Page 163 - Breeding and regulatory opportunities, Renaud

Broccoli phytochemical content

oxidative modiication of low-density lipoproteins in blood vessels (Kritchevsky

et al., 1999).

The genetic potential for high nutrient content has long been a concern of the

organic industry in order to meet the expectations of organic consumers. This

has often been manifested by questioning whether modern elite cultivars may

have lower levels of nutritional content than older open pollinated cultivars.

Indirect evidence supporting this argument comes from Davis et al. (2004),

who compared USDA nutrient content data for 43 garden crops released

between 1950 and 1999. Statistically signiicant decreases were noted for six

nutrients (protein, calcium, potassium, iron, ribolavin, and ascorbic acid), with

declines ranging from 6% for protein to 38% for ribolavin. Crop varieties in

1950 had been bred to be adapted to speciic regions and a relatively low

input agriculture system, but contemporary cultivars are selected for yield,

disease resistance, broad adaptation to high input agriculture systems, and for

increased‘shipability’andshelflife.Trakaetal.(2013)recommendbreedingwith

greater genetic diversity when the goal is enhanced phytochemical contentby

exploiting wild crop relatives. The genotype is important in determining the

level of nutrients in a crop cultivar (Munger, 1979; Welch and Graham, 2004;

Troxell Alrich et al., 2010). What is unclear, however, is whether the nutritional

content of a cultivar is associated with certain genotypic categorization, e.g.

old versus modern, open pollinated versus Fhybrid cultivars. In addition, there
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is no clear diferentiation as to what extent nutritional content in a crop is

determined by genotypic or by ield management factors or by the interaction

of both. Some studies comparing performance of genotypes in organic and

conventional production systems have shown that for certain agronomic traits,

cultivars perform diferently between the two production systems (e.g. for

winter wheat: Murphy et al., 2007; Baresel et al., 2008; for lentils: Vlachostergios

et al., 2008; for maize: Goldstein et al., 2012), while others have shown no

diferences in ranking performance (for maize: Lorenzana and Bernardo, 2008;

for onions: Osman et al., 2008; for cereals: Prsystalski et al., 2008). The results

of these studies have profound implications for organic cultivar selection and

breeding strategies and raise questions as to the need for cultivars to be bred

with broad adaptability or speciic adaptation for the requirements of regional

organic production and for designing breeding programs that optimize

phytochemicals in an adapted management system.

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