... on Species and Provenance Research with particular reference to the tropics . Tropical Forestry Papers # . 10 A. 1977 2.2.10.15.4 . Callahan , R.Z. Provenance research : investigation of genetic diversity associated with geography .

The presence of thorns is inversely related to the precipitation and average annual temperature of the collection site . 2.2.11.13.2.3 . ... Provenance research : investigation of genetic diversity associated with geography .

Although taxonomic studies are of great value in highlighting the nature of morphological variation , the genetic basis of such characteristics is often in doubt . More valuable are field trials , such as provenance or progeny tests ...