Abstract:
Onion (Allium cepa L.) is one of the most valuable vegetable spice crops that belongs to the
family Alliaceae (2n=16). It is a valuable economic crop as an entomophily cross-pollinated
vegetable. A hybridization experiment of onion was initiated in Sri Lanka in 1996 with a
reciprocal crossing parental combination. However, the existing knowledge about onion
genetic diversity and resources is to be reviewed periodically for the efficient management
of germplasm and selection of parents for crossing. This study was conducted at the Home
Garden, Faculty of Agriculture, University of Jaffna, Kilinochchi, located in the lowland dry
zone agroecological region, characterized by red-yellow latosol soil and flat to slightly
undulating topography. The objective was to identify promising third-generation hybrid
clones of cluster onion. This research was laid out as non-replicated from 94 clonal families
originating from a five-cross combination of selected parental lines. These materials were
studied morphologically and analysed with fourteen observed agronomic parameters for
evaluating the performance of hybrid clones. Five plants were selected for data
observation from the twenty plants of each clonal family. Results indicated that ample
variation was found in the traits of the tested entries. The population generated from
crosses showed a significant difference among all parameters tested. Flowering percentage
and average leaf count were removed for cluster analysis based on high correlation values
shown in the matrix. The first four principal components (PC) explained about 75.86% total
variability among the four components: PC1 (7 traits), PC2 (3 traits), PC3 (3 traits), and PC4
(4 traits) contributed to variability. The variable showed a moderate correlation with their
respective principal components. Performed cluster analysis revealed that there are three
major clusters at 100 distance level. This study will be used for further selection of the
tested clonal families.
