Page 165 - Breeding and regulatory opportunities, Renaud

Broccoli phytochemical content

in two contrasting broccoli production regions of the US: Oregon and Maine.

Speciically we addressed the following questions: (1) what is the impact of

organic management system compared to the environmental factors including

climatic region, season and their interactions [Genotype (G) x Environment (E) x

Management System (M)]?, (2) is there a signiicant diference in phytochemical

content between diferent genotypes and genotypic classes (old and modern

cultivars; open pollinated and Fhybrid cultivars; early and late maturing
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cultivars; and between diferent commercial seed sources)?, (3) what is the

best selection environment for a broccoli breeding program for enhanced

phytochemical content?

5.2 Materials & methods:

5.2.1 Plant Material and Field Trial Locations

Twenty-three broccoli cultivars including open pollinated (OP) cultivars, inbred

lines, and Fhybrids were included in ield trials (Table 5.1). Cultivars were
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grown in a randomized complete block design with three replicates in Maine

(ME)-Monmouth (Latitude 44.2386oN, Longitude 70.0356oW); and Oregon

(OR)-Corvallis (Latitude 44.5647oN, Longitude123.2608oW)] with each location

including organically (O) and conventionally (C) managed treatments. Plots

contained 36 plants, planted in three rows of 12 plants at 46 cm equidistant

spacing within and between rows. The 2006 trials had only 18 of the 23 entries,

and the Oregon 2006 trial had only two replicates at the organic location. Field

trials were conducted for three consecutive years with one production cycle in

Fall 2006, two production cycles in Spring and Fall 2007 and one production

cycle in Spring 2008. The primary management diferences between the

organic and conventional ield trial sites are outlined in Supplemental Figure

5.1, which describes the production system, soils, fertility applications, the

applied supplemental irrigation, and weather conditions for the area of study.

Further details of the ield design are reported in Renaud et al. (2014).

5.2.2 Field Data Collection

As plots approached maturity they were evaluated three times a week for

ield quality and broccoli heads that had reached commercial market maturity

(approximately 10 to 12 cm in diameter for most of the cultivars while retaining

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