Genetic Base of Wheat Cultivars Recommended in Nepal

Abstract

Plant breeding success is dependent, in part, upon the genetic diversity found within genetic
resources. The genetic base of wheat (Triticum aestivum L.) cultivars recommended in Nepal is not
well characterized. Therefore this study was carried out to quantify the genetic base of Nepalese
wheat cultivars by coefficient of parentage (COP). Analysis of pedigree information was based on
International Wheat Information System of the International Center for Maize and Wheat
Improvement (CIMMYT), which consists of WCOP for calculation of COP and WPDEND for
generating Mendelgram with contribution of ancestors to the cultivar if fully expanded. One
hundred eighteen ancestors from 23 countries were identified in the pedigree of 24 recommended
Nepalese cultivars. Of these, 32 ancestors contributed at least 1% each to the genetic base of
Nepalese cultivars, with a total contribution of 79%. Ancestors originating from USA contributed
19.8% of the genes, India 11.2%, Japan 9.5%, Argentina 7.5%, Kenya 7.5% Australia 6.2%, Brazil
5.6%, Canada 5.5%, Italy 4.1% and remaining from other countries. At 30% similarity, 18 clusters
were formed with largest cluster of five members. None of Nepalese landraces were traced in the
pedigree of these cultivars. Relatively large amount of diversity in Nepalese cultivars exits based on
their genetic background although small number of cultivars is recommended for cultivation.

Key words: Coefficient of parentage; diversity; Triticum aestivum; wheat breeding

DOI: 10.3126/narj.v6i0.3338

Nepal Agriculture Research Journal Vol.6 2005 pp.1-9