Ogtr document

Section 2 Origin and cultivation

2.1 Centre of origin, diversity and domestication

The earliest traces of Brassica spp. date back 7000 years: B. napa and B. juncea were found in excavations of a Neolithic village from the Shanxi province, China (OECD 2012; Wu et al. 2009). B. juncea is described as one of the earliest domesticated plants, with records of its use in Indian agriculture dating back to 2300 BC. As a polyphyletic species, its centres of origin have been widely discussed (Chen et al. 2013; Edwards et al. 2007; Gomez-Campo & Prakash 1999). Afghanistan (and adjoining regions) is currently described as a primary centre of origin for oilseed forms (Chen et al. 2013). China, where the largest diversity of subspecies is observed, is considered as a probable primary centre for vegetable types (OECD 2012; Wu et al. 2009). India/Pakistan and Asia Minor have been described as secondary centres. Using Simple Sequence Repeat (SSR), Amplified Fragment Length Polymorphism (AFLP) and Sequence Related Amplified Polymorphism (SRAP), it was demonstrated that oilseed varieties cultivated in China, India, Europe, Australia, Japan and Canada could be divided in two genetically distinct groups (Chen et al. 2013; Srivastava et al. 2004; Wu et al. 2009). One group consists of varieties from Central/Western India and Eastern China, the other consists of varieties from Northern/Eastern India, Central/Western China, Europe, Australia, Japan and Canada.

B. napus is of relatively recent origin and thought to have first emerged in the Mediterranean coastal region, where both its progenitor species are found. No reference to B. napus is in the ancient literature, unlike B. rapa and B. juncea. The first record of cultivation of oilseed rape in Europe dates back to the Middle Ages but it is not clear if the species grown was B. napus or B. rapa (Appelqvist & Ohlson 1972). Seeds were grown mainly for lamp oil and soap-making, as their bitter taste made them an unsuitable source of human food or animal feed (Appelqvist & Ohlson 1972; Daun et al. 2015).

Two main components of Brassica plant material, erucic acid and glucosinolates, have been shown to cause undesirable effects in humans and animals. Brassica ssp. seeds naturally contain up to 40% of erucic acid, a 22-carbon monounsaturated fatty acid, thought to cause growth retardation and heart diseases (Stefansson & Hougen 1964). Glucosinolates are allelochemicals^a naturally found at concentrations higher than 60 micromoles per gram in the seed of Brassica plants (Pessel et al. 2001). These compounds are responsible for the hot and pungent flavours of the Brassica vegetables. They can be either toxic, anti-nutritional or beneficial to health, depending on their structure and concentration (EFSA 2008). See Section 5 for more details.

B. napus and B. rapa forage and vegetable varieties were introduced to North and South America in the 18^th century. The oilseed form was only introduced in Canada in 1936 and in Australia in the early 1960s (OECD 2012). Because of health concerns, Canadian breeders produced a series of new cultivars with low erucic acid concentrations. The first very low erucic acid B. napus variety was produced in 1961, followed in 1968 by an “extremely low” erucic acid variety. Then, in 1974, in order to make seed meals more suitable for animal feed, a “double-low” cultivar was released with both extremely low erucic acid and very low glucosinolate levels. From 1978 onwards, this and subsequent cultivars have been referred to as canola, for Canadian oil, low acid (Eskin 2013; Fleury 2013).

B. juncea canola varieties are much more recent, dating back to 2002. B. juncea canola cultivars show good growing characteristics, less pod shattering and are more drought tolerant than B. napus cultivars. However, the first B. juncea canola varieties available have shown a lower yield than B. napus (Fleury 2013).

2.2 Production and commercial uses

An estimate of the world oil crop production for the 2014/2015 growing season was 547.4 million tonnes, with soybean, rapeseed^b, cotton, sunflower and palm the major producing plants (Table 1) (FAO 2015).

Table 1. World production of major oilseed crops. Adapted from FAO (2015).

	2013/2014 (million tonnes)	2014/2015* (million tonnes)	2015/2016^# (million tonnes)
Soybean	283.4	319.7	218.2
Rapeseed	71.9	71.4	64.3
Palm	54.4	63.2	65.1
Cottonseed	44.7	44.9	40.9
Sunflower	42.4	40.9	39.9

* estimated production (October 2015); ^# forecast production (October 2015)

The four major production areas for rapeseed are: China, India, Canada and the European Union, each producing approximatively 7 million hectares per year. Australia currently has 2.7 million hectares under cultivation (ABARES 2015; Carré & Pouzet 2014). Rapeseed represents 14% of oil production worldwide and is the second largest oil producing crop after soybean (which represents 55% of total oil production). It ranks third in edible oils after soybean and palm. Production has increased by a factor of 2.4 in the last 20 years to a record 71.9 million tonnes in 2014 (Table 1) (Carré & Pouzet 2014). In 2015/2016, production is forecast to drop due to adverse weather conditions in Europe and Canada, and to lower plantings in Australia and China (FAO 2015).

Both the oil and meal are used in food, feed and/or industry. Canola oil (B. napus and B. juncea) is mainly used in Europe, North America, Australia and Japan for cooking and in food products such as spreads, dressings and shortening or processed food (Daun et al. 2015). B. juncea is a particularly important crop in India where it represents 90% of rapeseed production and one third of total oil production (Kumar et al. 2009). Oil is used for cooking, while whole seeds/leaves are used as condiments.

Canola/rapeseed oil is also produced for cosmetics and oleochemical industries. Historically, rapeseed oil has been used as a marine engine lubricant, before being replaced by petrol-based oils. Industry currently considers ultra-high oleic acid varieties as a new class of “green” lubricants, with better characteristics than petrol-based oils (Lowell et al. 2010). High erucic acid varieties are also grown for industry purposes, with the purified erucic acid used to produce slip agents, emollients, food emulsifiers or lubricants (Daun et al. 2015). Canola oil is also considered a suitable biofuel but the current industry estimates point towards a decrease of biofuel production for 2015/2016 (FAO 2015). B. juncea has been described as a potential tool for phytostabilization for metal-contaminated soils (Perez-Esteban et al. 2014). See Section 6.1.2 for more details.

Canola meal is the second major oilseed meal produced worldwide, with 33.6 million tonnes. It is widely used as animal feed, with preferential use for dairy cattle, pig and poultry (Daun et al. 2015). It is also considered as a potential substitute to meal for fish farms (Enami 2011). Industry standards require canola meal to be low in glucosinolates (max 30 micromoles per gram of seed) and erucic acid (less than 2%) to be suitable for animal feed (AOF 2007; CODEX 2009). Canola meal is also used as a fermenting substrate for the production of industrial enzymes, such as phytases or xylanases (involved in food, paper or biofuel production) (Daun et al. 2015).

In case of drought or late frosts, canola can be cut and sold as hay or silage, as a way to mitigate the risks associated with taking the crop to grain (McCormick 2007). Canola hay is seen as a suitable feed source for dairy cows and other livestock (GRDC 2010a).