GENETIC VARIATION AND PATH ANALYSIS FOR YIELD AND OTHER AGRONOMIC TRAITS IN NIGELLA SATIVA L. GERMPLASM

Thirty two genotypes of Nigella sativa L. were evaluated for three consecutive years which showed significant differences for all the traits indicating high level of genetic variation. Heritability in broad sense ranged from 0.28 to 0.98 and the highest heritability was calculated for days to maturity and days to flowers. Grain yield was positively associated with plant height, capsule weight, capsule length, root length, whereas negatively with capsule width and 1000-seed weight that required the use of novel breeding techniques to break this undesired linkage to improve grain yield in N. sativa. Path coefficient indicated that direct effects of all the traits were positive except days to first flower, days to 50% flowers, flowering duration, number of capsules, root weight and harvest index. The characters exhibiting correlation along with direct effect towards grain yield viz., days to maturity, capsule weight, capsule length and root length should be given more preference while selecting high yielding N. sativa genotypes for future crop improvement programs. Introduction The genus Nigella contains 20 species of annual herbs indigenous to the Mediterranean and west Asia region (Weiss 2002). N. sativa is cultivated from Morocco to Northern India, in subSaharan Africa particularly Niger, and Eastern Africa (especially Ethiopia, Egypt, Tunisia),Europe including Russia, North America and Iran (Cheikh-Rouhou et al. 2006, Gharby et al. 2015). In South-East Asia, N. sativa seeds are used mainly for medicinal purposes. An evaluation and comparison of the chemical and morphological characteristics of different regional types of N. sativa is being compiled (Iqbal et al. 2005, Iqbal et al. 2013). More than 60% people are still relaying on herbal medicines for their ailments and cures across Asian continent. It is also used as food additive, an ingredient and supplementary food etc. Generally seeds have been serving as food preservative and spice (Iqbal et al. 2014). It is unique underutilized crop having potential both for agriculturally important traits and industry. Its evaluation and characterization at ex situ could accelerate genetic resources conservation efforts and availability of unique genes to select high yielding generic lines. N. sativa acts on the principle of immune system enhancement by natural healing process (Morsi 2000, Salem and Hussain 2000). Traditionally it was used to treat fever, headache, anxiety, diarrhea, asthma, and stroke (Mohammed et al. 2016). It increases body tone, stimulates menstrual periods and increases the flow of breast milk (Hussain and Hussain 2016). It contains more than 100 bioactive constituents of both herbal as well as industrial importance (Iqbal et al. 2014). It is reported to be rich in essential fatty acids, sterols and higher concentration of thymoquinone (Piras et al. 2013). Examination of genetic variance is important for plant breeders in general and particularly in a newly introduced crop like N. sativan (Iqbal et al. 2010). Dong et al. (2001) advocated that new *Author for correspondence: <drsajjad.iqbal@yahoo.com>, <sajjad.iqbal@uog.edu. pk>. Plant Genetic Resources Institute, National Agricultural Research Center, Islamabad, Pakistan.