Page 15 - Breeding and regulatory opportunities, Renaud

Management (M) main efect and G × M interactions were often small but G × M

× E (location and season) were large; (2) Cultivars with both greater head weight

and stability under conventional conditions generally had high head weight and

stability under organic growing conditions, although there were exceptions in

cultivar rank between management systems. Cultivars highest in tocopherols

and carotenoids were open pollinated or early maturing Fhybrids. Distinct
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locations and seasons were identiied where phytochemical performance was

higher for each compound; (3) Larger genotypic variances and increased error

variances were observed in organic compared to conventional management

systems led to repeatabilities for several horticultural and phytochemical traits

that were similar or even higher in organic compared to conventional conditions;

(4) The ratio of correlated response (predicting performance under organic

conditions when evaluated in conventional conditions) to direct response

(predicted performance in organic when evaluated under organic conditions)

for all traits was close to but less than 1.0 with the exception of bead uniformity.

This would imply that in most cases, direct selection in an organic environment

could result in a more rapid genetic gain than indirect selection in a conventional

environment; (5) Correlations among phytochemical traits demonstrated

that glucoraphanin was negatively correlated with the carotenoids and the

carotenoids were highly correlated with one another; and (6) There was little

or no association between phytochemical concentration and date of cultivar

release, suggesting that modern breeding has not negatively inluenced the

level of tested compounds and there were no signiicant diferences among

cultivars from diferent seed companies. Based on the indings strategies for

seed system models are discussed.

Keywords

Organic seed regulation, stakeholder analysis, crop improvement, Brassica

oleracea, horticulture traits, phytochemical concentrations, selection

environment, seed system models

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