Page 176 - Breeding and regulatory opportunities, Renaud

Chapter 5

Based on the results of our ield trials, the 23 cultivars of broccoli were grouped

into three distinct maturity classes: Early (55-63 days); Mid (64-71 days); and Late

(72-80 days) and analysed for the efect of the maturity class on phytochemical

content (Figure 5.2B). For glucoraphanin, late maturing cultivars had signiicantly

higher content levels, while for the carotenoids, early maturing cultivars tended

to have higher concentrations and were signiicantly higher for lutein.

When cultivar performance between genetic material originating from two

primary broccoli breeding companies was compared for phytochemical

content there were no signiicant diferences with the exception of lutein,

where company 1’s cultivars had signiicantly higher concentrations than those

of company 2 (data not shown).

A negative correlation between the date of release and levels of glucobrassicin

(R2= 0.21; p=0.03) (Figure 5.3) was observed, but no signiicant correlations for

any other phytochemical were seen when 21 cultivars (the total set minus the

two inbred lines) were analysed by their date of commercial release (1975-2005).

5.3.6 Correlation analysis among phytochemicals and horticulture traits

Phytochemical correlation across trials

Correlation among phytochemicals indicated that glucoraphanin was

signiicantly negatively correlated to glucobrassicin (Table 5.5). Correlations

between the glucosinolates and the tocopherols were not signiicant.

Glucoraphanin and neoglucobrassicin were negatively correlated to all

carotenoids but only lutein and glucoraphanin were statistically signiicant.

Glucobrassicin demonstrated a positive trend with all carotenoids. No statistically

signiicant correlations were observed within tocopherols. Δ-tocopherol

was positively correlated, while γ-tocopherol was negatively correlated to

all carotenoids. There were no signiicant correlations for α-tocopherol with

carotenoids. All carotenoids were highly positively correlated with one another.

158