Adie0002

10.1111/eva.12256My Name is Adane Gebeyehu Demissie and I am a PhD student at SLU, Department of Plant Breeding.

Noug (Guizotia abyssinica (L. f.) Cass.) is the only cultivated species of the genus and the most popular and indigenous oilseed crop of Ethiopia grown for its edible oil and seed (Baagoe, 1974). It is characterized by creeping growth habit, yellow flowers, strictly outcrossing and self-incompatibility; it is an erect, stout, branched dicotyledonous annual herb with epigeal emergence and diploid chromosome number of 2n=2x=30 (Dagne, 1994; 1995, Geleta et al., 2002; Geleta and Bryngelsson, 2010).

Noug is contributing 30% each to the area and production of oilseeds in Ethiopia and mostly grown by smallholder farmers as it grows in waterlogged and less fertile soils and can give reasonable yields (Oilseeds strategy-EIAR, 2017). According to CSA (2018) report 958,213 households cultivated noug on 290,495 ha of land producing 323,345 tons of seeds and it is the most widely grown oilseed crop with an average yield of 1.1 t/ha. Comparison of the year 2017/18 post-harvest crop yield with 2016/17 estimates that there was an increase in the area of production from 281,206 ha to 290,495 ha (3.3% increase) and an increase in total production from 302,432 to 323,345 tons (6.9% increase), indicating an increase in productivity during 2017/18 as compared to that of 2016/17. Since the rainfall was normal and adequate in the current crop-growing season, the 2017/18 (2010 E.C.) main season crop production has shown significant increment both in the estimated cropped land area and volume of grain crops production.

Noug seed is eaten by mixing with pulses and roasted cereals as well as with flour to make sweet cakes. The oil is used in food cooking, paints, soap and as an illuminant. In addition, it is used to treat burns and provide protection against cardiovascular disorders and cancer (Adarsh et al., 2014). The press cake is used for livestock feed. Noug meal can also be used as a growth medium for Bacillus species (Menezes et al., 2011). Ethiopian farmers prefer to grow noug because of the crop’s ability to grow and give acceptable seed yield under low soil fertility, moister stress and poor management practices. In addition, it tolerates pests and is suitable for soil conservation and rehabilitation (Getinet and Sharma, 1996; Adarsh et al., 2014).

Despite the fact that the crop has originated in Ethiopia, it has high genetic diversity and is among the major oilseed crop widely growing across different regions, efforts to increase its seed yield has not been as such successful and it has remained low yielding. The national average productivity is about 0.9 t/ha (CSA, 2016). Its cultivation is plagued by a number of critical drawbacks. The major factors are indeterminate growth habits leading to seed shattering, self-incompatibility, genetically low yielding characteristics, lodging, low responsiveness to management inputs, disease, insect pests and parasitic weeds (Getinet and Sharma, 1996; Teklewold and Wakjira, 2004). The cultivation of noug is limited to few countries, with Ethiopia the major country followed by India. Hence, it has received little attention from scientists and it is still considered as an underutilized or orphan crop. The availability of limited genetic information and the semi-domesticated nature of the crop are among the major challenges to improve its various desirable traits through breeding (Dempewolf et al., 2008, 2015).

Exploration of genetic diversity and the presence of rich genetic variability in noug germplasm have opened the door for its improvement and provision of new information for the scientific community. To make use of the genetic potential of the crop, developing phenotypic and molecular markers associated with various desirable traits such as oil content and quality and seed yield is very important.

Determination of noug genetic diversity has been done by different researchers. Based on the phenotypic study, high variability was observed between different noug genotypes and the result indicate that Ethiopian germplasm are considered as a good source for higher yield than Indian germplasm (Getinet and Sharma, 1996), late maturity, higher seed weight, resistance to waterlogging and drought (Adarsh et al., 2014). Teklewold and Wakjira (2004) also reported that Ethiopian noug accessions have a high amount of variation for morphological traits and other breeding attributes. According to Patil et al. (2013), substantial genetic variability was observed among the evaluated noug genotypes for the studied morphological traits. High heritability along with high genetic advance was recognized for the number of heads per plant and plant height. A heritability study of 35 noug accessions found that seed weight and total oil content had low variability (Yadav et al., 2012). In addition, high broad-sense heritability for noug seed weight, total oil content, palmitic acid, stearic acid, and oleic acid were reported (Yadav et al., 2012). Genetic divergence study of 52 noug accessions resulted in seven clusters, and plant height, days to 50% flowering and days to maturity had a maximum contribution to the genetic divergence (Parameshwarappa et al., 2009).