KERAGAMAN GENETIK DAN HERITABILITAS LIMA AKSESI BUNGA MATAHARI DI KOTA BENGKULU

Sunflower is a versatile plant that can be utilized as ornamental and it seeds
can serve as source of food, animal feed, skin and hair cares oil, and high quality and
healthy cooking oil. Nevertheless, the continuity of sunflower production is hampered
by low farmer knowledge on good cultural practice for the crop, including the choice
of variety that best for the existing environmental condition.
High genetic variation of a particular trait is an indication that improvement of
such trait can effectively gained through a breeding program. Objective of this study
was to determine the genetic variation and heritability of sunflower accessions
collected from City of Bengkulu area. Experiment was conducted from October 2007
to March 2008 at the experimental field of Faculty of Agriculture, University of
Bengkulu (10 above sea level). Five sunflower accessions (Kandang Limun, Beringin
Raya, Sawa Lebar Baru, Kandang Mas, and Semarang) were planted in a randomized
complete block arrangement with three replications. Observations were made on
flowering date, plant height, node number, node length, branch number, leaf width
and length, leaf greenness, capitula diameter, number of developed and empty seeds
per capitula, seed width and thickness, seed weight per capitula, and whole plant
biomass.
Most of the variables observed had low coefficient of genotypic variations,
except branch number, capitula diameter, number of developed and empty seed per
capitula, and seed weight per capitula. Low genotypic variation suggested that
additional accessions are required to make improvement, whereas high genotypic
variation means no additional accessions to gain improvement from selection.
High broadsense heritabilities were found on branch number, capitula
diameter, and number of developed and empty seed per capitula, indicating that
genetic factor is more dominant than environmental factor in the expression of these
traits. Medium broadsense heritabilities were showed by plant height, node number,
node length, and leaf length, indicating both genetic and environmental played a
balanced role in the expression of the traits. Similarly low broadsense heritabilities
showed by leaf width, leaf greenness, capitula diameter, seed width, seed thickness,
and plant biomass were more influenced by environmental factor.