บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Genetics and breeding of postharvest longevity in cut flowers of Gerbera x hybrida Hort. (Gerbera x hybrida).

Wernett, Heidi Carol.

Thesis of Ph.D., University of Florida, 1990, 124 pages

1990

บทคัดย่อ

GENETICS AND BREEDING OF POSTHARVEST LONGEVITY IN CUT FLOWERS OF GERBERA X HYBRIDA HORT. (GERBERA X HYBRIDA).

Two components of postharvest longevity, vase life and stem strength, were studied in cut flowers of Gerbera x hybrida Hort..  A broad based source of germplasm was evaluated initially.  Progeny means for vase life resulting from a topcross between 31 plants and 'Appleblossom' were used to select plants whose flowers had high vase life.  Analysis of a 5 x 5 diallel cross was made to determine vase life heritability.  No reciprocal effects were observed.  Heritability ranged from 22 to 39 percent.  Additive gene action possibly controls this character since broad sense and narrow sense heritability was nearly equal.  Repeatability was moderately high (r =.57).

 A senescence mode was recorded for each flower, i.e.  bending or folding of the scape or wilting of the ligulae.  "Flower" was defined as the composite inflorescence and its corresponding stem.  After selection and mating, frequency of bending decreased; frequency of folding and wilting increased.  Flowers that senesced due to wilting had the highest mean vase life before and after selection and mating.  Significant correlations were found between vase life of flowers that senesced due to wilting and shorter stem length, thinner stems, and smaller infloresences.

 A 7 x 7 diallel using plants whose flowers had high stem strength, measured using an Instron, was used to determine stem strength heritability.  No reciprocal effects were observed.  Heritability ranged from 28 to 53 percent.  Additive gene action possibly controls this character since broad sense and narrow sense heritability was nearly equal.  Repeatability was moderately high (r =.60).  Significant correlations were found between stem strength and shorter stem length, thicker stems, and heavier infloresences.

 Number of vascular bundles was compared among plants whose flowers exhibited high or low levels of vase life and stem strength.  Significant differences between high and low levels of vase life were observed for number of large bundles per 1.0 cm.  scape circumference, measured 12 cm.  below the peduncle; significant differences between high and low levels of stem strength were observed for number of small bundles per 1.0 cm.  scape circumference.