Understanding the Phenotypic Diversity and Ecological Distribution of Noug (Guizotia abyssinica) for Its Improvement and Conservation

Abstract

Noug (Guizotia abyssinica) is an important oil crop to Ethiopia where it has been cultivated as source of edible oil since antiquity. Despite the country harbors ample genetic resources of noug, diversity and ecological information useful for its improvement and conservation is very limited. The aim of this study was to assess noug phenotypic diversity along with its ecological distribution based on morphological characters and environmental data. During 2009/10 cropping season, one hundred noug accessions which were collected from different parts of Ethiopia were planted augmented with four standard checks at two testing sites namely Holetta and Ginchi. Diversity and correlation analysis followed by principal component analysis were conducted for agro-morphological traits using statistical software package R v. 2.10.0/1.17-3. Non-metric multidimensional scaling (NMDS) analysis was made to understand which environmental variable that drives phenotypic diversity. Ecological niche modeling using Maxent software programme was also employed to comprehend the agro-ecological niche of noug. According to diversity analysis of phenotypic data, most traits showed considerable diversity within and among populations. The correlation analysis revealed that the number of seeds per plant and number of heads was positively correlated with the number of primary or secondary branches. A significant positive correlation was also obtained between the number of heads and number of seed per plant, and 1000 seed weight and the number of seed per plant. Seven noug populations (N07027, N07028, N07001, N08009, N08002, N08048 and N07009) were found to be unique populations. NMDS analysis showed precipitation was the most important environmental factor that drives noug phenotypic diversity. Ecological niche modeling indicates that the northern and western parts of Ethiopia were found to be the dominant noug niches which accounts > 80% of the total noug growing areas. Kenya followed by Eritrea were other African countries where the crop was grown in some pocket area. A number of noug populations useful for breeding efforts were also identified. In conclusion, noug populations variable for many traits have been identified and such variability is useful for its improvement and ex situ conservation effort of the crop.

Keywords: - Noug (Guizotia abyssinica), genetic diversity, noug improvement and conservation.

DOI: 10.7176/JNSR/9-5-06

Publication date:March 31^st 2019