Fertility variation and its implications on relatedness in seed crops in seedling seed orchards of Eucalyptus camaldulensis and E. tereticornis

Frankfurt am Main

2007

S. 253-259

1 Abb., 3 Tab., 31 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200144937

Seedling seed orchards of Eucalyptus tereticornis
(N =192 & 505) and E. camaldulensis (N =182 & 525)
were established at two sites (one moist and one dry) in
southern India. The fertility (based on the number of
flowers and fruits) was registered for each tree at age
eight and nine years. E. camaldulensis on the moist
location had 73% fertile trees and low fertility difference
(sibling coefficient, Ø, was 2.27) at eight years. whereas
Only 23% trees were fertile in the E. tereticornis
orchard at the same site and the fertility variation was
high (Ø =11.71). In the dry location, fertility was almost
the same in both species at nine years, with 45 & 51%
fertile trees in E. camaldulensis (Ø =5.4) and E. tereticornis
(Ø = 5.2) respectively. Though the fertility trends
were the same in both years, the number of fertile trees
was comparatively higher at nine years (except in the
low flowering E. tereticornis orchard at the moist site) in
both the sites. Gene diversity values of the seed crop
estimated for two consecutive years are fairly high
except for the E. tereticornis (GD = 0.9650 and 0.9690)
orchard located in the moist site. The implications of fertility variation on diversity of progeny have been discussed in the light of domestication strategies and tree
breeding programs implemented for eucalypts.