traits. Twenty‐four cycles of recurrent selection for high oil concentration have been completed in maize population Alexho Synthetic. The objectives of this study were to determine the response of oil concentration direct selection and correlated responses of fatty acid concentration, grain yield, and other agronomic traits. Cycles 0, 3, 5, 9, 11, 15, 18, 21, and 24 per se, the same cycles crossed to inbreds B73 and R802A, and hybrid check B73 ✕ Mo17, were evaluated in six environments at Yugoslavia and at Urbana, IL in 1985 and 1986. Selection was effective in increasing oil concentration. Total oil concentration increased by 118, 51, and 57 g kg−1 of dry matter in cycles per se B73 and R802A testcrosses, respectively. The rate of response in oil concentration was 4.9, 2.1, and 2.4 g kg−1 cycle−1 for the cycles per se for B73 and R802A testcrosses, respectively. The quadratic response was significant in testcrosses, but not in cycles per se. Thus, oil concentration has not yet shown evidence of plateauing. Oleic and linoleic acid concentration changed with selection for oil concentration in cycles per se −1.39 and 1.39 g kg−1 cycle−1, respectively. Total grain yield of the cycles per se decreased by 1718 kg ha−1, which corresponds to a response of −71.6 kg ha−1 cycle−1. Yield of the testcrosses to inbreds B73 and R802 decreased 19.7 and 15.2 kg ha−1 cycle−1, respectively. Plant height, ear height, 500 kernel weight, ear length, and lodging decreased, while grain moisture and ear row number increased with selection for oil concentration. No change was found in days to silk.

Quantitative trait locus analysis of fatty acid concentrations in maize

“…Kernel oil concentration tends to be positively correlated with the level of 18: 1 in the kernel (Pamin et al 1986;Misevic and Alexander 1989). In this experiment the Pearson correlation coefficient was 0.46, which was highly significant.…”

Verification of QTL for Grain Starch Content and Its Genetic Correlation with Oil Content Using Two Connected RIL Populations in High-Oil Maize

“…Selection for oil increase in kernel was accompanied by decrease in kernel weight in IHO [9], [12], a synthetic population [39], and normal corn germplasm [45]. Negative relationship between grain oil content and starch content was commonly reported in research using Illinois strains [4,9,46], BHO [19], ASK high-oil [10], and popcorn germplasm [13].…”

Expression of Fungal diacylglycerol acyltransferase2 Genes to Increase Kernel Oil in Maize

“…Most of the oil in a maize seed is found in the embryo, which is about 33% oil by weight (Watson, 1987). Breeding approaches to increase maize kernel oil have had some success, but high kernel oil concentration has been linked to a decrease in grain yield (Dudley et al, 1977;Misevic and Alexander, 1989). Transgenic approaches to increasing oil in the maize embryo have shown promise in allowing increased oil production without yield drag (Zheng et al, 2008;Shen et al, 2010).…”